Anti-Pathogenic Bacterial Activities of Fractionated Venom of King Cobra (Ophiophagus Hannah)

Abstract

This study aimed at measuring the antibacterial activity of the semi-purified fractions

isolated from King Cobra venom and investigated the mechanism of action. The protein

fractions were isolated from King Cobra venom and designated F1-F7. The F5 showed the

highest antibacterial activity. The F5 was further concentrated and separated by Sephadex G-

75 column to obtain six fractions (F5.1-F5.6). The antibacterial assay showed that F5.1 could

inhibit the growth of gram-positive S. aureus and gram-negative E. coli, S. aeruginosa and S.

Typhimurium bacteria. The F5.1 showed antibacterial activity against S. aureus with the MIC

of 1.8 μg/ml. Its molecular weight was 69 kDa, which was determined by SDS-PAGE. The

mechanism of action may be damaging the cytoplasmic membrane, as shown from the

scanning electron microscopy. The MIC concentration of F5.1 showed potent cytotoxicity on

Human PBMCs cells. The results obtained from this study indicated that the F5.1 had

antibacterial activity against the S. aureus through membrane damage, it was also cytotoxic

to normal human cells. In conclusion, this study provides basic information on antibacterial

effect of the semi-purified F5.1 of King cobra venom. The F5.1 should be further purified or

modified to obtain the potential antibacterial compound which will be safe to the normal

human cells.