Evaluation of Antimicrobial Potential of Some Indian Ayurvedic Medicinal Plants

Introduction: Stereospermum suaveolens Roxb., Viscum articulatum Burm., Annona squamosa, Capsicum annuum cayenne, Ananas comosus Merrill. are used for the management of microbial infection in Ayurveda. The present study was designed to standardize the extract of S. suaveolens bark (SSB), V. articulatum aerial part (VAAP), A. squamosa leaf (ASL), C. annuum fruit (CACF), A. comosus fruit (ACF) and performed antibacterial activity. Methods: The antibacterial activity of the five extracts were evaluated against certain bacteria such as B. subtilis, B. cereus, S. aureus (gram positive); E. coli, S. typhi, and P. aureugenosa (gram negative) by disc diffusion method, time course assay, pH sensitivity assay and minimum inhibitory concentration (MICs) through broth micro-dilution method. Results: The plants extracts VAAP, ASL, and CACF showed potent inhibitory activity against S. aureus with MIC 728, 742, and 698 μg ml^-1, respectively, while CACF showed inhibitory activity against B. subtilis with MIC 690 μg ml^-1. The results further demonstrated that the inhibitory activity of CACF against E. coli with MIC 760 μg ml^-1. P. aeruginosa was inhibited by ASL and CACF with MIC 1100 and 1120 μg ml^-1, respectively. The ASL showed notable MBC against the tested microorganism. Moreover, all extracts were completely inactivated bacterial strains (except B. cereus, S. typhi) within 2-10 h of exposure, determined by time course assay. Conclusion: The outcomes of our study elucidate that standardized extracts of A. comosus, A. squamosa, C. annuum, S. suaveolens, and V. articulatum may be used as natural antimicrobial agents.