In Vitro and In Vivo Antibacterial Activity of Patchouli Alcohol from Pogostemon cablin

Objective: To investigate the antibacterial activity of patchouli alcohol (PA) against 127 bacteria strains, including the common bacteria and drug-resistant bacteria strains both in the in vitro and in vivo tests.

Methods: For the in vitro trial, the antibacterial property of PA against 107 Gram-positive and 20 Gram-negative bacteria strains was screened by agar double dilution method. For the in vivo trial, specific pathogen free Kunming strain of both male and female white mice, were used to test the protective ability of PA after being injected with the median lethal dose of the tested strains.

Results: PA possessed antibacterial activity against all the tested 127 strains. In the in vitro test, PA could inhibit both Gram-negative bacteria (25-768μg/mL) and Gram-positive bacteria (1.5-200μg/mL). Particularly, PA was active against some drug-resistant bacteria like methicillin-resistant Staphylococcus aureus (MRSA). PA also exhibited in vivo anti-MRSA activity in mice via intraperitoneal injection. PA could protect mice entirely infected with MRSA at 100 and 200 mg/kg, while 80% mice injected with MRSA could be protected at a low dose of 50μg/mL.

Conclusion: PA might be a potential antibacterial drug from natural sources and might be worthy to explore its mechanism and application in further study.