Potent antibacterial property of APC protein from curry leaves (Murraya koenigii L.)

A monomeric protein with molecular mass of ∼35 kDa, isolated from Murraya Koenigii L. (curry leaves) shows potent antibacterial activity. The protein designated as APC (antioxidant protein from curry leaves) demonstrated potent antibacterial activity against all the human pathogenic strains tested. APC effectively inhibited Escherichia coli, Staphylococcus aureus, Vibrio cholerae, Klebsiella pneumoniae, Salmonella typhi and Bacillus subtilis. The inhibition is comparable to that of commercial antibiotics chloramphenicol, streptomycin and gentamycin. APC inhibited bacterial growth, with MIC values ranging from 13 to 24 μg/ml, which are comparable to MIC values of standard antibiotics. APC is devoid of ribonuclease/deoxyribonuclease and protease activity. APC is non-toxic at tested doses. These results encourage further studies of APC as a potent therapeutic agent.