Abstract

The present study was conducted to investigate the antibacterial effect of Andrographis paniculata against selective human pathogens. The plant parts of A. paniculata such as leaf, stem and root were studied for its antibacterial activity. Different solvents were used to extract the active components from the plant parts. The antibacterial activity was studied against selective human pathogens viz., Staphylococcus sp., Escherichia coli, Salmonella sp. and Pseudomonas sp. Among the  different solvents, methanol extract showed greater antibacterial activity against E. coli (32.8 mm) followed by Salmonella Typhi (24.7 mm), Pseudomonas sp. (24.2 mm) and Staphylococcus sp. (18.4 mm). So the future investigation was carried out for leaf extract using methanol as solvent to find out the minimum inhibitory concentration for selective human pathogens. The results reveal that 75 µl was optimum for all the test cultures. It shows more activity in E. coli (32.3 mm) followed by S. Typhi (28.1 mm), Staphylococcus sp. (14.1 mm) and Pseudomonas sp. (13.4 mm).

Key words: Andrographis paniculata, Antibacterial, Andrographolide, minimum inhibitory concentration.