Pharmacognostical Standardization, Phytochemical Analysis and In-vitro Antioxidant Activity of rhizome of Polygonum alpinum All.

Abstract

The present study was designed to evaluate the pharmacognostic characters, physicochemical parameters and in-vitro antioxidant activity of rhizome of Polygonum alpinum . The powder microscopy revealed the presence of epidermis, hypodermis with calcium oxalate crystals, non lignified vascular bundle, calcium oxalate crystals, cork in surface view and fragments of bordered pitted vessels. Phytochemical screening of various extracts revealed the presence of carbohydrates, cardiac glycosides, coumarin, steroids, terpenoids, flavonoids, saponins and tannins. Physiochemical analysis showed 2.325% of total ash, 0.525% of water soluble ash, 0.650% of acid insoluble ash and 3.625% of sulphated ash w/w . Other parameters like extractive value, foreign matter, moisture content, swelling index, foaming index, pH of different solvents, total tannin content, total fat content and fluorescence analysis were also determined. The total phenolics in alcoholic and aqueous extract was found to be 41.06 and 23.30 mg/g GAE respectively while that of flavonoid content in alcoholic and aqueous extract was 182.13 and 123.71 mg/g RE respectively. The percentage inhibition of DPPH by alcoholic and aqueous extract at a concentration of 100 ?g/mL was found to be 96.50% and 49.44% respectively. The reducing power of alcoholic and aqueous extract at 100 ?g/mL was found to be 0.295 and 0.175 respectively and increased to 0.765 and 0.596 respectively at 500 ?g/mL. The results indicate that alcoholic extract has potent antioxidant activity as compared to the aqueous extract.