Evaluation of the antibacterial activities of methanol stem extract of Massularia acuminata and methanol twig extract of Garcinia kola on oral Bacteria and their effect in combination

Massularia acuminata and Garcinia kola are chewing sticks widely used in Nigeria rural population for oral and dental care. This research investigates the individual antibacterial effects of methanol extracts of stem and twigs of these plants respectively and the combined effect of both extracts, against isolates of the oral cavity. The isolates were obtained from the oral cavities of healthy undergraduate students. The bacteria isolates obtained were Staphylococcus aureus, Klebsiella pneumonia, Streptococcus spp., Pseudomonas aeruginosa and Escherichia coli. Screening for antibacterial effect of each of the extracts and the combined extract on the standardized isolates was done by the Agar well diffusion method. On S. aureus, the methanol extract of M. acuminate and G. kola had minimum inhibitory concentration (MIC) of 12.5mg/ml and 12.5mg/ml with mean inhibitory zone diameter (IZD) of 3mm and 10mm respectively. The combination of both plant extracts showed MIC of 25mg/ml and a mean IZD of 4mm. On E. coli, M. acuminate and G. kola had MIC of 25mg/ml and 12.5mg/ml with mean IZD of 2mm and 3mm respectively. The combination of both extracts gave MIC of 25mg/ml and a mean IZD of 1mm. Both extracts didn’t exhibit any effect on the other 3 isolates. Statistical analysis using ANOVA showed the values were significant at p<0.05 for antibacterial activity of G. kola, M. acuminata and the combined extracts against S. aureus, also significant for G. kola (p<0.05) against E. coli but insignificant for M. acuminata and the combined extracts (p>0.05). This study proved that M. acuminata and G. kola extracts can be used for oral hygiene, but not in combination