Screening of Antibacterial Activity of Nepeta Ciliaris Benth. against Respiratory Tract Pathogens

The aim of present study was to evaluate the antibacterial potential of various extracts (petroleum ether, acetone, methanol and aqueous) of Nepeta ciliaris against selected respiratory tract pathogens. The extracts from the aerial parts of N. ciliaris at concentration of 200 mg/ml were screened against three gram-positive (Staphylococcus aureus MTCC 1144, Streptococcus pneumoniae MTCC 655 and Streptococcus pyogenes MTCC 442) and one gram-negative (Pseudomonas aeruginosa MTCC 2474) bacterial pathogens. The agar well diffusion method was adopted to examine antibacterial and minimum inhibitory concentration (MIC) values of most effective extracts against the susceptible bacteria. Erythromycin was used as positive control to determine the sensitivity of the strains. Out of the four bacterial species tested, S. pneumoniae was the most susceptible. The acetone extract exhibited maximum activity against all the tested microorganisms while methanol extract showed activity against P. aeruginosa. The MIC values ranged from 40 to 50 mg/ml for all the organisms. The N. ciliaris is potentially a good source of antimicrobial agents.