S. Ramya et al.


Catharanthus roseus popularly known as Madagascar periwinkle is a potential source for anti-leukemic alkaloids. The present study aims to evaluate the possibility for the presence of novel bio-active compounds against pathogenic bacteria, as most of the pathogens develop drug resistance against commonly used antibiotics. To determine antibacterial activity, crude extracts from different parts of C. roseus were tested against bacterial strains of clinical significance. Extraction of bio-active principles in appropriate solvent was followed by evaluation of antibacterial activity by disc diffusion assay against selected bacterial stains. Data depicts that the pattern of inhibition largely depends upon extraction procedure, plant part, physiological and morphological state of plant, extraction solvent and microorganism tested. Of different plant materials tested, extracts prepared from leaves showed significantly higher efficacy. Extracts prepared using organic solvents exhibited higher antibacterial activity when compared to their corresponding aqueous extracts. However, no activity was observed in the aqueous extracts. Among the extracts that were significantly active, extract obtained using ethanol exhibited maximum activity against bacterial strains tested. Gram (-) stains were more sensitive when compared to Gram (+) bacteria. The study implicates that bio-active compound(s) of C. roseus could potentially be exploited as antibacterial agents.