ABSTRACT
This study explores the antimicrobial activity of ethanolic and aqueous extracts from Garcinia kola seed on selected gastrointestinal bacteria, including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Bacillus subtilis, and Pseudomonas aeruginosa. Extracts were obtained via maceration using ethanol and water, followed by antimicrobial evaluation through standard microbiological assays. Results showed significant antimicrobial activity from both extracts against all tested pathogens. The study assessed the zone of inhibition, minimum inhibitory concentration, minimum bactericidal concentration, and concentration dependency. Mean inhibition zones for aqueous extract were: S. aureus (16.20±1.356), Escherichia coli (14.80±1.06), Klebsiella pneumoniae (14.80±0.860), Bacillus subtilis (20.40±0.927), Pseudomonas aeruginosa (10.80±1.356). For ethanolic extract: S. aureus (15.89±0.860), Escherichia coli (16.00±2.82), Klebsiella pneumoniae (11.80±1.281), Bacillus subtilis (19.00±0.707), Pseudomonas aeruginosa (11.20±1.562). Significant differences were observed (p<0.001). Positive regression (p<0.05) indicated concentration dependency for both extracts: aqueous (S. aureus p=0.029, Escherichia coli p=0.014, Klebsiella pneumonia p=0.050, Bacillus subtilis p=0.017, Pseudomonas aeruginosa p=0.014); ethanolic (S. aureus p=0.050, Escherichia coli p=0.021, Klebsiella pneumonia p=0.043, Bacillus subtilis p=0.020, Pseudomonas aeruginosa p=0.009). Overall, both extracts showed antimicrobial potential, with aqueous extract exhibiting greater inhibition. This study highlights the therapeutic potential of Garcinia kola seed.
