IN VITRO EVALUATION OF ANTIBACTERIAL ACTIVITY OF LEAF EXTRACTS OF BALLOTA NIGRA AGAINST FIVE BACTERIAL PATHOGENS

Ballota nigra (Lamiaceae) has been widely used as traditional medicine in many countries for the treatment of neuro-sedative, antidepressant, antioxidant, antibacterial, insecticidal, anticholinesterase and antifeedant effects. The main objective of this study is to evaluate the antibacterial activity of leaf extracts of Ballota nigra Linn. against five bacterial pathogens. The leaves were extracted in five different organic solvents and their potential were tested against three Gram negative bacteria (Escherichia coli, Salmonella typhi and Salmonella paratyphi) and two Gram-positive bacteria (Micrococcus luteus and Bacillus subtilis) using Agar well diffusion method. The results indicate that most of the extracts showed prominent activity against all the bacterial strains. The methanol extract was most effective with zone of inhibition ranging from 12.20 ± 0.19 to 22.20 ± 0.19 mm for all the tested strains, while chloroform and ethyl acetate shows moderate activity. It clearly depicts that the methanol extract exhibit significant antibacterial activity due to the presence of phyto-constituents. This work can be further explored to in vitro studies for isolation and identifying the potential applications in pharmaceutical industries.