Evaluation of antioxidant and antimicrobial activities on various extracts of Himalayan medicinal plants

The DPPH radical scavenging potentials of the fractions were determined in comparison to positive controls such as quercetin with EC₅₀ = 4.12±1.27, ascorbic acid with EC₅₀ = 6.20±1.67, gallic acid with EC₅₀ = 4.75±1.24 and α-tocopherol with EC₅₀ = 32.50±1.57 μg/mL. The experiment showed that aqueous fractions of the bark extracts of Abies pindrow (fraction: C₂) and Cedrus deodara (fraction: E2) showed significantly lower EC₅₀ values of 2.5±0.5 and 2.5±0.6 μg/mL, respectively. In reducing power assay, lower EC₅₀ values of 5.5 and 4.5μg/mL were recorded for the aqueous fraction (fraction: C ₂) and final residue (fraction: C₅), of Abies pindrow, respectively. The ethyl acetate, acetone and final fractions of knot wood of Picea smithiana were found significantly active against all bacterial strains. Of the most sensitive fractions towards all the fungal strains was ethyl acetate fraction obtained from the bark of Cedrus deodara with a zone of inhibition ranging from 75 to 88 % that was more than the standard fluconazole.