In vitro evaluation of antibacterial activity of chloroform extract Andrographis paniculata leaves and roots, Durio zibethinus wood bark and Psidium guajava leaves against selected bacterial strains

Abstract

The study was designed to evaluate the antibacterial potential of three plants which are Andrographis paniculata, Durio zibethinus and Psidium guajava. Andrographis paniculata leaves (30mg/ml) and roots (30 mg/ml), Durio zibethinus wood bark (10mg/ml), and Psidium guajava leaves (15mg/ml) extract was obtained through the process called maceration, filtration, evaporation and the paste form was freshly reconstitute in dimethyl sulfoxide (DMSO) and tested against Staphylococcus aureus for Andrographis paniculata, Psidium guajava. Streptococcus agalactiae for Durio zibethinus and Psidium guajava and Escherichia coli for Durio zibethinus using Kirby Baur technique and the plates were incubated at 37 oC. The zone of inhibition was measured after 24 hours and recorded in millimeters. The combination study was conducted using extract in combination with Penicillin G (6.25 µg/ ml) and erythromycin (15 µg/ ml; Andrographis paniculata) with the propotion of 1:1 in homogenous condition and incubated at 37 oC for 24 hours. The zone of inhibition was measured and recorded. Mean and standard deviation was calculated. Andrographis paniculata do possesses some antibacterial activity against Staphylococcus aureus. Leaves (17.33 mm), roots (10.67 mm), erythromycin (24.00 mm), leaves and erythromycin (20.67 mm), roots and erythromycin (21.67 mm), leaves and roots (17.33 mm). Wood bark against Streptococcus agalactiae (14.67 mm), Penicillin G (14.00 mm), and combination (16.67 mm). Durio zibethinus showed antibacterial activity against Escherichia coli (11.00mm) and Penicillin G (13.33 mm). Psidium guajava leaves extract were having slightly higher activity than Penicillin G and in combination activity, leaves were having a slightly higher activity than Penicillin G.