In vitro Antimicrobial Activity of a Few Medicinal Plants against Human Cariogenic Bacteria

Abstract Introduction: The human body’s ability to heal is innate. This procedure is guided by potentials found in nature. We may harness these potentials by employing various therapeutic approaches that uphold the natural order, fortify the body and encourage vitality. The aim of the study is to develop novel anti-cariogenic antibacterial compounds from nine common medicinal plants easily available in West Bengal, India. Materials and Methods: The antibacterial efficacy of ethanolic, methanolic and aqueous extracts of selected plant samples was checked against freeze-dried Streptococcus mutans by the well diffusion method and the disc diffusion method. Results: In the well diffusion method, the methanolic extract of haritaki showed maximum inhibition zones at both higher (100 mg/ml) and lower (50 mg/ml) concentrations. The antimicrobial activity of methanol extracts of haritaki was also highest at a higher (40 μL) concentration against the standard bacteria sample (Microbial Type Culture Collection and Gene Bank-890) S. mutans and at a lower concentration (40 μL) in the disc diffusion method. Similarly, the ethanolic and aqueous extracts of Haritaki exhibited maximum potency at both higher and lower concentrations in both the well diffusion and disc diffusion methods tests. Conclusion: This work has investigated the in vitro antibacterial efficacy of medicinal herbs against freeze-dried S. mutans . Alcoholic plant extracts are more effective than aqueous extracts. Among all the plant extracts, Terminalia chebula (haritaki) demonstrated the highest antimicrobial efficacy against the standard freeze-dried bacterial sample. Azadirachta indica (neem), Curcuma longa (turmeric) and Psidium guajava (guava) exhibited moderate antibacterial efficacy against the test bacterial strains in all solutions. Minimum activity was shown by Aloe barbadensis miller (aloe vera).