Antimicrobial effects of Indian medicinal plants against acne-inducing bacteria

Propionibacterium acnes and Staphylococcus epidermidis have been recognized as pus-forming bacteria triggering an inflammation in acne. The present study was conducted to evaluate antimicrobial activities of Indian medicinal plants against these etiologic agents of acne vulgaris. Ethanolic extracts of Hemidesmus indicus (roots), Eclipta alba (fruits), Coscinium fenestratum (stems), Curcubito pepo (seeds), Tephrosia purpurea (roots), Mentha piperita (leaves), Pongamia pinnata (seeds), Symplocos racemosa (barks), Euphorbia hirta (roots), Tinospora cordyfolia (roots), Thespesia populnea (roots), and Jasminum officinale (flowers) were tested for antimicrobial activities by disc diffusion and broth dilution methods. The results from the disc diffusion method showed that 07 medicinal plants could inhibit the growth of Propionibacterium acnes. Among those Hemidesmus indicus, Coscinium fenestratum, Tephrosia purpurea, Euphorbia hirta, Symplocos racemosa, Curcubito pepo and Eclipta alba had strong inhibitory effects. Based on a broth dilution method, the Coscinium fenestratum extract had the greatest antimicrobial effect. The MIC values were the same (0.049 mg/ml) for both bacterial species and the MBC values were 0.049 and 0.165 mg/ml against Propionibacterium acnes and Staphylococcus epidermidis, respectively. In bioautography assay, the Coscinium fenestratum extract produced strong inhibition zones against Propionibacterium acnes. Phytochemical screening of Coscinium fenestratum revealed the presence of alkaloid which could be responsible for activity. Taken together, our data indicated that Coscinium fenestratum had a strong inhibitory effect on Propionibacterium acnes and Staphylococcus epidermidis.