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Antioxidant activity of dulse (Palmaria palmata) extract evaluated in vitro
Abstract
Palmaria palmata (dulse) is traditionally consumed as a snack food and garnish; but, little is known about its potential as a source of antioxidants. A I-butanol soluble fraction extracted from dulse exhibited (OH)-O-. scavenging activity EDTA (non-site and site specific activity) in a deoxyribose assay. EC50 concentrations of dulse extract to quench DPPH. and ABTS(.+) free radicals were 12.5 and 29.5 mg/ml. Dulse extract inhibited (p < 0.05) conjugated diene production in a linoleic acid emulsion at 24, 48 and 52 h, 38 degreesC and inhibited (p = 0.044) thiobarbituric acid reactive substances (TBARS) production at 52 h. One milligram dulse extract exhibited reducing activity = 9.68 mug L-ascorbic acid and total polyphenol content = 10.3 mug gallic acid; the dulse extract did not chelate transition metal ions. The antioxidant activity of the dulse extract was associated with aqueous/alcohol-soluble compounds characterized by phenolic functional groups with reducing activity.
... The effective concentration having 50% radical inhibition activity (EC50) expressed as μg extract/mL was determined from the graph of the free radical scavenging activity (%) versus extract concentration (Yuan et al. 2005). ...
... The diluted ABTS solution (2,850 μL) was mixed with 150 μL of sample extracts, and the mixture was left to stand at room temperature in the dark for 15 min, and then the absorbance was measured at 734 nm. As for DPPH assay, the antioxidant capacity of test samples was expressed as EC50, the concentration necessary to 50% reduction of ABTS + ( Yuan et al. 2005). ...
... The effective concentrations having 50% radical inhibition activity (EC50) were found to be 23.33 and 16.75 μg/mL for DPPH and ABTS assays, respec- tively. These results reflect the high ability of I. viscosa leaf extracts to donate electrons to inactivate radical species (Yuan et al. 2005). Regarding the DPPH assay, the obtained value was approximately 10-fold lower than those (0.26 mg/ mL) reported by Trimech et al. (2014). ...
In this study, a detailed phytochemical analysis of the medicinal herb I nula viscosa leaves was performed. Furthermore, in vitro antioxidant and antifungal properties of its methanolic extract were evaluated and compared with the corresponding phenolic profile obtained by high‐performance liquid chromatography and mass spectrometry. Data obtained underscore the high amount of total lipids (6.14%) in leaves. Chromatographic analysis revealed its high content of unsaturated fatty acids ( UFAs ) with the essential ones α‐linolenic and linoleic acids being the main compounds. It also showed good nutritional quality because of its high UFA /saturated fatty acid ratio and the lower values of atherogenic and thrombogenic indices. The volatile oil analyzed by gas chromatography‐mass spectrometry showed the abundance of nonterpenic compounds, namely aliphatic alkanes. The total phenol content ( TPC ) and total flavonoid content ( TFC ) were higher in I . viscosa leaves (103 mg GAE /g dw and 99 mg CE /g dw for TPC and TFC , respectively). The use of HPLC‐PDA ‐ ESI‐MS / MS allowed the identification of 17 components with hydroxycinnamic acids, namely mono‐ and dicaffeoylquinic acids being the most prominent components. The presence of these phenolic compound conferred strong free radical scavenging and antifungal properties to the methanol extract. Therefore, I . viscosa leaves could be considered as an excellent source of food functional ingredients with high nutritional value and health benefits.
Practical Applications
The outcome of this study shows that I nula viscosa leaves can be considered as a consolidated source of essential fatty acids, mainly α‐linolenic and linoleic acids. Moreover, they contain appreciable amounts of phenolic compounds with phenolic acids, recognized for their high biological activities, being the most abundant. In addition to its strong antioxidant activity, there is convincing evidence that I . viscosa extracts exhibit antifungal activity. On the light of this evidence, it is anticipated that this species may had greater potential as food additives and preservatives.
... Marine macroalgae are rich in bioactive compounds that have the potential to be used as functional ingredients in human and animal health (Gupta and Ghannam 2011), as a source of alginate, carrageenan, or agar in various industries, such as the food, pharmaceutical and cosmetics industries and also has the potential as a source of natural antioxidants (Yuan et al. 2005). Antioxidants play an important role in inhibiting and scavenging radicals to protect humans against infections and degenerative diseases. ...
... The compound of secondary metabolites of marine algae may contain alkaloids, phenols, flavonoids, saponins, steroids, terpenoids, and active metabolites that have great medicinal value (Abad et al. 2011). Recently, marine algae have been widely used in the pharmaceutical industries (Yuan et al. 2005). Much attention has been focused on the phytoconstituents of marine algal populations in different regions (Khairy and Sheik 2015). ...
Srimariana ES, Apituley DAN. 2019. Antioxidant activity of extracted green algae silpau (Dyctyosphaeria versluysii). Nusantara Bioscience 11: 153-156. Silpau (Dictyosphaeria versluysii) is a green algae that is widely available in Southwest Moluccas regency, living on coral reefs and not classified as seasonal plants. Silpau has long been used by local people, generally in the form of processed vegetables or colo-colo (traditional food). Except for its nutritional value, comprehensive information about silpau still unknown. Therefore, this study was carried out to determine its potential as an antioxidant. The phytochemical content of silpau was analyzed according to the standard method. The antioxidant activity of green algae silpau extract was carried out by reducing DPPH (1,1-diphenyl-2-picrylhydrazyl) free radicals. Phytochemical test of silpau revealed that silpau contain terpenoid compounds. The result of the study showed that the IC50 value of methanol extract of silpau was 547.97 ppm, indicated that silpau methanol extract categorized as a weak antioxidant.
... The antioxidant properties of its components has been related to the protection against cancer, coronary heart disease (CHD), inflammatory troubles, neurological deterioration, and aging [7,8]. Previous studies in animal models and cell culture have suggested that seaweed phytochemicals have the potential to inhibit the progression of carcinoma formation [9]. Further from these findings, a recent study has suggested that algae extracts can improve the glycaemic control in a non-insulin dependent diabetic mouse model [10]. ...
... The results of the present study are in line with Wang et al. (2009) and Yan et al. (1999) [34,44], who also found that brown algae contained higher amounts of polyphenols and DPPH radical scavenging activity than red and green algae. Much available evidence in the literature suggests the protective effects of seaweeds against oxidative stress in target tissues and lipid oxidation in foods [9]. Some of these active anti-lipid peroxidation compounds from marine algae were identified such as phlorotannins in Sargassum kjellamanianum [45] and fucoxanthin in Hijikia fusiformis [46]. ...
The main objective of this study was to investigate the in vitro antioxidant activities of three selected green (Codium tomentosum, Enteromorpha linza), red (Gelidium sesquipedale) and brown (Cystoseira spicata, Padina pavonica) seaweeds from western of Tripoli coast, Libya. After methanol extraction, polyphenol, flavonoids, and condensed tannins contents were assessed. Methanol extracts of the seaweeds were investigated for their total antioxidant activity, reducing power, DPPH radical scavenging activity, NO radical scavenging activity, deoxyribose scavenging activity, and nitric oxide radical inhibition assay. Brown seaweed especially C. spicata exhibited good antioxidant activity when compared to red and green seaweeds. The maximum antioxidant activity was shown by the methanol extract of C. spicata for DPPH and nitric oxide radicals scavenging assay (66%, and 53% respectively). Also C. spicata extract showed a noticeable protection levels against lipid peroxidation. However, extract of E. linza exhibited the lowest antioxidant activity. Macroalgae can be considered as a good source of natural antioxidants.
... On the other hand, the phenolics extracted by the non-polar solvents showed very little antioxidant activities (1.05 to 9.1 mmol/g) and among them ethyl acetate extract showed the highest activity (9.1 mmol/g) and diethyl ether showed the least (1.05 mmol/g). Variations in the antioxidant capacity of different extracts may be attributed to differences in their phenolic contents and, it has also been reported that the solvents used for extraction exert influence on the chemical species (Yuan et al., 2005). The antioxidant activity exhibited by the methanolic extracts may be due to the presence of gallic acid, ferulic acid, hydroxybenzoic acid and their derivatives. ...
... The non-polar solvents showed very little free radical scavenging activity compared to polar solvents. The ability of the millet polyphenols extracts to quench reactive hydroxyl radical species has potential application to extend shelf-life of food products (Yuan et al., 2005). ...
Finger millet (Eleusine coracana) or ragi, one of the important minor cereals is a rich source of several phytochemicals and among them polyphenols are the most important because of their nutraceutical potentials. The seed coat-rich fraction (SCF) of the millet contains over 70% of polyphenols of the millet. Treated with different polar and non-polar solvents as such and after acidification with HCl for the extraction, it was observed that the polar solvents extracted more (1.7 to 7.4%) than the non-polar solvents (0.28 to 1.54%) while the 1% HCl–methanol extracted the highest proportion of polyphenols (13%). Fractionation of extracted polyphenols by HPLC revealed the presence of a large number of constituent phenolics. The inhibitory concentration (IC50) values for the antioxidant activity of the polyphenols determined in terms of 1, 1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and 2, 2’- azinobis – 3 – ethylbenzothiazoline – 6 – sulfonate (ABTS) radicals scavenging activities of acidified methanolic extract, were 63, 109, and 114 μg/mL phenolic, respectively. The polyphenols extracted from finger millet seed coat using 1% HCl –methanol was fractionated by reverse phase– high performance liquid chromatography (RP-HPLC) and the constituent phenolics were characterized by electrospray ionization mass spectrometry (ESI-MS) and NMR. The phenolics identified were the benzoic acid derivatives (gallic, protocatechuic, p-hydroxybenzoic, vanillic, and ferulic acids) and cinnamic acid derivatives (syringic, trans-cinnamic and p-coumaric acids); and also a flavonoid compound namely, quercetin. The millet polyphenols showed proliferation inhibitory activities on Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Streptococcus pyogenes, Proteus mirabilis, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella pneumonia, and Yersinia enterocolitica. Quercetin exhibited substantial inhibition of the growth of these pathogenic bacteria revealing the potential nutraceutical properties of the millet polyphenols. From the observation, it could be inferred that finger millet polyphenols could be used as natural source of antioxidants especially for minimizing the risk of diseases arising from oxidative deterioration.
... ascorbate, glutathione) when it is fresh, but also has more stable molecules such as carotenoids, mycosporine like amino acids and a variety of polyphenols (catechins and phlorotannins) (Kakinuma et al., 2009). These works led to the isolation of antioxidant molecules of very different natures: tocopherols (Yuan et al., 2005), phenolic compounds (Plaza et al., 2008), carotenoids and sterols (Ayyad et al., 2011) and sulfated polysaccharides (Vijayabaskar et al., 2012). The aim of the present investigation was to screen the antioxidant activity of the marine red alga Champia parvula. ...
ARTICLE INFO ABSTRACT Marine algae are potential antioxidant natural resources and have gained recent attention. Reducing the strength of methanol extract improved with an increasing the extract concentration. In the current investigation, the use of DPPH and ABTS assay was done on antioxidant activity of methanol extract from marine red alga Champia purvula. The radical scavenging activity was noted in different concentrations from 100 to 900 μg/mL. An IC 50 value of DPPH radical was recorded in 33 μg/mL and ABTS was recorded at 33.5 μg/mL and compared to the standard. Thus, the findings showed that red alga C. purvula possesses powerful antioxidant activity that indicates their possible use in the development of pharmaceutical drugs.
... ascorbate, glutathione) when it is fresh, but also has more stable molecules such as carotenoids, mycosporine like amino acids and a variety of polyphenols (catechins and phlorotannins) (Kakinuma et al., 2009). These works led to the isolation of antioxidant molecules of very different natures: tocopherols (Yuan et al., 2005), phenolic compounds (Plaza et al., 2008), carotenoids and sterols (Ayyad et al., 2011) and sulfated polysaccharides (Vijayabaskar et al., 2012). The aim of the present investigation was to screen the antioxidant activity of the marine red alga Champia parvula. ...
... The intensive research has been conducted on the antioxidant activity due to the increasing demand for most food and pharmaceutical industries to develop bioactive natural compounds against aging and against cancer [7,[12][13][14][15][16][17][18][19][20][21][22]. These works led to the isolation of antioxidant molecules of very different natures: tocopherols [23], phenolic compounds [24], carotenoids and sterols [18] and sulfated polysaccharides [25,26]. ...
Objective: This work aimed to screen the antioxidant activity of marine macroalgae from the Moroccan Atlantic coast (region of El Jadida). Methods: Evaluation of the antioxidant activity of different collected species, lyophilized and extracted with a solvent mixture chloroform/methanol (2/1; v/v) was conducted according to two techniques, first by thin layer chromatography (tlc) then by spectrophotometry, using a free radical 2,2-diphenyl-1-picrylhydrazyl (dpph). The sampling on a distance of 110 km allowed to harvest 86 algal species (16 brown algae, 47 red algae, 14 green algae and 9 algae being identified). Results: The analysis by thin layer chromatography reveals an antioxidant activity in nearly half of harvested algal species (52.32 %). This activity varies depending on the concentration of the extract and in function of incubation time in the presence of dpph. The monitoring of the kinetics of degradation of dpph by spectrophotometer in the presence of extracts which were active by tlc allowed to confirm the results and select the most active algal species based on the percentage of remaining dpph in the medium after 120 min of reaction: Fucus spiralis (17.02 %), Cyctoseira ericoides (12.16 %) (Phaeophyceae), and Gracilaria multipartita (36%), Halopitys incurvus (5%) (Rhodophyceae). Conclusion: The results show that the methodology adopted in this work is reliable and can be used for rapid screening of antioxidant property in plants and the species: Fucus spiralis, Cyctoseira ericoides, Gracilaria multipartita, and Halopitys incurvus can be a promising source of natural compounds endowed with high antioxidant potential.
... The amount of phenolic compounds present in the R. alaternus leaf extracts was determined by Folin Ciocalteu reagent (Duh and Yen, 1997). Gallic acid was used as a standard for a calibration curve (Yuan et al., 2005). Aliquots of each extract (100 µl) were mixed with 2 ml of 2% Na 2 CO 3 and incubated at room temperature for 2 min. ...
The petroleum ether, chloroformic, ethyl acetate, methanolic, Total Oligomers Flavonoids (TOF) enriched extracts, water extract as well as its fractions A 1 , A 2 , A 3 obtained from aerial parts of Rhamnus alaternus, a Tunisian-Mediterranean medicinal species, were investigated for the contents of phenolic compounds, cytotoxic activity against the K562 human chronic myelogenous leukaemia cell line and L1210 leukaemia murine cells and for antibacterial activity against Gram positive and Gram negative bacterial reference strains. A pronounced cytotoxic effect on both the cell lines was shown in the TOF, ethyl acetate, methanolic, aqueous extracts and A 2 fraction, with respectively IC 50 values 75, 232, 298, 606 and 571 µg/ml on K562 cells and 198, 176, 767, 560 and 614 µg/ml on L1210 cell line. Significant activity against bacterial reference strains: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Salmonella enteritidis and Salmonella typhimurium was shown with ethyl acetate, TOF extracts and A2 fraction. The antimicrobial and cytotoxic activities showed by R. alaternus depended on the chemical composition of the tested extracts.
... GC-FID technique were used to indentified for chemical composition of essential oil and quantified by gas chromatogram. For each of leaves, stems and flower oils of O. africana, the amount of total phenolic was quantified by the regent of Folin and Ciocalteau using the procedure of Yan et al. 11 and Kumar et al. 12 . ...
This work is dedicated to the study of the plant Oudneya africana, the endemic plant, from the family of Brassicaceae. This plant is notably found in the Sahara area. The extraction, the antimicrobial and the antioxidant activities were realized for stems, leaves, and flowers. Hydrodistillation techniques used for the extraction of essential oil. Flowers contain the highest yield 5.75 %. The determination of the humidity showed that the leaves of Oudneya africana contain approximately half of their weight of water. The chemical analysis of essential oil by GC-MS shows that stems contain 28 compounds, leaves contain 43 compounds and flowers contain 12 compounds. The flavonoids and phenolics contents are ranged from 148 ± 29.44 (for stems) to 77.03 ± 24.5 μg/ml (for flowers) and from 238.8 ± 23.71 (for leaves) to 33.03 ± 13.79 mg/ml (for stems). For the DPPH (1,1-diphenyl-2-picrylhydrazyl) assay, the oils of the three parts showed various antioxidant activities. The most active part was the leaves, with an IC 50 value of 51.25 μg/l, followed by flowers (IC 50 = 40.37 μg/l). The essential oils showed significant antibacterial activities against Gram-positive and Gram-negative bacteria, but with various activity levels.
... After evaporation of the respective solutes, the extracts were stored in amber coloured bottles at -20°C till further use. All extracts were analyzed for 2-2-azinobis-3ethylbenthiazoline-6-sulphonic acid (ABTS+) radical cations (Re et al.,1999), 1, 1 diphenyl-2-picrylhydrazil (DPPH) radicals (Kato et al., 1988) and total phenolic (Yuan et al., 2005). ...
... After evaporation of the respective solutes, the extracts were stored in amber coloured bottles at -20°C till further use. All extracts were analyzed for 2-2-azinobis-3ethylbenthiazoline-6-sulphonic acid (ABTS+) radical cations (Re et al.,1999), 1, 1 diphenyl-2-picrylhydrazil (DPPH) radicals (Kato et al., 1988) and total phenolic (Yuan et al., 2005). ...
... Previous studies have suggested that the antioxidant mechanism may be due to the supply of hydrogen by glycosides, which combine with radicals and form a stable radical to terminate the radical chain reaction [38]. Seaweed extracts are able to prevent deoxyribose damage associated with the direct binding of iron to deoxyribose and/or the subsequent attack by hydroxyl radicals generated via the Fenton reaction [39]. ...
Background
Nitrite salts are still common additives in the meat industry. The present study provides a first approach on the employment of the lyophilized aqueous extract (WE) of the Tunisian seaweed
Methods
WE was supplemented as a natural antioxidant agent to investigate its effectiveness in delaying lipid oxidation turkey meat sausages containing reduced amounts of sodium nitrites.
Results
On storage day 5, all concentrations of WE (0.01–0.4 %) reduced the meat lipid oxidation by approximately 36 %, as compared to the negative control containing only 80 mg/kg of meat of sodium nitrites as antioxidant. It was noted that within 15 days of refrigerated storage, a meat system containing 80 mg/kg of meat of sodium nitrites and 0.02 % and 0.04 % of WE had similar Thiobarbituric Acid Reactive Substances (TBARS) levels (19±1.32 and 17±1.12 µmol/kg of meat, respectively), which were comparable to the positive control containing sodium nitrites (150 mg/kg of meat) and 0.045 % vitamin C (18.46±1.27 µmol/kg of meat). In-depth, the metabolomic profiling using gas chromatography–mass spectrometry (GC/MS) and liquid chromatography–quadripole–time–of–flight–mass spectrometry (LC-QTOF-MS) analyses of the Tunisian seaweed
Conclusions
Overall, the cold medium containing
... Seaweeds are known to contain reactive antioxidant molecules, such as ascorbate and glutathione (GSH) when fresh, as well as secondary metabolites such as carotenoids (α and β-carotene, fucoxanthin, astaxanthin), mycosporine amino acids (mycosporine-glycine) and catechins (e.g., catechin, epigallocatechin, epigallocatechin), gallate, phlorotannins (e.g., phloroglucinol), and tocopherols (αtocopherols) [1]. Macroalgae have received much attention as potential natural antioxidants [2][3][4][5][6][7] and there has been very limited information on antioxidant activity of macroalgae [8]. ...
Marine algae are in exhaustible sources of chemical compounds contain bioactive compounds that plays an
important role against various diseases against the aging process because they protect cells from oxidation. The present study is aimed to analyze the phenol and flavonoids content of the marine red alga Tolypiocladia glomerulata and their potential of free radical scavenging properties. The free radical scavenging capacity of the red alga was analyzed by inhibiting the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The maximum percentage of inhibition (61.13 ± 0.02% for DPPH and 50.35 ± 0.00 for ABTS) was observed at the concentration of 900 μg/mL. The free radicals scavenging ability of extracts followed close dependent trend. The results indicate that the red alga T. glomerulata have good free radical scavenging capacity with ABTS and DPPH and it could be used as a potential candidate for natural antioxidants.
... The total phenolic content was quantified by Folin-Ciocalteau's reagent and was expressed as gallic acid equivalents (Yuan et al., 2005). For preparation of sample extract same procedure as mentioned for DPPH was followed. ...
The present study was envisaged to optimize the extraction protocols viz. time, temperature and solvent concentration for extraction of phyto-extracts from aloe vera and cinnamon bark based on antioxidant efficacy in-vitro. These were optimized using Box-Behnken Design (BBD) and completely randomized design (CRD) of Response Surface Methodology (RSM). A total number of 17 different combinations of time, temperature and ethanol concentration in BBD and 13 different combinations of time, temperature in CRD were considered for optimizing extraction protocols for aloe vera and cinnamon respectively. The in-vitro 1, 1 diphenyl-2picrylhydrazyl (DPPH % inhibition) and 2, 2′-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) ABTS+ radical scavengering activity of aqueous extract of cinnamon bark was recorded highest for the combination of 99% concentration at 80°C temperature for 3h amongst all 13 runs. The 90% ethanolic extract of aloe vera and cinnamon bark exhibited higher in-vitro antioxidant ability than aqueous extract at time, temperature combination of 15 min for 65°C and 9h for 60°C respectively.
... Antioxidant compounds play an important role in various fields such as medical field (to treat cancers, cardiovascular disorders, and chronic inflammations), cosmetics (anti-ageing process) and food industries (food preservative) [1]. Seaweeds contain reactive antioxidant molecules, such as ascorbate and glutathione (GSH) when fresh, as well as secondary metabolites including carotenoids (α-and β carotene, fucoxanthin, astaxanthin), mycosporine-like amino acids (mycosporine-glycine), catechins (e.g., catechin, epigallocatechin, gallate, phlorotannins ,eckol and tocopherols (α-,χ-δ-tocopherols) [2] Oxidative stress is a crucial etiological factor to the pathophysiology of variety of degenerative or pathological conditions such as aging, cancer, coronary heart disease, Alzheimer's disease, atherosclerosis and inflammation [3,4].Multiple mechanisms of enzymatic and non-enzymatic antioxidant systems are present in human body to protect the cellular molecules against reactive oxygen species (ROS) induced damage [5]. The present study was conducted to evaluate the free radical scavenging activity of methanolic extract of Valoniopsis pachynema. ...
This study was conducted to investigate the in-vitro antioxidant activity of methanolic extract of green alga Valoniopsis pachynema. The free radical scavenging activity of the extracts was measured by DPPH and ABTS and the antioxidant potential were compared with commercial antioxidants, such as Butylated Hydroxy Toluene (BHT) and L- ascorbic acid. The antioxidant activity of experimental algae showed a dose dependent increase when compared to commercial antioxidants. The significant free radical scavenging activity of Valoniopsis pachynema might be attributed to algal contents of carotenoids, free phenols and fatty acids.
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... Seaweeds contain reactive antioxidant molecules, such as ascorbate and glutathione (GSH) when fresh, as well as secondary metabolites including carotenoids (α-and β carotene, fucoxanthin, astaxanthin), mycosporine-like amino acids (mycosporine-glycine), catechins (e.g., catechin, epigallocatechin, gallate, phlorotannins ,eckol and tocopherols (α-,χ-δ-tocopherols) [2] Oxidative stress is a crucial etiological factor to the pathophysiology of variety of degenerative or pathological conditions such as aging, cancer, coronary heart disease, Alzheimer's disease, atherosclerosis and inflammation [3,4]. ...
This study was conducted to investigate the in-vitro antioxidant activity of methanolic extract of green alga Valoniopsis pachynema. The free radical scavenging activity of the extracts was measured by superoxide; hydroxyl and nitric oxide radicals and the antioxidant potential were compared with commercial antioxidants, such as Butylated Hydroxy Toluene (BHT) and L- ascorbic acid. The antioxidant activity of experimental algae showed a dose dependent increase when compared to commercial antioxidants. The significant free radical scavenging activity of Valoniopsis pachynema might be attributed to algal contents of carotenoids, free phenols and fatty acids.
... Phenols are the aromatic metabolites which trigger various biochemical processes of the organisms. Phenolic compounds are known to act as antioxidants not only because of their ability to donate hydrogen atoms or electrons but also because of their stable radical intermediates, which prevent the oxidation of various ingredients, particularly fatty acids and oils (Yuan et al., 2005). Data presented in Table 4 revealed that, the total phenol was in inverse to carbohydrate content in most species under investigation. ...
PHYTOCHEMICAL screening was performed on six algal …….genera belonging to three marine macroalgal divisions (Chlorophyta, Phaeophyta and Rhodophyta) collected from the coastal region of Red and Mediterranean coasts, Egypt during spring (2012). The antioxidant potential of the candidate seaweeds was evaluated by measuring the ferric reducing power (FRAP), total antioxidant capacity (TAC), total phenol and flavonoids, ascorbic acid as well as glutathione contents were determined. Significant individual differences of the biochemical parameters were recorded in all tested marine algae. The macroalgal phytochemical analysis showed quantitative variations in the total soluble and insoluble carbohydrates and proteins as well as the glycerol contents. The highest accumulation of carbohydrate was estimated in the members of Chlorophyta followed by Phaeophyta and Rhodophyta divisions. The protein content was higher in the species of Rhodophyta, moderate in Chlorophyta and the lowest was estimated in the members of Phaeophyta. In addition, the maximum glycerol content was recorded in Dictyota. Green algae exhibited greater levels of chlorophylls a and b. However, among all the studied three groups, the highest carotenoids were estimated in Padina followed by Dictyota; both belonging to Phaeophyta while the lowest carotenoid content was recorded in Gracelaria (Rhodophyta).The highest carbohydrate content was recorded in Enteromorpha where the lowest phenol was estimated. Results also revealed that, there was no relation between antioxidant activity and total phenols or flavonoid content. All the studied species are considered to be a rich source of antioxidants (ASA and GSH). Accordingly, these seaweed species have a high anti-oxidative potential and can provide dietary alternatives.
... Polyphenol content of T. ramosissimum extracts was quantified by the Folin-Ciocalteau's reagent assay and was expressed as gallic acid equivalents (Yuan et al., 2005). Aliquots of test samples (100 μL) were mixed with 2 mL of 2% Na 2 CO 3 and incubated at room temperature for 2 min. ...
The in vitro antioxidant, antigenotoxic and antiproliferative activities of Teucrium ramosissimum extracts were investigated. The antioxidant activities of the tested extracts were evaluated through three chemical assays: The Cupric reducing antioxidant capacity, the reducing power and the ferric reducing antioxidant power. TR1 fraction from methanol extract showed the best antioxidant activity evaluated by the CUPRAC, RP and FRAP assays with TEAC values of 4.04, 1.77 and 1.48μM respectively compared to control. Yet, TR2 fraction exhibited the lowest antioxidant effect with a TEAC values of 1.97, 0.408 and 0.35μM respectively. All the tested extracts were also found to be effective in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals. Furthermore, the effects of T. ramosissimum extracts on cell proliferation were also examined. The cytotoxic study revealed that methanol extract significantly inhibited the proliferation of K562 cells (IC50=150μg/mL). The antigenotoxic properties of these extracts were investigated by assessing the induction and inhibition of the genotoxicity induced by the direct-acting mutagen, hydrogen peroxide (H2O2), using an eukaryotic system; the "Comet assay." The results showed that all the extracts inhibited the genotoxicity induced by H2O2, and particularly TR2 fraction (96.99%) and methanol extract (96.64%). The present study has demonstrated that T. ramosissimum extract possess potent antioxidant, antiproliferative and antigenotoxic activities, which could be derived from compounds such as flavonoids and polyphenols.
... Escrig et al. (2001) found that DPPH radical scavenging activities are positively correlated with the total polyphenol contents in aqueous and organic solvent extracts of brown and red algae. At the same concentration, the DPPH quenching activity of non-polar solvents (chloroform, ethyl acetate and acetone) extracts was stronger than that of polar solvents (water, ethanol, methanol) extracts of Rhodomelaceae seaweeds (Yan et al., 1998; Yuan et al., 2005). Four solvents were used to prepare the extracts of eelgrass in this study and the resultant fractions were investigated for their antioxidant activity. ...
... However, the ferrous ion chelating activities of compounds were lower than the EDTA (IC 50 =28.48±0.65µg/ ml)It was reported that the compounds with structures containing two or more of the functional groups, such as-OH.-SH.-COOH.-PO 3 H 2. C=O.-NR 2 .–S-.–Oin a favourable structure–function configuration should have chelation activity (Lindsay, 1996;Yuan et al., 2005;Gulcin, 2006). In this respect, compound G may chelate the ferrous ions with hydroxyl and thiol groups. ...
A series of 1,2,4-triazole derivative compounds substituted with groups of phenol and pyridine were synthesized in high yields and screened against several antioxidant activity parameters such as DPPH, ABTS, metal chelating, reducing power and the total antioxidant activity. The compounds showed better than expected antioxidant activity between the studied biological activity parameters. Among these, compound G(2-(5- mercapto-4H-1,2,4-triazol-3-yl)phenol) had a high total antioxidant activity potential with value of 232.12±6.89 mmol/ml. Also showed fairly good ABTS cation radical and DPPH radical scavenging activity with values of IC50 = 4.59±4.19 and IC50 = 7.12±2.32μg/mL respectively. Further, the antioxidant potential of heterocyclic compounds that 1,2,4-triazole derivatives containing different functional groups were compared with various tests performed and has been shown to increase the activity of electron donating groups. Therefore, the present study demonstrates that phenol and pyridine substituted 1,2,4-triazole compounds would be a better prospective in the development of antioxidant agent.
... The best activities were obtained for Met-fr, subfraction 10, and proanthocyanidin A1, with EC 50 values of 16.10, 15.65, and 18.25 lg/mL, respectively. Compared with the synthetic antioxidant BHA (EC 50 = 25 lg/mL) (Yuan, Bone, & Carrington, 2005), the two compounds isolated in this study and their extracts are very promising, since they have a great potential for applications in food and pharmaceutical industries. To the best of our knowledge, this is the first time that bioactive proanthocyanidins have been isolated from peanut skin using the bioassay-guided fractionation technique, and that their antioxidant activity and structure elucidated. ...
Purification and bioassay-guided fractionation were employed to isolate proanthocyanidins with antioxidant activity from peanut skin (Arachis hypogaea Runner 886). The crude extract was prepared with acetone (60% v/v) and purified using chromatographic methods, including a semipreparative HPLC technique. As a result, two proanthocyanidins were isolated and identified using NMR, epicatechin-(2 β→O→7, 4 β→8)-catechin (proanthocyanidin A1) and epicatechin-(β→2 O→7, 4 β→8)-epicatechin (proanthocyanidin A2). Despite the structural similarity, differences were observed in their antioxidant activity. Proanthocyanidin A1 proved to be more active, with EC50 value for DPPH radical scavenging of 18.25μg/mL and reduction of Fe(3+)-TPTZ complex of 7.59mmol/g, higher than that of synthetic antioxidant BHT. This compound evaluated by ABTS(+) was similar to that of natural quercetin. Therefore, peanut skin is an important source of bioactive compounds that may be used as a mild antioxidant for food preservation.
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... The polyphenol content was quantified by Folin-Ciocalteau's reagent assay and expressed as Gallic acid equivalents (mg/g) (Yuan et al., 2005). For preparation of sample extracts the same procedure for DPPH was followed. ...
The present study was conducted to develop emu meat nuggets with
better oxidative stability by incorporating broccoli powder. Four different
levels 0%, 4%, 6% and 8% were incorporated with the replacement of lean
meat and optimum level was selected on the basis of various physicochemical
(pH, water activity and moisture), instrumental colour and sensory
parameters. Oxidative stability was evaluated on the basis of total
phenolics, ABTS and 1, 1-diphenyl-2picrylhydrazyl (DPPH). Water
activity and moisture content decreased (p≥0.05), whereas pH increased
(p≥0.05) with the increase in the level of incorporation of broccoli powder
in the formulation. The total phenolics and radical scavenging activity was
also concentration dependent correlated with the level of incorporation of
broccoli powder. The sensory panelists observed poor juiciness and texture
in emu meat nuggets incorporated with broccoli powder and sensory scores
decreased with level of incorporation of broccoli powder. Results
concluded that oxidative stability and total fiber content of emu meat
nuggets has improved significantly (p<0.05) with some loss in sensory
attributes.
... It is also unknown if seaweed extracts affect stress tolerance via their influence on antioxidant activities or whether it is possible to manipulate the antioxidant levels in plants to increase drought tolerance. Literature reports suggest a potential for the application of seaweed extracts against lipid oxidation in foods and oxidative stress in target tissues (Yuan et al. 2005). In our study, we report how the use of seaweed extracts obtained from two macroalgae species, Ulva rigida and Fucus spiralis, affects drought stress tolerance in green bean plants (P. ...
The effect of seaweed extract (SWE) obtained from two macroalgae species, Ulva rigida and Fucus spiralis, on drought stress tolerance in green bean plants (Phaseolus vulgaris L.) was studied. Examination of growth parameters and some physiological and biochemical parameters showed that SWE extract enhanced vegetative growth in bean plant without stress and in plant under drought stress condition. Maximal plant height and dry weight were observed with application of 25 % U. rigida and F. spiralis extract. Enhanced chlorophyll a (Chl a) and chlorophyll b (Chl b) pigments and glycine betaine (GB) content were also observed with all SWE treatments under water deficit. The lipid peroxidation was low pronounced in stressed plants treated with SWE. Total phenolic content was increased in bean plants under different growth conditions (without stress (WS), moderate water stress (MWD), and severe water deficit (SWD)) and treated with SWE at all concentrations. The highest total phenolic content was attained with the application 25 % U. rigida extract in bean plant subjected to drought stress (MWD and SWD). There was a significant enhancement of superoxide dismutase (SOD) activity and catalase (CAT) activity with SWE treatment in plant under moderate water deficit. Plants stressed and treated with SWE showed maximal ascorbate peroxidase (APX) activity. The increased total phenolic content and the enhancement of antioxidant enzymatic activity by SWE in stressed bean plants may contribute to protection against peroxidation and reduce the severity of water deficit.
Antioxidants had a growing interest owing to their protective roles in food and pharmaceutical products against oxidative deterioration and in the body and against oxidative stress-mediated pathological processes. Screening of antioxidant properties of plants and plant derived compounds requires appropriate methods, which address the mechanism of antioxidant activity and focus on the kinetics of the reactions including the antioxidants. Many studies have been conducted with evaluating antioxidant activity of various samples of research interest using by different methods in food and human health. These methods were classified methods described and discussed in this review. Methods based on inhibited autoxidation are the most suited for termination-enhancing antioxidants and, for chain-breaking antioxidants while different specific studies are needed for preventive antioxidants. For this purpose, the most commonly methods used in vitro determination of antioxidant capacity of food and pharmaceutical constituents are examined and also a selection of chemical testing methods is critically reviewed and highlighting. In addition, their advantages, disadvantages, limitations and usefulness were discussed and investigated for pure molecules and raw plant extracts. The effect and influence of the reaction medium on performance of antioxidants is also addressed. Hence, this overview provides a basis and rationale for developing standardized antioxidant capacity methods for the food, nutraceuticals, and dietary supplement industries. Also, the most important advantages and shortcomings of each method were detected and highlighted. The underlying chemical principles of these methods have been explained and thoroughly analyzed. The chemical principles of methods of 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radical scavenging, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS·+) scavenging, ferric ions (Fe³⁺) reducing assay, ferric reducing antioxidant power (FRAP) assay, cupric ions (Cu²⁺) reducing power assay (Cuprac), Folin–Ciocalteu reducing capacity (FCR assay), superoxide radical anion (O2·−), hydroxyl radical (OH·) scavenging, peroxyl radical (ROO·) removing, hydrogen peroxide (H2O2) decomposing, singlet oxygen (¹O2) quenching assay, nitric oxide radical (NO·) scavenging assay and chemiluminescence assay are overviewed and critically discussed. Also, the general antioxidant aspects of the main food and pharmaceutical components were discussed through several methods currently used for detecting antioxidant properties of these components. This review consists of two main sections. The first section is devoted to the main components in food and their pharmaceutical applications. The second general section includes definitions of the main antioxidant methods commonly used for determining the antioxidant activity of components. In addition, some chemical, mechanistic, and kinetic properties, as well as technical details of the above mentioned methods, are provided. The general antioxidant aspects of main food components have been discussed through various methods currently used to detect the antioxidant properties of these components.
In the wild, the natural fluctuations of environmental factors (nutrients and light) are known to induce variations in Palmaria palmata growth and composition. To ensure standardized, high-quality products, land-based tank cultivation is a potential solution. However, further research is required to optimize indoor tank cultivation conditions and understand the impact of environmental parameters on P. palmata composition. Thus, P. palmata were cultivated in indoor tanks under varying conditions of light intensity (50, 100, 200 µmol photons m⁻² s⁻¹) for 4 weeks and nitrogen enrichment (0, 1, 3 mM NO3⁻) for 5 weeks. The specific growth rate (SGR), the chemical composition and the in vitro bioactive potential were investigated. The results suggested that the 200 µmol photons m⁻² s⁻¹ irradiance was associated with a higher carbohydrate content (53.01 ± 7.58%) but a lower ash content (24.57 ± 1.13%). Without considering the impact of cultivation weeks, a trend (R² = 0.9859) emerged of an increased SGR with the increasing irradiance (on average 0.33 ± 0.23% day⁻¹, 0.45 ± 0.19% day⁻¹, 0.59 ± 0.32% day⁻¹, respectively, for 50, 100 and 200 µmol photons m⁻² s⁻¹). Increasing the nitrogen enrichment did not impact the SGR (0.93 ± 0.07% day⁻¹ on average) but increased protein production (on average 18.51 ± 0.28% and 19.30 ± 0.23%, respectively, for 1 and 3 mM) by the seaweed. However, for both cultivation conditions no significant differences were found in the bioactive potential. Thus, tank cultivation parameters affected P. palmata growth and composition, and further research is needed to fully understand this potential in the context of commercial farming, might be considered to produce high-quality food.
Graphical Abstract
BACKGROUND
De‐oiled rice bran (DORB), a substantial yet underutilized byproduct of rice processing, boasts a rich composition of active ingredients but suffers from limited application. Previous studies have indicated that enzymatic or fermentation treatments enhanced these active components. In this study, lactobacilli and complex enzymes were employed to co‐treat DORB, involving the determination of the changes in active components and functionalities of DORB extract (DORBE) before and after this treatment.
RESULTS
Following fermentation–enzymolysis, the total phenol and total flavonoid contents in DORBE were significantly increased by 43.59% and 55.10%, reaching 19.66 and 34.34 g kg⁻¹, respectively. Antioxidant tests in vitro demonstrated that the co‐treatment enhanced the scavenging activities of DPPH, hydroxyl and ABTS radicals. Porcine intestinal epithelial cell experiments revealed that, compared to DORBE, the fermentation and enzymolysis DORBE (FDORBE) exhibited significantly improved cell viability and catalase activity as well as scavenging capacity for reactive oxygen species and malondialdehyde after induction by H2O2. Furthermore, FDORBE restored the decreased mRNA expression levels of Nrf2, HO‐1 and NQO1 in the nuclear factor erythroid 2‐related factor 2 (Nrf2) pathway stimulated by H2O2.
CONCLUSION
Fermentation–enzymolysis co‐treatment increases the contents of bioactive components of DORBE and enhances its antioxidant capacity, leading to a better protection against intestinal disorders induced by oxidative stress, suggesting that this co‐treatment is a rational and effective strategy to increase the value of grains and promotes the use of DORB as a functional feed in animal production. © 2024 Society of Chemical Industry.
Ocean harbors a large biodiversity of marine fauna and flora with about 5,000 species of sponges, 9,000 species of annelids, and 66,535 species of molluscs. The marine environment may contain over 80% of world's plant and animal species. In recent years, many bioactive compounds have been extracted from various marine macro and microorganisms. New metabolites from marine organisms have resulted in the isolation of more or less 10,000 metabolites, many of which are endowed with pharmacodynamic properties. The deep knowledge about nerve transmission has been learnt using squid and its giant nerve axons and the mesenteries of vision have been unraveled using the eyes of horseshoe crabs, sharks and skates. The surf clam is proving an excellent model for the cell cycle and its regulation while the sea urchin is a model for understanding the molecular basis of cellular reproduction and development. The objective of this chapter is to highlight some of the recent developments and findings in the area of marine biotechnology with special reference to the biomedical potential of marine natural products.
Nanotechnology captures great interest in various areas and has wide range of applications. Titanium dioxide (TiO2) has been synthesized through different means such as physical, chemical, and green methods, whereas green synthesis of nanoparticles is a cost-effective, economical, non-toxic, and eco-friendly method, and TiO2 nanoparticles have been used in cosmetic products as ultraviolet filters. Marigold (MG) being a strong antioxidant has been used for skin protection and contains anti-aging effects. In this study, MG-mediated TiO2 nanoparticles (NPs) were biosynthesized, and bioactive compounds of this plant act as reducing and capping agents during the fabrication of nanoparticles. Characterization of NPs was done by using different techniques such as UV/Vis, XRD, and SEM. UV–visible absorption spectroscopy illustrated MG-TiO2 NPs activity in visible light. X-ray diffractometry (XRD) confirmed the crystalline structure of TiO2, and scanning electron microscopy (SEM) discovered the cylindrical shape of MG-TiO2 NPs. The size of these NPs was found at 45.93 nm. MG extracts and NPs are analyzed for antioxidant activities, and MG nanoparticles showed strong antioxidant activity 50 µg/ml against DPPH. MG M and E also showed good oxidant scavenging activity. MG-TiO2 NPs exhibited excellent results 82% against hydrogen mediated hemolysis in anti-hemolytic activity whereas MGM and MGE scavenge oxidants up to 74 and 73%. Cytotoxicity studies revealed that MG-NPs, MGM, and MGE extracts presented good results 23.42828 µg/ml, 25.14318 µg/ml, and 49.97482 µg/ml against brine shrimp assay and represent 86%, 40%, and 25% anticancer potential against hepG2 cell lines. Antibacterial activity of medicinal plants illustrated the highest inhibition zone against 24-mm Salmonella gallinarum for MG-TiO2 NPs marigold methanol extract (MGM) and marigold ethanol extract (MGE) showing moderate antibacterial activity but no zones against Paeruginosa aeruginosa.
Three different species of seaweeds collected from south east coast of India such as Sargassum plagiophyllum, Padina gymnospora and Turbinaria conoides for evaluating anti-bacterial activity against selected Gram-positive and Gram-negative bacteria. Extracts prepared using solvents namely hexane, ethyl acetate, methanol, and water against human pathogenic strains of Proteus vulgaris, Staphylococcus aureus, Klebsiella pneumonia, Enterobacter aerogenes, Salmonella typhimurium, Yersinia pestis, Shigella fiexneri, Staphylococcus epidermidis and Bacillus subtilis. Gram-negative bacteria showed a lesser zone of inhibition than Gram-positive bacteria with various extracts tested. All the three solvent extracts of Turbinaria conoides showed, zone of inhibition for the Gram-positive bacteria, Staphylococcus epidermidis over the standard control, with a significant zone in hexane extract. Analysis of GC-MS of Turbinaria conoides hexane extract revealed 14 major and numerous minor phytochemical compounds that have to be fractionated and explored for specific anti-bacterial activity in order to isolate a potential anti-bacterial compound.
This study aimed to optimize pressurized liquid extraction (PLE) of phenolic compounds from the brown seaweed Fucus vesiculosus to obtain extract with high yield, rich in phenolic compounds, with good radical scavenging, and with metal chelating ability. The extraction was optimized with a Box–Behnken design experiment and response surface tool. Optimal condition was found at 137.18 °C, 58.65% v/v ethanol in water and 4.68 min extraction time which resulted in yield of 31.16% dry basis, total phenolic content (TPC) of 3.69 g gallic acid equivalent (100 g dry seaweed)⁻¹, effective concentration for 50% inhibition (EC50) of DPPH radical (92.6 μg mL⁻¹), ABTS radical (2.35 mg mL⁻¹), and metal chelating (1.10 mg mL⁻¹). The TPC value and radical scavenging activity of the PLE extract were insignificantly different from the one obtained from conventional solvent extraction, which proved PLE advantages in terms of shorter time and less solvent requirement. Gallic, protocatechuic, and gentisic acids were identified in the PLE extracts.
BACKGROUD
The Lanzhou lily (Lilium davidii var. unicolor) is the only Lilium species that is used for both culinary and medicinal purposes in China. Its bulbs contain various bioactive substances, such as polysaccharides, saponins and colchicine. Lanzhou lily polysaccharides are known to have anti‐immunity, anti‐tumor and anti‐oxidation functions.
RESULTS
The present study used a Box–Behnken design to optimize the ultrasound‐assisted extraction of Lanzhou lily polysaccharides. Compared to other enzymes, trypsin significantly increased the polysaccharide yields, whereas the protein content of polysaccharides extracted with trypsin was the lowest. Monosaccharide mainly includes glucose (> 50%) and mannose (> 10%). 1,1‐Diphenyl‐2‐picrylhydrazyl radical scavenging activity, chelating activity, total antioxidant capacity and hydroxyl radical scavenging activity of Lanzhou lily polysaccharides extracted with trypsin were stronger than those extracted without enzymes (control). Structural characteristics of Lanzhou lily polysaccharides extracted with trypsin and extracted without enzymes were characterized by scanning electron microscopy and nuclear magnetic resonance spectroscopy. When water extracted polysaccharide and trypsin extracted polysaccharide concentrations were 200 μg mL–1, Raw264.7 proliferation rates were 101.69% and 159.41%, respectively.
CONCLUSION
The Lanzhou lily polysaccharide was identified as α‐(1 → 6)‐d‐glucan. Consequently, the effects of both potential antioxidant and proliferative activity of trypsin are significant. © 2020 Society of Chemical Industry
In this study, the effect of solvent type and solvent concentration on the ultrasound assisted extraction (UAE) of polyphe-nols from popular tea samples (black, green, mate, blackberry and black mulberry) which have high antioxidant activities were investigated by chemometric approaches. For this purpose, green extraction method was preferred and hydroalcoholic solvents for applied this system in industry. Water, MeOH 100%, MeOH 75%, MeOH 50%, EtOH 100%, EtOH 75%, EtOH 50% were used as extraction solvent. Multivariate calibration analytical technique preferred for quantification of individual phenolic compounds in tea samples and the relationship between total phenolic content (TPC), total flavonoid content (TFC) and total antioxidant activity (TAA) and individual phenolics was determined by chemometric approaches. The results of the study suggest that only spectroscopic comparisons based on TPC, TFC and TAA correlations are insufficient or even incorrect , and this is due to the fact that in tea samples different molecules besides different flavonoid structures are sensitive to spectroscopic techniques. The determination of the appropriate type and the concentration of solvent would contribute the usage of the herbal plants as a source of natural antioxidants in foods and pharmacology in large-scale industrial applications.
Background
All over the world, people face the same skin problems. However, their skin characteristics are different. Thus, it is a challenge to prescribe treatments that will be effective on different skin types. Therefore, it is very important to consider the skin biology when indicating a dermocosmetic treatment.
Objectives
To assess skin biophysical parameters in French and Brazilian subjects and to verify the efficacy of four dermocosmetic treatments in these populations.
Methods
Five test areas were defined on each volar forearm of the eighteen Brazilian and eighteen French participants using a randomized design. Biophysical measurements in terms of skin hydration, skin barrier function, skin brightness, and skin viscoelasticity were performed before and after 60 minutes of treatment.
Results
Skin biophysical differences between populations were found. French skin has been shown to be more hydrated regarding epidermal mechanic properties and stratum corneum water content and more radiant when compared with Brazilian skin. However, it showed more signs of cutaneous aging and fatigue effects on skin. The Brazilian skin showed better skin barrier function. In addition, the treatments were effective in both populations.
Conclusions
Despite the differences found in French and Brazilian skin, the proposed dermocosmetic treatments showed effective in both populations.
BACKGROUND
Strawberries are appreciated for their taste, flavor, and juiciness; however, they are highly perishable during postharvest, handling, and storage stages, producing significant physical damage and loss of vitamins and other phytonutrients. This study therefore aimed to determine the applicability of edible coatings as an environmentally friendly strategy to improve the fresh appearance of strawberries and extend their shelf life.
RESULTS
The effectiveness of edible coatings formulated with chitosan (CHC) or chitosan and algae (Palmaria palmata Kuntze) (CH‐PC) was investigated with regard to quality and nutritional parameters for ready‐to‐eat strawberries processed and stored at 4 °C for 10 days. Chitosan significantly (P < 0.05) controlled the gradual decline of strawberries, reducing their respiration rate, microbial load, and nutritional loss. The addition of P. palmata to the edible coating significantly (P < 0.05) enhanced anthocyanin and ascorbic acid content.
CONCLUSION
These results suggest that CH‐PC could be used in the strawberry postharvest industry to slow senescence, while reducing product loss and enhancing its nutritional value. © 2018 Society of Chemical Industry
The properties of Plectranthus stocksii—a well-known folk medicinal plant—were investigated. The plant extracts were successively extracted and tested for phytochemicals using high performance liquid chromatography, while antioxidant and anticancerous properties were assessed using MCF-7, Caco-2 and RAW 264.7 cancerous cell line models. The methanolic extract of leaves showed higher concentrations of total phenolics (415.41 mg gallic acid equivalents/g extract) and tannins (177.53 mg gallic acid equivalents/g extract) contents than other studied extracts. In the case of flavonoids, ethyl acetate extract of leaf (LEA) showed a higher concentration (777.11 mg rutin equivalents/g extract) and was also found to have better antioxidant activity against stable radical 2,2-diphenylpicrylhydrazyl (3.46 μg/mL), 2,2’azinobis(3-ethylbenzothiozoline-6-sulfonic acid) disodium salt radical (27.41 mM Trolox equivalent/g extract) and superoxide (24.16 μg/mL) radicals and showed better IC50 (the concentration of the sample at which the inhibition rate reaches 50%) values on MCF-7 (48.874 μg/mL) and Caco-2 (36.088 μg/mL) cancerous cell line models. The immense anti-oxidant potential of P. stocksii leaf and stem extracts could be utilized as a good source of natural, anti-oxidant supplement in food to defend against oxidative-stress-related disorders and more generally in the food safety industry.
The present study aimed to describe the expression and purification of cyclophilin-type peptidylprolyl cis-trans isomerase (PPI) from the red alga Pyropia yezoensis. The antioxidant activity of the purified protein was also demonstrated, based on its ability to act against oxidative stress in HepG2 human hepatocellular carcinoma cells. HepG2 cells that were treated with recombinant PPI protein exhibited a reduction in the formation of hydrogen peroxide (H2O2)‑mediated reactive oxygen species (ROS). In HepG2 cells, treatment of recombinant PPI protein expression diminished H2O2‑mediated oxidative stress and restored both the expression and the activity of certain antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and thioredoxin reductase (TRR). CAT, SOD and TRR activities were upregulated by treatment with the purified protein. CAT mRNA expression was significantly increased in HepG2 cells treated with recombinant PPI protein. These enzymes are the first line of antioxidant defense against ROS generated in times of oxidative stress. Accordingly, data from the present study indicate that the recombinant PPI protein is able to regulate the expression of antioxidant enzymes. Recombinant PPI has antioxidant properties that prevent oxidative stress‑induced toxicity, enhance cell viability, decrease ROS production and inhibit oxidative damage and mitochondrial dysfunction in HepG2 cells. Therefore, the present study hypothesizes that the recombinant PPI protein has the potential to protect the liver against oxidative stress‑induced cell damage and should be considered as an antioxidant.
Natural extracts of macroalgae are widely recognized for their antioxidant properties. In this work, the antioxidant capacity of various aqueous and hydroalcoholic extracts obtained from red and green marine algae and from one marine lichen collected from different sites in southern Spain (intertidal and estuarine waters) was evaluated by different methods: ABTS free radical scavenging assay, DPPH assay, and β-carotene bleaching method (BBM). Contents of total lipids, total carbohydrates, and UV photoprotectors with antioxidant capacity, such as mycosporine-like amino acids and phenolic compounds, were determined. Among the extraction solvents, the highest extraction yield was observed in H2O and 20% MeOH (v/v). The highest antioxidant activity was found in the extracts of the red macroalgae Hydropuntia cornea, Gracilariopsis longissima, Halopithys incurva, and Porphyra umbilicalis, whereas the lowest activity was detected in the green macroalga Ulva rotundata. In general, the antioxidant activity was higher using DPPH than BBM and ABTS. Even so, the ABTS assay is an easy and quick test that provides a comprehensive view of the entire extract in both the lipophilic medium and hydrophilic medium. The antioxidant activity was related to the composition of bioactive compounds and synergistic action is not discarded. The biotechnological use of macroalgal extracts with high antioxidant capacity is discussed. © 2016, Universidad Autonoma de Baja California. All rights reserved.
Sea vegetables (also known as seaweeds) are gaining popularity among American consumers as a new superfood. Some sea vegetable farmers in New England have begun to distribute fresh or minimally processed sea vegetables to local restaurants and to retail distributors. However, limited knowledge about quality loss and processing effects on fresh, farm-raised sea vegetables postharvest obstructs the growth of a vibrant sea vegetable industry. The objectives of this research were to: 1) evaluate the quality changes and shelf life of four fresh sea vegetables species - dulse, Gracilaria, sugar kelp and winged kelp - during refrigerated storage, 2) determine the basic nutritional composition of these fresh sea vegetables, and 3) evaluate the effects of blanching and freezing on the antioxidant capacity of the aforementioned sea vegetables. Fresh dulse and Gracilaria were stored at 35 oF and 45 oF for up to two weeks and periodically tested for sensory, microbial, physical and biochemical quality attributes. The species exhibited opposite trends for the effect of storage temperature: the lower storage temperature resulted in a longer acceptable quality shelf life for dulse (11 days) whereas the higher temperature resulted in a longer acceptable quality shelf life for Gracilaria (10 days), based on sensory evaluation. For the brown sea vegetables, fresh sugar kelp (February and June harvest) and winged kelp (whole fronds and slaw) were stored 35 oF and 45 oF for up to two weeks and periodically tested for sensory attributes, microbial, physical and biochemical quality parameters. The lower storage temperature maintained the quality of whole fronds and shredded slaw better than the higher storage temperature. Harvest season impacted the shelf life of sugar kelp significantly, resulting in an acceptable quality shelf life of 12 days for sugar kelp harvested in June compared to a 6-day shelf life for sugar kelp harvested in February for samples stored at 35 oF. All four species under investigation contained ~80-90 g/100g moisture. The dry mass was rich in total minerals including potassium, calcium and magnesium but low (~2-3 g/100g) in crude lipid. The protein content was variable, with dulse containing the highest (22.1 g/100g) amount among the four species whereas winged kelp had the highest (58.4 g/100g) carbohydrate content. The highest (31.4 mg/100g) vitamin C content was found in sugar kelp whereas the lowest was found in Gracilaria (1.5 mg/100g). The antioxidant capacity of blanched, frozen and blanched frozen dulse, Gracilaria, sugar kelp and winged kelp was compared to that of fresh samples. Blanching significantly (p
Polyphenolic compounds isolated from marine algae exhibit a broad spectrum of beneficial biological properties, including antioxidant, anticancer, antimicrobial, anti-inflammatory, and antidiabetic activities, along with several other bioactivities centered on their antioxidant properties. Consequently, polyphenolic compounds are increasingly being investigated for their potential use in food, cosmetic, and pharmaceutical applications. The antioxidant activities of these compounds have been explored widely through experimental studies. Nonetheless, a theoretical understanding of the structural and electronic properties could broaden research perspectives, leading to the identification and synthesis of efficient structural analogs with prophylactic uses. This review briefly summarizes the current state of knowledge regarding antioxidant polyphenolic compounds in marine algae with an attempt to describe the structure-activity relationship.
This study was undertaken to evaluate the antidiabetic effect of edible seaweeds Sargassum wightii and Ulva fasciata with an objective to establish these seaweeds as add-on therapy for controlling diabetes. The ethyl acetate extract of Sargassum wightii (EAS) and Ulva fasciata (EAU) at 100 and 200 mg/kg dose was examined for antidiabetic activity in the high fat diet and multi-low-dose streptozotocin induced type 2 diabetic mice. Plasma glucose, oral glucose tolerance test [OGTT], lipid profile, liver and skeletal muscle glycogen content, triglycerides, superoxide dismutase [SOD], body and organ weight was estimated at the end of the study. Consequently, histopathology of liver was also studied. Both EAS and EAU showed significant reduction in plasma glucose level and the area under curve [AUC] of OGTT was significantly (p<0.001) attenuated. The extracts appreciably normalized lipid profile, body and organ weight. At higher doses of both EAS and EAU showed significant (p<0.05) improvement in SOD level of skeletal muscle and reduction in liver as well as skeletal muscle triglycerides. Both the extracts considerably enhanced hepatic and muscle glycogen content. Remarkable improvements were found in the histopathological observations of liver of all the treated groups as compared against the diabetes induced group. The findings suggest that these seaweeds offer a great opportunity to satisfy the food and nutrition requirement for rectifying and controlling diabetes.
The present study was envisaged to assess and compare the in vitro and in vivo antioxidant potential of apple peel extract (APE) and aloe vera gel (AVG). In vitro efficacy was studied on the basis of total phenolics, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, superoxide anion scavenging activity and 2-2-azinobis-3ethylbenthiazoline-6-sulphonic acid radical cation activity. The in vivo assessment was done using enrobed goat meat bites as model meat system viz. unenrobed (control), enrobed without antioxidants, enrobed with 3% APE and enrobed with 3% AVG at 4±1C and evaluated at 5-day intervals. In vitro assessment exhibited significantly (P<0.05) higher antioxidant activity of AVG than APE. In vivo assessment depicted that oxidative and color stability was better maintained in AVG treated samples with lowest thiobarbituric acid reactive substances values and had higher sensory scores among all with storage. Results concluded that AVG has comparatively higher potential both in vitro and in vivo system. Practical Applications: The present research is related to the efficacy of natural antioxidants in the meat system. The apple peel, a by-product of the apple juice industry, can be efficiently utilized to prepare anti-oxidative extracts and aloe vera is known worldwide to show antioxidant properties. Both have not been compared in fried meat modal system, so research had been carried out to study the viability of in vitro results in in vivo system. Moreover, the study meets the desires of consumers demanding more natural products nowadays.
This study sought to evaluate the effects of hot water treatment on the radicals [1,1-diphenyl-2 picrylhydrazyl (DPPH*) and hydroxyl (OH*)] scavenging, Fe2+-induced lipid peroxidation and α-amylase and a-glucosidase (enzymes linked to type 2 diabetes) inhibitory abilities of Crassocephalum crepidioides leaf using in vitro models. The phenolics and vitamin C contents of the leaf were also determined. Fresh C. crepidioides leaves were treated with hot water for 5 min and the extracts from raw (RL) and treated (TL) leaves were used for analysis. RL extract had significantly (p<0.05) higher radical scavenging abilities and inhibition of lipid peroxidation in pancreas homogenate than TL extract. Both extracts inhibited α-amylase and α-glucosidase activity dose-dependently. However, RL extract had higher α-amylase and α-glucosidase inhibitory ability, which could be linked to its higher (p<0.05) total phenolic content. These potentials could be part of the biochemical rationale behind the traditional use of C. crepidioides leaves in the management of type 2 diabetes. However, hot water treatment could reduce the effective utilization of C. crepidioides as a functional food ingredient in the management of oxidative stress and type 2 diabetes.
This study investigated the biological activities of essential oil from sweet basil leaves via its effect on α-amylase, α-glucosidase and angiotensin-I-converting enzyme (ACE) activities, inhibition of Fe2+ and sodium nitroprusside (SNP)-induced lipid peroxidation in rats’ pancreas and heart homogenates. The phytoconstituents of the oil were analysed using gas chromatography (GC). The essential oil exhibited a dose-dependent inhibition of α-amylase (IC50 = 3.21 mg/mL), α-glucosidase (IC50 = 3.06 mg/mL) and ACE (IC50 = 0.89 mg/mL) activities in vitro. The oil also inhibited both Fe2+- and SNP-induced lipid peroxidation in rats’ pancreas and heart. The GC analysis revealed the presence of about 28 phytoconstituents, with limonene (47.40 %), borneol (8.66 %), geranial (6.93 %), neral (5.71 %), myrcene (4.68 %), β-caryophyllene (4.68 %), α-terpineol (4.60 %), 1,8-cineole (4.17 %), linalool (3.53 %), β-elemene (3.05 %), germacrene D (2.68 %), and terpinen-4-ol (2.21 %) being the most prominent. Thus, the antioxidant and enzyme inhibitory effects of the essential oil could be attributed to the presence of these phytochemicals, which could be the principle responsible for the antidiabetic and antihypertensive properties of the essential oil. This study therefore, could provide the possible rationale for the application of essential oil from sweet basil leaves as functional foods and nutraceutical ingredient in the management of type 2 diabetes and hypertension.
The antioxidant properties of coconut sap were analyzed for which studies were conducted on the reducing power, levels of ascorbic acid, polyphenol content and alpha amylase inhibitory activity. Polyphenols and ascorbic acid are very good antioxidants and possess free radical scavenging activity and thereby exhibit good reducing power. Alpha amylase inhibitors cause delay in the digestion of carbohydrates, therefore causing reduction in the rate of glucose absorption. © 2015, International Journal of ChemTech Research. All rights reserved.
This study investigated the most appropriate drying method (sun drying, oven drying, or air drying) for mistletoe leaves obtained from almond tree. The phenolic constituents were characterized using high-performance liquid chromatography-diode array detector, while the inhibitory effect of the aqueous extracts of the leaves on angiotensin-I converting enzyme (ACE) was determined in vitro as also the antioxidant properties. Oven-dried extract (kidney [276.09 μg/mL] and lungs [303.41 μg/mL]) had the highest inhibitory effect on ACE, while air-dried mistletoe extract (kidney [304.47 μg/mL] and lungs [438.72 μg/mL]) had the least. Furthermore, the extracts dose-dependently inhibited Fe(2+) and sodium nitroprusside-induced lipid peroxidation in rat's heart and kidney. Also, all extracts exhibited antioxidative properties as typified by their radical scavenging and Fe-chelating ability. Findings from this study revealed that oven drying is the best of the 3 drying methods used for mistletoe obtained from almond host tree, thus confirming that diversity in drying methods leads to variation in phenolic constituents and biological activity of plants.
© The Author(s) 2015.
This study sought to investigate antioxidant and antidiabetic effects of gallic acid (GA) and protocatechuic acids (PCAs) based on their structure–function relationship. Twenty micromolar of phenolic acid (GA and PCA) solutions was prepared and their antioxidant properties determined. Then, interaction of the phenolic acids with key enzymes linked to type 2 diabetes (α-amylase, α-glucosidase) was subsequently assessed. The results showed that both phenolic acids significantly (P < 0.05) decreased Fe2+-elevated pancreas malondialdehyde (MDA) contents, chelated Fe2+, reduced Fe3+ to Fe2+, and scavenged 1,1-diphenyl-2-picrylhydrazyl, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonate), and hydroxyl radicals and furthermore inhibit α-amylase and α-glucosidase activities in a dose-dependent manner. However, GA (IC50 = 1.22 μM) had significantly (P < 0.05) higher inhibitory effect on the α-glucosidase activity than PCA (IC50 = 1.76 μM). Conclusively, both GA and PCA are rich sources of antioxidant and antidiabetic molecules. However, GA showed better antioxidant and antidiabetic effects than PCA. These effects may be due to additional hydroxyl group on its aromatic ring structure.
The leaves of Eriobotrya japonica (Thunb.) Lindl. (Rosaceae) are used in traditional medicine to treat inflammatory diseases. However, information about the antigenotoxic and antioxidant properties of its leaves remains to be elucidated.
The objective of this work was to evaluate the mutagenic/antimutagenic, genotoxic/antigenotoxic, and antioxidant potentials of aqueous and total oligomers flavonoid (TOF) extracts from E. japonica.
The mutagenic/antimutagenic and genotoxic/antigenotoxic potentials of extracts (50, 250, and 500 µg/plate) were evaluated, respectively, by the Ames test with 48 h incubation and the SOS chromotest test with 2 h incubation. The antioxidant capacity of these extracts (ranging from 50 to 700 µg/mL) was tested using xanthine/xanthine oxidase and the deoxyribose assays.
Eriobotrya japonica extracts showed neither mutagenic nor genotoxic effect. The highest protective effect against methyl methanesulfonate and 2-aminoanthracene was obtained in the presence of aqueous extract, with IC50 values of 80 and 140 µg/plate, respectively, against S. typhimurium TA104. Moreover, this extract (500 µg/plate) was also able to reduce significantly the genotoxicity induced by nitrofurantoin and aflatoxin B1 with IC50 values of 140 and 240 µg/assay, respectively. Likewise, aqueous and TOF extracts inhibited xanthine oxidase and superoxide anion formation with IC50 values ranging from 45 to 95 and from 70 to 90 µg/mL, respectively. However, TOF extract is more efficient in inhibiting hydroxyl radical and chelating iron ion with IC50 values of 140 and 400 µg/mL, respectively, when compared with the aqueous extract.
Eriobotrya japonica prevents the genotoxicity of some carcinogenic substances probably thanks to its antioxidant capacities.
This study sought to investigate the effect of two
traditional processing methods (roasting and hotwater treatment) of African pear (Dacryodes edulis[G.
Don] H.J. Lam. [Burseraceae]) on the phenolic content, antioxidant properties and inhibition of two
carbohydrate hydrolysing enzymes relevant to type
2 diabetes management (α-glucosidase and α-amylase). Some African pear samples were roasted for 5
min, while some were treated in hot water for 5 min.
Thereafter, the total phenolic and flavonoid content,
antioxidant activities, and interaction of the raw and
processed samples with α-amylase and α-glucosidase
were determined. The results of the total phenol and
flavonoid contents of the raw, hot-water-treated and
roasted African pear samples revealed that the roasted
samples had significantly (p<0.05) higher total phenol (22.4 mg/g) and flavonoid (3.14 mg/g) content
than hot-water-treated (total phenol [16.2 mg/g], total flavonoid [2.32 mg/g]) and raw samples (totalphenol [12.1 mg/g], total flavonoid [1.91 mg/g]).
The roasted samples had the highest radical-scavenging and Fe
2+
-chelating abilities, as well as inhibition of Fe
2+
-induced lipid peroxidation in rat pancreas
in vitro; the raw samples had the least. Similarly, the
samples inhibited both α-amylase and α-glucosidase
activities in a dose-dependent manner; however, the
processed samples had significantly higher inhibition
of α-amylase and α-glucosidase activities than the
raw samples. The higher phenolic content, antioxidant properties and inhibition of key enzymes (α-amylase and α-glucosidase) linked with type 2 diabetes in the roasted samples show that this is a better
processing method for African pear than hot-water
treatment.
Esta revisão de literatura teve como objetivo apresentar os produtos de algas marinhas disponíveis no mercado, as atividades antioxidante e antimicrobiana por elas apresentadas, os principais compostos envolvidos nessas bioatividades, além de aspectos fundamentais sobre a exploração e comercialização desses produtos naturais. Os dados descritos na literatura evidenciam o grande potencial das algas marinhas como fontes naturais de ingredientes funcionais. O estudo da composição química, além da descoberta dos mecanismos de ação que envolvem as atividades biológicas das diversas espécies de algas, será interessante fonte de dados para a exploração de novas drogas de interesse para as indústrias farmacêutica e de cosméticos, bem como de novos ingredientes funcionais para a indústria alimentícia. PALAVRAS-CHAVE: ALGAS MARINHAS; ATIVIDADE ANTIOXIDANTE; ATIVIDADE ANTIMICROBIANA.
The content of photosynthetic pigments (chlorophyll a, biliproteins, carotenoids) and UV-absorbing mycosporine-like amino acids (MAAs), as well as the activity of reactive oxygen species scavenging enzymes (catalase, superoxide dismutase, glutathione reductase) was investigated in six macroalgal species with respect to the seasonal changes of the solar radiation regime and the macronutrient levels in the seawater of the Kongsfjord (Spitsbergen, Svalbard, Norway). The brown algae Laminaria
saccharina, Saccorhiza
dermatodea, Desmarestia
aculeata; the red algae Palmaria
palmata and Devaleraea
ramentacea; and one green algal species, Monostroma aff. arcticum, were sampled from the same water depth, before, during and after the break-up of sea ice, first under clear and later under turbid water conditions in late winter, spring and summer 1998. In all species, chlorophyll a (chl a) and total carotenoid content were highest under the sea-ice cover, and decreased gradually upon the sea-ice break-up. Four species showed a subsequent recovery in chl a and total carotenoid concentration in parallel to increasing water turbidity and reduced light availability. In the two red algal species, total phycoerythrin and phycocyanin contents followed a similar trend. Coinciding with the increase in underwater radiation during the sea-ice break-up, both species exhibited a significant increase in the concentration of UV-absorbing MAAs, especially of shinorine and palythine. At the same time, the antioxidative activities of the enzymes superoxide dismutase and catalase in the green and red algae increased, while glutathione reductase activity decreased. Overall, the synthesis of UV-absorbing substances and the increase in the activity of the antioxidative systems in the open-water period imply an increased resistance to high underwater light conditions, including UV radiation. The seasonal changes in pigments and biochemical defence systems may additionally be related to variations in nutrient levels in the seawater. They also reflect the life strategy and the genetic adaptation of the seasonal development to the conditions in the Arctic.
Inhibitory effects of flavonoids rutin and quercetin on ferrous ion-dependent lipid peroxidation of lecithin liposomes and NADPH- and CCl4-dependent lipid peroxidation in rat liver microsomes were studied to elucidate the chelating and free radical scavenging activities of these compounds. The interaction of rutin with superoxide ion and ferrous ions and the reaction of quercetin with lipid peroxy radicals were also studied. Both flavonoids were significantly more effective inhibitors of iron ion-dependent lipid peroxidation systems due to chelating iron ions with the formation of inert iron complexes unable to initiate lipid peroxidation. At the same time, iron complexes of flavonoids retained their free radical scavenging activities. The chelating mechanism of inhibition was more important for rutin than for quercetin. The mutual effect of rutin and ascorbic acid on non-enzymatic lipid peroxidation was also studied. It was concluded that rutin and quercetin are able to suppress free radical processes at three stages: the formation of superoxide ion, the generation of hydroxyl (or cryptohydroxyl) radicals in the Fenton reaction and the formation of lipid peroxy radicals.
A proposed mechanism underlying the anticarcinogenic and antiatherogenic effects of flaxseed (flax) and its lignan secoisolariciresinol diglycoside (SDG) is the potential antioxidant activity of SDG and its mammalian lignan metabolites enterodiol (ED) and enterolactone (EL). Recent evidence indicates that SDG, ED and EL scavenge hydroxyl radicals in vitro. This study evaluated the effect of dietary flax on specific antioxidant enzymes and nonenzymatic antioxidant molecules in young rats. After 3 days acclimatization on an AIN-93G basal diet (BD), female Sprague Dawley rats (24 days of age) were randomized into three dietary groups: BD, BD supplemented with 10% flax or 3 mg SDG gavage. At 50 days of age, rats were sacrificed and livers removed for antioxidant enzyme determinations. Body weight gain, feed efficiency ratio and liver weights were not different between treatment groups indicating that animals grew well on the flax diet. Hepatic reactive oxygen species metabolizing enzymes catalase (CAT) and glutathione peroxidase (GSH-Px) were not different between treatment groups. Hepatic glutathione reductase (GSSG-Red) activity of SDG and flax-fed rats, when combined, were lower (P = 0.037) compared to BD-fed rats. Hepatic acid-soluble sulfhydryl groups as GSH were not influenced by flax or SDG treatment. Total urinary lignan excretion was higher in SDG- and flax-fed groups than in the BD group (P < 0.001). Reduced activity of GSSG-Red and unchanged GSH levels may relate to an antioxidant sparing effect of ED and EL in tissues of flax and SDG-fed rats.
The data reported in the literature and recent analyses of the composition ofPalmaria palmata (Rhodymenia palmata) are compiled and discussed. The reported values have a relatively wide spread ranging from 73–89% moisture and, on a dry
weight basis, 12–37% ash, 8–35% crude protein, 38–74% carbohydrate and 0.2–3.8% lipid. Some of the variation can be attributed
to seasonal and nutritional conditions.P. palmata has potassium, chlorine and sodium as its major mineral constituents and, in comparison to terrestrial fruits and vegetables,
is a good source of iron, magnesium, calcium and iodine. Vitamin A (as carotene) and, in the fresh plant, vitamin C, are present
in appreciable amounts.P. palmata is potentially a high protein food source, and its protein quality rates well with vegetables of good nutritional value.
The major polysaccharide is a ß-(l → 3) and ß-(l →4) linked xylan.P. palmata is a natural source of desmosterol.
Seaweeds, which have traditionally been used by the Western food industry for their polysaccharide extractives — alginate, carrageenan and agar — also contain compounds with potential nutritional benefits. Seaweeds have recently been approved in France for human consumption (as vegetables and condiments), thus opening new opportunities for the food industry. These seaweed ingredients must meet industrial and technical specifications and consumer safety regulations. This paper is a short review of biochemical and nutritional aspects associated with the use of seaweeds in food products.
A new amino acid with a maximum at 334 nm, supposed to be biogenetically related to the characteristic UV-absorbing compounds from the zoanthid Palythoa tuberculosa, has been isolated from Porphyra tenera Kjellman and its structure determined.
METHODS for measuring antioxidants and appraising antioxidant activity appear to be of two general types. If the chemical nature of the antioxidant is known, one may strive for a test specific for the compound or group of interest; for example, the nitroprusside test for sulphydryl groups. Alternatively one may observe the inhibition of some natural oxidative process such as the β-oxidation of fats, as a function of the added antioxidant.
The effect of sun-drying, oven-drying, and freeze-drying methods on the nutritional composition of the seaweed Sargassum hemiphyllum (Turn.) C. Ag. was investigated. Proximate and nutrient compositions (amino acids, fatty acids, minerals, and vitamin C) of the seaweed dried by the above methods were determined. The results indicated that dietary fiber and ash were the most abundant components of seaweed S. hemiphyllum. No significant differences in the content of crude protein and crude lipid were found among all three dried seaweed samples. Freeze-dried seaweed had the highest content of total amino acids, total polyunsaturated fatty acids, and total vitamin C when compared with sun-dried and oven-dried seaweed. However, sun-dried seaweed has the lowest values of ash, mineral, and total vitamin C contents among the three dried seaweed samples. This might be due to the leaching effect and long exposure time to air during sun-drying. Although oven-dried seaweed had the greatest nutrient losses, probably due mainly to the effect of high temperature during drying, it contained the highest mineral content. Thus, it can be concluded that the nutritional composition of seaweed S. hemiphyllum is greatly affected by different drying methods. Keywords: Seaweed; freeze-drying; oven-drying; sun-drying; nutritional composition
The relationship between antioxidant activity and antimutagenicity of various tea extracts (green tea, pouchong tea, oolong tea, and black tea) was investigated. All tea extracts exhibited markedly antioxidant activity and reducing power, especially oolong tea, which inhibited 73.6% peroxidation of linoleic acid. Tea extracts exhibited a 65-75% scavenging effect on superoxide at a dose of 1 mg and 30-50% scavenging effect on hydrogen peroxide at a dose of 400 mu g. They scavenged 100% hydroxyl radical at a dosage of 4 mg except the black tea. Tea extracts also showed 50-70% scavenging effect on alpha,alpha-diphenyl-beta-picrylhydrazyl radical. The antioxidant activity and the scavenging effects on active oxygen decreased in the order semifermented tea > nonfermented tea > fermented tea. Tea extracts showed strong antimutagenic action against five indirect mutagens, i.e., AFB(1), Trp-P-1, Glu-P-1, B[a]P, and IQ, especially oolong and pouchong teas. The antioxidant effect of tea extracts was well correlated to their antimutagenicity in some cases but varied with the mutagen and antioxidative properties.
The autoxidation of soybean oil in a cyclodextrin emulsion system was studied in the presence of an emulsion stabilizer consisting of polysaccharides such as xanthan, tragacanth gum, and methylcellulose. Xanthan strongly inhibited the peroxidation of soybean oil containing tocopherols but showed no antioxidant activity on soybean oil without tocopherols in the emulsion. Xanthan did not have hydrogen-donating ability but expressed Fe2+-binding activity. The Fe2+-binding activity corresponded to the pyruvate content of xanthan. Depyruvated xanthan did not inhibit effectively the autoxidation of soybean oil. The Fe2+-chelating structure of xanthan is discussed.
The antioxidant activity of aqueous/organic extracts of processed and raw edible seaweeds was determined using three methods, namely (a) free radical (DPPH·) scavenging, (b) ferric‐reducing antioxidant power (FRAP) and (c) inhibition of copper‐catalysed in vitro human low‐density lipoprotein (LDL) oxidation. Scavenging activity correlated well ( r = 0.73) with the corresponding total polyphenolic content measured by the Folin–Ciocalteu procedure and expressed as phloroglucinol equivalents (PGE). Of the seaweeds tested, Fucus showed the highest antioxidant activity in two of the test methods used (1 g (dry matter) had a DPPH· activity and a FRAP value equivalent to those 0.18 and 0.07 mmol of Trolox respectively) and the highest total polyphenolic content (41.4 gPGEkg ⁻¹ dry matter). The antioxidant activity and the content of phenolic compounds decreased with processing and storage in the seaweeds tested. In addition, Fucus showed good efficiency in the in vitro inhibition of LDL oxidation.
© 2001 Society of Chemical Industry
The antioxidant effect of seven species of marine algae on the preservation of sunflower oil were investigated by storage experiments at 75°. Laminaria digitata (Kombu) and Himanthalia elongata were the most effective in extending the induction period. Extracts of these two seaweeds were then compared with vitamin E and BHT as regards to their antioxidative activities, by kinetic studies in a model system. The thermal initiated oxidation of methyl linoleate was performed at 60° in heptanol, with or without antioxidants. When they reached 1 % of the substrate, seaweed extracts exhibited antioxidant activities by extending the induction period but they were not actually effective. Effects of the addition of algal extracts together with vitamin E on the preservation of methyl linoleate, sunflower oil or mixed ethyl eicosapentaenoate and docosahexaenoate were investigated at 60° by the same kinetic studies. Algal extracts synergistically enhance the antioxidant effect of vitamin E when the latter is present at a level higher than 1 × 10−4 M. On mechanistic grounds, the understanding of this synergism is outlined. Seaweed extracts should find applications in the cosmetic and food industries without any further purification.
Dietary antioxidants from plants are believed to help prevent aging and other diseases through radical scavenging activity. Free radical scavenging activities by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and deoxyribose assay were ascertained among 27 species of common seaweeds using a sequential extraction method. The results indicated that, DPPH scavenging activity existed in 15 species; Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres showed the strongest activities. On the other hand, the deoxyribose results showed that almost all the seaweed species had good ability to scavenge hydroxyl radicals. The most active species were Rhodomela teres and Chorda filum.
Fresh and dry specimens of Sargassum polycystum and Laurencia obtusa were collected from the Seribu Islands waters, Indonesia,
and crude methanol, diethylether and hexane extracts were tested for antioxidant activity using the thiocyanate method. None
of the extracts of dry S. polycystum and L. obtusa showed antioxidant activity, but extracts of fresh material did show activity.
L. obtusa extracts had higher antioxidant activity than those of S. polycystum. The methanol extract of S. polycystum was
more active than the other extracts, and the n-hexane extract of L. obtusa was more active than the diethylether and methanol
extracts.
The ability of Laminaria digitata, Himanthalia elongata, Fucus vesiculosus, Fucus serratus and Ascophyllum nodosum to scavenge peroxyl radicals was investigated by kinetic studies in a model system. The thermal initiated oxidation of methyl linoleate was performed at 60°C in heptanol, with or without antioxidants. When they reached 1% of the substrate, seaweed extracts exhibited antioxidant activities by extending the induction period, but they did not suppress the rate of oxygen uptake as did vitamin E.
A synergistic effect occurred when both algal extracts (1.5 g L-1) and vitamin E (0.4 mmol L-1) were present, and the effectiveness of the combined antioxidants during the whole induction period was vitamin E effectiveness. The synergistic effect of L. digitata, however, was subject to seasonal variations: samples collected in summer were effective synergists, whereas samples collected in winter displayed a marked negative synergism.
The phospholipid fractions of F. vesiculosus, F. serratus and A. nodosum, including pigments, accounted for only 6% of the total lipid fraction, and did not exhibit a large synergistic effect. The main phospholipid was not phosphatidyl ethanolamine as usually related, but phosphatidyl inositol. Fucoxanthin had some antioxidant activity per se under our experimental conditions, but did not act as a synergist of vitamin E. The most potent synergists were recognized as chlorophyll a and related compounds by the application of liquid-liquid partition and chromatography for the identification of active components.
The inhibition of lipid peroxidation and radical scavenging effects were studied to evaluate the antioxidant activity for
extracts of 17 species of seaweed. The antioxidant effect was evaluated by determination of lipoxygenase activity and by α,
α-diphenyl-β-picrylhydrazyl (DPPH) decolorization. Lipoxygenase activity was depressed in the presence of aqueous and ethanol
extracts of 4 algal species; Sargassum species had the highest antioxidant activity of all the species examined. The ethanol
extracts of one Sargassum species showed competitive inhibition with the substrate. The same species also showed radical scavenging
activity in the DPPH decolorization test. Comparison of these results shows no relationship between enzyme inhibition and
radical scavenging activity.
The antioxidant activities of several extracts from Susabinori (Porphyra yezoensis) were measured by the ferric thiocyanate method and the thiobarbituric acid method. The methanol, acetone, ethyl acetate,
and hexane extracts, and the chloroform-soluble and water-soluble fractions from the chloroform-methanol extract exhibited
higher activities than α-tocopherol. The hot water extract showed little activity. Thin-layer chromatography analysis of the
active extracts suggested the existence of several antioxidants. The activity of the chloroform soluble fraction was due to
chlorophyll analogs. A strong antioxidant was isolated from the methanol extract, accompanied by several amino acids such
as leucine and phenylalanine. This compound was identified as usujilene, a kind of mycosporine-glycine like amino acid.
Our objective was to study the influence of droplet composition on the rate of lipid oxidation in emulsions. A series of oil-in-water
emulsions stabilized by a nonionic surfactant (Tween 20) was studied. These emulsions had the same total oil concentration
(5 wt%) and initial droplet diameter (0.3 μm), but contained droplets with different ratios of ethyl linoleate (substrate)
andn-tetradecane (inert diluent). Lipid oxidation was measured as a function of time by three different methods: gas-chromatographic
determination of residual substrate; ultraviolet-visible spectrophotometric determination of conjugated dienes; and measurement
of aqueous thiobarbituric acid-reactive substances. All three methods showed similar trends for emulsions of similar composition.
The progress of lipid oxidation in the emulsions was dependent on the concentration of ethyl linoleate in the emulsion droplets.
At low concentrations (1% oil as substrate), oxidation proceeded at a relatively slow and constant rate. At intermediate concentrations
(20%), the oxidation rate was rapid initially and then slowed down with time. At high concentrations (100%), the oxidation
rate was slow at first, and then increased with time. An explanation of our results is proposed in terms of the distribution
of substrate molecules between the droplet interior and interface, and the ingress of aqueous radicals into the emulsion droplets.
Chia (Salvia sp) seeds were investigated as a source of natural lipid antioxidants. Methanolic and aqueous extracts of defatted chia seeds
possessed potent antioxidant activity. Analysis of 2 batches of chia-seed oils demonstrated marked difference in the fatty
acid composition of the oils. In both batches, the oils had high concentrations of polyunsaturated fatty acids. The major
antioxidant activity in the nonhydrolyzed extract was caused by flavonol glycosides, chlorogenic acid (7.1 × 10−4 mol/kg of seed) and caffeic acid (6.6 × 10−3 m/kg). Major antioxidants of the hydrolyzed extracts were flavonol aglycones/kaempferol (1.1 × 10−3 m/kg), quercetin (2.0 × 10−4 m/kg) and myricetin (3.1 × 10−3 m/kg); and caffeic acid (1.35 × 10−2 m/kg). Two methods were used to measure antioxidant activities. Both were based on measuring bleaching ofβ-carotene in the coupled oxidation ofβ-carotene and linoleic acid in the presence of added antioxidants.
The content, chemical composition and structure, some physicochemical properties and fermentation characteristics of dietary fibres from Palmaria palmata (dulse) were studied. The marine red algae contains 33·2–33·5% total dietary fibres measured on a dry weight basis using conditions simulating the gastric and intestinal environment (pH, temperature, ionic strength and time of incubation) and measured by an enzymatic/gravimetric method, respectively. The yield of soluble fibres by the simulated digestive tract conditions was lower (12·2%) than by the enzymatic/gravimetric method (18·9%).All soluble fibre fractions consisted of linear β-1,,3 mixed linked xylans containing similar amounts of 1,4 linkages (70·5–80·2%). The insoluble fibres contained essentially 1,4 linked xylans with some 1,3 linked xylose and a small amount of 1,4-linked glucose (cellulose). Low intrinsic viscosities were measured from the soluble fibres (49·4–97·0 ml g|2-1|0) and water holding capacities of dry dulse particles of 4·3 and 4·7 g g−1 were measured in buffer at pH 3·0 and 7·3, respectively.Soluble fibres are fermented within 6 h by human faecal bacteria into short chain fatty acids.
Six groups of female rats were fed diets containing 2% of one of six powdered seaweeds for 152 days and a basic diet for 59 or 60 successive days, and controls were fed the basic diet for the whole experimental period. The 7,12-dimethylbenz[a]anthracene was given to all rats intragastrically (20 mg/kg X 1), 27 days after the start of feeding. Diets with 3 weeds, Porphyra tenera (PT), Laminaria religiosa (LR) and L. japonica var. ochotensis (LO), showed an inhibitory effect on mammary tumorigenesis. Tumor incidences were 35% (7/20), 35% (7/20) and 50% (9/18), respectively, whereas that in the control group was 69% (20/29). There was a significant delay in the time to first palpable tumor in LR-fed and PT-fed rats (P less than 0.01). As for the tumor weight per rat in each group, it was significantly lower in the LR-fed group with a weight of 1.6 g, as compared with that of 16.3 g in the control group (P less than 0.02).
Hydroxyl radicals, generated by reaction of an iron-EDTA complex with H2O2 in the presence of ascorbic acid, attack deoxyribose to form products that, upon heating with thiobarbituric acid at low pH, yield a pink chromogen. Added hydroxyl radical "scavengers" compete with deoxyribose for the hydroxyl radicals produced and diminish chromogen formation. A rate constant for reaction of the scavenger with hydroxyl radical can be deduced from the inhibition of color formation. For a wide range of compounds, rate constants obtained in this way are similar to those determined by pulse radiolysis. It is suggested that the deoxyribose assay is a simple and cheap alternative to pulse radiolysis for determination of rate constants for reaction of most biological molecules with hydroxyl radicals. Rate constants for reactions of ATP, ADP, and Good's buffers with hydroxyl radicals have been determined by this method.
Nineteen preparations from 8 species of edible seaweeds, sodium alginate and cellulose powder were incorporated into a basic diet in proportions ranging from 0.05% to 2.0%, and used as experimental diets. Experimental rats were fed these diets and controls were fed the basic diet for 12 weeks. All rats also received the carcinogen, 1,2-dimethylhydrazine, during above period. After 20 weeks, all rats were autopsied and the incidence of intestinal tumors induced were examined. There was a significant decrease in incidence in rats fed 6 preparations from Eisenia bicyclis, Laminaria angustata, L. angustata var. longissima and Porphyra tenera (P less than 0.05).
The radical scavenging activity of Japanese edible seaweeds was screened by the DPPH (1-diphenyl-2-picrylhydrazyl) assay to evaluate the DPPH radical scavenging activity in organic extracts. The fresh brown alga Hijikia fusiformis showed the strongest DPPH radical scavenging activity, followed by Undaria pinnatifida and Sargassum fulvellum. The major active compound from Hijikia fusiformis in its acetone extract was identified as fucoxanthin by 13C-NMR spectroscopy.
A method for the screening of antioxidant activity is reported as a decolorization assay applicable to both lipophilic and hydrophilic antioxidants, including flavonoids, hydroxycinnamates, carotenoids, and plasma antioxidants. The pre-formed radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS*+) is generated by oxidation of ABTS with potassium persulfate and is reduced in the presence of such hydrogen-donating antioxidants. The influences of both the concentration of antioxidant and duration of reaction on the inhibition of the radical cation absorption are taken into account when determining the antioxidant activity. This assay clearly improves the original TEAC assay (the ferryl myoglobin/ABTS assay) for the determination of antioxidant activity in a number of ways. First, the chemistry involves the direct generation of the ABTS radical monocation with no involvement of an intermediary radical. Second, it is a decolorization assay; thus the radical cation is pre-formed prior to addition of antioxidant test systems, rather than the generation of the radical taking place continually in the presence of the antioxidant. Hence the results obtained with the improved system may not always be directly comparable with those obtained using the original TEAC assay. Third, it is applicable to both aqueous and lipophilic systems.
The antioxidant activities of the flaxseed lignan secoisolariciresinol diglycoside (SDG) and its mammalian lignan metabolites, enterodiol (ED) and enterolactone (EL), were evaluated in both lipid and aqueous in vitro model systems. All three lignans significantly (p < or = 0.05) inhibited the linoleic acid peroxidation at both 10 and 100 microM over a 24-48 h of incubation at 40 degrees C. In a deoxyribose assay, which evaluates the non site-specific and site-specific Fenton reactant-induced *OH scavenging activity, SDG demonstrated the weakest activity compared to ED and EL at both 10 and 100 microM; the greatest *OH scavenging for ED and EL was observed at 100 microM in both assays. The incubation of pBR322 plasmid DNA with Fenton reagents together with SDG, ED or EL showed that the inhibition of DNA scissions was concentration dependent. The greatest non site-specific activity of lignans was at 100 microM, thus, confirming the results of the deoxyribose test. In contrast, the protective effect of SDG and EL in the site-specific assay was lost and that of ED was minimal. Therefore, the results indicate a structure-activity difference among the three lignans with respect to specific antioxidant efficacy. All three lignans did not exhibit reducing activity compared to ascorbic acid, therefore, did not possess indirect prooxidant activity related to potential changes in redox state of transition metals. The efficacy of SDG and particularly the mammalian lignans ED and EL to act as antioxidants in lipid and aqueous in vitro model systems, at relatively low concentrations (i.e. 100 microM), potentially achievable in vivo, is an evidence of a potential anticarcinogenic mechanism of flaxseed lignan SDG and its mammalian metabolites ED and EL.
Prenylated flavonoids found in hops and beer, i.e., prenylchalcones and prenylflavanones, were examined for their ability to inhibit in vitro oxidation of human low-density lipoprotein (LDL). The oxidation of LDL was assessed by the formation of conjugated dienes and thiobarbituric acid-reactive substances (TBARS) and the loss of tryptophan fluorescence. At concentrations of 5 and 25 microM, all of the prenylchalcones tested inhibited the oxidation of LDL (50 microg protein/ml) induced by 2 microM copper sulfate. The prenylflavanones showed less antioxidant activity than the prenylchalcones, both at 5 and 25 microM. At 25 microM, the nonprenylated chalcone, chalconaringenin (CN), and the nonprenylated flavanone, naringenin (NG), exerted prooxidant effects on LDL oxidation, based on TBARS formation. Xanthohumol (XN), the major prenylchalcone in hops and beer, showed high antioxidant activity in inhibiting LDL oxidation, higher than alpha-tocopherol and the isoflavone genistein but lower than the flavonol quercetin. When combined, XN and alpha-tocopherol completely inhibited copper-mediated LDL oxidation. These findings suggest that prenylchalcones and prenylflavanones found in hops and beer protect human LDL from oxidation and that prenylation antagonizes the prooxidant effects of the chalcone, CN, and the flavanone, NG.
An aqueous decoction of mango (Mangifera indica L.) stem bark has been developed in Cuba on an industrial scale to be used as a nutritional supplement, cosmetic, and phytomedicine. Previously we reported its antioxidant activity, and we concluded that the product could be useful to prevent the production of reactive oxygen species and oxidative tissue damage in vivo. A phytochemical investigation of mango stem bark extract has led to the isolation of seven phenolic constituents: gallic acid, 3,4-dihydroxy benzoic acid, gallic acid methyl ester, gallic acid propyl ester, mangiferin, (+)-catechin, (-)-epicatechin, and benzoic acid and benzoic acid propyl ester. All structures were elucidated by ES-MS and NMR spectroscopic methods. Quantitative analysis of the compounds has been performed by HPLC, and mangiferin was found to be the predominant component. Total polyphenols were assayed also by the Folin-Ciocalteu method. The free sugars and polyols content was also determined by GC-MS.
Three methods widely employed in the evaluation of antioxidant activity, namely 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, static headspace gas chromatography (HS-GC) and beta-carotene bleaching test (BCBT), have been compared with regard to their application in the screening of plant extracts. The strengths and limitations of each method have been illustrated by testing a number of extracts, of differing polarity, from plants of the genus Sideritis, and two known antioxidants (butylated hydroxytoluene and rosmarinic acid). The sample polarity was important for the exhibited activity in the BCBT and HS-GC methods but not for the DPPH method. The complex composition of the extracts and partition phenomena affected their activity in each assay. The value of the BCBT method appears to be limited to less polar samples. Although slow, the HS-GC method is preferable for assessing the antioxidant inhibitory properties on the formation of unwanted secondary volatile products. Being rapid, simple and independent of sample polarity, the DPPH method is very convenient for the quick screening of many samples for radical scavenging activity.
Antioxidative activities of the extracts from Sargassum siliquastrum were determined using the inhibition of red blood cell (RBC) hemolysis induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) radicals, suppression of lipid peroxidation using rat brain homogenate, and scavenging activity of superoxide radicals. The dichloromethane fraction isolated from the methanol crude extract by differential solvent extractions exhibited the strongest antioxidant activity in both RBC hemolysis and lipid peroxidation assays. This fraction was further fractionated into four subfractions F1-F4 by silica gel column chromatography. F1 was found to be most effective in protecting RBC against AAPH radicals and in inhibiting lipid peroxidation. On the basis of thin-layer chromatography and UV and IR spectra analyses, all subfractions contained phenolic compounds. However, there was no correlation between the above antioxidant potency and total phenolic compounds estimated by using the Folin-Ciocalteau method.
Seaweeds grow in distinct vertical bands on the seashore and it is well known that their ability to recover physiological processes following desiccation is correlated to their shore position. Despite this, little is known of the cellular mechanisms by which intertidal seaweeds limit membrane damage during desiccation and subsequent rehydration. In this study, specimens of the intertidal red seaweed Stictosiphonia arbuscula were placed in sealed tanks and maintained at different relative humidities (control, RH 90-100%; moderate desiccation, RH 70-80% and severe desiccation, RH 40-50%) for 12, 24 or 48 h. Membrane damage and antioxidant metabolism was examined immediately following specimen rehydration. Amino acid leakage, through the plasmalemma, was greater for desiccated low-band specimens than high-band specimens, indicating greater membrane damage. In addition, low-band specimens produced more hydrogen peroxide and lipid hydroperoxides than high-band specimens. This indicates that, upon rehydration, high-band populations have a greater ability to reduce the build-up of hydrogen peroxide, limit lipid peroxidation and hence membrane and protein damage, than low-band populations. The greater ability to prevent or reduce the production of reactive oxygen species was not due to a larger antioxidant pool, but rather increased activity of the enzymes required to regenerate ascorbate and glutathione. These findings suggest that antioxidant metabolism is one of the defence mechanisms that protect S. arbuscula from cellular damage due to desiccation.