Anti-pathogenic bacterial activity from Garcinia cowa leaves extract

บทคัดย่อ

          Garcinia cowa Roxb., a tropical plant traditionally used in Southeast Asian ethnomedicine, is known for its diverse biological activities, including antioxidant, anti-inflammatory, and antimicrobial effects. The leaves of G. cowa contain a variety of bioactive phytochemicals that have garnered interest as potential natural agents against pathogenic microorganisms, particularly amid the global challenge of increasing antibiotic resistance. This study aimed to evaluate the antibacterial efficacy of G. cowa leaf extracts obtained using different solvents; methanol, ethyl acetate, dichloromethane, and hexane against six pathogenic bacterial strains including Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. Antibacterial activity was assessed by measuring inhibition zones, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using spread plate assays. The methanol extract exhibited the most potent antibacterial activity, particularly against S. aureus, with the largest inhibition zone (10 mm), the lowest MIC (0.0037 mg/mL), and a significant MBC (0.15 mg/mL). Ethyl acetate extracts showed moderate activity against several strains, while dichloromethane and hexane extracts demonstrated minimal to no antibacterial effects. Notably, the methanol extract’s efficacy approached that of the reference antibiotic kanamycin for certain bacteria. In conclusion, G. cowa leaf methanol extract holds strong potential as a natural antibacterial agent, offering a promising alternative for combating bacterial infections and addressing antibiotic resistance. This research supports further investigation into isolating and characterizing the active compounds responsible for these effects, potentially advancing the development of novel phytotherapeutics for clinical and pharmaceutical applications.