Lipases play an important role in pathogenesis of acne by hydrolysing sebum triglycerides and releasing irritating free fatty acids in the pilosebaceous follicles. Lipase is a strong chemotactic and proinflammatory antigen. Therefore, lipase has generated a high interest as a pharmacological target for antiacne drugs. The aim of this study was to identify inhibitory effects of plant extracts on the lipase activity of Propionibacterium acnes. Colorimetric microassay was used to determine lipase activity. Extracts from Terminalia chebula and Embelia ribes showed lower IC(50) value (1 μg mL(-1) ) for lipase inhibition as compared to Vitex negundo and Picrorhiza kurroa (19 and 47 μg mL(-1) , respectively). The active component responsible for lipase inhibition was isolated. This study reports for the first time the novel antilipase activity of chebulagic acid (IC(50) : 60 μmol L(-1) ) with minimum inhibitory concentration value of 12.5 μg mL(-1) against P. acnes. The inhibitory potential of plant extracts was further confirmed by plate assay. The organism was grown in the presence of subinhibitory concentrations of extracts from P. kurroa, V. negundo, T. chebula, E. ribes and antibiotics such as clindamycin and tetracycline. Extract from T. chebula showed significant inhibition of lipase activity and number of P. acnes.

Modern antibiotics against acne vulgaris has led to resistance among Propionibacterium acnes. This may be overcome with the use of ancient Indian medicines documented against skin diseases. Methanolic extracts of 21 medicinal plants were screened for antipropionibacterium activity to provide a scientific basis for indigenous cures derived from traditional knowledge. Seven medicinal plants were found to inhibit the gr owth of P. acnes. Of these Embelia ribes, Salmalia malabarica and Terminalia chebula showed strong inhibitory effects. The novel antipropionibacterium activity of embelin isolated from Embelia ribes and chebulagic acid isolated from Terminalia chebula which strongly inhibited the growth of P. acnes with minimum inhibitory concentration of 12.5 μg/ml has been reported.