Asian Journal of Research in Pharmaceutical Sciences

In Siddha medication, along with herbal formulations, some mineral formulations are used clinically to prevent or cure infectious diseases. The therapeutic values of some siddha formulations have been well documented earlier, but a huge number of them remain unexplored in terms of safety and efficacy. The aim of this study was to screen the antimicrobial potential of Siddha polyherbal formulation Tulasi oil (SPHTO) against respiratory tract infection (RTI) causing pathogens. The antimicrobial activity of SPHTO was examined by using the methods of agar well diffusion, Minimum inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC), Minimum Fungicidal Concentration (MFC) and Microbicidal action. Ciprofloxacin (bacteria) and Amphotericin B (fungi) were used as the positive control for this study. The potassium leakage was determined using a flame emission and atomic absorption spectroscopy. All tested concentrations gave notable antimicrobial activity against all tested pathogens. The 100mg/ml concentration showed the highest activity against E. coli followed by 200mg/ml against K. pnuemonia and C. neoformans when compared to 50 and 25mg/ml. For MIC, the highest activity was registered at 150mg/ml concentration against E. coli, while MBC/MFC was 200mg/ml concentration has shown the better activity against K. pneumonia and C. neoformans. Tulasi oil induced leakage of potassium ions from cells of E. coli and K. pneumonia suspended in glycil-glycine buffer solution and the leakage started within 10 minutes of contact of drugs with target cells. From this study, it may support the clinical claims of Tulasi oil to have potent antibacterial and antifungal activities and offer profound therapeutic benefits against respiratory tract infection.