Inhibition of Naja nigricollis nigricollis venom acetylcholinerase activity by kolaviron isolated from Garcinia kola

Abstract

Acetylcholinerase (AChE) enzyme often predominant in cobra venom causes paralysis, respiratory failure and other life-threatening complications, but kolaviron (KV) inhibits brain AChE, showing therapeutic potential. This study attempt to investigate the inhibitory effect of KV against Naja nigricollis nigricollis (NNN) venom AChE activity. The identity and purity of KV compound was authenticated using Liquid Chromatography-Mass Spectrometry (LC-MS) analysis. The activity of AChE and its inhibition studies were performed via standard protocol. The chromatographic analysis of KV gave six (6) peaks, which corresponds to its basic components. The activity of NNN AChE was inhibited in dose-dependent pattern, when pre-incubated with increasing doses of KV ranging from 0.2 to 1.0 µg/mL. A maximum inhibition of 90 % was observed at 1.0 µg/mL of KV and half maximal inhibitory concentration (IC50) of KV was estimated at 0.59 µg/mL. The data suggest that kolaviron is a potent inhibitor of snake venom acetylcholinerase (AChE), and its inhibitory activity likely occurs through direct contact, a common mechanism characteristic of flavonoid compounds and may be employed in snakebite treatment. Keywords: Cobra venom, Naja nigricollis nigricollis, neurotoxin, acetylcholinerase, acetylcholine, kolaviron, physical interaction