STUDIES ON THE ANTIMICROBIAL ACTIVITIES OF EXTRACTS FROM Oroxylum indicum L.

Abstract

This study aims to evaluate the antibacterial activity of Oroxylum indicum (OI) extracts (extracts of stem bark, leaves, root, and wood trunk) against Staphylococcus aureus ATCC 6538, Listeria innocua ATCC 33090, Bacillus cereus ATCC ® 10876TM, Escherichia coli ATCC ® 25922TM, Salmonella typhimunum ATCC ® 13311TM và Pseudomonas aeruginosa ATCC 27855. However, all extracts had no antibacterial activities against Salmonella typhimunum and Escherichia coli. The dichloromethane extract of OI leaves produced the strongest antimicrobial effect, inhibiting the growth of Listeria innocua (320<MIC<640; 640<MBC<1280), Staphylococcus aureus (320<MIC<640; 640<MBC<1280), Pseudomonas aeruginosa (320<MIC<640; 640<MBC<1280) and Bacillus cereus (320<MIC<640; 640<MBC<1280). The dichloromethane extract of OI root also exhibited significant effect against Listeria innocua (320<MIC<640; 640<MBC<1280), Staphylococcus aureus (320<MIC<640; 640<MBC<1280) Pseudomonas aeruginosa (640<MIC≤1280 µg/mL; 1280<MBC≤2560 µg/mL) and Bacillus cereus (640<MIC≤1280 µg/mL; 1280<MBC≤2560 µg/mL). In summary, the antibacterial activity of OI leaves and root were seemingly associated with its chemical composition (alkaloids, flavonoids, glycosides, tanins, steroids). Findings of this study indicate that leaves and root of OI have antibacterial activity against the different tested bacterial strains.