Antibacterial activity of methanol leaf extract and fruit decoction from Morinda persicifolia Buch. – Ham

The study investigated antibacterial potentials of Morinda persicifolia Buch. – Ham collected from Lang Sen Wetland Reserve, Long An Province in Vietnam. Antimicrobial activity of M. persicifolia Buch. – Ham was evaluated based on size of antibacterial zone of methanol leaf extract by agar well diffusion method, values of minimum inhibitory concentration (MIC) by micro-well dilution method, minimum bactericidal concentration (MBC) by spread plate method and MBC/MIC ratios of fruit decoction against five test bacteria. The results showed that the methanol leaf extract produced growth inhibition zones against test bacteria with diameters of smaller than 6 mm (2.41 mm -5.63 mm). The fruit decoction had MIC of 100 mg/mL for P. aeruginosa and 200 mg/mL for B. cereus, B. subtilis, S. aureus and E. coli; and MBC about 300 mg/mL to B. cereus and E. coli and 400 mg/mL to B. cereus, B. subtilis, S. aureus and P. aeruginosa. MBC/MIC ratios of the fruit decoction against test bacteria were from 1.5 to 4. Thus, the methanol leaf extract was considered antibacterial at weak level and the fruit decoction was considered bactericidal.