In vitro antimicrobial appraisal of the potentials of Morinda lucida against some selected bacteria

Abstract

The bioactive compounds from plant extract represent a potent alternative to combating the increasing antimicrobial resistance (AMR) to synthetic drugs. This study aimed to investigate the phytochemical, and antibacterial activities of Morinda lucida. Leaves of M. lucida was extracted successively using n-hexane, acetone, methanol and distilled water. The crude plant extracts were evaluated for their antibacterial activity against pathogens found in food and other sources such as Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella enterica serovar Typhi, Escherichia coli, and Klebsiella spp. using the agar well diffusion technique. Minimum inhibitory concentration (MIC) was carried out using the microbroth dilution technique. The phytochemical analysis showed the presence of alkaloids and sterols in all extracts. Flavonoid was only present in the n-Hexane extract. The result showed that n-Hexane extract had the widest zone of inhibition against P. aeruginosa - 13.67 mm (12.5 mg/mL MIC), B. subtilis - 15 mm (12.5 mg/mL MIC), while acetone extract was most active against S. enterica ser. Typhi - 24.67 mm (6.25 mg/mL MIC), S. aureus - 24.83 mm (3.13 mg/mL MIC), E. coli - 13.33 mm (1.56 mg/mL MIC) and Klebsiella spp. - 18.33 mm (12.5 mg/mL MIC). These findings indicated that n-Hexane and acetone extract of M. lucida exhibited significant antimicrobial activity. Therefore, further research should be carried out to isolate the bioactive compounds with potentials in developing new drug leads against drug-resistant microbial strains.