Evaluation of Anti-Propionibacterium Acnes and Anti-Inflammatory Effects of Polyphenolic Extracts of Medicinal Herbs in Jordan

Acne vulgaris is one of the most common health problem where medical treatment is sought in adults worldwide. It has been long described the integral role of Propionibacterium acnes in the pathogenesis of this disease. In this study, a group of local herbs known for their antimicrobial effects were selected for the evaluation of potential anti-acnes effects in vitro. Phenolics and flavonoid contents of methanolic extracts of Eucalyptus globulus, Mentha rotundifolia, Inula viscosa, Utrica dioica, Malva sylvestris, Quercus calliprinos, Arum palaestinum and Achille aodorata collected from different regions in Jordan during 2016-2017 were screened for antimicrobial activity against Propionibacterium acnes by disc diffusion and by broth microdilution method. Measurement of release of interleukin 1 alpha from human skin explants by ELISA was used for the evaluation of anti-inflammatory effects of the herbal preparations and extracts. M. rotundifolia and E. globulus, showed the highest phenolic and flavonoid contents in contrast to M. sylvestris which showed the least phenolic contents. Moreover, polyphenolic fractions exhibited modest anti-acne activity of herbal extracts of E. globulus and A. palaestinum (MIC 0.125 mg/ml), U. dioica (0.25 mg/ml) and I. viscosa (0.5 mg/ml), compared to not significant antimicrobial activity for others (MIC >1mg/ml). Regarding anti-inflammatory effects of the tested fractions, E. globulus and A. palaestinum extracts showed inhibition of interleukin 1 alpha release by more than 60 % for concentrations of 0.5 mg/ml respectively. The presence of anti-inflammatory and anti-acne activities in the polyphenolic extracts of local medicinal plants would increase the potential of using these herbs in the control of Acne vulgaris.