In Vitro Antibacterial Activity of Crude Leaf Extracts from Tecoma Stans (l) Juss. Et Kunth, Coleus Forskohlii and Pogostemon Patchouli against Human Pathogenic Bacteria

Medicinal plants are the wealthy source of antibacterial agents and curatives. Tecoma stans, Coleus forskohlii and Pogostemon patchouli are commonly practiced medicinal plants in the villages of Salem District, Tamilnadu (India). Plants grown in this region are not systematically tested for their biological activities in general and antimicrobial activity in particular. Hence, In vitro antibacterial activity of crude leaf extracts of these 3 plants was tested by disc diffusion method against 5 human pathogenic bacteria Staphylococcus aureus, Staphylococcus epidermidis, Salmonella typhi, Klebsiella pneumoniae and Vibrio parahemolyticus. Gram-negative bacterial strains were more susceptible to the crude extracts as compare to gram-positive. However, this study revealed maximum growth inhibition and effectiveness was remarkably observed in the extracts of Coleus forskohlii, Pogostemon patchouli and then in Tecoma stans. These results indicate that leaves have a potential broad spectrum antibacterial activity.