Antibacterial activity against Staphylococcus epidermidis and inhibition of glucose-stimulated oxygen consumption by Garcinia mangostana extract

Staphylococcus epidermidis, a skin flora, is one of the major opportunistic pathogen which has been recognized as a leading cause of nosocomial infections [1]. Due to multi-drug resistance of S. epidermidis [2], the search for medicinal plant-derived antibacterial agents against this pathogen has accelerated in recent years. It has been previously reported that mangosteen, Garcinia mangostana, exhibits an antimicrobial action against certain bacteria, fungi and viruses [3]. Our current study is to investigate the antibacterial activity of G. mangostana extract against S. epidermidis. G. mangostana used in this study was collected from Chum-porn province located in the southern region of Thailand. The crude extract was prepared by extracting the pericarps with ethanol, and the extract was then used to evaluate the antibacterial activity against S. epidermidis. The result showed that the ethanolic extract of G. mangostana exhibited the antimicrobial effect against S. epidermidis with MIC of 50µg/ml. In addition, we had observed that the extract inhibited the glucose-induced increase in oxygen consumption of intact S. epidermidis cells. This result suggested that the extract interfered with the bacterial glucose metabolism; and this action may play a role in the antibacterial activity of G. mangostana extract against S. epidermidis.

References: 1. Ziebuhr, W., Hennig, S., Eckart, M., Kränzler, H., Batzilla, C., Kozitskaya, S. (2006) Int J Antimicrob Agents. 28:14–20.

2. Raad, I.; Alrahwan, A.; Rolston, K. (1998) Clin. Infect. Dis. 26:1182–1187.

3. Pedraza-Chaverri, J., Cárdenas-Rodríguez, N., Orozco-Ibarra, M., Pérez-Rojas, JM. (2008) Food Chem Toxicol. 10:3227–3239.