Antimicrobial activity of methanol extracts of <i style="">Plumeria</i><i style=""> acuminata</i> Ait. leaves and <i style="">Tephrosia</i><i style=""> purpurea</i> (Linn.) Pers. roots

Abstract

Methanol extract of leaves of <b><i>Plumeria acuminata</i> Ait.</b> (MEPA) and roots of <b>Tephrosia purpurea (Linn.) Pers.</b> (METP) were investigated for their in vitro antimicrobial properties by agar disc diffusion method. The crude methanolic extracts MEPA and METP inhibited the growth of both Gram positive bacteria (<i>Bacillus subtilis, Staphylococcus aureuspers.</i>and <i>Micrococcus luteus</i>) and Gram negative bacteria (<i>Escherichia coli, Pseudomsonas aeruginosa</i> and <i>Salmonella typhimurium</i>). The Gram positive bacteria tested appeared to be more susceptible to the extracts than the Gram negative bacteria. Both the extracts at the concentration ranging between 250 μg/ml and 1000 μg/ml showed inhibitory activity against all tested bacteria except MEPA which did not show activity against <i>S. typhimurium</i> at 250 μg/ml concentration. At 100 μg/ml concentration. MEPA was found neutral against <i>M. luteus, E. coli, P. aeruginosa</i> and <i>S. typhimurium</i> while METP was neutral against <i>E. coli</i> and <i>P. aeruginosa</i> at same concentration. The extracts also showed significant antifungal activity against <i>Aspergillus niger</i> and <i>Candida albicans</i>. All tested microorganisms showed dose dependent susceptibility towards the methanol extracts. The antibacterial and antifungal activity of the extracts and standard drugs were statistically significant. Based on the current findings, it can be concluded that both the plants possess potent antimicrobial activity.