In-vitro Evaluation of Antimicrobial Property of Catharanthus roseus (Linn.) G. Don. var. “ rosea ” and “ alba ” on Various Bacterial Pathogens

Objective: To evaluate the antibacterial property of crude, aqueous and organic solvent extracts from leaf, stem and root parts of two different cultivars of Catharanthus roseus (i.e. “rosea” and “alba”) under in-vitro conditions on various human pathogenic bacteria. Methods: Antibacterial activity of C. roseus was performed by crude (Fresh), aqueous, ethanol, methanol and mixture of ethanolic leaf extracts (Dried) against various pathogenic bacteria viz. Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) by disk diffusion assay under in-vitro conditions. Results: Gram positive bacteria were found to be more susceptible rather Gram negative bacteria. Dried extracts of root, stem and leaf of C. roseus var. “rosea” and “alba” plants show maximum antibacterial potential activity against all test microorganisms. The equimolar (1:1) concentration (Mixture) of ethanolic leaf extracts of species “rosea” and “alba” exhibit maximum zone of inhibition against all the test organisms (B. subtilis, E. coli, and S. aureus) rather than individually extracted form. Findings of ethanolic mixture on the tested bacterium confirm the effect may be potentiating or synergistic or additive or antagonistic. Conclusions: From the findings it could be inferred that C. roseus varieties “rosea” and “alba” could be efficiently used in the development of new life saving drugs.