Inhibitory effects of Mezoneuron benthamianum root extracts on oral cariogenic microorganisms and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging radical

Background Chewing sticks are commonly used as oral hygiene tool in Africa and reactive oxygen species have been linked to the cause of degenerative diseases because of their ability to induce oxidative damage to biological molecules. Plants have been a long source of dietary antioxidants as most plants have been found to exhibit excellent antioxidant potentials. Mezoneuron benthamianum is a plant that is used locally as chewing sticks in southwest, Nigeria, but its use as a therapeutic agent in dental caries, a disease caused by bacteria especially Streptococcus mutans is poorly investigated. This study was therefore designed to investigate the anticaries activities of the crude extracts of M. benthamianum root against four clinical oral pathogens ( Staphylococccus aureus, Escherichia coli, Pseudomonas aeruginosa and Streptococcus mutans ) and the antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Results The results of this study showed that M. benthamianum had a consistent activity against all the bacterial organisms tested, with the ethyl acetate extract having the highest anticaries activity with minimum inhibitory concentration values of 78 and 156 μg/mL, while the hexane extract had the least anticaries activity with MIC values of 2500 μg/ml against S. mutans and E. coli respectively. The results also revealed that the ethyl acetate and aqueous methanol extract exhibited a higher antioxidant activity (IC 50 = 23.70 and 21.30 μg/mL) than standard ascorbic acid (IC 50 = 38.20 μg/mL). Conclusion This study demonstrated the anticaries and antioxidant potentials of M.benthamianum and therefore justifies the folkloric use of M. benthamianum in oral hygiene.