Anti-Methicillin-Resistant Staphylococcus aureus Activities of Artocarpus lakoocha Roxb Extract and Its Mode of Action

Antibacterial activities and mode of action of Artocarpus lakoocha Roxb extracts against methicillin-resistant Staphylococcus aureus (MRSA) were evaluated, with its biological properties including antioxidant activity and total phenolic content also measured. Heartwoods of A. lakoocha Roxb were extracted by solvents including water, ethanol, acetonitrile, ethyl acetate, isopropanol, and hexane. Results showed that antibacterial activity against MRSA, antioxidant activity, and total phenolic content were highest in the acetonitrile extract. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were 312.5 and 625.0 μg/mL, respectively. Time-killing evaluation indicated a bactericidal mode of action with IC(50) values against ABTS and DPPH radicals of 2.37 ± 0.09 and 32.10 ± 0.74 mg/mL, respectively, and total phenolic content 455.29 ± 18.35 mg GAE/g extract. Results suggested that acetonitrile extract of A. lakoocha Roxb had good potential activity against MRSA, with promise for further development as a novel alternative drug.