Effects of apigenin and tt-farnesol on glucosyltransferase activity, biofilm viability and caries development in rats
ABSTRACT Propolis, a resinous hive product secreted by Apis mellifera bees, has been shown to reduce the incidence of dental caries in rats. Several compounds, mainly polyphenolics, have been identified in propolis. Apigenin and tt-farnesol demonstrated biological activity against mutans streptococci. We determined here their effects, alone or in combination, on glucosyltransferase activity, biofilm viability, and development of caries in rats. Sprague-Dawley rats were infected with Streptococcus sobrinus 6715 and treated topically twice daily as follows: (1) tt-farnesol, (2) apigenin, (3) vehicle control, (4) fluoride, (5) apigenin +tt-farnesol, and (6) chlorhexidine. Apigenin (1.33 mM) inhibited the activity of glucosyltransferases in solution (90-95%) and on the surface of saliva-coated hydroxyapatite beads (35-58%); it was devoid of antibacterial activity. tt-Farnesol (1.33 mM) showed modest antibacterial activity against biofilms and its effects on glucosyltransferases were minimal. The incidence of smooth-surface caries was significantly reduced by apigenin +tt-farnesol (60%), fluoride (70%), and chlorhexidine (72%) treatments compared to control (P < 0.05).
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- "was prepared and purified to near homogeneity via hydroxylapatite column chromatography as detailed elsewhere (Koo et al. 2002). Glucosyltransferase activity was measured by the incorporation of [ 14 C]-glucose from labeled sucrose (NEN Research Products, Boston, MA, USA) into glucans (Schilling and Bowen 1992; Koo et al. 2002). One unit of enzyme activity was defined as the amount of glucosyltransferase enzyme that incorporates 1 µmol of glucose into glucans over the 2-h reaction. "
ABSTRACT: Candida albicans cells are often detected with Streptococcus mutans in plaque biofilms from children affected with early childhood caries. The coadhesion between these 2 organisms appears to be largely mediated by the S. mutans-derived exoenzyme glucosyltransferase B (GtfB); GtfB readily binds to C. albicans cells in an active form, producing glucans locally that provide enhanced binding sites for S. mutans. However, knowledge is limited about the mechanisms by which the bacterial exoenzyme binds to and functions on the fungal surface to promote this unique cross-kingdom interaction. In this study, we use atomic force microscopy to understand the strength and binding dynamics modulating GtfB-C. albicans adhesive interactions in situ. Single-molecule force spectroscopy with GtfB-functionalized atomic force microscopy tips demonstrated that the enzyme binds with remarkable strength to the C. albicans cell surface (~2 nN) and showed a low dissociation rate, suggesting a highly stable bond. Strikingly, the binding strength of GtfB to the C. albicans surface was ~2.5-fold higher and the binding stability, ~20 times higher, as compared with the enzyme adhesion to S. mutans. Furthermore, adhesion force maps showed an intriguing pattern of GtfB binding. GtfB adhered heterogeneously on the surface of C. albicans, showing a higher frequency of adhesion failure but large sections of remarkably strong binding forces, suggesting the presence of GtfB binding domains unevenly distributed on the fungal surface. In contrast, GtfB bound uniformly across the S. mutans cell surface with less adhesion failure and a narrower range of binding forces (vs. the C. albicans surface). The data provide the first insights into the mechanisms underlying the adhesive and mechanical properties governing GtfB interactions with C. albicans. The strong and highly stable GtfB binding to C. albicans could explain, at least in part, why this bacterially derived exoenzyme effectively modulates this virulent cross-kingdom interaction. © International & American Associations for Dental Research 2015.Journal of dental research 07/2015; 94(9). DOI:10.1177/0022034515592859 · 4.14 Impact Factor
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- "In the process of developing new pharmacologically active compounds from natural products for using in dentistry , the Southeastern Brazilian propolis may prevent dental caries  . B. dracunculifolia is the most important botanical source of Southeastern Brazilian propolis, which due to its colour is called green propolis, whose healthy benefits, including the hepatoprotective effect, are well described in the literature . "
ABSTRACT: Baccharis dracunculifolia DC (Asteraceae), popularly known as "alecrim-do-campo, " is largely distributed in South America, is shown to exhibit protective actions against gastric ulcers, has anti-inflammatory properties, and is hepatoprotective. Several essential oils obtained from Baccharis species possess biological activities, such as antimicrobial and antivirus activities. This randomized controlled trial evaluated the efficacy of B. dracunculifolia in the reduction of dental biofilm, comparing this natural product with other mouthwashes already known in the dental market. In measuring the time after use of mouthwash (= 1), there was no difference between products (= 0.602); that is, subjects in the study had a similar PI after the first use. After one week (= 2), there was no difference between the four products evaluated (= 0.674), so, all research individuals completed the study with a similar reduction in dental biofilm between themselves but it was different from initial state (Friedman test). It is possible to conclude that B. dracunculifolia had the same efficiency of the materials used to oral hygiene in reduction of dental plaque and, consequently, prevention of dental caries. Thus, we can consider B. dracunculifolia as a good candidate for new material to be implemented in dental care.The Scientific World Journal 11/2014; DOI:10.1155/2015/712683 · 1.73 Impact Factor
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- "Animal experiments were performed using previously described methods (19,20). Briefly, pathogen-free male Wistar rats (19 days of age; purchased from Kunming Medical University, Kunming, China) were infected daily for five consecutive days with a growing culture of S. mutans ATCC 25175. "
ABSTRACT: Emodin is an active herbal component traditionally used in East Asian countries for treating a variety of diseases. The present study investigated the effects of emodin on specific virulence factors of Streptococcus mutans (S. mutans) in vitro and on caries development in vivo. The growth and acid production of S. mutans were significantly inhibited by emodin (0.5-2 mg/ml). Emodin also significantly suppressed the synthesis of insoluble glucans by S. mutans. Furthermore, the topical application of emodin reduced the incidence and severity of carious lesions in rats. These results suggest that the natural compound emodin may be a novel pharmacological agent for the prevention and treatment of dental caries.Experimental and therapeutic medicine 10/2014; 8(4):1308-1312. DOI:10.3892/etm.2014.1857 · 1.27 Impact Factor