RESUMEN
Objective: To evaluate the synergistic effect of α-mangostin with tetracycline, erythromycin, and clindamycin against bacteria involved in acne production. Methods: A broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of α-mangostin and a range of antibiotics. Synergistic effects on antibacterial activity were determined based on their own MIC, and then using a checkerboard method and a time-kill assay at 37 °C for 24 h. Results: α-Mangostin exhibited antibacterial activity against Propionibacterium acnes, Staphylococcus aureus, S. epidermidis and S. pyogenes with MIC values of 0.78, 3.13, 0.78, and 6.25 µg/mL, respectively. The results of the checkerboard assay showed that α-mangostin produced synergistic effects with tetracycline, erythromycin, and clindamycin against all tested bacteria, with a fractional inhibitory concentration index (FICI) between 0.09 and 0.32. Moreover, time-kill curve data indicated that α-mangostin increased the antibacterial activity of tetracycline, erythromycin, and clindamycin. Conclusion: These findings suggested that α-mangostin may be used to enhance the antibacterial activity of some antibiotics against bacteria involved in acne production.