Alpinia officinarum is a rhizome belonging to the family zingeberaeceae. Hydro alcoholic extract by hot and cold maceration and methanol extract by percolation process Qualitative phytochemical analysis of extract of Alpinia officinarum rhizome showed a majority of the compound including tannins, alkaloids, flavonoids and saponins. Hydroalcoholic extract prepared by hot maceration process was found to contain more phenol and flavonol and it was measured as 50.1 mg/g and 54.02 mg/g, respectively. All the three extracts showed moderate to potent antimicrobial activity against the Bacillus cereus, Staphylococcus aureas, Pseudomonas auroginosa, Escherichia coli. None of the extracts showed antifungal activity against Aspergillus niger and Candida albicans. All the three extracts showed a concentration dependent radical scavenging activity by inhibiting diphenylpicrylhydrazyl free radical at the same time hydroalcoholic extract prepared by hot maceration process showed better reducing and total antioxidant activity.

Aim of this paper is to find out the relationship between antioxidant activity of Abutilon indicum Linn and their phytochemical composition especially phenols and flavonols. Successive extractions were carried out for the Abutilon indicum plant with petroleum ether, chloroform, ethyl acetate, n-butanol, ethanol and water. All these extracts were evaluated for their antioxidant activities. Their antioxidant activities were correlated with their total phenol and flavonol content present in the plant. Ethyl acetate showed maximum free radical scavenging activity. IC50 value for various antioxidant methods for all extract showed no significance with total antioxidant capacity except IC50 value of LPO (r2 = 0.7273). Correlation between total antioxidant capacity and total phenolic content was not significant with r2 = 0.2554, P<0.3065. Total antioxidant capacity and total flavonol content showed similar correlation with r2 = 0.2554, P<0.0962.

During the process of screening for a potent antimicrobial compound, a new strain was isolated from the soil sample of Thalaikunda village in Ooty, Tamil Nadu. That organism was name as NK2. It was found to be antagonistic to both bacterial and fungal test organisms. Production of antibiotic was more in a newly formulated broth. Antibiotic production reached maximum at the end of the 70 h of fermentation by stirred flask culture. The antimicrobial compound was extracted in n-butanol, ethyl acetate and methanol. Antimicrobial compound, which was produced by the soil isolate NK2 did not showed cytotoxic activity on Vero cell lines.

Objective: Now the important field of research in phytomedicine is to search a new plant source as well as new phytoconstituents that have fewer side effects and low cost with the free radical scavenging activity. Methods:Different in vitro models such as DPPH, hydroxyl radical, hydrogen peroxide radical, nitric oxide radical and superoxide radical scavenging activity were performed using different concentrations of formononetin ranging from 0.1-50 μg/ml.Results: Formononetin showed only 84.39% inhibitory activity against DPPH radical and it was found to be 16 % less than the butylated hydroxytoluene with the IC 50 value of 4.65 μg/ml concentration. In scavenging hydroxyl radicals, formononetin inhibited only 67.63% with the IC50 value of 9.48 μg/ml concentration and it showed 12 % lesser inhibitory activity than standard alpha-tocopherol. Formononetin could able to scavenge maximum 73.53% of hydrogen peroxide radicals with the IC50 value of 4.75 μg/ml and its activity of scavenging hydrogen peroxide were found to be 10 % less than the standard ascorbic acid. Formononetin showed 94.33 % nitric oxide radical inhibitory activity with the IC50 value of 5.0 μg/ml and it showed 6% lesser activity when compared to standard quercetin. Formononetin showed 94.79 % activity against the scavenging of superoxide radical with the IC50 Conclusion: All these results suggested that, formononetin is a good natural antioxidant which is capable of scavenging almost all types of free radicals. So this could be used to treat various diseases like diabetes, atherosclerosis, cancers, the aging and cardiovascular disease which is being caused by free radicals.value of 4.27 μg/ml. Superoxide inhibitory activity of formononetin was 5.3 %less than the standard quercetin.

Leaves of Gymnema sylvestre were extracted by hot and cold maceration.  Qualitative phytochemical analysis of the plant extract showed the presence of majority of compounds like alkaloids, carbohydrates, flavonoids, terpienoids, glycosides, proteins, amino acids, phenolic compounds and tannins..  Among the two extracts, the            hydro- alcoholic extract prepared by the hot maceration has shown high phenol content 6.51 ± 0.231 mg/g, high total favonolid content 89.51 ± 0.100 mg/g. By DPPH method, total antioxidant capacity, reducing power ability of the               hydro-alcoholic extract prepared by hot maceration process was evaluated. The freshly prepared rat hepatocytes were treated with different concentration of hydro-alcoholic extract prepared by the hot maceration process. The antihepatotoxicity produced by the extract at the concentration of 200, 400,600 µg/ml was found effective against the          D – galactosamine-induced hepatotoxicity, where as at the concentration of 800 µg/ml was found to be cytotoxic. A significant increase in the levels of ASAT, ALAT,ALP, total bilirubin, direct bilirubin ( P< 0.001) were observed. The cells were treated with  the hydro-alcoholic extract different extracts of Gymnema sylvestre showed a significant restoration of the altered biochemical parameters towards the normal (P<0.001) when compared to D- galactosamine treated groups and were found to be  dose  dependent.  A similar result was obtained when D- galactosamine intoxicated hepatocytes were treated with silymarin.