Antimicrobial Activity Of Thevetia Peruviana (Pers.) K. Schum. And Nerium Indicum Linn.

Abstract

The main objective of the present study was to analyze the antimicrobial potential of various concentrations (2mg, 4mg, 6mg and 8mg/well) of leaf extracts of Thevetia peruviana (Pers.) K. Schum. and its close relative Nerium indicum Linn. (Apocynaceae). The dried leaves of these plants were extracted with 95% alcohol using soxhlet apparatus. The obtained extracts were concentrated to dryness in a flash evaporator (Buchi type) under reduced pressure and controlled temperature, (40 - 50∞C) and note down the yield of the crude extracts, then subjected to antimicrobial activity for the assessment of inhibitory effects of these plants against ten medically important antibiotic resistant pathogenic microbes by in vitro agar well diffusion method. The results of the present study clearly demonstrated that, the extracts of both the plants significantly inhibited the growth of all the pathogens used in this study in a dose dependent manner. The extract of Thevetia peruviana proved to be effective against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, where as, Proteus vulgaris showed susceptibility only at higher doses. Thevetia extract also showed moderate antibiotic activity against Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor, Rhizopus and Penicillium species. The alcoholic extract of Nerium indicum was effectively inhibited the growth rate of Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor, Rhizopus and Penicillium species even at lower concentrations. The same extract was also effective to other tested pathogens only at higher concentrations. In conclusion, the different concentrations of Thevetia peruviana and Nerium indicum have to possess non-specific broad spectrum antimicrobial activity.