Antibacterial activity of selected plants extract against pathogenic bacteria and detection of phytochemicals

Abstract

Aim: The aim of the present study was to assess the antibacterial activity of selected plants extract against Gram- positive and Gram- negative pathogenic bacteria. Methodology: Extracts of neem leaf (Azadirachta indica), rose petal (Rosa indica), amla fruit (Emblica officinalis) and clove buds (Syzygium aromaticum) were prepared in different solvents. Antibacterial activity against selected microorganisms was assayed using agar cup diffusion method, thereby measuring the zone of inhibition. The extracts with higher zone of inhibition were run on Thin Layer Chromatography (TLC) plates. The presence of phytochemicals was detected using iodine fumigation method followed by contact bioautography. Results: The extracts of neem leaf, rose petal, amla fruit and clove bud prepared in solvents like acetone, ethanol and ethyl acetate showed higher antibacterial effect against Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium in agar cup diffusion assay. TLC separation of the extract of plant products showed dark brown bands of phytochemicals on silica-gel G 60 plate. Contact bioautography results showed maximum antibacterial activity against Klebsiella pneumoniae. Interpretation: The results of the present study provide scientific evidence for the traditional uses of Azadirachta indica, Rosa indica, Emblica officinalis and Syzygium aromaticum.