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Effects of Cistus-tea on bacterial colonization and enzyme activities of the in situ pellicle
Abstract
Polyphenols are expected to have antibacterial properties. Cistus is a tea rich in polyphenols. The aim of the present in situ study was to investigate the effect of Cistus-tea on the pellicle and on the initial oral biofilm.
For in situ pellicle formation and initial biofilm formation, bovine enamel slabs were fixed on maxillary splints and carried by four subjects at buccal sites for up to 2 h. Bacteria present in 120-min pellicles were determined with DAPI-staining and fluorescence in situ hybridization with and without a 10 min rinse with Cistus-tea performed 1 min after incorporation of the slabs. In addition, amylase, lysozyme, glucosyltransferase and peroxidase activities immobilised in the pellicle layer were measured before and after rinsing for 10 min with Cistus-tea.
The amount of bacteria detected in the 120-min biofilm was reduced significantly, if a 10 min rinse with Cistus-tea was performed one min after insertion of the enamel slabs. DAPI-staining yielded 13.2+/-3.5 for controls and 6.5+/-1.1 x 10(4) bacteria/cm(2), if a rinse with Cistus-tea was applied. Lysozyme, amylase and glucosyltransferase activities immobilised in the pellicle were not affected following a rinse with Cistus-tea. However, peroxidase activity was reduced significantly.
Cistus-tea may be used to reduce the initial bacterial adhesion in the oral cavity.
... Cystus® tea could be suitable for clinical practice. Cystus® tea is made from the leaves and small twigs of the Cistaceae family of plants as Halimium halimifolium (16,17). The Cistaceae family of plants contain polyphenol, flavonoid, and tannin, so they are used as antioxidants (18). ...
... Many studies have shown the antiinflammatory, antioxidant, and antimicrobial properties of Cystus® extracts (19). Cystus® tea is often used for the treatment and prevention of upper respiratory tract infectious diseases (16,20). A marked decrease in microbial growth in the oral cavity could be noted after mouthrinses with Cystus® tea (16,21). ...
... Cystus® tea is often used for the treatment and prevention of upper respiratory tract infectious diseases (16,20). A marked decrease in microbial growth in the oral cavity could be noted after mouthrinses with Cystus® tea (16,21). Cystus® tea has a mild flavor, and it contains no side-effect-inducing ingredients. ...
Herbal teas are very common around the world. It has a good therapeutic effect. But due to adulteration, we face an obstacle to using them. The author has collected some clinical trials on commercial herbal tea formulations on the market that have proven their efficacy and safety. So, the future is for herbal medicine owing to people's psychology, minimum adverse reactions, and lower cost. The pharmaceutical manufacturing of herbal tea formulations should be encouraged to use them as add-on therapy or healthy daily beverages at least.
... Furthermore, the pellicle serves in a limited scale as protection barrier during acid attacks (Hannig & Hannig, 2014). As demonstrated in situ, rinses with certain teas and watery plant extracts rich in polyphenols resulted in an enhanced resistance of the pellicle against erosive noxae and further, led to a significant reduction of bacterial colonization of the tooth surface (Hannig, Spitzmüller, Al-Ahmad, & Hannig, 2008;Weber, Hannig, Pötschke, Höhne, & Hannig, 2015). ...
... In general, it can be expected that the main antimicrobial properties of Inula viscosa can be attributed to containing polyphenols. Besides the influence on bacterial growth, polyphenols might have an effect on the proteinaceous pellicle components, leading to masking or denaturation of functional groups of receptor proteins and, in the following, aggravated interaction with bacteria (Hannig et al., 2008). A negative synergy of polyphenolic compounds with pellicle enzymes cannot be excluded as rinses with Cistus tea, rich in polyphenols, yielded a considerable reduction of peroxidase activity in the in-situ pellicle (Hannig et al., 2008). ...
... Besides the influence on bacterial growth, polyphenols might have an effect on the proteinaceous pellicle components, leading to masking or denaturation of functional groups of receptor proteins and, in the following, aggravated interaction with bacteria (Hannig et al., 2008). A negative synergy of polyphenolic compounds with pellicle enzymes cannot be excluded as rinses with Cistus tea, rich in polyphenols, yielded a considerable reduction of peroxidase activity in the in-situ pellicle (Hannig et al., 2008). However, Hernandez et al. found no influence of Inula viscosa containing Fig. 8. Transmission electron microscopic evaluation of representative pellicle samples before (a, c, e, g) and after incubation in HCl at pH-value 2.3 for 1 min (b, d, f, h). ...
Objectives:
The present in situ study investigated the effect of Inula viscosa tea on the pellicle's acid protective properties and on initial oral biofilm formation.
Design:
Biofilm formation was performed on bovine enamel slabs on individual maxillary splints. Following 1min of pellicle formation, eight subjects rinsed for 10min with Inula viscosa tea and the splints remained for 8h intraorally. Samples carried after 1-min rinsing with CHX (0.2%) or without rinse served as controls. BacLight™ staining, 4',6-diamidino-2-phenylindole (DAPI)-staining and fluorescence in situ hybridization (FISH) were used for fluorescence microscopic detection of adherent bacteria. For investigation of acid protective properties, three subjects rinsed for 10min with Inula viscosa tea after 1min pellicle formation and kept the splints intraorally for further 19min. Physiological 30-min pellicles and native enamel samples served as controls. After HCl incubation of the samples ex-vivo over 120s (pH 2.0, 2.3, 3.0) calcium- and phosphate release were quantified photometrically. Potential influences on the pellicle's ultrastructure by Inula viscosa tea were evaluated by transmission electron microscopy (TEM).
Results:
Application of Inula viscosa tea yielded a significant reduction of adherent bacteria on all enamel samples as detected by fluorescence microscopy. For calcium- and phosphate release no significant effect was recorded. TEM investigation indicated a modification of the pellicle's ultrastructure, but no enhanced protection against erosive noxae.
Conclusion:
Rinsing with Inula viscosa tea influences the bacterial colonization on enamel in situ over 8h but has no impact on acid protective properties of the pellicle.
... Afterwards, a total of 436 articles that did not meet the inclusion criteria were excluded and 149 full-text articles were reassessed for eligibility. Finally, after this second screening process 135 articles were excluded according to the aforementioned inclusion criteria and 14 of the reports were considered suitable for this review (Yamanaka et al., 2007;Alviano et al., 2008;Furiga et al., 2008Furiga et al., , 2014Hannig et al., 2008Hannig et al., , 2009Xie et al., 2008;Sampaio et al., 2009;Antonio et al., 2011Antonio et al., , 2012Badet and Quero, 2011;Brighenti et al., 2012;Meckelburg et al., 2014;Muñoz-Gonzalez et al., 2014). All 14 selected reports were found in English language databases from the time of their establishment until 10th October, 2014. ...
... All selected studies were written in English and involved treatment of in vitro, ex vivo and in situ formed multispecies oral biofilms with different plant extracts. The extract treatments were applied with a duration time ranging from 1 min (Furiga et al., 2008(Furiga et al., , 2014Hannig et al., 2008Hannig et al., , 2009Xie et al., 2008;Sampaio et al., 2009;Antonio et al., 2011;Brighenti et al., 2012;Meckelburg et al., 2014) to 64 h (Badet and Quero, 2011). In terms of the medicinal herbs, four studies reported the effects of Vitis products and by-products, red wine, and/or grape seed extracts on multispecies oral biofilms (Furiga et al., 2008(Furiga et al., , 2014Hannig et al., 2009;Muñoz-Gonzalez et al., 2014), three studies highlighted the anti-biofilm properties of FIGURE 2 | Flowchart of the search strategy, study selection, and data management procedure. ...
... Frontiers in Microbiology | www.frontiersin.org Coffea canephora extracts (Antonio et al., 2011(Antonio et al., , 2012Meckelburg et al., 2014) two studies focused on the antimicrobial traits of tea (black tea, green tea, cistus tea; Hannig et al., 2008Hannig et al., , 2009 and one study reported the high antimicrobial efficacy of Chinese galls (Xie et al., 2008) Individual reports on the antibiofilm activity of cranberry juice concentrate (Yamanaka et al., 2007), manuka honey (Badet and Quero, 2011), Caesalpinia ferrea Martius fruit extracts (Sampaio et al., 2009), Psidium cattleianum leaf extract (Brighenti et al., 2012), and Brazilian plant extracts (Alviano et al., 2008) were also taken into consideration. ...
Oral diseases such as caries and periodontitis are mainly caused by microbial biofilms. Antibiotic therapy has reached its limits with regard to antimicrobial resistance, and new therapeutic measures utilizing natural phytochemicals are currently a focus of research. Hence, this systematic review provides a critical presentation of the antimicrobial effects of various medicinal herbs against in vitro, ex vivo, and in situ formed multispecies oral biofilms. Searches were performed in three English databases (PubMed, EMBASE, CAMbase) and the electronic archives of five German journals from the times of their establishment until October 10th, 2014, with the search terms “(plant extracts OR herbal extracts OR plant OR herb) AND (oral biofilm OR dental biofilm OR dental plaque OR oral disease OR dental disease).” The pooled data were assessed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). Initially, 1848 articles were identified, out of which 585 full-text articles were screened, 149 articles were reevaluated for eligibility and finally, 14 articles met all inclusion criteria. The data of 14 reports disclosed enhanced antiadhesive and antibiofilm activity by the plant extracts obtained from Vitis vinifera, Pinus spp., Coffea canephora, Camellia sinensis, Vaccinium macrocarpon, Galla chinensis, Caesalpinia ferrea Martius, Psidium cattleianum, representative Brazilian plants and manuka honey. Overall, a positive correlation was revealed between herb-based therapies and elimination rates of all types of multispecies oral biofilms. In that context, integrating or even replacing conventional dental therapy protocols with herbal-inspired treatments can allow effective antimicrobial control of oral biofilms and thus, dental diseases.
... Only in situ or in vivo experiments give optimal insight into the interactions of oral health care devices with the dental hard tissues and the oral biofilm. As in many previous publications, bovine enamel slabs fixed to individual upper jaw splints were adopted, the different fluorescence microscopic assays have also been used in former studies investigating initial oral bioadhesion [13,[15][16][17][22][23][24]. This methodical approach has certain drawbacks, sometimes the bacteria are difficult to count, and typically a considerable variability of the results is observed. ...
... This has to be considered when interpreting the data. However, this corresponds to previous studies and seems to be characteristic for bioadhesion in the oral cavity [13,[15][16][17][22][23][24]. Despite this fact, the experimental setup offers direct insight into the process of bioadhesion to enamel in the oral cavity which cannot be achieved by other methods, e.g., determination of the colony forming units after desorption. ...
... Application of customary Biorepair, Biorepair free of hydroxyapatite microclusters, of microclusters in saline solution, and of chlorhexidine reduced bacterial adherence over 6-12 h considerably. The structures in one image are extensions of an epithelial cell which is sometimes detected on the samples (arrow) [13,16,17,[22][23][24]. Another limitation of the present study certainly is the small number of subjects. ...
Objective
The aim of the present study was to investigate the efficacy of a new preparation in dental prophylaxis containing zinc-carbonate hydroxyapatite microclusters (Biorepair) for oral biofilm management.
Methods and materials
Initial biofilm formation was carried out in situ with bovine enamel slabs fixed to individual upper jaw splints worn by six subjects. Rinses with the customary preparation as well as with subfractions (hydroxyapatite microclusters in saline solution; liquid phase without particles) were adopted for 1 min in situ after 1 min of pellicle formation, and the bacterial colonization was recorded after 6 h and 12 h, respectively. Rinses with chlorhexidine served as a reference. The adherent microorganisms were quantified and visualized using DAPI staining and live–dead staining (BacLight). Furthermore, the effects on Streptococcus mutans bacteria were tested in vitro (BacLight).
Results
Application of the customary preparation and of the separate components distinctly reduced the initial bacterial colonization of the enamel surface in situ as visualized and quantified with all techniques. After 12 h, 1.3 × 107 ± 2.0 × 107 bacteria/cm² were detected on unrinsed control samples with DAPI staining; 2.4 × 106 ± 3.3 × 106 after application of Biorepair (12 h after CHX-rinse; 1.3 × 105 ± 9.2 × 104). Also, pure hydroxyapatite microclusters in saline solution (2.1 × 106 ± 3.0 × 106) as well as the liquid phase without particles (5.1 × 105 ± 3.3 × 105) reduced the amount of adherent bacteria. Furthermore, antimicrobial effects on S. mutans were observed in vitro.
Conclusion
The preparation is an effective compound for biofilm management in the oral cavity due to antiadherent and antibacterial effects.
Clinical relevance
The tested mouthrinse seems to be a reasonable amendment for dental prophylaxis.
... In addition, plants have the ability to produce endogenous antimicrobial peptides that have a broad spectrum of activity against microorganisms and a low level of resistance [6]. Natural substances such as coffee extracts [18,19], tea extracts [20], cranberry extracts [21], cranberry juice concentrate [22], or Manuka honey [23] have been shown to reduce the total bacterial count of adherent microorganisms. They all exhibit anti-adhesive and antimicrobial activity based on different mechanisms. ...
... All results showed large intraindividual and interindividual differences, which is in line with previous studies investigating initial oral biofilms [20,33,51]. The composition of a biofilm is highly dependent on local or individual factors [57] such as diet, salivary flow rate, and salivary pH. ...
Objective
In the last few decades, there has been a growing worldwide interest in the use of plant extracts for the prevention of oral diseases. The main focus of this interest lies in the identification and isolation of substances that limit the formation of microbial biofilm which plays a major role in the development of caries, periodontitis, and peri-implantitis. In this clinical ex vivo study, we investigated the antimicrobial effects of Rosmarinus officinalis extract against oral microorganisms within in situ initial oral biofilms.
Materials and methods
Initial in situ biofilm samples (2 h) from six healthy volunteers were treated ex vivo with R. officinalis extract at concentrations of 20 mg/ml and 30 mg/ml. The number of viable bacterial cells was determined by counting the colony-forming units. All surviving bacteria were isolated in pure cultures and identified using MALDI-TOF and biochemical testing procedures. Additionally, live/dead staining in combination with epifluorescence microscopy was used for visualizing the antimicrobial effects in the initial biofilms.
Results
The number of colony-forming units in the R. officinalis–treated biofilms was significantly lower than in the untreated controls (p < 0.001). The reduction range of log10 was 1.64–2.78 and 2.41–3.23 for aerobic and anaerobic bacteria, respectively. Regarding the bacterial composition, large intra- and interindividual variability were observed. Except for Campylobacter spp., the average amount of all bacterial taxa was lower after treatment with R. officinalis than in the untreated biofilms. A total of 49 different species were detected in the untreated biofilms, while only 11 bacterial species were detected in the R. officinalis–treated biofilms. Live/dead staining confirmed that the R. officinalis–treated biofilms had significantly lower numbers of surviving bacteria than the untreated biofilms.
Conclusions
The treatment with R. officinalis extract has a significant potential to eliminate microbial oral initial biofilms.
Clinical relevance
The results of this study encourage the use of R. officinalis extracts in biofilm control and thus in the treatment of caries and periodontitis as a herbal adjuvant to synthetic substances.
... od zastosowania płukanki. Wykryto zmniejszenie adhezji Eubacterium i Streptococcus w porównaniu z próbą kontrolną [57]. W kontynuacji swoich badań, naukowcy testowali wpływ różnych napojów bogatych w polifenole (czarna i zielona herbata, czerwone wino, sok winogronowy i napar z czystka). ...
... Właściwości przeciwbakteryjne i przeciwgrzybicze można przypisać określonym związkom polifenolowym oraz możliwości występowaniu efektów synergistycznych z innymi, niefenolowymi, składnikami obecnymi w wodnych wyciągach z C. incanus, co wymaga dalszych badań. Niemniej jednak, dostępne wyniki potwierdzają możliwość wykorzystania olejku eterycznego, żywicy i ekstraktów z czystka szarego i jego podgatunków jako potencjalnego, alternatywnego źródła składników o działaniu przeciwbakteryjnym i przeciwgrzybiczym w przemyśle farmaceutycznym, kosmetycznym i spożywczym [27,[57][58][59] oraz w profilaktyce np. chorób przyzębia. ...
One of the modern nutritional trends is to enthusiastically look for natural products that can be considered functional food and be a source of ingredients with a health-promoting effect. Today, many food manufacturers offer Cistus × incanus leaves to prepare common self-preparations (e.g., infusions) or as ready-to-use dietary supplements. Cistus × incanus (rock rose, pink rock-rose, hoary rock-rose), belonging to the family Cistaceae, is widespread in Mediterranean countries. For many years, cistus extracts and its aromatic resin have been used in traditional Middle East medicine to treat, among others, colds, fever, stomach problems, and skin wounds. In past years, this plant was rediscovered by the public. Due to the growing popularity of Cistus products, the most recent scientific literature on this subject is reviewed here. This article aims to present the latest research results on the phytochemical composition of Cistus × incanus and the impact of its consumption on human health. Particular emphasis is put on antioxidant, anti-inflammatory, antibacterial, antiviral, and antiproliferative activities and support of digestive system functions. Studies have shown that the main active ingredients of Cistus × incanus are flavonoid compounds, including flavonol glycosides (myricetin, quercetin, kaempferol), flavan-3-ols, and tannins. It was demonstrated that the presence of these compounds determines the therapeutic and health-promoting properties of cistus leaves and its products. That applies primarily to a strong antioxidant effect, which may reduce the risk of noncommunicable diseases, including cardiovascular diseases, neurodegenerative diseases, and cancer. Cistus preparations are also recommended as immunostimulants, supporting the treatment of bacterial and viral infections. Labdanum oleoresin and essential oil are a valuable source of substances with strong antibacterial and anti-inflammatory properties, which can be used in the future in the production of pharmaceutical and cosmetic preparations, and also serve as a natural food preservative.
... Cystus ® tea could be suitable for clinical practice. Made from the leaves and small twigs of the cistaceae family of plants, it might qualify as a reasonable mouthwash with similar characteristics as sage tea [10,11]. Various studies showed anti-inflammatory, antifungal, and antioxidant properties of Cystus ® extracts [12]. ...
... Cystus ® tea is often used for prevention and treatment of infections in the upper respiratory tract [11,13]. A reduction of the initial bacterial colonization and adherence to enamel in the oral cavity could be demonstrated after mouthrinses with Cystus ® tea [10,14] providing a rationale for its use. In addition, the tea has a mild flavor and it contains no ingredients which could be expected to cause any noteworthy side effects. ...
Purpose:
To determine the effect of Cystus® tea (Naturprodukte Dr. Pandalis GmbH & Co. KG) as mouthwash compared to sage tea on oral mucositis in patients undergoing radio(chemo)therapy for head and neck cancer.
Methods:
In this randomized, prospective phase III study, 60 head and neck cancer patients with primary or postoperative radio(chemo)therapy were included between 04/2012 and 06/2014. They received either sage or Cystus® tea for daily mouthwash under therapy. Mucositis was scored twice a week following the Radiation Therapy Oncology Group and the European Organization for Research and Treatment Cancer (RTOG/EORTC) scoring system. Dental parameters were also recorded. Statistical evaluation of the primary endpoint was performed using t‑test and log rank test.
Results:
Data from 57 patients could be evaluated. Patient characteristics showed no significant difference between the two groups (n = 27 sage; n = 30 Cystus®). A total of 55 patients received the prescribed dose (60-66 Gy postoperative; 70-76.8 Gy primary). Mucositis grade 3 was observed in 23 patients (n = 11 sage; n = 12 Cystus®) and occurred between day 16 and 50 after start of therapy. There was no significant difference between the two groups in latency (p = 0.75) and frequency (p = 0.85) of the occurrence of mucositis grade 3. The self-assessment of the oral mucosa and the tolerability of the tea also showed no significant differences. Occurrence of dental pathologies appeared to increase over time after radiotherapy.
Conclusion:
Cystus® and sage tea have a similar effect on the occurrence of radiation-induced mucositis regarding latency and incidence. Cystus® tea mouthwash solution is tolerated well and can be applied in addition to intensive oral care and hygiene along with the application of fluorides.
... Their homeostatic, antipyretic, expectorant and sedative properties have also been reported [4]. Pharmacological activities including the cytotoxic [5][6][7], anti-microbial [8][9][10][11], anti-viral [12][13][14][15], antiinflammatory [6,[16][17][18], antioxidant [19][20][21], analgesic [18,22,23], spasmolytic [24][25][26][27], antiulcerogenic and gastro protective [28][29][30], antihyperglycemic [31], and platelet aggregation inhibitory [32,33] activities of Cistus species have been previously reported. Simple phenols, flavonoids [34,35], flavan-3-ols [36,37], lignans [17] and phloroglucinol glycosides [37,38], labdane type diterpenoids [5,[38][39][40][41], triterpenoids and steroids [42,43], have been isolated from different Cistus species. ...
... The n-BuOH fraction (24 g) was subjected to polyamide (PA) column chromatography and eluted with H 2 O, followed by increasing concentrations of MeOH to yield 5 main fractions (Frs. [1][2][3][4][5] 10). Three fractions were obtained from this separation and the third fraction gave pure compound 4 (50 mg). ...
To our knowledge this is the first report on the isolation of a flavonoid glycoside: quercetin 3-O-alpha-arabinopyranoside (5), two phenylbutanon glycosides: 4-(4'-O-[6''-O-galloyl-beta-galactopyranosyl]-3'-hydroxyphenyl)-butan-2-on (8), 4-(3'-O-beta-glucopyranosyl-4'-hydroxyphenyl)-butan-2-on (9), one phloroglucinol glycoside: 1-O-beta-glucopyranosyl-3,5-dimethoxybenzene (10) and a steroid glycoside: sitosterol-3-O-(6''-O-butanoyl)-beta-galactopyranoside (14) from the Cistus species (Cistaceae). Additional to these compounds three flavonol aglycones: kaempferol (1), quercetin (2), myricetin (3); three flavonoid glycosides; kaempferol 3-O-beta-(6''-O-trans-p-coumaroyl)-glucopyranoside (4), quercetin 3-O-beta-galactopyranoside (6), myricetin 3-O-beta-galactopyranoside (7); one phloroglucinol glycoside: 1-O-beta-glucopyranosyl-3,5-dimethoxybenzene (11); one steroid aglycone: beta-sitosterol (12); one steroid glycoside: Sitosterol-3-O-beta-glucopyranoside (13) were isolated from the aerial parts of the Cistus salviifolius L.. Their structures were identified using spectral methods (UV, IR, 1D- and 2D-NMR, and ESI-MS).
... Because of this result, tannins might prevent bioadhesion and therefore reduce oral diseases. 48,49 On the other hand, activity of amylase in the in situ pellicle is not influenced by a tea rich in polyphenols (Cistus). 49 Nevertheless, secretion of salivary a-amylase may increase due to stimulation of sympathetic pathways when animals are fed with tannins. ...
... 48,49 On the other hand, activity of amylase in the in situ pellicle is not influenced by a tea rich in polyphenols (Cistus). 49 Nevertheless, secretion of salivary a-amylase may increase due to stimulation of sympathetic pathways when animals are fed with tannins. 47 All in all, it would be of considerable interest to know whether amylase and glycosyltransferases are also present in the pellicles of different animal species and whether tooth decay is present. ...
... Moreover, using an MTT assay, blank TPLGA NPs were nearly noncytotoxic against breast cancer cells, indicating that the pH responsive delivery platform could be a promising method to enhance the safety and efficacy of therapeutic agents. It is noteworthy that tannin acid (TA) in the nano-platform had a high binding affinity to both the pellicle layer and free salivary enzymes [165,166], which could be used for extending the residential time of the delivered nanoparticles in the oral environment and blocking specific receptors for bacterial attachment [167,168]. ...
Dental caries is a common and costly multifactorial biofilm disease caused by cariogenic bacteria that ferment carbohydrates to lactic acid, demineralizing the inorganic component of teeth. Therefore, low pH (pH 4.5) is a characteristic signal of the localised carious environment, compared to a healthy oral pH range (6.8 to 7.4). The development of pH-responsive delivery systems that release antibacterial agents in response to low pH has gained attention as a targeted therapy for dental caries. Release is triggered by high levels of acidogenic species and their reduction may select for the establishment of health-associated biofilm communities. Moreover, drug efficacy can be amplified by the modification of the delivery system to target adhesion to the plaque biofilm to extend the retention time of antimicrobial agents in the oral cavity. In this review, recent developments of different pH-responsive nanocarriers and their biofilm targeting mechanisms are discussed. This review critically discusses the current state of the art and innovations in the development and use of smart delivery materials for dental caries treatment. The authors' views for the future of the field are also presented.
... It was used as an effective anti-inflammatory and skin protective plant agent in Mediterranean folk medicines. Moreover, the use of C. incanus tea to rinse the mouth contributes to the degradation of biofilm, a well-known virulence factor, and the prevention of biofilm-induced diseases by decreasing the load of associated bacteria [19]. In addition to these properties, the extracts obtained from some Cistus species with compositions similar to C. incanus extracts are known for their antibacterial activity against oral cavity pathogens and have been suggested as alternative natural antibacterial and antibiofilm components against oral infections [20]. ...
Periodontal diseases are oral inflammatory diseases ranging from gingivitis to chronic periodontitis. Porphyromonas gingivalis is one of the major pathogens responsible for severe and chronic periodontitis. Plant extracts with antimicrobial activity could be considered possible alternatives to chlorhexidine, an antiseptic substance used in oral hygiene thatcan cause bacteria resistance. Here, two commercial extracts obtained from Cistus × incanus L. and Scutellaria lateriflora L. were chemically characterized usingUltra-High-Performance Liquid Chromatography (UHPLC) coupled with a Q-Exactive Hybrid Quadrupole Orbitrap Mass Spectrometer. The extracts were studied for their bioaccessibility after simulated in vitro oral digestion, their antimicrobial activity against P. gingivalis, their protective effects against cellular invasion by P. gingivalis, and their antibiofilm activity. The extracts were found to contain very complex mixtures of polyphenols, which were quite stable after in vitro simulated oral digestion and demonstrated mild, dose-dependent inhibitory activity against P. gingivalis growth. This activity increased with the combination of the two extracts. Moreover, the combination of the extracts induced a reduction in P. gingivalis HaCaT invasiveness, and the reduction in biofilm came to around 80%. In conclusion, a combination of C. incanus and S. lateriflora showed promising effects useful in the treatment of gingivitis.
... In a study investigating the effect of Cistus-tea on the pellicle and on the initial oral biofilm, it was reported that the amount of bacteria (Streptococci and Eubacteria) detected in the 120-min biofilm was reduced. [51] In another study, Hickl et al. investigated the antimicrobial and anti-biofilm effects of mediterranean herb extracts including the methanol extracts of C.creticus ssp. creticus and C. monspeliensis, and reported that the extracts showed the antibiofilm activity against Streptococcus mutans, as C. albicans showed no sensitivity to the tested extracts. ...
In this study phytochemical compounds and antioxidant capacity, cytotoxic, antimicrobial and anti‐biofilm activities of hydroethanolic extracts of five Cistus species (C. creticus L., C. laurifolius L., C. monspeliensis L., C. parviflorus Lam. and C. salviifolius L.) distributed in Turkey were investigated. (+)‐catechin, epigallocatechin gallate, quercetin‐3‐O‐rutinoside, quercetin‐3‐O‐glucoside, kaempferol‐3‐O‐glucoside, luteolin were detected in different amounts. Strongest antioxidant capacities were observed with C. creticus, and C. parvifolius (0.476 and 0.452 respectively). Minimum inhibitory concentrations (MIC) of the extracts were determined between 32 and 128 µg/mL against different bacteria and Candida strains. C. monspeliensis and C. laurifolius extracts were inhibited the biofilm production levels of three Gram‐negative bacteria (E. coli, S. enterica, P. aeruginosa), two Gram‐positive bacteria (S. aureus, B. subtilis) and three Candida strains (C. albicans, C. parapsilosis, C. krusei). C. creticus extract showed strongest cytotoxic activity against human breast adenocarcinoma (MCF‐7) and prostate cell line (PC‐3) (IC50: 14.04 ± 2.78 µg/mL and 34.04 ± 2.74 µg/mL, respectively) among all plants tested.
... n of Cl-dH2O, Cc-dH2O and Cs-dH2O extracts were effective as MBIC50 and MBEC50 of positive controls applied to pathogen test microorganisms. Although numerous studies have been conducted to evaluate biological effects of Cistus sp., there is limited research on antibiofilm activity of Cistus sp. against pathogen microorganisms(Zalegh et al., 2021).Hannig et al. (2008) revealed that Cistus-tea may be used to reduce the initial bacterial adhesion.Lekbach et al. (2018) showed that C. ladanifer extract inhibited the growth of P. aeruginosa planktonic cells and the biofilm formation. In another study,Álvarez-Martínez et al. (2021) revealed that C. salviifolius extract exhibited higher antimicrobial activi ...
Recently, the potential antibacterial or antibiofilm effects of some plant species belonging to the Cistus sp. have motivated investigation of their use as herbal remedies. In this study, antibiofilm activities of aqueous (dH2O) leaf extracts of Cistus laurifolius L., C. creticus L. and C. salviifolius L. on some pathogenic microorganisms with biofilm forming ability were investigated. Biofilm forming ability of pathogen test microorganisms were evaluated by congo red agar method and microtiter plate method and all tested microorganisms were confirmed as biofilm producers. Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 11778, S. aureus ATCC 6538, P. aeruginosa ATCC 27853 and S. aureus ATCC 12600 were evaluated as strong biofilm producers. The highest concentration of examined extracts both showed biofilm inhibition and biofilm eradication against the tested pathogen microorganisms. In particular, studied plant extracts showed good antibiofilm effect, and biofilm eradication against S. aureus ATCC 6538 and S. aureus ATCC 12600. MBIC50 values of S. aureus ATCC 6538 were found as 6.25 µg/ml of C. laurifolius, and 50 µg/ml of C. creticus extracts. Also, 50 µg/ml of C. creticus extract showed ≥ 90% inhibition of biofilm growth (MBIC90 = 50 µg/ml). MBEC50 values of S. aureus ATCC 12600 were determined as 6.25 µg/ml in all tested plant extracts and 50 µg/ml of C. creticus extract was required to induce ≥ 90% eradication (MBEC90) of biofilm growth of S. aureus ATCC 12600. Our study revealed that aqueous leaf extracts of C. laurifolius, C. creticus and C. salviifolius could be potential candidates for drug discovery to treat pathogen test microorganisms capable to induce infectious diseases especially by their biofilm forming ability.
... Cistus incanus aqueous solutions contain important bioactive compounds such as rutin, gallic acid, flavonoid (quercetin, kaempferol, glycoside), catechin, epicatechin, gallocatechin (Dimcheva and Karsheva, 2017). It is recorded by several studies that Cistus incanus extraxts have antibacterial and antifungal activity (Simeray et al., 1982;Chinou et al., 1994;Bouamama et al., 1999;Hannig et al., 2008;Barrajón-Catalán et al., 2010;Barros et al., 2013;Wittpahl et al., 2015;) and anti-cancer (Chinou et al., 1994;Dimas et al., 1998;Dimas et al., 2006;Hatziantoniou et al., 2006;Barrajón-Catalán et al., 2010;Skoric et al., 2012), also protective effects against DNA cleavage in cell culture (Attaguile et al., 2000). Therefore, anti-influenza virus activities in mice Ehrhardt et al., 2007;Kalusa et al., 2009) and antiviral activity against HIV and Filoviruses (Rebensburg et al., 2016) of Cistus incanus were confirmed. ...
Coronavirus disease affects all the world with the pandemic way that we are still living. The fight against the disease continues with vaccination all over the world. Considering the protection time and the difficulties in attaining the vaccine, in order to be successful in fighting against the disease, we need drugs that enable to kill or hinder replication of the viruses. In drug studies, after analyzing the effect of phytochemicals on the viruses, isolated phytochemical is modified in order to synthesize a more effective molecule. It is not possible to analyze the anti-viral activity of each isolated molecule by in-vitro methods, and in-silico methods can help to overcome this problem. Cistus incanus is a plant whose anti-viral activity has been confirmed by previous trials on many viruses. In this study, the interaction of myricetin 3-O-hexoside, myricitrin, quercitrin and kaempferol 3-O-rutinocide which were detected in the Cistus incanus, were analyzed by molecular docking methods with papain-like protease and main protease crystal. Strong H-bonds were detected between the investigated molecules and papain-like protease and main protease.
... Furthermore, polyphenols also have an antimicrobial effect on the growth of biofilms by denaturing or obscuring functional groups of the receptor proteins and thus reducing the interaction between different bacterial species. Therefore, a negative effect on biofilm formation could also be achieved with Cistus tea, which is rich in polyphenols [60]. Hertel et al. investigated the effect of I. viscosa tea on initial oral biofilm formation [27]. ...
Given the undesirable side effects of commercially used mouth rinses that include chemically synthesized antimicrobial compounds such as chlorhexidine, it is essential to discover novel antimicrobial substances based on plant extracts. The aim of this study was to examine the antimicrobial effect of Inula viscosa extract on the initial microbial adhesion in the oral cavity. Individual test splints were manufactured for the participants, on which disinfected bovine enamel samples were attached. After the initial microbial adhesion, the biofilm-covered oral samples were removed and treated with different concentrations (10, 20, and 30 mg/mL) of an I. viscosa extract for 10 min. Positive and negative controls were also sampled. Regarding the microbiological parameters, the colony-forming units (CFU) and vitality testing (live/dead staining) were examined in combination with fluorescence microscopy. An I. viscosa extract with a concentration of 30 mg/mL killed the bacteria of the initial adhesion at a rate of 99.99% (log10 CFU value of 1.837 ± 1.54). Compared to the negative control, no killing effects were determined after treatment with I. viscosa extract at concentrations of 10 mg/mL (log10 CFU value 3.776 ± 0.831; median 3.776) and 20 mg/mL (log10 CFU value 3.725 ± 0.300; median 3.711). The live/dead staining revealed a significant reduction (p < 0.0001) of vital adherent bacteria after treatment with 10 mg/mL of I. viscosa extract. After treatment with an I. viscosa extract with a concentration of 30 mg/mL, no vital bacteria could be detected. For the first time, significant antimicrobial effects on the initial microbial adhesion in in situ oral biofilms were reported for an I. viscosa extract.
... To reinforce the use of C. incanus herbal tea (from Dr. Pandalis) as an appropriate alternative available in everyday life and verify its possible exploitation in dentistry as well. The study of Hanning [158] showed that the impact of cistus-tea on initial oral biofilm using a model. Indeed, the fluorescence microscopy showed a pronounced reduction of initial bacterial colonization due to rinses with cistus-tea. ...
Resistance to drugs is reaching alarming levels and is placing human health at risk. With the lack of new antimicrobials drugs, infectious diseases are becoming harder to treat. Hence, there is an increasing awareness of active phytochemicals with therapeutic functions. The tremendous research interest on the Cistus L. genus includes numerous plants used in traditional medicine by people living around the Mediterranean Sea, also resulted in some interesting discoveries and written literature. This review aimed at gathering scientific literature about Cistus species, describing phytochemical profiles and the various pharmacological activities. We also extensively reviewed the antimicrobial activities, including antiviral, antiparasitic, antifungal, and antibacterial potentials of Essential Oils (EO), raw extracts as well as isolated compounds. Mechanisms of action along with methods used are also investigated in this review. Considering the findings of the Cistus species extracts, this genus offers an adequate reserve of active phytochemicals since many have been used to create drugs. Therefore, this review work can serve society by providing a global view on Cistus L. sp. regarding pharmacological potentials and their chemical profiles.
... Es wurde eine 5%ige Lösung verwendet, die einen pH-Wert von pH = 2,5 aufwies. Die Spülung mit der Lösung resultierte im Spülprotokoll 1 in einer signifikant (p < 0,05) reduzierten Bedeckung (4,6%) der Schmelzoberfläche mit Biofilm.Damit wirkt die Tanninsäure an Schmelz-PK antiadhärent, was mit den Ergebnissen der Literatur übereinstimmt[52,54,65,125,144].Mit Ausnahme von Hertel et al. (2017) wurden in den Studien andere Polyphenole als die Tanninsäure verwendet. Zwar haben sich die aufgeführten Studien bezüglich der Applikationsdauer, Tragedauer sowie Konzentration und Volumen der verwendeten Mittel untereinander und zu dem vorliegenden Versuch unterschieden, sie konnten aber allesamt eine antiadhärente Wirkung von polyphenolhaltigen Mundspüllösungen nachweisen. ...
... The low pH value needed to dissolve chitosan and chitosan itself impart a positive charge to the pellicle in vitro [49,50] and, as suggested by Rehage et al. [51], this observation may inhibit further the accumulation of chitosan on dental surfaces. Furthermore, the salivary protein lysozyme, which is present in the pellicle maintaining its enzymatic activity, can degrade chitosan, and thus, inhibit its antibiofilm properties [52][53][54][55]. ...
In contrast to enamel, dentin surfaces have been rarely used as substrates for studies evaluating the effects of experimental rinsing solutions on oral biofilm formation. The aim of the present in situ study was to investigate the effects of tannic acid and chitosan on 48-h biofilm formation on dentin surfaces. Biofilm was formed intraorally on dentin specimens, while six subjects rinsed with experimental solutions containing tannic acid, chitosan and water as negative or chlorhexidine as positive control. After 48 h of biofilm formation, specimens were evaluated for biofilm coverage and for viability of bacteria by fluorescence and scanning electron microscopy. In addition, saliva samples were collected after rinsing and analyzed by fluorescence (five subjects) and transmission electron microscopy (two subjects) in order to investigate the antibacterial effect on bacteria in a planktonic state and to visualize effects of the rinsing agents on salivary proteins. After rinsing with water, dentin specimens were covered by a multiple-layered biofilm with predominantly vital bacteria. In contrast, chlorhexidine led to dentin surfaces covered only by few and avital bacteria. By rinsing with tannic acid both strong anti-adherent and antibacterial effects were observed, but the effects declined in a time-dependent manner. Transmission electron micrographs of salivary samples indicated that aggregation of proteins and bacteria might explain the antiadhesion effects of tannic acid. Chitosan showed antibacterial effects on bacteria in saliva, while biofilm viability was only slightly reduced and no effects on bacterial adherence on dentin were observed, despite proteins being aggregated in saliva after rinsing with chitosan. Tannic acid is a promising anti-biofilm agent even on dentin surfaces, while rinsing with chitosan could not sufficiently prevent biofilm formation on dentin.
... The tannic acid used in the present study was obtained from gall apples of Quercus infectoria oak. Rinsing with a 5% solution, which had a pH of 2.5, resulted in a significantly reduced coverage in the first protocol that was in accordance with the literature [24,36,[55][56][57]. Except to Hertel et al. (2017), other polyphenols than tannic acid were used, and the study designs differed from each other, but they were all able to demonstrate an anti-adherent effect. ...
Chitosan and tannic acid are known for their antibacterial properties. In the present in-situ study, their antibacterial and anti-adherent effects on biofilm formation on enamel were investigated. Six subjects carried upper jaw splints with bovine enamel specimens, allowing in-situ biofilm formation. During the two-day trial, subjects rinsed with experimental solutions that contained either chitosan, tannic acid (pH = 2.5), tannic acid (pH = 7) or hydrochloric acid. Water served as the negative and chlorhexidine as the positive control. Rinsing occurred four or five times following two different rinsing protocols to investigate both the immediate and long-lasting effects. After 48 h of intraoral exposure, the dental plaque was stained with LIVE/DEAD® BacLight, and fluorescence micrographs were evaluated by using the software ImageJ. The results were verified by scanning electron microscopy. Rinsing with chitosan resulted in little immediate antibacterial and anti-adherent effects but failed to show any long-lasting effect, while rinsing with tannic acid resulted in strong immediate and long-lasting effects. Except for a slightly lower antibacterial effect, the neutral solution of tannic acid was as good as the acidic solution. Hydrochloric acid showed neither an antibacterial nor an anti-adherent effect on dental biofilm formation. Experimental solutions containing tannic acid are promising anti-biofilm agents, irrespective of the pH values of the solutions. Chitosan, on the other hand, was not able to prevent biofilm formation.
... Although bovine enamel was shown to possess structural and chemical differences to human enamel, it represents a practicable model for biofilm analyses and was used in numerous studies on the in situpellicle formation, composition, modification, and its protective properties. [6,24,[49][50][51] In combination with the applied protocol, the use of bovine enamel enabled large amounts of proteins to be harvested. The efficiency of the chemical elution was verified by transmission electron microscopy-analysis and demonstrated a virtually complete removal of the pellicle from the enamel surface (data not shown). ...
Purpose
: Dental pellicle formation starts instantaneously after oral hygiene due to the adsorption of salivary proteins to all orally exposed surfaces. The pellicle acts as a physiological mediator, protects the tooth surface from mechanical damages and reduces acid‐induced enamel demineralization. The aim of this pilot study was to identify and characterize individual proteomic profiles of the initial pellicle formed on dental enamel and to compare the profiles with the corresponding saliva to analyze specific adsorption patterns occurring during pellicle formation.
Experimental Design
: The 3‐min pellicle of five subjects formed in situ on bovine enamel was eluted chemically and analyzed separately by nano‐mass spectrometry. The analysis of the corresponding saliva was conducted in parallel.
Results
: Up to 498 pellicle proteins and up to 1032 salivary proteins were identified on individual level. Comparison of the salivary and pellicle protein profiles demonstrates the pellicle formation to be highly individual. Nineteen proteins were significantly enriched in the 3‐min pellicle of all subjects and 22 proteins were significantly depleted indicating that pellicle formation relies on selective adsorption.
Conclusions and Clinical Relevance
: The short‐term enamel pellicle is composed of several hundreds of adsorbed salivary proteins and reveals a highly individual proteomic profile.
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... Aqueous leaves extract of Cistus ladaniferus was effective in decreasing blood glucose levels in STZ-induced diabetic rats and showed hypolipidemic effect by a significant reduction in plasma lipid parameters (El Kabbaoui et al., 2016). This herbal tea has antibacterial properties because it decreases significantly the amount of bacteria in organisms (Hannig et al., 2009), reduces bacterial adhesion (Hannig et al., 2008) and shows the Gram-positive bacteria inhibition (Viapiana et al., 2017). In addition, the identification of antibacterial components of fraction from Cistus incanus, as apigenin, kaempferide, cis-and trans-tiliroside, and the isomers of the p-coumaric acid-conjugated tiliroside was lately presented (Móricz et al., 2018). ...
The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.jfca.2019.01.021. The duplicate article has therefore been withdrawn.
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... Aqueous leaves extract of Cistus ladaniferus was effective in decreasing blood glucose levels in STZ-induced diabetic rats and showed hypolipidemic effect by a significant reduction in plasma lipid parameters (El Kabbaoui et al., 2016). This herbal tea has antibacterial properties because it decreases significantly the amount of bacteria in organisms (Hannig et al., 2009), reduces bacterial adhesion (Hannig et al., 2008) and shows the Gram-positive bacteria inhibition (Viapiana et al., 2017). In addition, the identification of antibacterial components of fraction from Cistus incanus, as apigenin, kaempferide, cis-and trans-tiliroside, and the isomers of the p-coumaric acid-conjugated tiliroside was lately presented (Móricz et al., 2018). ...
Cistus incanus is called a medicine herbal plant due to its antimicrobial, anti-inflammatory, cytotoxic and antiulcerogenic properties. Considering these unique properties, quantification of the bioactive compounds of its infusion by liquid chromatography-tandem mass spectrometry is very important because of the rising consumption of this beverage. In this study the content of 28 phenolic compounds and theirs derivatives, alkaloids and vitamin B of water extract of Cistus incanus tea was examined and the results were compared with the results from other types of popular in the market teas. The Cistus incanus infusions were tested for content of flavanols, flavonols, organic acids, vitamin B and alkaloids and were compared with Camellia sinensis, Hoan Ngoc herbal tea and Rooibos infusions. Camellia sinensis infusions generally contained more catechins (1.56–82.65 mg/g) than Cistus incanus (1.02–2.73 mg/g) but there was no catechin-3-gallate in any Camellia sinensis infusions. Caffeine, theobromine and theophylline were found practically only in Camellia sinensis (6.22–14.19 mg/g) and Vietnamese herbal tea (2.97 mg/g) while trigonelline was found at higher concentrations in both Cistus incanus (6.29–14.34 μg/g) and Rooibos infusions (10.54–14.29 μg/g) than in Camellia sinensis infusions (0.30–2.88 μg/g). Principal component analysis revealed both similarities and differences among the infusions.
... Oral bacterial biofilms remain one of the greatest challenges in dental research [13]. Despite extensive research, there is still a strong demand for fundamental investigation of bacterial adherence to dental surfaces and research of coated enamel surface with initial biofilm, in vivo and in situ [8,10,11]. ...
... Cistus-tea did not affect the activities of lysozyme, amylase and glucosyltransferase, but significantly reduced peroxidase activity. 63,64 On the other hand, chlorhexidine and black tea significantly reduced lysozyme activity. 65 Lipids account for approximately 25% of the dry weight of the AP. ...
Dental erosion is a multifactorial condition that can result in the loss of tooth structure and function, potentially increasing tooth sensitivity. The exposure of enamel to acids from non-bacterial sources is responsible for the progression of erosion. These erosive challenges are counteracted by the anti-erosive properties of the acquired pellicle (AP), an integument formed in vivo as a result of selective adsorption of salivary proteins on the tooth surface, containing also lipids and glycoproteins. This review provides an in-depth discussion regarding how the physical structure of the AP, along with its composition, contributes to AP anti-erosive properties. The physical properties that contribute to AP protective nature include pellicle thickness, maturation time, and site of development. The pellicle contains salivary proteins embedded within its structure that demonstrate anti-erosive properties; however, rather than individual proteins, protein-protein interactions play a fundamental role in the protective nature of the AP. In addition, dietary and synthetic proteins can modify the pellicle, enhancing its protective efficiency against dental erosion. The salivary composition of the AP and its corresponding protein-profile may be employed as a diagnostic tool, since it likely contains salivary biomarkers for oral diseases that initiate at the enamel surface, including dental erosion. Finally, by modifying the composition and structure of the AP, this protein integument has the potential to be used as a target-specific treatment option for oral diseases related to tooth demineralization.
... Several foods, such as polyphenolic beverages, are recognized for their wholesome effect [42]. Polyphenols are regarded as strong antioxidants with potential health benefits [43][44][45] and they exhibit a wide range of antibacterial, antifungal, and anti-inflammatory effects which also qualify them for the prevention of caries and periodontitis [46]. Another promising approach in dental prevention methods can be to reinforce the protective pellicle properties by modifying its composition. ...
Objectives
There is still a great demand for the improvement of oral prophylaxis methods. One repeatedly described approach is rinsing with edible oils. The aim of the present review paper was to analyze the role of lipids in bioadhesion and preventive dentistry.
Materials and methods
Despite limited sound scientific data, extensive literature search was performed to illustrate possible effects of lipids in the oral cavity.
Results
It is to be assumed that lipophilic components modulate the process of bioadhesion to the oral hard tissues as well as the composition and ultrastructure of the initial oral biofilm or the pellicle, respectively. Thereby, lipids could add hydrophobic characteristics to the tooth surface hampering bacterial colonization and eventually decreasing caries susceptibility. Also, a lipid-enriched pellicle might be more resistant in case of acid exposure and could therefore reduce the erosive mineral loss. Furthermore, anti-inflammatory effects on the oral soft tissues were described. However, there is only limited evidence for these beneficial impacts. Neither the lipid composition of saliva and pellicle nor the interactions of lipids with the initial oral biofilm and the pellicle layer have been investigated adequately until now.
Conclusion
Edible oils might qualify as mild supplements to conventional strategies for the prevention of caries, erosion, and periodontal diseases but further research is necessary.
Clinical relevance
Against the background of current scientific and empirical knowledge, edible oils might be used as oral hygiene supplements but a decisive benefit for the oral health status is questionable.
... As an example, transglutaminase, derived from oral epithelial cells, has been identified within the in situ pellicle in an active conformation (Hannig et al., 2009c), which may lead to the intrinsic AEP maturation due to crosslinking acidic or basic PRPs with statherin, as shown in vitro (Yao et al., 2000). Other enzymes, such as alkaline phosphatase and transaminase, have also been demonstrated within the in situ pellicle, supporting a potential role in the intrinsic maturation of the pellicle, whereas in situ studies have demonstrated little to no acid phosphatase or proteinase activity (Hannig et al., 2008b(Hannig et al., , 2009b. ...
The acquired enamel pellicle (AEP) is a thin acellular film that forms on tooth surfaces upon exposure to the oral environment. It consists predominantly of salivary proteins, but also includes non-salivary-derived proteins, carbohydrates, and lipids. Since it is the interface between teeth and the oral environment, the AEP plays a key role in the maintenance of oral health by regulating processes including lubrication, demineralization, and remineralization and shaping the composition of early microbial flora adhering to tooth surfaces. Knowledge of the 3D structure of the AEP and how that correlates with its protective functions may provide insight into several oral pathological states, including caries, erosion, and periodontal disease. This review intends to update readers about the latest discoveries related to the formation, ultrastructure, composition, and functions of the AEP, as well as the future of pellicle research, with particular emphasis on the emerging role of proteomic and microscopy techniques in oral diagnosis and therapeutics.
... Regarding the remaining three enzymes amylase, peroxidase and lysozyme, significant differences between the three groups were only found for peroxidase activity, which was clearly reduced in patients with regular vomiting. In contrast to other enzymes salivary peroxidase is inactivated by its substrate and several other metabolites [Hannig et al., 2008a, b]. Due to enhanced oxidative stress in the oral cavity of subjects with bulimia, induced by gastric juice, it was to be expected that peroxidase is inactivated. ...
Patients with bulimia nervosa are at high risk for dental erosion. However, not all bulimic patients suffer from erosion, irrespective of the severity of their eating disorder. It is often speculated that differences in the saliva are important, however, little is known about salivary parameters in bulimic patients, particularly directly after vomiting. The aim of the clinical trial was to compare different salivary parameters of subjects suffering from bulimia with those of healthy controls. Twenty-eight subjects participated (14 patients with bulimia nervosa, 7 of them with erosion; 14 matched healthy controls). Resting and stimulated saliva of all participants was analysed as well as saliva collected from bulimic patients directly and 30 min after vomiting. Parameters under investigation were flow rate, pH, buffering capacity and the enzyme activities of proteases in general, collagenase, pepsin, trypsin, amylase, peroxidase, and lysozyme. Regarding flow rate, pH and buffering capacity only small differences were found between groups; buffering capacity directly after vomiting was significantly lower in bulimic subjects with erosion than in subjects without erosion. Differences in enzymatic activities were more pronounced. Activities of proteases, collagenase and pepsin in resting and proteases in stimulated saliva were significantly higher in bulimic participants with erosion than in controls. Peroxidase activity was significantly decreased by regular vomiting. Proteolytic enzymes seem to be relevant for the initiation and progression of dental erosion directly after vomiting, maybe by both hydrolysis of demineralized dentine structures as well as modulation of the pellicle layer.
... In addition , many natural agents have been explored for their effect on Gtf activity, such as hops, green tea, traditional medicinal plants and food extracts [Wu-Yuan et al., 1988; Ikeno et al., 1991; Otake et al., 1991; Nakahara et al., 1993; Wolinsky et al., 1996; Tagashira et al., 1997; Osawa et al., 2001; Steinberg et al., 2004; Furiga et al . , 2008; Hannig et al., 2008b; Yaegaki et al., 2008]. Carbohydrate fatty esters had no effect on Gtf activity from S. sobrinus despite inhibiting growth of the organisms [Devulapalle et al., 2004]. ...
The importance of Streptococcus mutans in the etiology and pathogenesis of dental caries is certainly controversial, in part because excessive attention is paid to the numbers of S. mutans and acid production while the matrix within dental plaque has been neglected. S. mutans does not always dominate within plaque; many organisms are equally acidogenic and aciduric. It is also recognized that glucosyltransferases from S. mutans (Gtfs) play critical roles in the development of virulent dental plaque. Gtfs adsorb to enamel synthesizing glucans in situ, providing sites for avid colonization by microorganisms and an insoluble matrix for plaque. Gtfs also adsorb to surfaces of other oral microorganisms converting them to glucan producers. S. mutans expresses 3 genetically distinct Gtfs; each appears to play a different but overlapping role in the formation of virulent plaque. GtfC is adsorbed to enamel within pellicle whereas GtfB binds avidly to bacteria promoting tight cell clustering, and enhancing cohesion of plaque. GtfD forms a soluble, readily metabolizable polysaccharide and acts as a primer for GtfB. The behavior of soluble Gtfs does not mirror that observed with surface-adsorbed enzymes. Furthermore, the structure of polysaccharide matrix changes over time as a result of the action of mutanases and dextranases within plaque. Gtfs at distinct loci offer chemotherapeutic targets to prevent caries. Nevertheless, agents that inhibit Gtfs in solution frequently have a reduced or no effect on adsorbed enzymes. Clearly, conformational changes and reactions of Gtfs on surfaces are complex and modulate the pathogenesis of dental caries in situ, deserving further investigation.
Z surowców ekologicznych, tj. szynki wieprzowej i słoniny, przygotowano sześć
wariantów kiełbas: dwie próby kontrolne (Kd50 i Kd100) o zróżnicowanym dodatku
NaNO2 (odpowiednio 50 i 100 mg/kg) oraz cztery próby badawcze: Kd50-O1 i Kd50-O2
(zawierające po 50 mg NaNO2/kg i 1 g lub 2 g liofilizatu z ostropestu plamistego/kg
farszu) oraz Kd100-O1 i Kd100-O2 (zawierające po 100 mg NaNO2/kg i 1 g lub 2 g
liofilizatu z ostropestu plamistego/kg farszu). Kiełbasy badano przez 12 tygodni, tj. po
zakończeniu dojrzewania produkcyjnego (w 15°C przez 3 tygodnie) oraz po zakończeniu dojrzewania poprodukcyjnego w opakowaniach próżniowych (w 4°C, przez kolejne
9 tygodni). Określano wartość pH, aktywność wody, stabilność oksydacyjną (TBARS),
trwałość barwy oraz jakość mikrobiologiczną wyrobów.
Stwierdzono dodatnią korelację pomiędzy wyższym dodatkiem azotanu(III) sodu
a trwałością oksydacyjną kiełbas, zarówno po dojrzewaniu produkcyjnym, jak i po kilkutygodniowym dojrzewaniu poprodukcyjnym. Dodatek liofilizowanego ostropestu,
w obu stężeniach, dodatkowo obniżył stężenie wtórnych produktów oksydacji tłuszczu
(wskaźnik TBARS) w kiełbasach. Zarówno aktywność wody, jak i wartość pH kiełbas
dojrzewających były typowe dla tego typu produktów mięsnych, niezależnie od zastosowanego stężenia dodatku liofilizatu. Dodatek ostropestu nie wpłynął na trwałość
barwy, której stabilność zależała wyłącznie od stężenia peklosoli. Stwierdzono, że dodatek roślinny nie ograniczał rozwoju bakterii kwaszących typu mlekowego w produkcie. Po zakończeniu dojrzewania wszystkie warianty charakteryzowały się wysoką
liczbą LAB (> 8,2 log jtk/g), przy jednocześnie niskiej liczbie bakterii tlenowych (< 7,1
log jtk/g).
Uzyskane wyniki wskazują, że możliwe jest wykorzystanie liofilizowanego ostropestu plamistego jako skutecznego przeciwutleniacza w technologii ekologicznych
kiełbas dojrzewających o obniżonym dodatku NaNO2 (< 100 mg/kg)
Cistaceae family is widespread in the Mediterranean regions with several species and istraditionally known as a natural remedy. Cistus genus is present in Sardinia with populations of C.monspeliensis, C. salvifolius, C. albidus and C. creticus subspecies : C. creticus subsp. creticus, C.creticus subsp. corsicus and C. creticus subsp. eriocephalus, but few previous phytochemicalresearches have been reported on Cistus species growing in Sardinia.The aim of this research is to characterize the secondarymetabolites in extracts of differentspecies of Cistus in Sardinia and to evaluate antimicrobial and antioxydant activities. The freshaerial parts of the plants were extracted by using hydro distillation for essential oils and severaltraditional solvent s for the phenolic compounds.The chemical characterization of extracts has beenrealized by means of different chromatographic techniques such as GC/MS, HPLC DAD ESI MSand CL UHP SM/SM. Antimicrobial activity was determined as Minimum Inhibitory Concentra tionby using an agar macrodilution method. Antioxidant activity has been measured by using DPPHassay and it has been verified with EPR.A comparative analysis on the composition of essential oils showed the existence of six differentprofiles. C. cretic us subsp. eriocephalus showed a high amount of manoyl oxide and its isomer. C.salvifolius has pointed out the group of labdans; another consistent percentage is made ofperfumed molecules as ionone and its derivate. Several linear hydrocarbons were produc ed by C.monspeliensis, and the heneicosane was the most represented element. In C. albidus no labdanetype diterpenes were identified. Analysis of C. creticus subsp creticus revealed several oxygenatedsesquiterpenes and labdane type diterpenes, especiall y manoyl oxide. C. creticus subsp. corsicuswas qualitatively very similar to C. creticus subsp. creticus, notably concerning the labdane typecompounds. The analysis of the seven essential oils of Cistus creticus subsp. eriocephalus showinteresting chara cteristics and they would appear divided in two groups with different metabolicprofiles. Among solvent extracts the obtained results allowed the detection of several phenoliccompounds including phenolic acids, monomeric and dimeric flavan 3 ols, flavonolglycosides.They are characterized by a hight percentage of rosmarinic acid and derivatives and ofquercitin and derivatives. C. salvifolius is quantitatively most rich of phenolic compounds. Theextracts exhibited any pronounced differences in their anti microbial activities and revealed thatGram positive bacteria are more sensitive to the Cistus extracts than Gram negative bacteria.None of the extracts showed any noticeable action against Candida species. The extracts showedthat Cistus plants of Sardin ian origin have a greater antioxidant activity.
Polyphenols are natural substances that have been shown to provide various health benefits. Antioxidant, anti-inflammatory, and anti-carcinogenic effects have been described. At the same time, they inhibit the actions of bacteria, viruses, and fungi. Thus, studies have also examined their effects within the oral cavity. This review provides an overview on the different polyphenols, and their structure and interactions with the tooth surface and the pellicle. In particular, the effects of various tea polyphenols on bioadhesion and erosion have been reviewed. The current research confirms that polyphenols can reduce the growth of cariogenic bacteria. Furthermore, they can decrease the adherence of bacteria to the tooth surface and improve the erosion-protective properties of the acquired enamel pellicle. Tea polyphenols, especially, have the potential to contribute to an oral health-related diet. However, in vitro studies have mainly been conducted. In situ studies and clinical studies need to be extended and supplemented in order to significantly contribute to additive prevention measures in caries prophylaxis.
Objectives:
to investigate the effects of Chinese gallnut extracts and pure tannic acid on in situ biofilm formation on enamel and dentin samples over 24 h.
Methods:
Bovine enamel and dentin samples were buccally fixed on maxillary splints. Six volunteers wore the splints for 24 h, and rinsed their mouths with tap water (control), 1% tannic acid- and 1% Chinese gallnut extracts-containing solution twice a day, 3 min after the splints were placed in the mouth and before night sleep. Live/dead staining was used for fluorescence microscopic (FM) visualization and quantification of bacteria viability of biofilms formed on enamel and dentin samples. Biofilm coverage was evaluated and recorded by FM and scanning electron microscopy (SEM). In addition, biofilms were analyzed by transmission electron microscopy (TEM). The Kruskal-Wallis test was used to analyze biofilm data.
Results:
Rinsing with tannic acid- and Chinese gallnut extracts-containing solutions significantly reduced in situ biofilm coverage on enamel and dentin samples (P < 0.05). The bacterial viability of biofilms formed on enamel samples was significantly reduced compared to the control (P < 0.05). TEM analysis revealed an increase in pellicle's electron density and thickness and only few or no bacteria adherent to the pellicle in the experimental samples.
Conclusions:
Rinsing with tannic acid- and Chinese gallnut extracts-containing solutions can effectively inhibit in situ biofilm formation, modify the ultrastructure of biofilms on enamel and dentin surfaces and significantly reduce the bacterial viability of biofilm on enamel surfaces.
Clinical significance:
Tannic acid- and Chinese gallnut extracts-containing solutions might be used for dental biofilm management.
Objective
The presentin situ study aims to examine the influence of the polyphenolic tea drugs fragaria vesca, hamamelis and tormentil on the initial oral bioadhesion.
Design
Initial biofilm formation was performed on bovine enamel slabs which were carried intraorally by 12 subjects. After 1 min of intraoral pellicle formation, the subjects rinsed with fragaria vesca, tormentil (0.8 mg/8 ml) and hamamelis (0.2 mg/8 ml) for 10 min. Tap water served as negative control, 0.2% CHX as positive control. The investigations took place on different days (wash-out: 2 days). Afterwards, fluorescence microscopy has been performed per test solution (n = 5) and per subject (n = 12) to visualize bacterial adhesion and glucan formation (8 h oral exposition) with DAPI, ConA and BacLight. Additionally, TEM was used to visualize the pellicle ultrastructure and expectorate samples. Statistical evaluation was carried out using the Kruskal-Wallis- (p < 0.5), Mann–Whitney U-test (p < 0.5) and Bonferroni-Holm-correction (p < 0.1).
Results
Rinsing with the polyphenolic tea extracts reduced significantly initial bacterial colonization (DAPI) compared to the negative control. There was no significant difference betweenfragaria vesca, hamamelis and tormentil. All solutions showed a reducing effect on the glucan formation. No significant difference was observed between fragaria vesca and CHX. Considerable alterations of the pellicle’s ultrastructure manifested by an increase in thickness and electron density resulted from rinsing with the three polyphenolic aqueous extracts.
Conclusions
Fragaria vesca, hamamelis and tormentil significantly reduce initial bioadhesion and glucan formation in situ and are therefore recommended as adjuvant antibacterial oral therapeutics.
Background:
To investigate the bactericidal effect of tea polyphenols on multi-drug resistant Klebsiella pneumoniae and its antibacterial efficacy in combination with common antibiotics, and to explore its mechanism.
Methods:
The VITEK 2 Compact automatic microbial identification system was used to identify 20 strains of Klebsiella pneumoniae isolated from clinical isolates. The KB method was used to detect sensitivity of common drugs such as imipenem, piperacillin, piperacillin/tazobactam and cefepime, cefotaxime and ceftazidime; agar dilution method was used for detection of minimum inhibitory concentration (MIC) of tea polyphenols; the variation of the diameter of the antibacterial ring after different concentrations (0.25 MIC, 0.5 MIC) of tea polyphenols in combination with commonly used antibacterial drugs was detected to judge the feasibility of the inhibition of the multidrug-resistant Klebsiella pneumoniae by the combination of tea polyphenols and commonly used antibacterial drugs. Congo red and crystal violent staining was used to detect the impact on bacterial biofilm formation and extracellular mucus-like substance (slime).
Results:
The K-B values of 20 strains of Klebsiella pneumoniae against common antibiotics were 6-14 mm; the MIC of tea polyphenols against 20 strains of multi-drug resistant Klebsiella pneumoniae was 1024 ug / ml; 0.5 MIC tea polyphenols can increase the diameter of the bacteriostatic ring of imipenem, piperacillin, piperacillin/tazobactam, cefepime, cefotaxime and ceftazidime by 3-28 mm. Tea polyphenols at sub-inhibitory concentrations significantly inhibited the production of Klebsiella pneumoniae biofilm and extracellular mucus (slime).
Conclusions:
Tea polyphenols could be used in combination with commonly used antibiotics (imipenem, piperacillin, piperacillin/tazobactam, cefepime, cefotaxime and ceftazidime) against multidrug-resistant Klebsiella pneumoniae. It has a synergistic bactericidal effect and affects the formation of bacterial outer membrane and the production of extracellular slime-like substances (slime).
One of the most popular drinks worldwide, tea is rich in polyphenols and is beneficial to our health because it contributes to the prevention of many diseases. In the human oral cavity, there are more than 750 different species of bacteria living together within dental plaque. Some of the bacteria are pathogens that contribute to the development of oral diseases such as dental caries, periodontitis, pulpitis, mucosal disease, or halitosis through their virulence factors and their metabolites. Until now, many studies have reported that tea polyphenols (TPs) have evident inhibitory effects on some oral pathogenic microorganisms by suppressing pivotal steps of their pathogenic processes. The aim of this review is to summarize the effectiveness and mechanisms of TPs in inhibiting microorganisms, so as to provide new ideas for the prevention and treatment of oral diseases, and to contribute to the global dental public health.
Some information about Cistus creticus L.
This study was carried out to evaluate the antioxidant properties of Greek endemic Cistus creticus L. (rock rose) bee pollen and define its phenolic compounds. In the framework of our scientific studies on Greek bee keeping products, we report herein our research on three Greek bee pollen samples from Cistus. Their pollinic spectra were obtained by Louveaux's quantitative microscopical analysis and it showed that one of them had Cistus sp. (Cistaceae) as abundant pollen (together with low percentage of Brassica sp. (Cruciferae). Throughout the chemical analysis of the extracts, several secondary metabolites of flavonoid structure have been identified as major components. Specifically, quercetin-7-rhamnoside (1), quercetin-3-neohesperidoside (2), kaempferol-3- neohesperidoside (3), myricetin-3-neohesperidoside (4), kaempferol-3-glucoside (5) and quercetin-3-glucoside (6) have been isolated and their structures were elucidated on the basis of spectral evidence. Moreover, the total phenolic and flavonoid content was estimated and the free radical scavenging activity was determined by DPPH and ABTS assays. The antimicrobial activity of the extracts was tested against six Gram-positive and -negative bacteria and three pathogenic fungi, and the butanol extract showed a very interesting broad antimicrobial profile (MIC 1.98·10⁻³ - 2.98·10⁻³ mg/ml) against all the assayed microorganisms.
Objectives:
In the present in situ/ex vivo study the impact of tannic acid on the erosion-protective properties of the enamel pellicle was tested. Additionally, the antiadherent and antibacterial effects of tannic acid were evaluated.
Methods:
The pellicle was formed in situ on bovine enamel samples fixed on individual splints worn by 6 subjects. Following 1 min of pellicle formation the volunteers rinsed for 10 min with tannic acid. After further oral exposure for 19 min, 109 min, and 8 h overnight, respectively, slabs were incubated in HCl ex vivo (pH 2.0, 2.3, 3.0) over 120 s. Subsequently, kinetics of calcium and phosphate release were measured photometrically. Samples after a 1-min fluoride mouth rinse as well as enamel samples with and without a 30-min in situ pellicle served as controls. Antiadherent effects were evaluated after a 1-min rinse with tannic acid and oral exposure of the slabs overnight. DAPI (4',6-diamidino-2-phenylindole) combined with concanavalin A staining and live/dead staining was used for fluorescence microscopic visualization and quantification of adherent bacteria and glucans. Modification of the pellicle's ultrastructure by tannic acid was evaluated by transmission electron microscopy (TEM).
Results:
Tannic acid significantly improved the erosion-protective properties of the pellicle in a pH-dependent manner. Bacterial adherence and glucan formation on enamel were significantly reduced after rinses with tannic acid as investigated by fluorescence microscopy. TEM imaging indicated that rinsing with tannic acid yielded a sustainable modification of the pellicle; it was distinctly more electron dense.
Conclusion:
Tannic acid offers an effective and sustainable approach for the prevention of caries and erosion.
The oral fluids are of essential relevance for the protection of the oral cavity and the whole organism against external noxae and pathogenic microorganisms. Furthermore, they mediate the process of bioadhesion to all surfaces in the oral cavity and promote numerous interactions with any substance entering the oral cavity. Due to this fact the oral fluids as well as the processes of bioadhesion, bioadsorption and microbial biofilm formation certainly have an impact on taste perception. However, there is only a limited number of studies on this topic. The present review tries to give an overview on the present knowledge and intends to draft some hypotheses for future research.
The human oral microbiota is one of the most diverse biofilms colonizing the human body consisting of over 700 individual taxa. Two of the most common human diseases, caries and periodontal disease, are the result of a healthy microbial biofilm becoming a dysbiotic one due to mechanisms not completely understood. These are special cases of infectious diseases in which the origin of the infection is not an exogenous organism but a commensal organism that somehow overgrows and modifies the features of the microbial biofilm to its advantage. Dental Unit Water Systems (DUWS) deserve special consideration when studying biofilm control methods in oral health. In dentistry, dental chair units (DCU) are equipped with complex networks of plastic pipes that supply water to the DCU instruments and constitute an ideal environment for the growth of biofilms, especially bacterial biofilms. In the present chapter we present a brief overview of different methods that have been used in dentistry to control biofilm growth both in the oral cavity as well as in DUWS, with special focus on new strategies whose goal it is to modulate the composition and growth of the biofilm rather than the complete removal of the microbial community.
The Mediterranean plant Cistus incanus is rich in polyphenols and has shown several pharmacological activities, mainly antibacterial effects. Furthermore, in situ studies revealed that a C. incanus infusion reduces the initial bacterial adhesion in the oral cavity due to the polyphenols, an indication that C. incanus might reduce the risk of caries disease. In the present study, the polyphenols from four different commercial C. incanus herbal teas were extracted by standardized accelerated solvent extraction for in vitro tests and by an infusion for in situ tests. Both extracts were characterized qualitatively and quantitatively by high-performance liquid chromatography and only the polyphenol content differed slightly. By means of diode array detection and mass spectrometry, 29 polyphenols, including ellagitannins, flavanols, and glycosylated flavonols, were identified. Thereby, only quantitative but no qualitative differences between the four samples were detected. Furthermore, the in vitro antibacterial activity of the C. incanus accelerated solvent extracts against Streptococcus mutans, one of the primary cariogenic bacterial species, was examined using a live/dead assay (BacLight®). With this approach, C. incanus yielded antibacterial properties. Additional in situ experiments indicated that rinses with a C. incanus infusion reduced the initial bacterial colonization of enamel samples exposed to oral fluids for over eight hours. Furthermore, it was shown by transmission electron microscopy that the application of a C. incanus infusion modifies the ultrastructure of the acquired enamel pellicle, yielding a more electron-dense morphology. It can be assumed that the polyphenols are responsible for the observed effects.
Georg Thieme Verlag KG Stuttgart · New York.
Antiadherent and antibacterial effects of certain plant extracts have been proven to be beneficial in preventive dentistry. In the present in situ/in vitro crossover study, the impact of plant extracts rich in polyphenols on the erosion-protective properties of the in situ pellicle was evaluated.
Individual splints were prepared for 12 subjects for intraoral exposure of bovine enamel specimens. Following formation of a 1-min pellicle, watery plant extracts (leaves of the wild form of Ribes nigrum, the wild form of Origanum as well as a combination of both) were administered for 10 min in situ. Alternatively, a mouth rinse with fluorides (Elmex Kariesschutz) was performed for 1 min. After further oral exposure for 19/28 min, respectively, slabs were removed and incubated with HCl in vitro over 120 s (pH 2, 2.3, 3). The resulting calcium and phosphate release was quantified photometrically. Slabs with and without a 30-min in situ pellicle served as controls. The modification of pellicle ultrastructure was evaluated by transmission electron microscopy (TEM).
Plant extracts modulated the erosion-protective properties of the native in situ pellicle in all test groups in a pH-dependent manner. The combination of R. nigrum leaves and Origanum enhanced the protective properties of the pellicle at all pH values; the administration of this preparation was comparable, yet superior, to the effect of the fluoridated mouth rinse. TEM images indicated that rinsing with R. nigrum leaves/Origanum yielded a distinctly thicker and more electron-dense pellicle.
The combination of certain plant extracts offers a novel approach to the complementary prevention of dental erosion. © 2015 S. Karger AG, Basel.
Currently numerous manufacturers offer herbal infusions or dietary supplements based on the plant Cistus incanus. These products are especially promoted as offering a high content of phenolic substances together with an associated strong antioxidant activity. For the customers it is of interest, if the advertised phenolic contents are valid, plant material is authentic and if the suggested effects can be obtained through ingestion. As it is known from the literature, phenolic compounds can undergo severe changes resulting from cooking. Therefore, it is important to consider processing parameters such as brewing water, brewing temperature, and brewing duration for the preparation of C. incanus herbal infusions. The aims of this study were to analyze the phenolic compounds of C. incanus herbal infusions, to estimate the antioxidant capacity of the individual phenolic substances, as well as to investigate the influence of the brewing process on the phenolic compound profile. By the use of LC–DAD/ESI–MS/MS thirty-two phenolic compounds (e.g. phenolic acids, flavan-3-ol monomers and -dimers as well as flavonol glycosides) were identified. Additionally, specific antioxidant capacities were attributed to corresponding substances by using the LC–onlineTEAC (Trolox Equivalent Antioxidant Capacity) methodology. Moreover, the selection of brewing water, boiling time as well as boiling temperature had a significant influence on the content of the phenolic compounds in C. incanus infusions. On the basis of these results, it can be concluded, that an incorrect choice of brewing process parameters could result in a decreased amount of phenolic substances in the final C. incanus beverages accompanied with a reduced antioxidant activity.
A variety of Cistus incanus products and thereof a majority of herbal teas are offered by manufacturers despite a classification as Novel Food. For a re-evaluation of this legal status, a characterization of bioactive ingredients will provide data. These teas consist of varying compositions of plant parts and particle sizes. While some include high leaf contents with a small particle size, others mainly consist of woody stem parts. For the consumer it is of interest which product yields the highest concentrations of bioactive phenolic compounds in the final infusions. In this study, four commercially available samples were divided into leaves and stems. Additionally, one sample was reconstituted in three mixtures of these plant parts. The amount of wood was determined by cellulose concentration. The aim was to estimate the influence of the plant parts on the concentration of phenolic compounds which were identified by LC-DAD-ESI-MS/MS and quantitated by LC-DAD. Furthermore, one herbal tea was separated into six fractions with different particle sizes to investigate the influence of particle size on the extractability of phenolic compounds. On basis of the results, the highest concentrations of bioactive compounds in the infusions were yielded when brewing leafy parts with a small particle size.
Sucrose-glucan glucosyltransferase (Gtf) is an important enzyme involved in the cavity formation process where insoluble glucan is synthesized. In this study, we purified Gtf from Streptcoccus mutans Ingbritt through ammonium sulfate precipitation, Sephadex G-150, CM-Sephadex, and DEAE-Sephadex column chromatographies. A 13-fold of purification was achieved with a total yield of 6.3%. The apparent molecular mass of the enzyme was determined to be 66 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal pH and temperature were established to be 6.0 and , respectively. The enzyme activity could be inhibited to 22-59% by 1 mM , and , and to 68% by 1 mM EDTA. It was also inhibited 40% by 2 mM xylitol and 35-45% by 0.05% soluble chitosan, glycol chitosan, and glycol chitin. This is the first report to reveal the inhibition effect of chitin derivatives on Gtf activity, which may be further applicable to develop gargles to overcome cavity.
Abstract Infections caused by opportunistic human fungal pathogens are very
common and have shown steady increase in recent years. The typical hosts,
which are prone to fungal infections, are those who possess suppressed immune
systems due to conditions such as HIV and transplantation surgery. Due to
prolonged chemotherapy, fungal cells also develop tolerance to the most commonly
used azole antifungals by employing several strategies. Interestingly, biofilms
which are routinely formed by fungal cells on medically implanted devices employ
different strategies to become highly resistant to antifungals. Apart from the known
tactics, newer approaches have revealed novel mechanisms and regulatory circuits
that are responsible for the development of multidrug resistance. Overcoming the
major clinical hurdle of fungal resistance demands a great deal of knowledge about
the function of fungal machinery that is used under drug stress.
Aim:
Mouth rinses containing enzymes are designed for patients suffering from xerostomia. The objective of the present in situ study was to investigate the efficacy of these rinses for targeted accumulation and immobilisation of protective enzymes in the acquired pellicle.
Methods:
A number of six healthy subjects carried bovine enamel slabs fixed on individual upper jaw splints for pellicle formation in situ. After 1 min, they rinsed with biotène or BioXtra for 10 min, respectively. Enzyme activities of lysozyme, peroxidase and glucoseoxidase in the in situ pellicle and in the saliva were assayed before as well as 0, 20 and 40 min after the rinses. The assays for the respective enzyme activities were based on fluorogenic substrates. Separate experiments were performed for the different enzymes and mouth rinses, respectively. Statistical evaluation was carried out with the Kruskal-Wallis test.
Results:
None of the investigated rinses had any significant impact on the activities of lysozyme, peroxidase and glucoseoxidase detectable in the in situ pellicle or in the saliva (Kruskal-Wallis test, p>0.05). Despite the fact that both products should contain lactoperoxidase activity according to manufacturers' instructions, no peroxidase activity was measurable in the pure mouth rinses.
Conclusion:
With the tested enzymatic mouth rinses targeted accumulation and immobilisation of protective enzymes in the in situ pellicle did not seem possible.
Saliva is thought to have a significant impact on the colonization of microorganisms in the oral cavity. Salivary components may participate in this process by one of four general mechanisms: binding to microorganisms to facilitate their clearance from the oral cavity, serving as receptors in oral pellicles for microbial adhesion to host surfaces, inhibiting microbial growth or mediating microbial killing, and serving as microbial nutritional substrates. This article reviews information pertinent to the molecular interaction of salivary components with bacteria (primarily the oral streptococci and Actinomyces) and explores the implications of these interactions for oral bacterial colonization and dental plaque formation. Knowledge of the molecular mechanisms controlling bacterial colonization of the oral cavity may suggest methods to prevent not only dental plaque formation but also serious medical infections that may follow microbial colonization of the oral cavity.
Various components in green and black tea, the beverages made by infusing appropriately processed dried leaves of Camellia sinensis, notably simple catechins, have properties in vitro that suggest an anti-cariogenic activity. These include: a direct bactericidal effect against Streptococcus mutans and S. sobrinus; prevention of bacterial adherence to teeth; inhibition of glucosyl transferase, thus limiting the biosynthesis of sticky glucan; inhibition of human and bacterial amylases. Studies in animal models show that these in-vitro effects can translate into caries prevention. A limited number of clinical trials in man suggest that regular tea drinking may reduce the incidence and severity of caries. If substantiated, this could offer a very economical public health intervention.
Flow cytometry, using propidium iodide and 4',6-diamidano-2-phenylindole staining, was used to estimate the nuclear DNA content (2C) and the proportion of A-T base pairs in 16 species of the Mediterranean genus Cistus. Genome sizes were shown to be constant within species, since no significant intraspecific variation in 2C DNA content was detected. At the genus level, up to about 1.5-fold differences in absolute DNA amounts were observed, ranging from 3.92 pg in C. crispus to 5.88 pg in C. monspeliensis. The (AT) : (GC) ratio was close to 1, and was similar for all species examined, ranging from 47.87% A-T content in C clusii, to 50.67% in C. populifolius. Pink-flowered species (subgenus Cistus) had lower DNA amounts than white-flowered species (subgenera Leucocistus and Halimioides). However, the distribution of DNA amounts in Cistus appeared to be continuous and did not permit a clear separation of infra-generic ranks in the genus.
With a questionnaire addressed to general dental practitioners in Sweden, the Swedish Council on Technology Assessment in Health Care launched a project group in 1999 to systematically review and evaluate the existing literature on various caries preventive methods. The aim of this article was to report findings concerning the caries preventive effect of fluoride toothpastes in various age groups, with special emphasis on fluoride concentration and supervised versus non-supervised brushing. A systematic search in electronic databases for articles published between 1966 and April 2003 was conducted with the inclusion criteria of a randomized or controlled clinical trial, at least 2 years follow-up and caries increment in the permanent (deltaDMFS/T) or primary (deltadmfs/t) dentition as endpoint. Out of 905 articles originally identified, 54 met the inclusion criteria. These studies were assessed independently by at least two reviewers and scored A-C according to predetermined criteria for methodology and performance. The measure of effect was the prevented fraction (PF), expressed as percent. The results revealed strong evidence (level 1) (i) for the caries preventive effect of daily use of fluoride toothpaste compared to placebo in the young permanent dentition (PF 24.9%), (ii) that toothpastes with 1,500 ppm of fluoride had a superior preventive effect compared with standard dentifrices with 1,000 ppm F in the young permanent dentition (PF 9.7%), and (iii) that higher caries reductions were recorded in studies with supervised toothbrushing compared with non-supervised (PF 23.3%). However, incomplete evidence (level 4) was found regarding the effect of fluoride toothpaste in the primary dentition. In conclusion, this review reinforced the importance of daily toothbrushing with fluoridated toothpastes for preventing dental caries, although long-term studies in age groups other than children and adolescents are still lacking.
The formation and composition of dental plaque biofilm in vivo are important factors which influence the development of gingivitis, caries and periodontitis. Studying dental plaque biofilm in in vitro models can cause an oversimplification of the real conditions in the oral cavity. In this study, bovine enamel slabs were fixed in an individual acrylic appliance in situ to quantify dental plaque formation and composition using multiplex fluorescence in situ hybridization (FISH) and confocal laser scanning microscopy. Each of the five oligonucleotide probes used for FISH was specific for either eubacteria or one of four frequently isolated bacterial constituents belonging to early and late colonizers of tooth surfaces. The thickness of formed biofilm increased from 14.9+/-5.0 microm after 1 day to 49.3+/-11.6 microm after 7 days. Streptococcus spp. were predominant in 1-day-old dental plaque and decreased significantly after 7 days (P=0.0061). Compared to the first day, Fusobacterium nucleatum decreased after 2 days and increased significantly after 7 days (P=0.0006). The decreases of Actinomyces naeslundii content on day 2 and day 7 were significant (P=0.0028). Changes in Veillonella spp. were not significant during the study period (P >0.05). The results showed that an in vivo observation period of 7 days was required to detect significant changes in Streptococcus spp. and F. nucleatum. The multiplex FISH used is suitable for analysing the dynamics of four important bacterial constituents in the oral biofilm in epidemiological studies.
The minimum inhibitory concentrations (MIC) of commercially available and 70% aqueous propanone (P70) extracts from plants chosen for polyphenol content on Streptococcus mutans and other bacteria were determined using a standard susceptibility agar dilution technique to investigate their potential use as anticariogenic agents. The effects on adhesion of S. mutans to glass were also studied. The lowest MICs were for the P70 extracts of red grape skin (0.5 mg ml(-1)) and green tea and sloe berry skin (2 mg ml(-1)). The commercial extracts generally had a lower activity with a minimum MIC of 2 mg ml(-1) for tea extracts, grape seed extracts and Pynogenol (extract of maritime pine). All other extracts had MICs of > or = 4 mg ml(-1). Unfermented cocoa had greater antimicrobial activity than fermented cocoa and the activity of the fractionated extract increased with the extent of epicatechin polymerization. Epicatechin polymer had an MIC of 1 mg ml(-1) and an MBC of 64 mg ml(-1). Selected extracts were tested against other oral bacteria and showed activity against gram-positive organisms. P70 extracts of unfermented cocoa, epicatechin polymer fraction, green tea and red grape seed were bacteriostatic and prevented acid production when added at the MIC to cultures of S. mutans grown in a chemically defined medium supplemented with either glucose or sucrose. There was a reduction in viability which was greater when added to washed cells, but there were some viable cells after 24 h. The extracts also reduced adherence of S. mutans to glass.
Fifteen species of Tunisian traditional medicinal plants, belonging to 10 families, were selected for this study. They were Inula viscosa (L.) Ait and Reichardia tingitana (L.) Roth ssp. discolor (Pom.) Batt. (Asteraceae), Mesembryanthemum cristallinum L. and M. nodiflorum L. (Aizoaceae), Arthrocnemum indicum (Willd.) Moq., Atriplex inflata Muell., A. parvifolia Lowe var. ifiniensis (Caball) Maire, and Salicornia fruticosa L. (Chenopodiaceae), Cistus monspeliensis L. (Cistaceae), Juniperus phoenicea L. (Cupressaceae), Erica multiflora L. (Ericaceae), Frankenia pulverulenta L. (Frankeniaceae), Hypericum crispum L. (Hypericaceae), Plantago coronopus L. ssp. eu-coronopus Pilger var. vulgaris G.G. (Plantaginaceae) and Zygophyllum album L. (Zygophyllaceae). Fifty extracts prepared from those plants were screened in order to assay their antiviral activity against Herpes simplex virus type 1 (HSV-1), using neutral red incorporation. Extracts from eight plants among these 15 showed some degree of antiviral activity, while the methanolic extract of E. multiflora was highly active with EC(50) of 132.6 microg mL(-1). These results corroborate that medicinal plants from Tunisia can be a rich source of potential antiviral compounds.
The sequencing of 16S and 23S ribosomal RNA (rRNA) molecules is currently the gold standard for the classification of new microbial isolates. Comparative analyses of these sequences are for the first time in the history of microbiology facilitating the reconstruction of universal phylogenetic trees [38]. Among many other important findings the work of Carl Woese and his colleagues demonstrated that only certain (by far not all) phenotypic/physiological groups of micro-organisms are monophyletic (e.g., methanogenes, cyanobacteria, spirochetes). About 10 years ago it has been proposed to use an rRNA approach for studies in microbial ecology [21]. The microbial diversity should be analyzed in a cultivation-independent way by direct rRNA sequence retrieval, whereas nucleic acid probes complementary to rRNA or rRNA genes should be the tools to monitor population dynamics in the environmental samples. By their own nature rRNA-targeted probes track genotypes which are not necessarily linked to one phenotype. Microbial ecologists who want to apply this approach to investigate correlations between community structures and functions should be aware of this fact and design or apply rRNA-targeted probes accordingly.
A sensitive assay for secretory peroxidase activity has been developed utilizing the fluorogenic substrate 2',7'-dichlorofluorescin in the presence of thiocyanate. The assay has been characterized using bovine lactoperoxidase and used to determine the peroxidase activities of salivas and extracts obtained from rat submandibular glands. Comparison of the 2',7'-dichlorofluorescin-thiocyanate assay and the commonly used 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) colorimetric assay indicates that the new assay is approx. 50-fold more sensitive. This has enabled measurement of peroxidase activities present in parasympathetic saliva samples which were beyond the detection limit of the colorimetric assay. Despite great differences in the peroxidase activities and protein concentrations of parasympathetic and sympathetic salivas and tissue extracts, the activities per unit protein were very similar. Unlike most other published methods, prior dialysis of samples to remove interference by endogenous thiocyanate is not required. The assay is therefore convenient and will be particularly useful for applications in which sample volume or peroxidase activity is low.
Many polyphenols are potent antioxidants in foods and model systems and they have therefore very naturally been linked with the hypothesis that their redox actities may confer them with specific health benefits. Their prevalence in plant derived foods, which are generally accepted as healthy has supported this view and inspired researchers to conduct human intervention trails with polyphenol rich food items in order to investigate their ability to counteract oxidative stress. Several biomarkers have gained widespread use to assess oxidative damage and antioxidative defence capabilities in humans. These markers pioneer our knowledge about factors related to oxidative stress in proteins, lipids and DNA and present results indicate that oxidative damage may be very localised and that refined markers may be necessary in order to disentangle the complex local factors which determine the extent of oxidative damage in different molecular structures. The present text reviews the human short-term intervention s
The dental caries inhibiting effect of the extract from Japanese green tea, one of the most popular drinks in Japan, was studied both in vitro and in vivo. The crude tea polyphenolic compounds (designated Sunphenon) from the leaf of Camellia sinensis were found to effectively inhibit the attachment of Streptococcus mutans strain JC-2 (serotype c) to saliva-coated hydroxyapatide discs. Sunphenon was also inhibitory to water-insoluble glucan formation from sucrose by crude glucosyltransferase of S. mutans JC-2 (c). Among the tea catechins tested, (-)-epigallocatechin gallate and (-)-epicatechin gallate showed the most potent inhibition of the glucosyltransferase activity. Finally, significantly lower caries scores were observed in specific pathogen free rats infected with S. mutans JC-2 (c) and fed a cariogenic diet and/or drinking water containing 0.05% Sunphenon as compared with control rats not receiving polyphenolic compounds.
Fluorescent oligonucleotide hybridization probes were used to label bacterial cells for analysis by flow cytometry. The probes, complementary to short sequence elements within the 16S rRNA common to phylogenetically coherent assemblages of microorganisms, were labeled with tetramethylrhodamine and hybridized to suspensions of fixed cells. Flow cytometry was used to resolve individual target and nontarget bacteria (1 to 5 microns) via probe-conferred fluorescence. Target cells were quantified in an excess of nontarget cells. The intensity of fluorescence was increased additively by the combined use of two or three fluorescent probes complementary to different regions of the same 16S rRNA.
Some fruit juices and beverages inhibit the glucosyltransferases of Streptococcus mutans. Inhibition by cocoa, coffee and tea was due partly to gelatin-precipitable tannins and partly to components that exhibited properties of monomeric polyphenols. Charcoal treatment removed all inhibitory activity. Catechin, a known constituent of these beverages, was an effective inhibitor of the enzymes. The effects of the fruit juices were attributable mainly to the inhibition of the glucosyltransferases by the endogenous fructose and glucose. The findings show that naturally-occurring constituents of foods can inhibit extracellular polysaccharide formation from sucrose. Such constituents may play a role in regulating dental plaque formation in vivo and, thereby, may have long-term effects on the development of dental caries.
A collaborative study was carried out on an enzymatic method for the determination of L-citric acid in wine, using the enzymes citrate lyase, malate dehydrogenase, and lactate dehydrogenase and the coenzyme nicotinamide-adenine dinucleotide phosphate. The study was performed by 18 laboratories using 4 blind duplicates of commercial wine. The method is simple and shows good precision. Coefficients of variation (CV) for reproducibility ranged from 1.8 to 3.4%; CVs for repeatability ranged from 0.76 to 2.62%. Analysts are cautioned to check the linear absorbance response of their spectrophotometers when performing this assay and also to take care in pipetting the relatively small volumes used in this procedure. The method has been adopted official first action.
This collaborative study on the determination of glucose and fructose in wine was performed by 18 laboratories on 4 matched pairs of commercial wine. The method uses the enzymes hexokinase, glucose-6-phosphate dehydrogenase, and phosphoglucose isomerase and the coenzyme nicotinamide-adenine dinucleotide phosphate. Both glucose and fructose can be determined in the same sample without separation. The method is simple but care is necessary to ensure precise transfer of small volumes. Repeatability and reproducibility standard deviations for glucose ranged from 2.6 to 14.6 mg/L and 4.7 to 16.5 mg/L, respectively. Repeatability and reproducibility values for fructose ranged from 2.4 to 16.1 mg/L and 6.0 to 21.3 mg/L, respectively. The method has been adopted official first action.
A method was developed to visualize individual DNA molecules in solution under a fluorescent microscope connected to a highly sensitive video camera. DNA stained with a fluorescent dye, DAPI, revealed thin extended filaments, thicker filaments and rapidly transforming folded structures dependent upon the solution conditions. Structural transitions were observed and recorded as video images. Our observations indicated the possibility that DNA has the ability of supercoiling itself. This DAPI staining method will have wide possible application in the study of DNA and chromatin.
A new sensitive, rapid and simple method for lysozyme assay is described which is based on either fluorescence polarization or fluorescence intensity using fluorescein-labeled peptidoglycan as a substrate. The peptidoglycan was obtained from Micrococcus lysodeikticus after extensive digestion with Pronase and washing with Triton X-100 followed by various solvents. Subsequently, it was labeled with fluorescein isothiocyanate (FITC) at the amino group of the peptide. When the FITC-labeled substrate was subjected to lysozyme digestion, an increase of fluorescence intensity or a decrease of fluorescence polarization value (P value) was apparent in five minutes at a lysozyme concentrations as low as 0.1 or 0.01 micrograms/ml, respectively. The effect of other hydrolytic enzymes including alpha-mannosidase, proteases and RNase on the P value was found to be negligible. The measured values represented the specificity and dose of lysozyme added. Apparent Vmax and Km values for two different lysozymes, chicken egg white and human, could be determined by this method.
The inhibitory effect of oolong tea extract (OTE) containing polymerized polyphenols on plaque deposition was examined in 35 human volunteers. Thirty-five human volunteers, aged 18-29 years, who received extensive oral prophylactic procedures were requested to refrain from all oral hygiene procedures for 4 days, and to rinse their mouth with 0.5 mg/ml OTE solution in 0.2% ethanol before and after every intake of food and before sleeping at night. No restriction regarding meals was given during the test period, except to refrain from teas or coffee. Plaque deposition was evaluated after disclosing the teeth with Erythrocin at the termination of this experiment. The study was repeated 1 week after the first trial, but only 0.2% ethanol without OTE was used for mouthrinsing in the second trial. OTE was found to significantly inhibit plaque deposition in volunteers, although mouthrinsing with OTE solution had no significant effect on the number of mutans streptococci in unstimulated whole saliva.
A sensitive assay for secretory peroxidase activity has been developed utilizing the fluorogenic substrate 2',7'-dichlorofluorescein in the presence of thiocyanate. The assay has been characterized using bovine lactoperoxidase and used to determine the peroxidase activities of salivas and extracts obtained from rat submandibular glands. Comparison of the 2',7'-dichlorofluorescein-thiocyanate assay and the commonly used 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) colorimetric assay indicates that the new assay is approx. 50-fold more sensitive. This has enabled measurement of peroxidase activities present in parasympathetic saliva samples which were beyond the detection limit of the colorimetric assay. Despite great differences in the peroxidase activities and protein concentrations of parasympathetic and sympathetic salivas and tissue extracts, the activities per unit protein were very similar. Unlike most other published methods, prior dialysis of samples to remove interference by endogenous thiocyanate is not required. The assay is therefore convenient and will be particularly useful for applications in which sample volume or peroxidase activity is low.
Dental plaque is the diverse microbial community found on the tooth surface embedded in a matrix of polymers of bacterial and salivary origin. Once a tooth surface is cleaned, a conditioning film of proteins and glycoproteins is adsorbed rapidly to the tooth surface. Plaque formation involves the interaction between early bacterial colonisers and this film (the acquired enamel pellicle). To facilitate colonisation of the tooth surface, some receptors on salivary molecules are only exposed to bacteria once the molecule is adsorbed to a surface. Subsequently, secondary colonisers adhere to the already attached early colonisers (co-aggregation) through specific molecular interactions. These can involve protein-protein or carbohydrate-protein (lectin) interactions, and this process contributes to determining the pattern of bacterial succession. As the biofilm develops, gradients in biologically significant factors develop, and these permit the co-existence of species that would be incompatible with each other in a homogenous environment. Dental plaque develops naturally, but it is also associated with two of the most prevalent diseases affecting industrialised societies (caries and periodontal diseases). Future strategies to control dental plaque will be targeted to interfering with the formation, structure and pattern of development of this biofilm.
Tannins (commonly referred to as tannic acid) are water-soluble polyphenols that are present in many plant foods. They have been reported to be responsible for decreases in feed intake, growth rate, feed efficiency, net metabolizable energy, and protein digestibility in experimental animals. Therefore, foods rich in tannins are considered to be of low nutritional value. However, recent findings indicate that the major effect of tannins was not due to their inhibition on food consumption or digestion but rather the decreased efficiency in converting the absorbed nutrients to new body substances. Incidences of certain cancers, such as esophageal cancer, have been reported to be related to consumption of tannins-rich foods such as betel nuts and herbal teas, suggesting that tannins might be carcinogenic. However, other reports indicated that the carcinogenic activity of tannins might be related to components associated with tannins rather than tannins themselves. Interestingly, many reports indicated negative association between tea consumption and incidences of cancers. Tea polyphenols and many tannin components were suggested to be anticarcinogenic. Many tannin molecules have also been shown to reduce the mutagenic activity of a number of mutagens. Many carcinogens and/or mutagens produce oxygen-free radicals for interaction with cellular macromolecules. The anticarcinogenic and antimutagenic potentials of tannins may be related to their antioxidative property, which is important in protecting cellular oxidative damage, including lipid peroxidation. The generation of superoxide radicals was reported to be inhibited by tannins and related compounds. The antimicrobial activities of tannins are well documented. The growth of many fungi, yeasts, bacteria, and viruses was inhibited by tannins. We have also found that tannic acid and propyl gallate, but not gallic acid, were inhibitory to foodborne bacteria, aquatic bacteria, and off-flavor-producing microorganisms. Their antimicrobial properties seemed to be associated with the hydrolysis of ester linkage between gallic acid and polyols hydrolyzed after ripening of many edible fruits. Tannins in these fruits thus serve as a natural defense mechanism against microbial infections. The antimicrobial property of tannic acid can also be used in food processing to increase the shelf-life of certain foods, such as catfish fillets. Tannins have also been reported to exert other physiological effects, such as to accelerate blood clotting, reduce blood pressure, decrease the serum lipid level, produce liver necrosis, and modulate immunoresponses. The dosage and kind of tannins are critical to these effects. The aim of this review is to summarize and analyze the vast and sometimes conflicting literature on tannins and to provide as accurately as possible the needed information for assessment of the overall effects of tannins on human health.
The effects of milk and kappa-casein rinses on the salivary pellicle formed on hydroxyapatite discs carried in the mouth were studied. SDS-PAGE analyses revealed an increase in the number of proteins deposited onto the discs carried after the water and milk rinses only. Scanning electron microscopy studies revealed the deposition of an amorphous material, small, micelle-like structures, cocci and rods on discs carried in the mouth after the water rinse. Large, micelle-like structures were seen on discs carried in the mouth after the milk and kappa-casein rinses; bacteria were not seen. Glucosyltransferase (Gtf) activity on discs carried in the mouth after the milk and kappa-casein rinses were 45+/-5 and 67+/-2% lower than the activity of Gtf on discs carried in the mouth after a water rinse, respectively. These data suggest that milk and kappa-casein may influence pellicle formation in vivo.
The formation of acquired enamel pellicle on hydroxyapatite (HA) discs of known surface area carried in the mouth was studied; discs were carried in the mouth for 30 s, 1, 5, 10 and 20 min. Similar amounts of protein were found on the discs at each time-point, as determined by ninhydrin analyses. The amounts of amylase and lysozyme detected remained stable after 5 min of exposure of the discs to the mouth. Assay of the discs for fructosyl- and glucosyltransferase activities revealed that fructosyltransferase activity increased up to 1 min of exposure to the mouth and decreased when kept in the mouth for longer periods; glucosyltransferase activity, in contrast, increased the longer the discs were kept in the mouth. This in situ model provides insight into the activities of various enzymes during the first 20 min of pellicle formation. The effects of rinsing with sucrose and sugar alcohols on pellicle formation on the discs were also explored. The discs were placed in the mouth for 30 s, 1, 5, 10 and 20 min, preceded by rinsing with either distilled deionized water, sucrose, sorbitol, xylitol or phosphate-buffered saline. Western blot analyses of disc eluates with antiserum/antibody preparations to various salivary components revealed distinct patterns of deposition of bacterial and salivary components depending on the composition of the rinse. These studies confirm that salivary molecules and bacteria are deposited on apatitic surfaces in a selective manner and reveal that pellicle formation may be influenced by composition of diet. It is apparent that this in situ model could be used in screening potential antiplaque agents.
Many polyphenols are potent antioxidants in foods and model systems and they have therefore very naturally been linked with the hypothesis that their redox actities may confer them with specific health benefits. Their prevalence in plant derived foods, which are generally accepted as healthy has supported this view and inspired researchers to conduct human intervention trails with polyphenol rich food items in order to investigate their ability to counteract oxidative stress. Several biomarkers have gained widespread use to assess oxidative damage and antioxidative defence capabilities in humans. These markers pioneer our knowledge about factors related to oxidative stress in proteins, lipids and DNA and present results indicate that oxidative damage may be very localised and that refined markers may be necessary in order to disentangle the complex local factors which determine the extent of oxidative damage in different molecular structures. The present text reviews the human short-term intervention studies with polyphenol-rich foods, which address their impact on biomarkers of oxidative damage and antioxidative defence. None of the oxidative damage markers seem to be consistently affected by polyphenol-rich foods or to be consistently related to one another. The most consistent finding regarding antioxidative defence markers is a postprandial effect on plasma antioxidative capacity after ingestion of foods rich in catechins and complex procyanidins.
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Amylase is an important salivary component and structural element of the acquired enamel pellicle. Aim of the study was to establish a method for precise and direct determination of pellicle bound amylase activity in order to analyse kinetics and activity of the immobilised enzyme. Six bovine enamel slabs (5mm diameter) were fixed on individual maxillary trays and worn by five subjects for different times (3, 30 and 120 min) on buccal and palatal sites on different days. Slabs were removed from the trays and rinsed with aqua dest. Afterwards, pellicle bound amylase activity was determined directly with a photometric method using 2-chloro-4-nitrophenyl-4-O-beta-D-galactopyranosylmaltotriosid (GalG2CNP) as substrate yielding the coloured product chloronitrophenolate (CNP). All investigated pellicles exhibited immobilised amylase activity. Mean activity was 1.39 +/- 187 mU/cm(2) (n=87, range 0.14-11.5 mU/cm(2)). Product formation of CNP by immobilised amylase was linear over time. Pellicle bound amylase showed a Michaelis type kinetic (Km = 3.3 x 10(-3) M). Immobilised activity on buccal surfaces ranged between 0.25 and 11.1 mU/cm(2) (palatal slabs: 0.14-3.06 mU/cm(2)). Thirty minutes pellicles formed on buccal sites exhibited significantly higher immobilised amylase activity (2.85 +/- 3.65 mU/cm(2)) than palatal ones (0.63 +/- 0.32 mU/cm(2)). Amylase activity showed great intraindividual variability when comparing same positions on different days.
Conclusion:
Pellicle bound amylase activity can be determined directly with GalG2CNP and shows a Michaelis Menten kinetic. Enzyme activity of the amylase immobilised in the in situ pellicle reveals great intra- and interindividual differences.
The aim of this paper was to examine recent evidence for the effect of the antibacterial approach to prevent and control caries with special reference to the use of chlorhexidine (CHX). Existing information from the mid 1990s provided limited evidence for the effectiveness of CHX gels, rinses and toothpaste in preventing caries in permanent teeth of children and adolescents. An updated literature search on CHX intervention in controlled clinical trials from 1995 to May 2003 unveiled 22 studies covering over 4,500 patients with clinical caries as end point. The vast majority (n = 21) were dealing with CHX-containing varnishes. Since the studies exhibited disparities in design, diagnosis and intervention, the findings were subgrouped with respect to caries type and localization. According to the ranking system of the Swedish Council on Technology Assessment in Health Care, the evidence for an anticaries effect of CHX varnishes was rated as inconclusive for caries-active schoolchildren and adolescents with regular fluoride exposure. Regarding fissure caries, a preventive effect of CHX varnishes was demonstrated in 4 studies out of 5 when compared to no treatment in children with low fluoride exposure. The evidence for arresting root caries in dry-mouth patients and frail elderly subjects was inconclusive. In conclusion, the evidence from the recent literature was inconclusive for the use of CHX varnishes for caries prevention in risk groups.
New technologies have provided novel insights into how dental plaque functions as a biofilm. Confocal microscopy has confirmed that plaque has an open architecture similar to other biofilms, with channels and voids. Gradients develop in areas of dense biomass over short distances in key parameters that influence microbial growth and distribution. Bacteria exhibit an altered pattern of gene expression either as a direct result of being on a surface or indirectly as a response to the local environmental heterogeneity within the biofilm. Bacteria communicate via small diffusible signalling molecules (e.g. competence-stimulating peptide, CSP; autoinducer 2); CSP induces both genetic competence and acid tolerance in recipient sessile cells. Thus, rates of gene transfer increase in biofilm communities, and this is one of several mechanisms (others include: diffusion-reaction, neutralization/inactivation, slow growth rates, novel phenotype) that contribute to the increased antimicrobial resistance exhibited by bacteria in biofilms. Oral bacteria in plaque do not exist as independent entities but function as a co-ordinated, spatially organized and fully metabolically integrated microbial community, the properties of which are greater than the sum of the component species. A greater understanding of the significance of dental plaque as a mixed culture biofilm will lead to novel control strategies.
The acquired pellicle is a biofilm, free of bacteria, covering oral hard and soft tissues. It is composed of mucins, glycoproteins and proteins, among which are several enzymes. This review summarizes the present state of research on enzymes and their functions in the dental pellicle. Theoretically, all enzymes present in the oral cavity could be incorporated into the pellicle, but apparently enzymes are adsorbed selectively onto dental surfaces. There is clear evidence that enzymes are structural elements of the pellicle. Thereby they exhibit antibacterial properties but also facilitate bacterial colonization of dental hard tissues. Moreover, the immobilized enzymes are involved in modification and in homeostasis of the salivary pellicle. It has been demonstrated that amylase, lysozyme, carbonic anhydrases, glucosyltransferases and fructosyltransferase are immobilized in an active conformation in the pellicle layer formed in vivo. Other enzymes, such as peroxidase or transglutaminase, have been investigated in experimental pellicles. Despite the depicted impact of enzymes on the formation and function of pellicle, broader knowledge on their properties in the in vivo-formed pellicle is required. This might be beneficial in the development of new preventive and diagnostic strategies.
Black tea, obtained by tea leaves fermentation, is an oxidized product and contains mainly multimeric polyphenols, whose biological activity is not well documented. This paper reviews the available literature on the effects of black tea on health with a focus on its antioxidative activity.
A review of the different issues and studies relating to composition, manufacturing, and antioxidative effects of black tea and its components in vitro as well as in vivo is presented.
It is generally believed that polyphenols such as theaflavins and thearubigins as well as catechins as major constituents of black tea are mainly responsible for antioxidant actions. Antioxidative properties of black tea are manifested by its ability to inhibit free radical generation, scavenge free radicals, and chelate transition metal ions. Black tea, as well as individual theaflavins, can influence activation of transcription factors such as NFkappaB or AP-1. Theaflavins have been also proved to inhibit the activity of prooxidative enzymes such as xanthine oxidase or nitric oxide synthase.
Black tea consumed throughout the world is believed to be not only a popular beverage but also an antioxidative agent available in everyday life.
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Lysozyme is one of the most abundant enzymatic components in the salivary pellicle. The purpose of the present in situ study was to determine if and to which extent lysozyme immobilised in pellicles exposes enzymatic activity. Influence of different oral sites and pellicle formation time on enzyme activity was also evaluated. Bovine enamel slabs (5mm diameter) were fixed on buccal and oral sites of individual trays worn by six subjects for 3 and 30 min on different days. After pellicle formation, slabs were removed from the trays and rinsed with running water. Afterwards, pellicle-bound lysozyme activity was determined via lysis of Micrococcus lysodeicticus photometrically in two steps. In a first step, lysozyme was desorbed in phosphate buffer and dissolved activity was measured. In a second step, slabs were incubated in phosphate buffer with the substrate and remaining immobilised activity was determined. All investigated pellicles exhibited lysozyme activity. Great intra- and inter-individual differences were observed. Mean desorbed activity of 3 min-pellicles amounted to 26.06+/-17.81 U/cm(2) (30 min; 26.79+/-17.48). The remaining immobilised activity was 13.54+/-11.42 for 3 min-pellicles and 16.08+/-12.81 for 30 min-pellicles. Pellicle derived lysozyme showed a Michaelis type kinetic.
Conclusion:
In situ pellicle exposes lysozyme activity even after a 3 min formation period. Exposed enzyme activity is neither influenced by pellicle formation time nor by the site of pellicle formation. It shows great inter- and intra-individual differences.
Several foods have been shown to contain natural components (especially polyphenols) which display anti-adhesive properties against Streptococcus mutans, the aetiological agent responsible for dental crown caries, as well as inhibition of glucosyltransferases, which are the S. mutans enzymes involved in the synthesis of an adherent, water-insoluble glucan from sucrose. Other studies have demonstrated an in vitro action on oral plaque biofilm formation and desorption. This study evaluated whether the activity displayed in vitro by food compounds could affect the microbiological composition of saliva and dental plaque of subjects with a diet rich in these foods, comparing the results with those obtained from subjects with a different diet. The foods considered were: coffee, barley coffee, tea and wine. A total of 93 subjects were recruited into the study. Six samples of both plaque and saliva were collected from each subject at roughly one-monthly intervals. Total bacteria, total streptococci, S. mutans and lactobacilli counts were determined by culture in both saliva and dental plaque. The highest bacterial titres were recorded for the control population, while each drinking habit subgroup showed counts roughly one log lower than the controls. These differences in bacterial counts proved statistically significant (P<0.05). As far as dental plaque was concerned, while total counts did not significantly vary per mg of plaque in the subjects belonging to the different drinking habit subgroups, a significant decrease (P<0.05) was observed in those subjects drinking coffee, tea, barley coffee and wine when mutans streptococci and lactobacilli were evaluated. In several cases a more than one log decrease was observed. Plaque indices were also determined, and a significant (P<0.05) reduction in values was recorded in the subjects belonging the specific drinking habit subgroups compared to the control group. This study indicates that there is a correlation between consumption of specific foods and oral health in terms of reduced plaque deposition and lower counts of odontopathogens.
The influence of two disinfection techniques on natural biofilm development during drinking water treatment and subsequent distribution is compared with regard to the supply of a high-quality drinking water.
The growth of biofilms was studied using the biofilm device technique in a real public technical drinking water asset. Different pipe materials which are commonly used in drinking water facilities (hardened polyethylene, polyvinyl chloride, steel and copper) were used as substrates for biofilm formation. Apart from young biofilms, several months old biofilms were compared in terms of material dependence, biomass and physiological state. Vital staining of biofilms with 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) and the DNA-specific 4',6-diamidino-2-phenylindole (DAPI) staining resulted in a significant difference in physiological behaviour of biofilm populations depending on the disinfection technique. Compared with chlorine dioxide disinfection (0.12-0.16 mg l-1), the respiratory activities of the micro-organisms were increased on all materials during u.v. disinfection (u.v.254; 400 J m-2). The biofilm biocoenosis was analysed by in situ hybridization with labelled oligonucleotides specific for some subclasses of Proteobacteria. Using PCR and additional hybridization techniques, the biofilms were also tested for the presence of Legionella spp., atypical mycobacteria and enterococci. The results of the molecular-biological experiments in combination with cultivation tests showed that enterococci were able to pass the u.v. disinfection barrier and persist in biofilms of the distribution system, but not after chlorine dioxide disinfection.
The results indicated that bacteria are able to regenerate and proliferate more effectively after u.v. irradiation at the waterworks, and chlorine dioxide disinfection appears to be more applicative to maintain a biological stable drinking water.
As far as the application of u.v. disinfection is used for conditioning of critical water sources for drinking water, the efficiency of u.v. irradiation in natural systems should reach a high standard to avoid adverse impacts on human health.
Influenza, a respiratory disease caused by influenza viruses, is still a worldwide threat with a high potential to cause a pandemic. Beside vaccination, only two classes of drugs are available for antiviral treatment against the pathogen. Here we show that CYSTUS052, a plant extract from a special variety of Cistus incanus that is rich in polymeric polyphenols, exhibits antiviral activity against a highly pathogenic avian influenza A virus (H7N7) in cell culture and in a mouse infection model. In vitro and in vivo treatment was performed with an aerosol formulation, because the bioavailability of high molecular weight polyphenols is poor. In MDCK cells, a 90% reduction of plaque numbers on cells pre-incubated with the plant extract was achieved. For in vivo experiments we used a novel monitoring system for influenza A virus-infected mice that allows measurement of body temperature and gross motor-activity of the animals. Mice treated with CYSTUS052 did not develop disease, showed neither differences in their body temperature nor differences in their gross motor-activity and exhibited no histological alterations of the bronchiolus epithelial cells.
Infections with influenza A viruses still pose a major threat to humans and several animal species. The occurrence of highly pathogenic avian influenza viruses of the H5N1 subtype capable to infect and kill humans highlights the urgent need for new and efficient countermeasures against this viral disease. Here we demonstrate that a polyphenol rich extract (CYSTUS052) from the Mediterranean plant Cistus incanus exerts a potent anti-influenza virus activity in A549 or MDCK cell cultures infected with prototype avian and human influenza strains of different subtypes. CYSTUS052 treatment resulted in a reduction of progeny virus titers of up to two logs. At the effective dose of 50 microg/ml the extract did not exhibit apparent harming effects on cell viability, metabolism or proliferation, which is consistent with the fact that these plant extracts are already used in traditional medicine in southern Europe for centuries without any reported complications. Viruses did not develop resistance to CYSTUS052 when compared to amantadine that resulted in the generation of resistant variants after only a few passages. On a molecular basis the protective effect of CYSTUS052 appears to be mainly due to binding of the polymeric polyphenol components of the extract to the virus surface, thereby inhibiting binding of the hemagglutinin to cellular receptors. Thus, a local application of CYSTUS052 at the viral entry routes may be a promising approach that may help to protect from influenza virus infections.
The acquired salivary pellicle has been defined as proteinaceous film free of bacteria. However, due to the large numbers of microorganisms existent in the oral fluids, it is conceivable that adherent bacteria are already present in the initial pellicle. The aim of this in situ study was to visualize and to quantify these bacteria.
Initial biofilm formation was performed on bovine enamel slabs mounted buccally on individual splints and carried in situ by six subjects for 3, 30 and 120 min, respectively. After intraoral exposure, the slabs were rinsed with saline solution and the adherent bacteria were investigated with the following fluorescence microscopic methods: staining with 4',6-diamidino-2-phenylindole (DAPI), staining of vital and nonvital bacteria with fluoresceinediacetate and ethidiumbromide (live/dead staining) and fluorescence in situ hybridization (FISH) of eubacteria and streptococci, respectively. In addition, determination of colony forming units after ultrasonically induced detachment of bacteria was performed.
With all the methods, bacteria were detected in the initial in situ biofilm irrespective of the formation time. The numbers of bacteria revealed high intraindividual and interindividual variability and the microorganisms were distributed randomly in small aggregates. The results of the epifluorescence microscopic techniques corresponded well. The mean number of adherent bacteria detected was in the range of 10-20x10(4)cm(-2).
Already after 3 min, adherent bacteria are present in the initial pellicle. For the first time, DAPI-staining as well as FISH have proven success for visualization of initial intraoral colonization of enamel specimens.
The acquired enamel pellicle is a proteinaceous layer formed on all solid substrata exposed to the oral cavity. It has been supposed that the pellicle undergoes maturation after protein adsorption. The aim of the present study was to investigate enzyme activities with an impact on intrinsic maturation processes in in situ formed pellicles.
Bovine enamel specimens were exposed to the oral cavity in six subjects to allow in situ pellicle formation over 3, 30 and 120 min. The slabs were fixed on the buccal and palatal surfaces of individual splints fixed with silicone impression material. After rinsing with deionised water, the pellicle samples were tested fluorimetrically for transglutaminase, protease and elastase activity. Phosphatase activities were tested photometrically. Separate samples were used for each of the enzymes tested.
Transglutaminase was detected in in situ pellicle (16.7+/-21.2 mU/cm(2)) as was alkaline phosphatase activity (0.87+/-0.99 mU/cm(2)). For both enzymes, there was no correlation of enzyme activities with time or localisation of pellicle formation. Acidic phosphatase- and protease-activities were not detectable. Only traces of elastase activity were found in 57% of the samples.
Transglutaminase and phosphatase activity are detectable within in situ pellicle. Enzymatic crosslinking and dephosphorylation appear more important for intrinsic maturation of the acquired enamel pellicle than proteolysis.