Effect of the Alcoholic Extract of Curcuma longa on Acne-Causing Bacteria: Staphylococcus aureus, Propionibacterium acnes (Cutibacterium acnes), and Staphylococcus epidermidis

Abstract

The present study investigated the antibacterial activity of the alcoholic extract of Curcuma longa (turmeric) against acne-causing bacteria. Acne vulgaris is a common irritating skin condition in adolescents and adults, comprising pimples, comedones, pustules, and cysts due to chronic inflammation of hair follicles and associated sebaceous glands. Visual manifestations of acne often result in psychological complications such as depression and social morbidity. Three bacterial species, including Staphylococcus aureus, Propionibacterium acnes (Cutibacterium acnes) and Staphylococcus epidermidis, were used in this study. The alcoholic extract was prepared using (75%) ethanol, and evaluated through the disc diffusion method to measure inhibition zones. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. Results revealed that the turmeric extract exhibited antibacterial activity against all tested strains, with inhibition zone increasing proportionally with the extract concentration. The highest concentration (100 mg/mL), the mean inhibition zones for S. aureus, P. acnes, and S. epidermidis were (39.21±0.75 mm), (33.04±1.06 mm), and (42.30±0.90 mm) respectively. Positive control (tetracycline 10 μg) produced inhibition zones of (40.00±0.71 mm), (34.45±0.06 mm), and (43.45±0.21 mm) against S. aureus, P. acnes, and S. epidermidis, respectively. The MIC for all tested bacteria was (25 mg/ml), while the MBC was (100 mg/mL). The findings suggest that the alcoholic extract of Curcuma longa may serve as a natural alternative or complementary treatment for acne, particularly against S. aureus and S. epidermidis.