Antimicrobial Effects of Thai Plants Against Acne-inducing Bacteria

Abstract

Abstract

Introduction: Propionibacterium acnes has been recognized as a pus-forming bacteria that triggers inflammation in acne. The present study was conducted to evaluate antimicrobial activities of Thai plants against this etiologic agent of acne vulgaris. Materials and Methods: Ethanolic and aqueous extracts of Lagerstroemia floribunda Jack (flowers), L. speciosa Pers. (flowers), Cassia fistula L. (flowers), Bougainvillea hybrid (flowers), Caesalpinia pulcherrima Sw. (flowers) and ethanolic extracts of fresh pod of Moringa oleifera Lam. (seed, pulp and peel) were tested for antimicrobial activities by three methods; disc diffusion method for inhibition zone, broth dilution method for MIC value and agar dilution method for MBC value. Results: The results from the disc diffusion assays revealed that both ethanolic and aqueous extracts of L. floribunda Jack, L. speciosa Pers.  and the ethanolic extract of C. pulcherrima Sw. inhibited the growth of P. acnes. Based on broth dilution and agar dilution methods, the ethanolic extracts of L. floribunda Jack and L. speciosa Pers. had strong antimicrobial effects. The MIC and MBC values of both extracts were 0.325 and 0.625 mg/ml, respectively. Conclusion: Among all the test extracts, L. floribunda Jack and L. speciosa Pers. had strong inhibitory effects on P. acnes. Therefore, both plants would be interesting for further study of alternative treatment for acne.