Abstract: OBJECTIVE:To examine the efficacy of Silene arenosa extract on acetylcholinesterase (AChE) of krait (Bungarus Sindanus) snake venom.METHODS:The present project designed to evaluate the inhibition of AChE by following standard procedures.RESULTS:Statistical analysis of the results showed that Silene arenosa exerted 73%inhibition against the krait venom acetylcholinesterase at fixed substrate acetylcholine (ACh) concentration (0.5 mM).Kinetic analysis using the Lineweaver Burk plot revealed that Silene arenosa caused a competitive type of inhibition i.e.K_m values increased from 26.6 to 93.3 mM (26.6%to 93.3%) and V_(max)remained constant in a concentration-dependent manner.Silene arenosa competes with the substrate to bind at the active site of the enzyme.The K_(mapp)of venom AChE for Silene arenosa increased from 60%to 81.6%and the V_(maxapp)remains constant.K_i(inhibition constant was estimated to be 48μg for snake venom;while the K_m(Michaelis-Menten constant of AChE-substrate into AChE and product) was estimated to be 0.5 mM.The IC_(50)of AchE calculated for Silene arenosa was 67μg.CONCLUSION:The present results suggest that Silene arenosa extract can be considered as an inhibitor of snake venom AChE.

Key words: acetylcholinesterase, snake venoms, silene arenosa, competitive inhibition