Antioxidant activity

Methanolic extracts of 4 Indian medicinal plants, traditionally used in different ailments, were evaluated for antioxidant activity using DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging assay. Among the extracts, C. lanceolatus significantly decreased the absorption at 10 µg/ml indicating that it is effective even at a very low concentration.

Synthesis of phenyl (5-substituted phenyl-1,3,4-thiadiazol-2-yl) methanediamine (TDZ-A to TDZ-C), reaction between aryl aldehydes and Thiosemicarbazide yielded thiosemicarbazone. Thiosemicarbazone in the presence of citric acid and sodium acetate gives 2-amino-5-aryl -1,3,4-thiadiazole, which is treated with aniline in the presence of formaldehyde to obtained targeted compounds phenyl(5-substituted phenyl-1,3,4-thiadiazol-2-yl)methanediamine. The synthesized Thiadiazoles have been characterized on the basis of analytical spectral data. The resulted compounds were screened for their antibacterial, antifungal and antioxidant activities.

The objectives of this study was to examine the antioxidant activities of aqueous extracts of bark of Psidium guajava bellowing to family Myrtaceae, which is originated in Mexico and extends all over the South America, Europe, Africa and Asia. The Psidium guajava is used traditionally  for the treatment of various ailments like  antioxidant, hepatoprotective, anti-allergy, antimicrobial, antigenotoxic, antiplasmodial, cytotoxic, antispasmodic, cardioactive, anticough, antidiabetic, anti-inflammatory and antinociceptive activities. For the antioxidant activity of aqueous extract of bark of Psidium guajava Linn, In-vitro and In-vivo methods are used. In-vitro assessment of the ability of the extract to scavenge the Hydrogen peroxide (H2O2) was determined with reference to the synthetic antioxidant vitamin C and ascorbic acid was used as standard antioxidants. The scavenging activity of plant extract on hydrogen peroxide was found similar as scavenging activity of vitamin C. The Psidium guajava showed the strong In-vitro antioxidant activity and exhibited over 86.01% inhibition at 12 µg/ml concentration. For In-vivo antioxidant activity catalase (CAT) enzyme level was used. CAT levels were measured in fresh liver tissue using ELISA. CAT in hepatic tissue compared to control group. CAT enzymes were significantly increased when treated with aqueous extract of bark of Psidium guajava. In human beings, the highest levels of CAT are found in the liver, kidney and erythrocytes, where it is believed to account for the majority of H2O2 decomposition. These results show that the Psidium guajava could be considered as a natural antioxidant source.

A straight forward method has been developed for the synthesis of novel heterocycles such as benzo[4,5]thiazolo[3ˈ,2ˈ:1,2]pyrimido[4,5-d][1,3]thiazine derivatives (5a-i) by condensation of 6-imino-4-(methylthio)-2-phenyl-6H-1,3-thiazine-5-carbonitrile (3) with 2-amino 1/2/3/4-substituted benzothiazoles (4a-i) in DMF by using anhydrous potassium carbonate as catalyst. Compound (3) was prepared by reaction of benzothioamide (1) and bis(methylthio)methylene malononitrile (2) with same reaction condition which is used for title compounds. The chemical structures of newly constructed derivatives were corroborated by IR, 1H-NMR 13C-NMR and Mass spectral analysis. Synthesized compounds were screened for antimicrobial as well as antioxidant activity.

The present study was designed to investigate the antioxidant and gastro-protective potential of Cow urine betel vine extract. Antioxidant and gastro-protective activity was evaluated by using ethanol induced ulcer model; the animals were fed with Cow urine betel vine extract at the dose of 250 and 500mg/kg b.w orally for a period of 14 days. The pretreated extract reduced the gastric ulcers in a dose dependent manner which was determined by measuring the ulcer index and with marked attenuation in the levels of oxidative stress enzymes like SOD, LPO and CAT. Also Cow urine betel vine  increased the gastric mucous content in the selected ulcer model.

The aim of present study was to evaluate the antioxidant activities of four different solvent extracts of four wild leafy vegetables e.g. Solanum nigrum  Phytolacca esculenta, Piper pedicellatum and Pouzolzia hirta  and fruits of Melodinus khasianus collected from Arunachal Pradesh  state in India. The extracts of the plants were examined for their antioxidant activities by using free radical 1,1-diphenyl-2-picryl hydrazyl (DPPH) scavenging method, ABTS radical scavenging ability, reducing power capacity, estimation of total phenolic content, flavonoid content and flavonol content.. The result showed that the total phenolics, flavonoids and flavonols of the different extracts of the investigated samples ranged from 7.49 ±3.55 - 305.38 ±2.78 mg gallic acid equivalents (GAE)/g dry extract, 4.13±0.02 - 171.01±0.99 mg rutin equivalent /g dry extract and 18.90±0.15 to 326.21±1.84 mg quercetin equivalent /g dry extract respectively. Furthermore the plant extracts exhibited good free radical scavenging capacity. The solvent used to extract the active constituents from plants were benzene, chloroform, acetone and methanol. The different levels of antioxidant activities were found in the solvent systems used. The results indicate that these wild edible vegetables could be utilized as natural antioxidant.

This study reports the antioxidant potential and chemical composition of muscle from 30 fish species of different feeding habits namely carnivore, herbivore and omnivore.Different in vitro assays used for determining antioxidant potential of extracts of fish species were: thin layer chromatography (TLC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity. No significant difference of antioxidant activity or nutrient content was observed among carnivorous, herbivorous and omnivorous fishes. The IC50 measured by DPPH method varied from 154 to 2139 µg/ml of wet weight. The lowest IC50 value was observed in C. idellafollowed by P.ticto, C. striatus, C. punctatus, L. rohita, A. testudineus, M. cordyla, O. mossambicus and G. giuris. Themoisture content of samples ranged from 62 - 85%. The protein content washigh in C. idella (24.3%) and low in L. calbasu (10.57 %). The lipid and ash content analyzed in the selected fish species ranged from 1.17-7.94% and 1.31-4.80%, respectively. Overall, the results suggestthat fish of different feeding habit can be exploited for their antioxidant and nutrients components and used for consumption as well as value addition in food formulations.

Sterculia foetida L. seed protein flour (SSPF) was produced by dehulling, defatting, drying, grinding, passing through mesh sieve 240 µ and evaluated its physico- chemical characteristics. The antioxidant activity increases with increasing in concentration of the SSPF. The total polyphenol content was determined by the Folin-Ciocalteu reagent. Amino acid composition by using Biochrom automatic amino acid analyzer and they were detected after post column derivatization with Ninhydrin reagent. The antioxidant activity was determined by DPPH and ferric reducing power methods and storage stability by sorption isotherm method. SSPF was possessed higher contents of protein (40.10%), calcium (58 mg) and phosphorus (1138 mg/100 g). Glutamic acid, arginine, aspartic acid, leucine, lysine, valine and phenylalanine are the major amino acids. The ratio of essential to nonessential amino acids was 0.45. All essential amino acids were higher than the reported amounts for 70 kg person (100 ± 5g SSPF) as per FAO/WHO/UNU requirements. The seed protein flour was rich in polyphenols, which showed considerable antioxidant activity. SDS-PAGE showed nine protein bands, in which five kDa proteins are matching with molecular marker. The antioxidant activity increases with increasing in concentration of the SSPF. The sorption isotherm studies indicated that the SSPF was non-hygroscopic in nature.

The aerial parts of plant contain a number of medicinally important compounds. The present study was carried out to extract the flavonoid rich fraction from the aerial parts of Hemidesmus indicus Linn. R. Br. and identified the phytochemicals presents in the flavonoid rich fraction of aerial parts of Hemidesmus indicus Linn. R. Br. & determined the total flavonoid contents and antioxidant potential of obtained favonoid rich fraction of Hemidesmus indicus Linn. R. Br. Total flavonoid content was estimated by Aluminium Chloride colorimetric method and the flavonoid content was 0.406 % TFC (Total Flavonoids Contents) in grams of Quercetin equivalent. Antioxidant activity was evaluated by DPPH method and IC50 value of flavonoid rich fraction of aerial parts of Hemidesmus indicus Linn. was found to be 21.39 µg/ml. Key words: Total flavonoids, Aluminium chloride, Antioxidant activity, DPPH, IC50 value.

Asparagus racemosus and Centella asiatica are two very common and well known medicinal plant available in India. Both the plants are traditionally used as antiamoebic drugs. Not only are those, both the drugs used as the herbal treatment of several diseases of human beings. In between them some are really critical disease. Several important phytoconstituents have been already isolated and characterized from both the plants and in between them some are the major active marker for the treatment of above said critical diseases. Instead of all those characters, these two plants have very potent antioxidant property. Here, we have taken an attempt to prepare a formulation of the mixture (50:50) of the aqueous extracts of both the plants and compare the antioxidant property of that formulation and extracts. In this study calcium chloride cross linked alginate microsphere and chitosan coated microsphere have been prepared by using the above said plant extracts and the anti-oxidant property of those formulations were compared with the extracts and also standard drugs. The result therefore reflects that the antioxidant potency of the combined extract entrapped in formulations was almost equivalent to the original extract combinations. This entails despite of the different process control stresses in the manufacturing steps the potency of the polymer entrapped drug substances does not changed. So researchers may look forward in further purification of the extract and then an effective drug loading to get an equivalent potent action from the same quantity of a standard antioxidant.