Propionibacterium acnes GehA lipase, an enzyme involved in acne development, can be successfully inhibited by defined natural substances

Propionibacterium acnes, a usual inhabitant of human skin, plays an important role in acne development, related to the production of numerous enzymatic activities involved in the degradation of host molecules. Among these enzymes, P. acnes lipase (GehA, glycerol-ester hydrolase A) has been recognized as one of the major factors in the pathogenesis of acne, being responsible for the hydrolysis of sebum and the release of inflammatory compounds. Anti-acne treatments are based on the use of retinoids or benzoyl peroxide, frequently in combination with antibiotics. However, the low effectiveness of such treatments and the increasing antibiotic resistance has led to the development of alternative therapies such as Kampo formulations, containing traditional herbal drugs. Search for new anti-acne treatments led us to perform the cloning, characterization and inhibition of P. acnes GehA, considered an interesting pharmaceutical target for anti-acne therapies. The genetic, molecular and biochemical properties of the cloned lipase were analysed, and several inhibitor agents were tested, including natural substances like saponins, alkaloids or flavonoids. Among these, the flavonoids (±)-catechin and kaempferol were the most promising candidates for acne treatment, whereas saponins like glycyrrhicic acid and digitonin produced a lower inhibition of the enzyme. No inhibition by alkaloids was found. Therefore, the inhibition caused by (±)-catechin and kaempferol on GehA, together with their wide anti-acne properties and low toxicity, make them very suitable candidates for the treatment of acne and other P. acnes-related diseases.