1-1-diphenyl-2-picrylhydrazyl and thiobarbituric-acid

In this study, the efficiency of the different nitrogen doses (0, 5, 10, 15 and 20 kg ha-1) on biological activity levels (antioxidant and antimicrobial activity) of Stevia rebaudiana Bert. was investigated. In addition, methanol extracts were obtained by maceration method from different doses of fertilizer applied stevia. The components in methanol extracts of plants were determined by gas chromatography-mass spectrometry (GC-MS) method. Antimicrobial activities of stevia extracts were investigated by microdilution method. The antioxidant activity evaluated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric thiocyanate (FTC), thiobarbituric acid (TBA), reducing power, total phenol content (TPC), and total flavonoid content (TFC) methods. According to the results, the fertilizer doses effects on antimicrobial activity of stevia were not made much difference. But in antioxidant activity, there were some variations in the activity-dependent on fertilizer amount.

Topics: Anti-Infective Agents; Antioxidants; Benzene Derivatives; Biphenyl Compounds; Dose-Response Relationship, Drug; Fertilizers; Flavonoids; Iron; Methanol; Nitrates; Picrates; Plant Extracts; Plant Leaves; Stevia; Thiobarbiturates; Thiocyanates

Spices and their bioactive components are more promising attractions for their inclusion in diet-based regimes to improve human health. These are sources of natural antioxidants and play an important role in the chemoprevention of diseases and aging. The aim of the current study was to explore the antioxidant potential of cinnamon; a widely used spice throughout the world.. The current research was aimed to investigate the antioxidant potential of cinnamon extract. For the purpose, cinnamon sticks were procured from local super market, while palm oil was obtained from local oil industry. The resultant extract was analyzed for its antioxidant activity through total phenolic content (TPC), free radical scavenging activity (DPPH assay), and total antioxidant activity was measured by ferric reducing antioxidant power (FRAP) test. The shelf life of palm oil was checked by adding cinnamon extract in oil at different levels. From the present study, it can be concluded that the cinnamon extract proved effective in reducing the lipid oxidation of palm oil and it can be successfully used in place of synthetic antioxidants in food preparations.

Topics: Antioxidants; Biphenyl Compounds; Cinnamomum zeylanicum; Drug Stability; Fatty Acids, Nonesterified; Humans; Lipid Peroxidation; Palm Oil; Phenols; Picrates; Plant Bark; Plant Extracts; Thiobarbiturates

In the last decade a large amount of research has been directed at targeting algal resources for biologically active molecules. High-throughput in vitro antioxidant assays are routinely used to screen for biologically active compounds present in algal extracts when the requirement is to identify samples for progression to more detailed biological scrutiny. Whilst a myriad of antioxidant assays have been developed, this present chapter aims to give step-by-step practical guidance on how to carry out some of the most popular and biologically relevant assays at the bench.

Topics: Antioxidants; Benzothiazoles; Biphenyl Compounds; Carotenoids; Fluorometry; Free Radicals; High-Throughput Screening Assays; Hypochlorous Acid; Iron; Phenols; Picrates; Seaweed; Sulfonic Acids; Thiobarbiturates; Thiocyanates

The inflorescence of cultivated Coptis chinensis has been valued for tea production for many years in China. The antioxidant activities of C. chinensis inflorescence extracts prepared by various solvents were investigated by using several established in vitro systems: 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS), α,α-diphenyl-β-picrylhydrazyl (DPPH) and superoxide radical scavenging assays, reducing power assay, and ferrothiocyanate (FTC) and thiobarbituric acid (TBA) assays. The results showed that the 70% ethanol extract (EE) had the strongest antioxidant activity in vitro among the various extracts. Based on the in vitro results, EE was used to evaluate the antioxidant activity of C. chinensis inflorescence in vivo. The liver and kidney of intoxicated animals showed a significant decrease in superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels, while the malondialdehyde (MDA) level showed a significant increase. These changes were significantly reversed after treatment with EE and the standard vitamin E. Thus, the C. chinensis inflorescence may be a valuable natural source that can be applicable to food industries.

Topics: Animals; Antioxidants; Benzothiazoles; Biphenyl Compounds; Catalase; China; Coptis; Drug Evaluation, Preclinical; Ethanol; Free Radical Scavengers; Glutathione; Inflorescence; Kidney; Liver; Male; Malondialdehyde; Mice; Picrates; Plant Extracts; Sulfonic Acids; Superoxide Dismutase; Thiobarbiturates; Vitamin E

The object of the present study was to investigate the in vitro antioxidant properties and cholinesterase inhibitory activity of Salvia leriifolia Benth extracts and fractions. The functional role of herbs and spices and their constituents is a hot topic in food-related plant research. Salvia species have been used since ancient times in folk medicine for cognitive brain function and have been subjected to extensive research. Thus, we hypothesize that S leriifolia, because of its functional properties, would be a good candidate to use as a nutraceutical product for improving memory in the elderly or patients affected by Alzheimer disease (ad). To test this hypothesis, we examined the cholinesterase inhibitory activity using the modified colorimetric Ellman's method against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The n-hexane exhibited the highest activity, with inhibitory concentration 50% (IC(50)) values of 0.59 and 0.21 mg/mL, for AChE and BChE, respectively. This extract was fractionated, and 9 of these fractions (A-I) were obtained and tested. Fraction G, characterized by the presence of sesquiterpenes as major components, was the most active against AChE (IC(50) = 0.05 mg/mL). Because oxidative stress is a critical event in the pathogenesis of AD, we decided to screen the antioxidant activity (AA) using 2,2-diphenyl-1-picrylhydrazyl test, β-carotene bleaching test, and bovine brain peroxidation (thiobarbituric acid) assay. The ethyl acetate extract showed the highest activity, with IC(50) values of 2 and 33 μg/mL on β-carotene bleaching test and thiobarbituric acid test, respectively. These results suggest potential health benefits of S leriifolia extracts. However, this finding requires additional investigation in vivo.

Topics: Antioxidants; beta Carotene; Biphenyl Compounds; Cholinesterase Inhibitors; Colorimetry; Picrates; Plant Components, Aerial; Plant Extracts; Salvia; Sesquiterpenes; Thiobarbiturates

Free radicals induce numerous diseases by lipid peroxidation, protein peroxidation, and DNA damage. It has been reported that numerous plant extracts have antioxidant activities to scavenge free radicals. Whether Polygonum aviculare L. (Polygonaceae) has antioxidant activity is unknown. In this study, dried Polygonum aviculare L. was extracted by ethanol, and the extract was lyophilized. The antioxidant activities of extract powder were examined by free radical scavenging assays, superoxide radical scavenging assays, lipid peroxidation assays and hydroxyl radical-induced DNA strand scission assays. The results show that the IC50 value of Polygonum aviculare L. extract is 50 microg/ml in free radical scavenging assays, 0.8 microg/ml in superoxide radical scavenging assays, and 15 microg/ml in lipid peroxidation assays, respectively. Furthermore, Polygonum aviculare L. extract has DNA protective effect in hydroxyl radical-induced DNA strand scission assays. The total phenolics and flavonoid content of extract is 677.4 +/- 62.7 microg/g and 112.7 +/- 13 microg/g. The results indicate that Polygonum aviculare L. extract clearly has antioxidant effects.

Topics: Animals; Antioxidants; Biphenyl Compounds; DNA Damage; Flavonoids; Free Radical Scavengers; Hydroxybenzoates; Inhibitory Concentration 50; Lipid Peroxidation; Male; Mice; Mice, Inbred BALB C; Nitroblue Tetrazolium; Picrates; Plant Extracts; Polygonum; Thiobarbiturates

Methanolic extracts of Viscum album ssp. album (mistletoe) grown on different host trees were investigated for their potential antioxidant activity. Scavenging activity was tested by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and the inhibitory effect on lipid peroxidation was examined by ferric thiocyanate and thiobarbituric acid methods. The extract from mistletoe grown on lime tree in summer showed the highest activity. It was found that antioxidant capacity of the plant differed according to the harvesting time as well as the host tree.

Topics: Antioxidants; Biphenyl Compounds; Free Radical Scavengers; Humans; Iron; Lipid Peroxidation; Phytotherapy; Picrates; Plant Extracts; Plant Leaves; Thiobarbiturates; Thiocyanates; Viscum album

This study examined the antioxidant and anticancer activities of the petroleum ether extracts from the roots of Platycodon grandiflorum A. DC, which is a plant used as both a herbal medicine and food in Asia. Extracts from Platycodon grandiflorum in petroleum ether were fractionated (fractions I-V) by silica gel column chromatography using gradient solvents (petroleum ether: ethyl ether, 9:1-5:5, v/v). The antioxidant activities of the fractions were evaluated in terms of their inhibition of lipid peroxidation as well as their free radical scavenging activity. Fraction II, which was extracted at an 8:2 mixture of petroleum ether and ethyl ether, exhibited the greatest antioxidant activity among the fractions. On the other hand, the cytotoxicity of each fraction, which was evaluated by the MTT assay using human cancer cell lines (HT-29, HRT-18 and HepG2), was greatest in fraction III, which was extracted with a 7:3 petroleum ether and ethyl ether mixture. Both fractions, II and III, were sub-fractionated by thin layer chromatography, and the sub-fractions each were screened for their antioxidant and anticancer activities. In addition, the antioxidant activity was closely related to the content of phenolic compounds, and the anticancer active fraction exhibited a typical UV absorbance spectrum of polyacetylene.

Topics: Antineoplastic Agents, Phytogenic; Antioxidants; Biphenyl Compounds; Cell Line, Tumor; Free Radical Scavengers; Humans; Iron; Lipid Peroxidation; Phytotherapy; Picrates; Plant Extracts; Plant Roots; Platycodon; Thiobarbiturates; Thiocyanates

The in vitro antioxidant properties of some flavone-6(4)-carboxaldehyde oxime ether derivatives (Ia-f, IIa-f) were determined by their effects on the rat liver microsomal NADPH-dependent lipid peroxidation (LP) levels by measuring the formation of 2-thiobarbituric acid reactive substances. The free radical scavenging properties of the compounds were also examined in vitro by determining their capacity to scavenge superoxide anions and interact with the stable free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH). The most active compounds, IIb (Flavone-4'-carboxaldehyde-O-ethyl oxime) and Id (Flavone-6-carboxaldehyde-O-[2-(1-pyrolidino) ethyl] oxime), caused 98 and 79% inhibition of superoxide anion production and DPPH stable free radical at 10(-3) M, respectively.

Topics: Animals; Antioxidants; Biphenyl Compounds; Flavones; Free Radical Scavengers; Free Radicals; In Vitro Techniques; Lipid Peroxidation; Male; Microsomes, Liver; Picrates; Rats; Rats, Wistar; Structure-Activity Relationship; Superoxides; Thiobarbiturates