Antibacterial activity and mechanism of Pogostemon cablin against bacteria from milk of dairy cows suffering with mastitis

Abstract

Minimum Inhibitory Concentrations (MICs) of 3 extracts and oil from Pogostemon cablin against isolates from milk produced by dairy cow with mastitis were determined by Agar Dilution Method. Water extract had low activity; ethanol extract and ethanol-water extract had moderate effects having MICs ranging from 25.0-100.0, 12.5-100.0 mg mL-1, respectively. Oil had strong activity against Gram-positive and Gram-negative isolates with MICs ranging from 0.2-8.2 mg mL-1. Oil also, showed strong efficacy in mouse peritonitis model infected with 5. aureus or E. coli. Their actions were dose-dependent. Obvious morphological changes were observed by TEM in oil-treated E. coli or S. aureus such as a remarkable electron-light region small electron-dense granules disturbed cytoplasmic membrane and abnormal cell division. In conclusion, antibacterial substance of P. cablin was oil which had broad-spectrum antibacterial activities so to make it a potential candidate as antibacterial agent to treat bovine mastitis. © Medwell Journals, 2012.