Azadirachta indica Hexane Extract: Potent Antibacterial Activity Against Propionibacterium acne and Identification of its Chemicals Content

Background: Acne is a skin surface disease that appears when the excessive fat deposits clogged the skin pores, causes the growth of acne-causing bacteria and stimulates inflammation. Propionibacterium acnes is one of common acne-causing bacteria which usually manage by synthetic chemical-based drug. However, the presence of its long- used side effects pointed the urgent need of new anti P. acne drug discovery. Azadirachta indica is a medicinal plant which empirically used as antibacterial. A. indica leaves has been reported to exhibit activity against P. acne but limited to ethanol extract. Thus, the evaluation of other extract- and identification of active compound(s) against P. acne is needed to be explore. Methods: First, the microscopic morphology of A. indica leaves were observed using Scanning Electron Microscope. The leaves were then extracted sequentially by hexane, ethyl acetate, and methanol solvent using the ultrasonic assisted extraction method, followed by its in vitro anti- P. acne activity evaluation. The most active extract was further evaluated for its chemical(s) content by LC-MS. Results: Scanning Electron Microscope identified the presence of oxalate in the leaves of A. indica. Evaluation of the anti-P. acne activity showed that the hexane extract had highest anti-P. acne compared to others. Further chemical identification showed that hexane extract contains three steroids, one saturated acids and one phenolic compounds. Conclusions: A. indica hexane extract leaf is prospective to be developed as an acne antibacterial.