Comparative Study on Antimicrobial Activity of Vitex negundo var. negundo and Vitex negundo var. purpurascens

Abstract

The present study was conducted with an aim of determining antimicrobial activity of Vitex negundo var. negundo (Vnvn) and Vitex negundo var. purpurascens (Vnvp).The powdered leaf materials of both varieties were extracted using methanol in soxhlet assembly. The content of total phenolics and flavonoids were estimated by Folin-Ciocalteau reagent and Aluminium chloride colorimetric estimation method respectively. Antibacterial activity of extracts was determined against five drug resistant urinary tract pathogens by agar well diffusion assay. Poisoned food technique was performed to determine antifungal effect of extracts. The extracts caused concentration dependent inhibition of urinary tract isolates. Marked antibacterial effect was shown by extract of Vnvp. Among bacteria, Staphylococcus aureus and Klebsiella pneumoniae were inhibited to high and least extent respectively by extracts. The extracts were effective in inhibiting test fungi as revealed by reduction in mycelial growth in plates poisoned with extracts. Here also, high inhibitory activity was observed in case of extract of Vnvp. Among fungi, Helminthosporium sp., Alternaria sp., and C. capsici displayed similar susceptibility to both extracts at concentration 1mg/ml. Aspergillus flavus was inhibited to least extent by extracts. Phytoconstituents viz., tannins, alkaloids, flavonoids, saponins, steroids and glycosides were detected in extract of both Vnvn and Vnvp. The total phenolic and flavonoid contents were high in extract of Vnvp. The extracts were effective against bacteria and fungi. The presence of high phenolic and flavonoid content could be ascribed to the marked inhibitory activities of the extract of Vnvp.