Antibacterial Activities of Gel Containing 5% Hydroalcoholic Extract of Rhamnus cathartica L. bark

Background and purpose: Acne is a chronic inflammatory disease of the pilosebaceous glands caused by opportunistic microorganisms. The Rhamnus cathartica is known to have biological and antioxidant properties. This research aimed at investigating the in vitro effect of gel containing 5% R. cathartica extract on acne vulgaris. Materials and methods: The gel formulation contained 25g of dried R. cathartica bark extract, 0.5 liters distilled water, glycerin 50g, carbopol 940 5g, methyl paraben 0.75g, and propyl paraben 0.5g. After 24 hours, the formulation was put outside the refrigerator. Then, triethanolamine was added to the formulation under stirring with 500 rpm to solidify the gel. The effect of the product was measured against Cutibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus and MIC and MBC values were also determined. Results: Total phenolic content of R. cathartica was 351.6±4.5 mgGA/g/DW, total flavonoid content was 23.15±1.355 mgCE/g/DW, and total anthraquinone content was 1.85 ± 0.05 mgAE/g/DW. The pH of the product was 5.5-6. The MIC values of R. cathartica 5% gel were 195.3 µg/ml, 24.41 µg/ml, and 97.65 µg/ml against C. acnes, S. epidermidis and S. aureus, respectively. The MBC testing showed 25000 µg/ml, 25000 µg/ml, and 12500 µg/ml against C. acne, S. epidermidis and S.aureus. Conclusion: R. cathartica is believed to contain active ingredients and can act as an antibiotic against acne causing microorganisms.