Phytochemical investigation and antimicrobial screening of local chewing stick- Homanium africanum against selected oral bacterial isolates

Most chewing stick plants are reported to be rich in phyto constituents and mineral composition apart from exerting mechanical cleansing and dislodging oral pathogens. This study is aimed at investigating the phytochemical, proximate, mineral composition, and antimicrobial activity of the local chewing stick (Homanium africanum) against selected oral bacterial isolates. The phytochemical, proximate, and mineral analyses were evaluated using standard methods and procedures. The oral bacterial isolation was carried out using the pour plate method, while the antibacterial assay was done using the agar diffusion method. Glycosides, alkaloids, phenolics, saponins, and terpenoids were present in the three plant samples (dried plant powder, methanol extract, and hexane extract). Carbohydrate content of 53.97±8.6% was recorded as the highest, followed by crude fibre (44.51±11.5%), ash (13.27±3.5%), moisture content (6.99±1.3%), crude fat (4.06±1.6%), and the least was the crude protein content (1.35 ±1.1%), while calcium, sodium, potassium, and zinc were among the elements detected. The oral bacterial isolates (S. mutans, L. bulgaricus, K. pneumonia, P. vulgaris, and E. coli) were all susceptible to the inhibitory effect of the methanol extract. The most susceptible was L. bulgaricus with a minimum inhibitory concentration of 12 mg/mL, followed by S. mutans (14 mg/mL), P. vulgaris (16 mg/mL) while E. coli and K. pneumonia had 18 mg/mL. This finding corroborates and validates the local use of the plant stem as a chewing stick or teeth cleanser, mostly in rural areas.