Determination of polyphenolic content and antioxidant activity from various extracts of boerhaavia diffusa linn root: An in vitro approach for selection of appropriate extracting solvent

Abstract

Objective: This study is aimed to evaluate extraction capacity of different solvents (toluene, dichloromethane, chloroform, ethyl acetate, ethanol, methanol, water, 60% aqueous methanol, 60% aqueous ethanol and 60% aqueous acetone) and its effect on total phenolic content, total flavonoid content, and antioxidant assay. Methods: Extraction was performed from dried root powder of Boerhavia diffusa using various solvents at 25C on magnetic sirr (300 rpm). Extraction yield, total phenolic content, total flavonoid content and total tannin content of the extracts were determined spectrophotometrically using gallic acid, quercetin as standards. Antioxidant potential determines by using various in vitro methodologies such as DPPH, FRAP, and ABTS assay. Result: The 60% aqueous methanol showed the highest extracting yield, in contrast, toluene and hexane showed the lowest yield. Highest total phenolic content (239.8±0.25 mg GAE/g) and total flavonoid content (131.1±4.20 mg QCE/g), were found from methanolic extract. While, acetone extract showed highest tannin content. The Methanolic extract of Boerhaavia diffusa exhibited the highest antioxidant activity. Conclusions: The highest correlation was found between phenolic content and the antioxidant assay. It seems that phenolic contents are responsible for free radicle scavenging activity. From the observation, it concluded that methanolic extract rich with polyphenolic content and acetone extract showed the highest amount of tannin content.