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1.
Total phenolic content, proanthocyanidins, gallotannins, flavonoids, and antioxidant activities of Sclerocarya birrea and Harpephyllum caffrum methanolic extracts were evaluated using in vitro assays. S. birrea young stem extract contained the highest levels of total phenolic content (14.15 ± 0.03 mg GAE/g), flavonoids (1.21 ± 0.01 mg CE/g) and gallotannins (0.24 ± 0.00 mg GAE/g). H. caffrum stem bark extract had the highest content of proanthocyanidins (1.47%). The EC50 values of the extracts in the DPPH free radical scavenging assay ranged from 4.26 to 6.92 μg/ml, compared to 6.86 μg/ml for ascorbic acid. A dose-dependent linear curve was obtained for all extracts in the ferric-reducing power assay. Dichloromethane and methanol extracts exhibited dose-dependent acetylcholinesterase inhibitory activity. Similarly, all extracts exhibited high antioxidant activity comparable to butylated hydroxytoluene based on the rate of β-carotene bleaching (84.1–93.9%). The two Anacardiaceae species provide a source of natural antioxidants and acetylcholinesterase inhibitors, and may be beneficial to the health of consumers.  相似文献   

2.
The objectives of this study were to determine phenolic content and antioxidant activity of methanolic extracts from different parts of cantaloupe (leaf, stem, skin, seed and flesh). The flesh extract afforded the highest yield (89.6 ± 0.3%) whilst the lowest yield was obtained from the seed (13.7 ± 0.5%) (p < 0.05). The leaf extract showed the highest total phenolic content (26.4 ± 0.3 mg GAE/g extract) and total flavonoid content (69.7 ± 3.37 μg RE/g extract) accompanied with best antioxidant activity through all antioxidant assays (p < 0.05). In addition, the stem extract also exhibited good antioxidant activity. Thus, these results suggest that methanolic extracts of cantaloupe leaf and stem may serve as a potential source of natural antioxidant for food and nutraceutical application.  相似文献   

3.
The antioxidant properties and total phenolic contents of methanol, acetone and water extracts of mulberry (Morus indica L.) leaves were examined. Various experimental models including iron (III) reducing capacity, total antioxidant capacity, DPPH radical scavenging activity and in vitro inhibition of ferrous sulphate-induced oxidation of lipid system were used for characterization of antioxidant activity of extracts. The three extracts showed varying degrees of efficacy in each assay in a dose-dependent manner. Methanolic extract with the highest amount of total phenolics, was the most potent antioxidant in all the assays used. In addition, the effect of temperature (50 °C and 100 °C), pH (3, 5, 7, 9 and 11) and storage (5 °C) on the antioxidant activity of methanolic extract was investigated. The antioxidant activity of the extract remained unchanged at 50 °C and was maximum at neutral pH. The extract stored at 5 °C in the dark was stable for 30 days after which the antioxidant activity decreased (p ? 0.05) gradually. On the basis of the results obtained, mulberry leaves were found to serve as a potential source of natural antioxidants due to their marked antioxidant activity.  相似文献   

4.
Sour prickly pears (xoconostles) are fruits from Opuntia joconostle cactus, which are cultivated in the central Mexico area. Phenolic and pigment content in various parts of O. joconostle fruits were analyzed. The antioxidant activity of a methanolic extraction and different semi-purified fractions were also evaluated by the DPPH+ method. Xoconostle fruits were obtained from a commercial orchard in Mexico State. Fruits were analyzed as whole fruit and each fruit part including pericarp, mesocarp and endocarp. Samples were homogenized and kept at 4 °C until sample preparation. Total phenolic content and total flavonoid content varied among the different parts of the fruit. The highest amount of phenolic compounds and total flavonoids content were found in pericarp 2.07 mg gallic acid equivalents (GAE)/g fresh weight (FW) and 0.46 mg(+)-catechin equivalents (CE)/g FW respectively. Seven phenolics were identified as protocatechuic, 4-hydroxybenzoic, caffeic, vanillic and syringic acids, rutin, and quercetin. The color of the fruit parts was mainly due to the presence of betacyanins. The betacyanin concentration was higher in the endocarp (23.03 mg betanin equivalents/100 g fresh weight) than in the pericarp and mesocarp. Betacyanins were identified by HPLC-PDA-MS as betanin, isobetanin, betanidin, isobetanidin, and phyllocactin. Methanolic extracts and semi-purified fractions A (phenolics and flavonols) and B (betacyanins) of xoconostle showed high antioxidant activity mainly in the pericarp. These results suggest that xoconostle is a rich source of antioxidant compounds such as phenolic compounds and betacyanins.  相似文献   

5.
Citrus sulcata was subjected to ultrasound, high-pressure, and Soxhlet extractions. The antioxidant and anti-inflammatory activities of the extracts were evaluated qualitatively and quantitatively. The antioxidant content of the peel extract was twice that of the fruit extract. The quantitative analysis showed that the narirutin and hesperidin contents in the peel extracts were 8.8 and 7.5 mg/100 g, respectively. These extracts had a total phenolic content of 112.22 ± 2.89 gallic acid equivalent (GAE) mg/100 g, a total flavonoid content of 54.09 ± 1.01 rutin equivalent (RE) mg/100 g, DPPH radical scavenging activity of 46%, and antioxidant activity of 213.25 ± 2.82 μM of Trolox equivalents (TEAC). C. sulcata extracts could prevent hydrogen peroxide (H2O2)-induced oxidative stress, reduce expression of the inflammatory markers nuclear Factor kappa B (NFκB) and phosphorylated IκBα (p-IκBα) in A549 human lung carcinoma cells, and inhibit Lipopolysaccharide (LPS)-induced THP-1 monocyte differentiation to an extent of 85%.  相似文献   

6.
Ether, methanolic and aqueous extracts of lyophilized rambutan (Nephelium lappaceum L.) peels and seeds were evaluated for phenolic contents, antioxidant and antibacterial activities. High amounts of phenolic compounds were found in the peel extracts and the highest content was in the methanolic fraction (542.2 mg/g dry extract). Several potential antioxidant activities, including reducing power, β-carotene bleaching, linoleic peroxidation and free radical scavenging activity, were evaluated. The peel extracts exhibited higher antioxidant activity than the seed extracts in all methods determined (P < 0.05). The methanolic fraction was found to be the most active antioxidant as shown by their 50% DPPH inhibition concentration, 4.94 μg/mL. The results indicated this fraction exhibited greater DPPH radical scavenging activity than BHT and ascorbic acid (0.32 g dry extract/g BHT or ascorbic acid). Antibacterial activity against eight bacterial strains was assessed by disc diffusion and broth macrodilution methods. All peel extracts exhibited antibacterial activity against five pathogenic bacteria. The most sensitive strain, Staphylococcus epidermidis, was inhibited by the methanolic extract (MIC 2.0 mg/mL).  相似文献   

7.
In vitro antioxidant activities of three selected Indian brown seaweeds – viz., Sargassum marginatum, Padina tetrastomatica and Turbinaria conoides – were investigated. Total phenolic content and reducing power of crude methanolic extract were also investigated. The activity of total methanolic extract and five different fractions (viz., petroleum ether (PE), ethyl acetate (EA), dichloromethane (DCM), butanol (BuOH) and aqueous) were studied using total antioxidant activity, DPPH radical scavenging and deoxyribose assays. EA fraction of S. marginatum exhibited higher total antioxidant activity of 39.62 mg ascorbic acid equivalent/g extract (or 0.31 mg ascorbic acid equivalent/g seaweed on dry weight basis) among the all the fractions. Among the fractions obtained from different seaweeds, EA fraction of S. marginatum showed higher DPPH scavenging activity of 23.16%; while PE fraction of T. conoides exhibited lower deoxyribose activity of 47.81%. Higher phenolic content (49.16 mg gallic acid equivalent/g extract or 0.86 mg GAE/g of seaweed on dry weight basis) was noticed in aqueous fraction of T. conoides. Reducing power of crude methanolic extract increased with increasing concentration. Reducing power of T. conoides and P. tetrastomatica were higher compared to standard antioxidant (α-tocopherol). Among the seaweeds, total methanolic extract of T. conoides had significantly higher phenol content (P < 0.05) compared to the other two species. In vitro antioxidant activity of methanolic extracts from all the three seaweeds showed an increase with increasing concentration indicating the dose dependency of these properties.  相似文献   

8.
Four underutilized Georgia-grown fruit crops, namely loquat (Eriobotrya japonica), mayhaw (Crataegus sp.), fig (Ficus carica), and pawpaw (Asimina triloba), and their leaves were analysed for total polyphenols by Folin–Ciocalteau method, and antioxidant capacity by ferric-reducing antioxidant power (FRAP) and Trolox-equivalent antioxidant capacity (TEAC) assays. Organic acids and phenolic compounds were identified by RP-HPLC. For lipid profile, fruits were separated into two fractions – seed and fruit (i.e., without seed); lipid was extracted using the Folch method and analysed for fatty acids, phytosterols, tocopherols, and phospholipids. The major organic acid identified in all samples was malic acid (177–1918 mg/100 g FW). The predominant phenolic acids in all the fruits were gallic (1.5–6.4 mg/100 g FW) and ellagic (0.2–33.8 mg/100 g FW), and the most abundant flavonoid was catechin (12.2–37.8 mg/100 g FW). Total lipid content varied from 0.1% in mayhaw fruit to 21.5% in pawpaw seed. Linoleic acid was the predominant fatty acid in all of the samples (28.2–55.7%).  相似文献   

9.
Gulcan Ozkan  Osman Sagdic  Orhan Unal 《LWT》2010,43(1):186-4637
In this study, total contents of phenolic, flavanol and flavonol, antioxidant activities and antimicrobial activities of the Turkish endemic Salvia pisidica Boiss. & Heldr. ex Bentham (Lamiaceae) extract and essential oil were assessed in vitro. Total phenolic, flavanol and flavonol contents in the extract were 54.57 mg gallic acid equivalents (GAE)/g, 16.70 mg catechine equivalents (CE)/g and 18.19 mg rutin equivalents (RE)/g, respectively. Antioxidant activities (IC50 value) of the extract and essential oil were determined as 4.88 and 6.41 mg/mL by DPPH assay, respectively. 31 compounds were determined in the essential oil using GC-MS and the major compounds (%) were camphor (23.76), sabinol (19.2), α-thujone (14.2) and eucalyptol (1.8-cineole) (5.8).The antimicrobial activity of the methanolic extract and the essential oil against 13 bacterial and two yeast strains was determined. The extract (concentration 5 g/100 ml or 10 g/100 ml) was effective against most of the strains tested, yet not against Bacillus cereus, Staphylococcus aureus, Aeromonas hydrophila and the two yeast strains tested. The essential oil (2 g/100 ml) showed an antimicrobial effect against all the gram (+) bacteria tested, against Saccharomyces cerevisiae, but was not effective against all gram (−) bacteria and Candida albicans. These results show that S.piscidica essential oil and extract could be considered as a natural alternative to traditional food preservatives and be used to enhance food safety and shelf life.  相似文献   

10.
The objectives of this study were to determine phenolic content, antioxidant activity of methanolic extracts from different parts of Cordia evolutior (leaf, bark, and fruit), and nutrition composition. The leaf extract showed the highest total phenolic content (25.40 ± 0.34 mg GAE/g extract) and total flavonoid content (69.70 ± 3.37mg RE/g extract) accompanied with the best antioxidant activity through all antioxidant assays. The fruit proximate compositions of crude protein, ash, carbohydrate, fiber, and fat were analyzed. Macro-nutrient contents were found to be higher in the fruit when compared to micronutrients. The analysis also showed the presence of almost all of the essential and non-essential amino acids. Linolenic acid content was higher than stearic acid among the fatty acids in the fruit.  相似文献   

11.
Antioxidant capacity of freeze-dried aqueous and methanolic extracts of soy protein isolate (SPI) and soybean meal (SBM) were assessed by 2, 2′-Diphenyl-1-picrylhydrazyl (DPPH) assay and total phenolic content (TPC). Caffeic and chlorogenic acids in liquid aqueous extracts, and genistein and daidzein in liquid methanolic extracts were measured by HPLC. Freeze-dried extracts were applied (1000 and 4000 μg/g) to trout mince and TBARS formation monitored during 14 days refrigerated storage. SBM aqueous extracts-treated mince (4000 μg/g) had significantly lower (P < 0.05) TBARS than all other treatments. SPI methanolic extract had the highest TPC (100 mg chlorogenic acid equivalents/100 g extract) and genistein and daidzein contents. SPI aqueous extracts had the highest chlorogenic acid (280 μg/g) while SBM aqueous extracts had the highest caffeic acids content (484 μg/g). SPI had the best in vivo antioxidant profile. SBM extracts were most effective at retarding lipid oxidation in refrigerated trout mince.  相似文献   

12.
Dorystoechas hastata (D. hastata) is a monotypic plant endemic to Antalya province of Turkey. D. hastata leaves are used to make a tea locally called “çalba tea”. Diethyl ether (E), ethanol (A), and water (W) were used for the sequential preparation of extracts from dried D. hastata leaves. A hot water extract (S) was also prepared by directly boiling the powdered plant in water. The antioxidant activities of the extracts were tested by ferric thiocyanate (FTC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging methods. E extract exhibited the greatest antioxidant activity with FTC method, whereas S extract exhibited the lowest IC50 value (6.17 ± 0.53 μg/ml) for DPPH radical scavenging activity. Total phenolic contents of the extracts were estimated by Folin–Ciocalteu method and S extract was found to contain the highest amount (554.17 ± 20.83 mg GAE/g extract) of phenolics. Extract A contained highest flavonoid content and there was a inverse linear correlation (R2 = 0.926) between IC50 values for DPPH radical scavenging activity and flavonoid contents of all extracts. Reducing power of extracts increased in a concentration-dependent manner. S extract was found to possess higher reducing power than equivalent amount of ascorbic acid at 20 and 25 μg/ml concentrations. Linear correlation between reducing power and concentration of E, A, and W extracts (R2 > 0.95) was observed. A, W, and S extracts contained relatively high levels of proline. The results presented suggest that D. hastata may provide a natural source of antioxidants and proline.  相似文献   

13.
Consumption of fruits and vegetables has been associated with a healthy state which has been attributed, in part, to their antioxidant capacity. Characterization of the bioactive compounds with antioxidant activity found in fruits cultivated in the tropic is limited. Thus, the objective of the present work was the characterization of phytochemicals and antioxidants of the fruit of black sapote (Diospyros digyna Jacq.). HPLC-DAD-Mass Spectrometry (HPLC-MS) analyses were used to identify and quantify phenolics, carotenoids and tocopherols. Total soluble phenolic content was 247.8 mg GAE/100 g fw (fresh weight). Important phenolics identified were sinapic acid, myricetin, ferulic acid, and catechin. Total carotenoid content was 399.4 ??g of ??-carotene/100 g fw, and ??-carotene and lutein were the main carotenoids identified. ??-Tocopherol concentration was 672.0 ??g/100 g dry weight. Antioxidant capacity as measured by the DPPH and FRAP assays was higher in the hydrophilic than in the lipophilic extract, and it is thought to be due mainly to the phenolic content of this fruit. Results suggest that the fruit of black sapote has an antioxidant capacity comparable to other important fruits, and its inclusion in the diet is therefore recommended.  相似文献   

14.
Defatted wheat germ (DWG) is the main by-product of the wheat germ oil extraction process. Its nutritional value has well been accepted. In this study, the antioxidant properties of 30% ethanol, 50% ethanol, 70% ethanol, 100% ethanol, and aqueous extracts of DWG were measured using various in vitro assays. Among the DWGEs (DWG extracts) tested, the 70% ethanol extract showed the best DPPH radical scavenging power while the 100% ethanol extract showed the highest ABTS radical scavenging activity and reducing power. In addition, both the 70% ethanol extract and the 50% ethanol extract exhibited relatively higher antioxidant activity in linoleic acid system. The extracts in question exhibited total phenolic contents ranging from 13.98 to 16.75 mg GAE/g. DWG, as a source of natural antioxidants, can be used to formulate nutraceuticals with potential applications to reducing the level of oxidative stress. The antioxidant potency of the DWG extracts could be the basis for its health promoting potential.  相似文献   

15.
This study is designed to examine the fruit essential oil composition, the total phenolic amounts and the antioxidant activities in methanolic extracts of Coriandrum sativum under saline conditions. Increasing NaCl levels to 75 mM reduced significantly the fruit yield by 36%. The essential oil yield was 0.30%, based on the dry weight; it increased by 77% and 84% at 50 and 75 mM NaCl, respectively, in comparison to the control. The major constituents were linalool and camphor, whose amounts increased with increasing NaCl concentrations. Antioxidant activities of the methanol extracts were determined by three different test systems, namely DPPH, β-carotene/linoleic acid and reducing power assays. In these three test systems, the highest activity was exhibited in control plants and was reduced significantly with increasing NaCl levels. In control plants, the total phenolic amount was 1.04 mg GAE/g DW which decreased by 43% and 66% at 50 and 75 mM NaCl, respectively.  相似文献   

16.
The aim of this study was to determine the antioxidant potency and total phenolic and flavonoid contents of kiwifruit (Actinidia deliciosa) in vitro by analysing the radical scavenging activity of lyophilised water extract from kiwifruit (LEK) for 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picryl-hydrazyl (DPPH), N,N-dimethyl-p-phenylenediamine (DMPD), and superoxide anion radical (O2) as well as the total reducing power by FRAP and CUPRAC assays and the metal chelating activities. LEK showed efficient radical scavenging activity with DPPH, ABTS, DMPD, and O2 radicals; ferric (Fe3+) and cupric (Cu2+) ion reducing power and metal chelating activities. Moreover, the amounts of phenolic compounds, such as caffeic acid, ferulic acid, syringic acid, ellagic acid, catechol, pyrogallol, p-hydroxy benzoic acid, vanillin, p-coumaric acid, gallic acid, quercetin, ??-tocopherol and ascorbic acid, in LEK were quantified by LC-MS-MS. The results show that pyrogallol (2070.0 mg/kg LEK) is the main phenolic compound responsible for the antioxidant and radical scavenging activities of LEK. Finally, total phenolic and flavonoid contents were determined as gallic acid (GAE) and quercetin equivalents (QE). The GAE and QE values in LEK were 16.67 ± 2.83 ??g GAE/mg and 12.95 ± 0.52 ??g QE/mg, respectively. The results suggest that consumption of kiwifruit (A. deliciosa) can be beneficial effects due to its antioxidant properties.  相似文献   

17.
Freeze-dried fenugreek (Trigonella foenum-graecum) seeds and bitter melon (Momordica charantia) fruit were extracted sequentially using non-polar to polar solvents, with further separation carried out on polar extracts by molecular weight cut off dialysis. The fenugreek ethyl acetate crude extract (FGE3) demonstrated the highest antioxidant activity, in terms of Trolox Equivalents (TE), for both the DPPH (35.338 ± 0.908 mg TE/g) and FRAP (77.352 ± 0.627 mg TE/g) assays. This extract also contained the highest phenolic content, in terms of Gallic Acid Equivalents (GAE) (106.316 ± 0.377 mg GAE/g). Despite having considerably lower antioxidant activity than fenugreek, the highest antioxidant activities for bitter fruit were observed in the hexane (BME1) and methanol hydrophilic < 3.5 kDa dialysed (BME4 < 3.5 kDa) extracts, while the highest phenolic content was found in the methanol hydrophilic > 3.5 kDa (BME4 > 3.5 kDa) dialysed extract. UPLC-MS was used to quantify 18 phenolic compounds from fenugreek and 13 from bitter melon in active crude extracts. The flavonoids apigenin-7-O-glycoside (1955.55 ng/mg) and luteolin-7-O-glycoside (725.50 ng/mg) were the most abundant compounds in FGE3, while bitter melon extracts contained only small amounts of mainly phenolic acids. A further 5 fenugreek and 1 bitter melon compounds were identified in trace amounts from the same extracts, respectively.  相似文献   

18.
The ethyl acetate and methanol extracts from 16 Salvia L. species were screened for their inhibitory activity against acetylcholinesterase, butyrylcholinesterase, lipoxygenase, and tyrosinase; the enzymes linked to neurodegeneration. Their antioxidant activity was also tested using DPPH radical scavenging, metal-chelation, and ferric-reducing antioxidant power (FRAP) assays. Total flavonoid content of the extracts was determined by AlCl3 reagent, while HPLC technique was applied for analysis of various phenolic acids in the extracts. The extracts exerted weak cholinesterase and tyrosinase inhibition, and remarkable inhibition against lipoxygenase (13.07 ± 2.73-74.21 ± 5.61%) at 100 μg ml−1. The methanol extracts showed higher antioxidant activity in DPPH radical scavenging and FRAP assays. The extracts were analyzed for their gallic, protocateuchic, p-hydroxy-benzoic, vanillic, caffeic, chlorogenic, syringic, o- and p-coumaric, ferulic, rosmarinic, and tr-cinnamic acid contents and the methanol extract of Salvia ekimiana (153.50 mg 100 g−1) was revealed to be the richest in terms of rosmarinic acid.  相似文献   

19.
Determination of total phenolic (TPC), flavonoid and anthocyanin contents, and various antioxidant activities (2,2-diphenyl-1-picrylhydrazyl radical scavenging, ferric reducing power, ferrous ion chelating and lipid peroxidation inhibition) of leaves and flowers of Bauhinia kockiana, Caesalpinia pulcherrima and Cassia surattensis were performed in this study. The B. kockiana flower was found to possess the highest TPC (8280 ± 498 mg GAE/100 g), free radical scavenging activity (ascorbic acid equivalents 14,600 ± 2360 mg AA/100 g) and reducing ability (72.4 ± 8.7 mg GAE/g). Rutin and chlorogenic acid were detected in the plants, where the C. pulcherrima leaf contained the highest amount of rutin (669 ± 26 mg/100 g), while minute amounts of chlorogenic acid were detected in C. surattensis leaf (9.13 ± 0.44 mg/100 g). The C. pulcherrima leaf displayed the highest ferrous ion chelating and lipid peroxidation inhibition activities. Positive correlation was observed between TPC and various antioxidant activities.  相似文献   

20.
The nutritional and antioxidant properties of peels, pulp and seeds of kembayau (Dacryodes rostrata) fruits were evaluated. Kembayau seeds and pulp were rich in fat, while peels had the highest ash contents. Potassium was the most prevalent mineral in peels (380.72-1112.00 mg/100 g). In kembayau fruits, total flavonoid content (1012.74-28,022.28 mg rutin equivalent/100 g) was higher than total phenolic and total monomeric anthocyanin contents. Kembayau seeds exhibited high flavonoid and phenolic contents compared to the contents in peels and pulp. Antioxidant capacities were also higher in seeds as typified by trolox equivalent antioxidant capacity assay (51.39-74.59 mmol TE/100 g), ferric reducing antioxidant power assay (530.05-556.98 mmol Fe2+/100 g) and by 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity (92.18-92.19%) when compared to peels and pulp. Pulp and peels of kembayau fruit may be an important source of energy and minerals for human consumption, while seeds have a good potential as antioxidants.  相似文献   

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