Antibacterial Activity of Ethanol Extract of Monodora myristica Seed

Abstract

The study evaluated the antibacterial activity of ethanol seed extract of Monodora myristica (African nutmeg). Extraction was done by soxhlet method with 75% ethanol, test organisms were clinical isolates of S. aureus , B. subtilis , P. aeruginosa and E. coli , Broth culture and Mueller-hinton agar were prepared, Lorkes method was employed in carrying out acute toxicity, antibacterial action and Minimum Inhibitory Concentration (MIC) were determined by agar well diffusion method, and agar dilution respectively. Standard antibacterial agents used were gentamicin, amoxicillin and chloramphenicol. Phytochemical screening revealed the presence of saponin, tannin, flavonoids, steroids, terpenoids, cardiac glycoside, protein and carbohydrate. Acute toxicity testing showed no mortality up to 5000 mg/kg in mice. The seed extract had antibacterial against B. subtilis and P. aeruginosa . Minimal inhibitory concentration of seed extract demonstrated resistance to Staph . aureus and E. coli at high concentration (MIC) (400 mg/ml) whilst P. aureuginosa and B. subtilis showed no growth at varying concentration at certain doses, notably 400 mg/ml and 200 mg/ml, even at lesser doses with B. subtilis . When compared with standard antibacterials cell/L (viz; gentamycin, chloramphenicol, amoxicillin) the activity of the standard ratio (10 ug/ml) of gentamicin was higher than that of the seed extracts on different concentration against S. aureus , against the plant extract agent with the post-hoc tukey test (0.00, p = 0.008). The conventional chloramphenicol produced statistically insignificant values (p > 0.05) on P. aeruginosa and B. subtilis . The assessment of activity of seed extract on test organism against standard amoxicillin revealed that there were great differentiation in favor of standard amoxicillin (P < 0.05). These findings suggest that M. myristica seed extract possesses moderate antibacterial potential.