Antibacterial activity of α-mangostin against vancomycin resistant Enterococci (VRE) and synergism with antibiotics

α-Mangostin, isolated from the stem bark of Garcinia mangostana L., was found to be active against vancomycin resistant Enterococci (VRE) and methicillin resistant Staphylococcus aureus (MRSA), with MIC values of 6.25 and 6.25 to 12.5 μg/ml, respectively. Our studies showed synergism between α-mangostin and gentamicin (GM) against VRE, and α-mangostin and vancomycin hydrochloride (VCM) against MRSA. Further studies showed partial synergism between α-mangostin and commercially available antibiotics such as ampicillin and minocycline. These findings suggested that α-mangostin alone or in combination with GM against VRE and in combination with VCM against MRSA might be useful in controlling VRE and MRSA infections.