tannins and 2-2--azino-di-(3-ethylbenzothiazoline)-6-sulfonic-acid

Medicinal plants belonging to the genus Mimosa, such as Mimosa tenuiflora, M. caesalpinifolia, and M. verrucosa are known for their popular use for asthma, bronchitis and fever. Ethnopharmacological studies report that Mimosa acutistipula is used to treat alopecia and pharyngitis, conditions that can be related to oxidative stress, inflammatory processes and painful limitations. However, there is no studies on its efficacy and mechanism of action.. To elucidate the antioxidant, anti-inflammatory, analgesic and antipyretic activity of M. acutistipula leaves.. Phytochemical profile of M. acutistipula extracts was evaluated by several reaction-specific methods. Secondary metabolites such as tannins, phenols and flavonoids were quantified with colorimetric assays. In vitro antioxidant potential was evaluated using DPPH and ABTS + as free radical scavenging tests, FRAP and phosphomolybdenum as oxide-reduction assays, and anti-hemolytic for lipid peroxidation evaluation. In vivo anti-inflammatory evaluation was performed by paw edema, and peritonitis induced by carrageenan. Analgesic effect and its possible mechanisms were determined by acetic acid-induced abdominal writhing and the formalin test. Antipyretic activity was evaluated by yeast-induced fever.. M. acutistipula leaves ethyl acetate extract showed expressive concentrations of phenolic compounds and antioxidant activity. It also exhibited anti-inflammatory and analgesic activity, besides its antipyretic effect. Thus, these results provide information regarding its popular use and might help future therapeutics involving this specimen.

Topics: Analgesics; Anti-Inflammatory Agents; Antioxidants; Antipyretics; Edema; Flavonoids; Methanol; Mimosa; Pain; Peritonitis; Phenols; Plant Extracts; Tannins

Topics: Antioxidants; Benzothiazoles; Biphenyl Compounds; Caffeine; Chlorogenic Acid; Ethanol; Flavonoids; Phenols; Plant Extracts; Propylene Glycols; Solvents; Sulfonic Acids; Tannins

The effectiveness of tannic acid as antimicrobial and wound healing for burns have been shown for a century; however, uncontrolled target dosage may result in undesirable side-effects. Remarkably, tannic acid polyphenols compounds crosslinked with polymeric materials produce a strong composite containing the beneficial properties of this tannin. However, investigation of the crosslink structure and its antibacterial and regenerative properties are still unknown when using nanocellulose by mechanical defibrillation; additionally, due to the potential crosslink structure with chitosan, its structure can be complex. Therefore, this work uses bleach kraft nanocellulose in order to investigate the effect on the physical and regenerative properties when incorporated with chitosan and tannic acid. This film results in increased rigidity with a lamellar structure when incorporated with tannic acid due to its strong hydrogen bonding. The release of tannic acid varied depending on the structure it was synthesised with, whereas with chitosan it presented good release model compared to pure cellulose. In addition, exhibiting similar thermal stability as pure cellulose films with antibacterial properties tested against S. aureus and E. coli with good metabolic cellular viability while also inhibiting NF-κB activity, a characteristic of tannic acid.

Topics: Anti-Bacterial Agents; Anti-Infective Agents; Antioxidants; Bandages; Benzothiazoles; Biphenyl Compounds; Cell Line; Cell Survival; Cellulose; Chitosan; Cross-Linking Reagents; Drug Liberation; Escherichia coli; Gels; Humans; Hydrogen Bonding; Keratinocytes; Microscopy, Electron, Scanning; NF-kappa B; Picrates; Polyphenols; Spectroscopy, Fourier Transform Infrared; Stress, Mechanical; Sulfonic Acids; Tannins; Temperature; Wound Healing

Layer-by-layer (LBL) assembled films have been exploited for surface-mediated bioactive compound delivery. Here, an antioxidative hydrogen-bonded multilayer electrospun nanofibrous film was fabricated from tannic acid (TA), acting as a polyphenolic antioxidant, and poly(ethylene glycol) (PEG) via layer-by-layer assembly. It overcame the burst release behavior of nanofibrous carrier, due to the reversible/dynamic nature of hydrogen bond, which was responded to external stimuli. The PEG/TA nanofibrous films disassembled gradually and released TA to the media, when soaked in aqueous solutions. The release rate of TA increased with increasing bilayer number, pH and temperature, but decreased with enhancing ionic strength. The surface morphology of the nanofibrous mats was observed by scanning electron microscopy (SEM). The following antioxidant activity assay revealed that it could scavenge DPPH free radicals and ABTS(+) cation radicals, a major biological activity of polyphenols. This technology can be used to fabricate other phenolic-containing slowly releasing antioxidative nanofibrous films.

Topics: Benzothiazoles; Biphenyl Compounds; Cellulose; Free Radical Scavengers; Hydrogen Bonding; Nanofibers; Nanotechnology; Picrates; Polyethylene Glycols; Sulfonic Acids; Tannins; Temperature

Four varieties (Rihane, Manel, Roho, and Tej) of Tunisian barley were analysed for their antioxidant activities (AA) using ABTS and DPPH radicals cation, and ferric reducing/antioxidant power (FRAP) methods. The total phenolic (TPC), total flavonoid (TFC) and condensed tannins (CTC) contents were measured. The results indicated that the total phenolic contents ranged from 195.02 ± 0.32 to 220.11 ± 0.32 mg gallic acid equivalent/100g fresh weight. Results showed that Rihane has the highest TPC, TFC and CTC compared to other varieties. Roho barley had a lower activity than Tej barley. A significant correlation (p<0.05) was found between TPC, TFC, CTC and AA. This study suggests that Tunisian barley varieties may serve as a good source of natural antioxidants.

Topics: Antioxidants; Benzothiazoles; Flavonoids; Hordeum; Oxidation-Reduction; Phenols; Phytochemicals; Sulfonic Acids; Tannins; Tunisia

The aqueous methanolic extracts of two plants from Algeria, Helichrysum stoechas subsp. rupestre and Phagnalon saxatile subsp. saxatile, were investigated for their antioxidant activity.. Total phenolics, flavonoids, and tannins were determined by spectrophotometric techniques. In vitro antioxidant and radical scavenging profiling was determined by spectrophotometric methods, through: Total antioxidant capacity, and radical scavenging effects by the DPPH and ABTS methods, reducing and chelating power, and blanching inhibition of the β-carotene.. All of the extracts showed interesting antioxidant and radical scavenging activity. The highest contents in phenolics, tannins, and the highest total antioxidant capacity as gallic acid equivalents of 97.5 ± 0.33 mg GAE/g DW was obtained for the flowers of H. stoechas subsp. rupestre extract in the phosphomolybdenum assay. An extract of the leafy stems of P. saxatile subsp. saxatile revealed the highest content of flavonoids, and the highest antioxidant activity by the radical scavenging and β-carotene assays when compared with standards. The best activity was by the scavenging radical DPPH with an IC50 value of 5.65 ± 0.10 μg·mL(-1).. The studied medicinal plants could provide scientific evidence for some traditional uses in the treatment of diseases related to the production of reactive oxygen species (ROS) and oxidative stress.

Topics: Algeria; Antioxidants; Asteraceae; Benzothiazoles; Biphenyl Compounds; Flavonoids; Helichrysum; Oxidative Stress; Phenols; Picrates; Plant Extracts; Plant Structures; Spectrophotometry; Sulfonic Acids; Tannins

In this study, we evaluated total phenolics, condensed tannins, ascorbic acid, lycopene, β-carotene, total antioxidant activity, reducing power, ferric-reducing antioxidant power, and radical scavenging activity (RSA) on ABTS and DPPH as well as metal chelating activity of methanolic and aqueous extract from caps and stipes of Calocybe indica and Pleurotus sajor-caju mushrooms. Per gram of extract, the different mushroom extracts contained 18.09-27.47 mg gallic acid equivalent of phenolics, 5.06-8.89 mg catechins of tannins, and 0.15-0.21 mg ascorbic acid. Principal component analysis (PCA) revealed that methanolic extract from caps of C. indica and P. sajor-caju contained higher ascorbic acid, total antioxidant activity, β-carotene and radical scavenging activity (RSA) on 2,2-diphenyl-1-picrylhydrazyl (DPPH) than did the stipes. The aqueous extract from cap and stipe of P. sajor-caju had higher total phenolics and RSA on 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) as well as higher metal-chelating activity and ferric-reducing antioxidant power. The antioxidant potential is higher in the caps of P. sajor-caju and C. indica than in the stipes; the cap contributes most to antioxidant activity.

Topics: Antioxidants; Ascorbic Acid; Basidiomycota; Benzothiazoles; beta Carotene; Biphenyl Compounds; Carotenoids; Chelating Agents; Fluorescence Recovery After Photobleaching; India; Lycopene; Picrates; Polyphenols; Sulfonic Acids; Tannins

The present study evaluated the levels of total phenolics, flavonoids, tannins and anthocyanins from Peganum harmala L. seeds and determined their antioxidant, antiplasmodial and anticancer potentials. Antioxidant activity was determined by DPPH and ABTS assays. Extracts of P. harmala seeds from Oudref and Djerba (two places in Tunisia) were obtained by successive extraction solvents: petroleum ether, chloroform, ethyl acetate, ethanol and water. Their composition was evaluated for phenolics (gallic acid equivalent 2.48 to 72.52 g/kg), tannins (catechin equivalent 0 to 25.27 g/kg), anthocyanins (cyanidin equivalent 0 to 20.56 mg/kg) and flavonoids (quercetin equivalent 0 to 3.12 g/kg). Ethanolic extract exerted the highest activities against a chloroquine-resistant strain of Plasmodium falciparum (IC₅₀=23 mg/L), against human breast cancer cells MCF7 (IC₅₀=32 mg/L) and against free radical (IC₅₀=19.09±3.07 mg/L). Correlations were studied between each chemical family and the three activities. Total phenolics content exhibited the highest correlation with antiplasmodial activity (R²=0.92) and with anticancer activity (R²=0.86), respectively.

Topics: Anthocyanins; Antimalarials; Antineoplastic Agents, Phytogenic; Antioxidants; Benzothiazoles; Biphenyl Compounds; Cell Survival; Erythrocytes; Female; Flavonoids; Humans; Liquid-Liquid Extraction; MCF-7 Cells; Parasitic Sensitivity Tests; Peganum; Phenols; Picrates; Plant Extracts; Plasmodium falciparum; Seeds; Structure-Activity Relationship; Sulfonic Acids; Tannins

Phenolic compounds were extracted from European and Japanese grapevine species (Vitis vinifera and V. coignetiae) seeds using 80% methanol or 80% acetone. The total content of phenolic compounds was determined utilizing Folin-Ciocalteu's phenol reagent, while the content of tannins was assayed by the vanillin and BSA precipitation methods. Additionally, the DPPH free radical and ABTS cation radical scavenging activities and the reduction power of the extracts were measured. The HPLC method was applied to determine the phenolic compounds, such as phenolic acids and catechins. The seeds contained large amounts of tannins and gallic acid and observable quantities of catechins, p-coumaric, ferulic and caffeic acids. The dominant form of phenolic acids in the extracts was the ester-bound form. The content of total phenolics was higher in the European grape V. vinifera seeds, which also contained more tannins, catechins and phenolic acids, except for caffeic acid. Extracts from V. vinifera seeds showed better radical scavenger properties and stronger reducing power. The total contents of phenolic compounds and tannins in acetone extracts were higher than in methanolic extracts. Acetone extracts also exhibited stronger antiradical properties as well as stronger reducing power.

Topics: Acetone; Benzothiazoles; Biphenyl Compounds; Catechin; Chromatography, High Pressure Liquid; Free Radical Scavengers; Free Radicals; Grape Seed Extract; Humans; Hydroxybenzoates; Methanol; Oxidation-Reduction; Picrates; Reducing Agents; Solvents; Spectrophotometry, Ultraviolet; Sulfonic Acids; Tannins; Vitis

Layer-by-layer (LbL) assembled films have been exploited for surface-mediated drug delivery. The drugs loaded in the films were usually released via diffusion or the degradation of one of the film components. Here we demonstrate that drug release can also be achieved by exploiting the dynamic nature of hydrogen-bonded LbL films. The films were fabricated from tannic acid (TA), a model polyphenolic drug, and poly(vinyl pyrrolidone) (PVPON). The driving force for the film buildup is the hydrogen bonding between the two components, which was confirmed by Fourier transform infrared (FTIR) spectra. The film growth is linear, and the growth rate of the film decreases with increasing assembly temperature. Because of the reversible/dynamic nature of hydrogen bonding, when soaked in aqueous solutions, the PVPON/TA films disassemble gradually and thus release TA to the media. The release rate of TA increases with increasing pH and temperature but decreases with increasing ionic strength. Scanning electron microscopy (SEM) studies on the surface morphology of the film during TA release reveal that the film surface becomes smoother and then rougher again because of the dewetting of the film. The released TA can scavenge ABTS(+•) cation radicals, indicating it retains its antioxidant activity, a major biological activity of polyphenols.

Topics: Antioxidants; Benzothiazoles; Drug Delivery Systems; Hydrogen Bonding; Hydrogen-Ion Concentration; Microscopy, Electron, Scanning; Polyphenols; Povidone; Spectroscopy, Fourier Transform Infrared; Sulfonic Acids; Tannins

Phytochemicals are extensively found at different levels in many medicinal plants. To investigate the phenolic compound content and in vitro antioxidant activity of hydro-methanolic extract from Prasium majus L. (Lamiaceae). The present investigation comprises, estimation of total polyphenol, flavonoid, tannin, in vitro antioxidant assays such as total antioxidant capacity, DPPH, ABTS, beta-carotene and ferric reducing power. P. majus exhibited 64.25 mg GAE g(-1) extract of polyphenol phenol content and better scavenging activity of DPPH (IC50 = 7.95 microg mL(-1)), ABTS*+ (IC50 = 373.78 microg mL(-1)) and beta-carotene (IC50 = 122.56 microg mL(-1)). Our results clearly demonstrated that hydro-methanolic extract P. majus has antioxidant capacity. Therefore is a valuable source of natural antioxidants.

Topics: Antioxidants; Benzothiazoles; beta Carotene; Biphenyl Compounds; Flavonoids; Lamiaceae; Methanol; Phenols; Picrates; Plant Extracts; Plants, Medicinal; Polyphenols; Sulfonic Acids; Tannins

Reactive oxygen species (ROS) is a metabolic side product of oxidative stress process, which causes several diseases like atherosclerosis, cancer, etc. In defense of ROS, antioxidants play a key role in combating them. As the process of aging increases, the level of antioxidants in our body decreases and thereby needs utmost attention for its repair process, which is generally administered externally. Plant products serve a best source for controlling these activities by its own metabolic pathway. Studies on the antioxidant activities of Maytenus emarginata leaf extracts are lacking. Antioxidant activity of the methanol extract of Maytenus emarginata was determined by DPPH free radical nitric oxide scavenging assays, superoxide ion scavenging assays, ABTS, and iron chelating methods. Preliminary phytochemical screening revealed that the extract of Maytenus emarginata leaves possesses phenols, flavonoids, steroids, glycosides, saponins, tannins, and triterpenoids. The extract showed significant activities in all antioxidant assays compared to the standard antioxidant (ascorbic acid) in a dose-dependent manner, and remarkable activities to scavenge ROS may be attributed by the presence of the above active compounds in the leaves. The amount of total phenolics and flavonoid contents were also estimated. The DPPH, ABTS, Nitric oxide, superoxide, and iron chelating IC(50) values of the methanolic extracts were 12.44, 24.27, 22.41, 5.85, and 2.74 μg/mL, respectively. The total phenolic content of the methanolic extract was 10.69 mg CA/g, whereas the total flavonoid was 1.56 mg CAE/g. The antioxidant activities were correlated with the total phenolic content. This result suggests that the relatively high antioxidant activity of the methanolic extract compared to standard could be possibly be due to its high phenolic content.

Topics: Alkaloids; Antioxidants; Benzothiazoles; Biphenyl Compounds; Flavonoids; Free Radical Scavengers; Iron Chelating Agents; Maytenus; Nitric Oxide; Picrates; Plant Extracts; Plant Leaves; Reactive Oxygen Species; Saponins; Sulfonic Acids; Superoxides; Tannins; Thiazoles

Many Bauhinia species, including those indigenous to South Africa, are used in traditional medicine across the world for treating ailments such as gastrointestinal tract (GIT) disorders, diabetes, infectious diseases and inflammation.. Several relevant aspects of different fractions of leaf extracts of Bauhinia bowkeri (BAB), Bauhinia galpinii (BAG), Bauhinia petersiana (BAP), and Bauhinia variegata (BAV) used in South African traditional medicine to alleviate diarrhoea related symptoms were evaluated.. The antioxidative activities of the extracts were determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS(+)) radical scavenging and ferric reducing antioxidant power (FRAP) methods. In vitro antimicrobial activities of the extracts were determined against bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis) and clinical isolates of the opportunistic fungal strains (Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans) using a serial dilution microplate method. The polyphenolic contents were quantified using standard methods, and anti-inflammatory activities of the crude extracts were determined using the cyclooxygenase and soybean 15-lipoxygenase enzyme inhibitory assays. The safety of the extracts was evaluated by determining the cytotoxicity against Vero cell lines.. The acidified 70% acetone crude extract and their fractions had good antiradical potency against the DPPH and ABTS radicals. The methanol soluble portions of the butanol fractions were more potent (EC(50) ranges from 0.64 ± 0.05 to 1.51 ± 0.07 and 0.88 ± 0.18 to 1.49 ± 0.09 μg/ml against DPPH and ABTS radical respectively) compared to the standard, trolox and ascorbic acid (EC(50) ranges from 1.47 ± 0.24 to 1.70 ± 0.27 μg/ml) for both DPPH and ABTS. The crude extracts contained variable quantities of phenolic content. The crude extracts and their fractions had weak to good antimicrobial activities, inhibiting the growth of the organisms at concentrations ranging from 39 to 2500 μg/ml. The BAG crude extract and its fractions were the most active against the fungi (MICs ranging from 39 to 625 μg/ml) while the BAB extract and its fractions were the least active with the MICs ranging between 39 and 2500 μg/ml. Aspergillus fumigatus was the least susceptible fungus while Cryptococcus neoformans was the most susceptible. The phenolic-rich crude extracts of BAB, BAG, and BAP had moderate to good dose-dependent cyclooxygenase-1 enzyme inhibitory activity with inhibitions between 22.8% and 71.4%. The extracts were however, inactive against cyclooxygenase-2. The extracts had some level of cytotoxicity towards Vero cell lines, reducing cell viability to less than 10% at concentrations more than 50 μg/ml.. The biological activities observed in Bauhinia species provide a scientific basis for the use of the plants in traditional medicines to treat diseases with multi-factorial pathogenesis such as diarrhoea, with each aspect of activity contributing to the ultimate therapeutic benefit of the plants. However, the use of the phenolic-rich extracts of these plants to treat diarrhoea or any other ailments in traditional medicine needs to be monitored closely because of potential toxic effects and selective inhibition of COX-1 with the associated GIT injury.

Topics: Animals; Anti-Infective Agents; Anti-Inflammatory Agents; Antioxidants; Bacteria; Bauhinia; Benzothiazoles; Biphenyl Compounds; Cell Survival; Chlorocebus aethiops; Diarrhea; Fungi; Medicine, Traditional; Microbial Sensitivity Tests; Phenols; Picrates; Plant Extracts; South Africa; Sulfonic Acids; Tannins; Vero Cells

The evaluation of the mutagenic and antimutagenic actions of extracts obtained from aerial part of Teucrium ramosissimum was assayed using the Salmonella typhimurium assay system. The effect of the same extracts on genotoxicity and SOS response induced by aflatoxin B(1) as well as nitrofurantoin was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. The different extracts showed no mutagenicity when tested with Salmonella typhimurium strains TA100, TA98 and TA1535 either with or without S9 mix. In contrast, our results prove that T. ramosissimum extracts possess antimutagenic effects against sodium azide, aflatoxin B1, benzo[a]pyrene and 4-nitro-o-phenylenediamine. Moreover, the T. ramosissimum tested extracts exhibited no genotoxicity either with or without the external S9 activation mixtures. However, all the extracts significantly decreased the genotoxicity induced by aflatoxin B(1) and nitrofurantoin. The result obtained by the Ames test confirms those of SOS chromotest. Antioxidant capacity of the tested extracts was evaluated using the enzymatic (xanthine/xanthine oxidase assay) and the non enzymatic (NBT/riboflavine, DPPH and ABTS assays) systems. All extracts exhibited high antioxidant activity except the chloroform and the methanol extracts in DPPH and NBT/riboflavine assays respectively. Our results underline the potential of T. ramosissimum to avoid mutations and also its antioxidant potential.

Topics: Affinity Labels; Antimutagenic Agents; Antioxidants; Bacteria; Benzothiazoles; Biphenyl Compounds; DNA Repair; Dose-Response Relationship, Drug; Flavonoids; Free Radical Scavengers; Microbial Sensitivity Tests; Mutagenicity Tests; Mutagens; Phenols; Picrates; Plant Extracts; Plant Leaves; Salmonella typhimurium; Sterols; Sulfonic Acids; Tannins; Teucrium; Thioinosine; Xanthine Oxidase

In this work, an evaluation of the biological activities of Globularia alypum L. extracts and their global chemical composition was realized. Extracts from G. alypum were obtained by two extraction methods. The composition of polyphenols (8.5-139.95 g gallic acid equivalent/Kg of dry mass), tannins (1.39-18.65 g catechin equivalent/Kg of dry mass), anthocyanins (8.17-70.69 mg cyanidin equivalent/Kg of dry mass) and flavonoids (0.31-19.28 g quercetin equivalent/Kg of dry mass) was evaluated. The samples were subjected to a screening for their antioxidant activities using the DPPH* and ABTS*+ assays. For the first time, the anti-tuberculosis activity (H(37)Rv) for G. alypum was tested against Mycobacterium tuberculosis. The strongest antioxidant activity was obtained for the methanol extract (IC(50 ) = 15.58 ± 0.168 mg/L) and the best anti-tuberculosis activity was obtained for the petroleum ether extract (IC(50 )= 77 mg/L). We have found a positive correlation between the total phenolics content and the antioxidant activity R2 = 0.88 (DPPH*) and R2 = 0.97 (ABTS*+). We have found also a positive correlation between the flavonoid content and the antioxidant activity R2 = 0.91 (DPPH*) and R2 = 0.91 (ABTS*+).

Topics: Anthocyanins; Antioxidants; Antitubercular Agents; Benzothiazoles; Biphenyl Compounds; Flavonoids; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Picrates; Plant Extracts; Plant Leaves; Scrophulariaceae; Sulfonic Acids; Tannins

In our work, we evaluate the potential antioxidant, antimalarial activity and also activity against human breast cancer cells (MCF7) of Argan fruit extracts using in vitro models to validate the traditional use of this plant. Its chemical composition was also studied to begin the understanding of its activities, waiting to find the structure-activity relationship.. Polyphenols (89.4-218.5 eqGallic acid (mg/g dry)), tannins (39.3-214.0 eqCatechin (mg/g dry)), flavonoids (3.4-11.1 eqQuercetin (mg/g dry)) and anthocyanins (0.74-10.92 eqCyanindin (mug/g dry)) were quantified. A good (ethyl acetate and decoction) and moderate (petroleum ether) antioxidant activity were obtained for DPPH (IC(50) 32.3-600.8 microg/ml) and ABTS (IC(50) 11.9-988.8 microg/ml) assays. In addition, we found a good antimalarial activity (IC(50) 35 to >100 microg/ml) and human breast cancer cells activity (IC(50) 42 to >100 microg/ml).. The ethyl acetate extract and the decoction show interesting antimalarial and antioxidant activities. The results indicate a good correlations between anthocyanins quantitiy and the potential antioxidant (R(2)=0.9867) and also to antimalarial activity (R(2)=0.8175).

Topics: Antimalarials; Antineoplastic Agents, Phytogenic; Antioxidants; Benzothiazoles; Biphenyl Compounds; Breast Neoplasms; Cell Line, Tumor; Female; Flavonoids; Fruit; Humans; Inhibitory Concentration 50; Phenols; Phytotherapy; Picrates; Plant Extracts; Plasmodium falciparum; Sapotaceae; Sulfonic Acids; Tannins

Ethanolic extracts of 30 Thai medicinal plants, traditionally used as alternative treatments in diabetes, were evaluated for antioxidative activity by the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) method. They were evaluated in vitro for oxidative stress by thiobarbituric acid-reactive substance (TBARS) assay in pooled plasma of diabetic patients compared to without treatment of the extracts (control). The extracts were also assayed for protein glycation. The results showed that five plants had strong antioxidant activity: Phyllanthus emblica Linn. (PE), Terminalia chebula Retz. (TC), Morinda citrifolia Linn. (MC), Kaempferia parviflora Wall. (KP) and Houttuynia cordata Thunb.(HC), respectively. Thirty plant extracts were good correlation between total antioxidant activity and antiradical activity by TBARS as well as by glycation (r = 0.856, p<0.01 and r = 0.810, p<0.01). PE had stronger antioxidative activity as well as inhibition of TBARS and glycation than the other plants. The investigation showed that total polyphenol and tannin content of PE and the flavonoid content of HC were the highest. The results imply that these plants are potential sources of natural antioxidants which have free radical scavenging activity and might be used for reducing oxidative stress in diabetes.

Topics: Antioxidants; Benzothiazoles; Caffeic Acids; Catechin; Diabetes Mellitus, Type 2; Flavonoids; Free Radicals; Gallic Acid; Glycation End Products, Advanced; Humans; Lipid Peroxidation; Medicine, Traditional; Molecular Structure; Oxidative Stress; Phenols; Plant Extracts; Plants, Medicinal; Polyphenols; Pyrogallol; Rutin; Sulfonic Acids; Tannins; Thailand; Thiobarbituric Acid Reactive Substances

The aim of this study was to assess the influence of 9 winemaking technologies (traditional, delestage, saignée, delayed punching-down, addition of grape seed tannins, addition of ellagic-skin-seed tannins, heating of must-wine, cryo-maceration, and prolonged maceration) on the phenolic content and antioxidant activity of Primitivo musts and wines. Three methods for the determination of the antioxidant activity were compared: DPPH, beta-carotene bleaching assay, and ABTS. Oenological parameters and composition of the phenolic fraction of 1-y-aged wines was also determined. The addition of tannins allowed the increase of the phenolic content of musts and wines in a greater amount than the other technologies. The results concerning the antioxidant activity depended on the method applied. Concerning musts, the DPPH assay did not highlight great differences among technologies, whereas the addition of tannins allowed the obtainment of the highest antioxidant activity according to beta-carotene and ABTS assays. The wine aging determined an increase of the antioxidant activity, independently on the method applied. Wine obtained through traditional technology, saignée, and addition of tannins showed the highest antioxidant activities according to DPPH and beta-carotene. The highest correlation coefficients (0.961 and 0.932) were calculated between phenolic content and ABTS values of musts whereas the lowest values (0.413 and 0.517) were calculated between phenolic content and ABTS values of wines. Wines produced through traditional technology were the richest in anthocyanins. The addition of tannins allowed to obtain high content in monomeric anthocyanins, flavonoids, flavans reactive to vanillin, and coumaroylated malvidin and a low content in acetylated malvidin. Practical Applications: It is well known that a moderate consumption (equivalent to 2 glasses per day) of red wine is actually recommended since it appears associated with a decreased incidence of cardiovascular diseases. The mechanisms involved in this protective effect are not completely understood although they appear related to the presence of phenolic compounds. To increase the intake of these compounds without increase of the wine consumption, it is necessary to improve their extraction during maceration. This study could represent a helpful tool for wineries aimed to know the way to increase the antioxidant content of their wines, thus changing them in functional beverages and prolonging their s

Topics: Anthocyanins; Antioxidants; Benzothiazoles; beta Carotene; Biphenyl Compounds; Flavonoids; Food Handling; Food Technology; Phenols; Picrates; Seeds; Sulfonic Acids; Tannins; Vitis; Wine

The EtOAc-soluble fraction from a methanolic extract of Hovenia dulcis Thunb. exhibited neuroprotective activity against glutamate-induced neurotoxicity in mouse hippocampal HT22 cells. The neuroprotective activity-guided isolation resulted in 8 phenolic compounds (1-8), such as vanillic acid (1), ferulic acid (2), 3,5-dihydroxystilbene (3), (+)-aromadendrin (4), methyl vanillate (5), (-)-catechin (6), 2,3,4-trihydrobenzoic acid (7), and (+)-afzelechin (8). Among these, compounds 6 and 8 had a neuroprotective effect on the glutamate-induced neurotoxicity in HT22 cells. Furthermore, compound 6 had a DPPH free radical scavenging effect with an IC50 value of 57.7 microM, and a superoxide anion radical scavenging effect with an IC50 value of 8.0 microM. Both compounds 6 and 8 had ABTS cation radical scavenging effects with IC50 values of 7.8 microM and 23.7 microM, respectively. These results suggest that compounds 6 and 8 could be neuroprotectants owing to their free radical scavenging activities.

Topics: Animals; Benzopyrans; Benzothiazoles; Biphenyl Compounds; Catechin; Cell Line; Flavonoids; Free Radical Scavengers; Glutamic Acid; Inhibitory Concentration 50; Mice; Neurons; Neuroprotective Agents; Phenols; Picrates; Plant Bark; Plant Extracts; Plants, Medicinal; Rhamnaceae; Sulfonic Acids; Superoxides; Tannins