Beneficial Effects of Statins in Experimental Amnesia

The present study was undertaken to investigate the beneficial effects of widely-prescribed lipid lowering drugs, pitavastatin, atorvastatin and simvastatin 3-hydroxy-3-methylglutaryl-coenzyme-A (HMG-CoA) reductase inhibitors in cognitive dysfunctions of mice. Intra-cerebroventricular (ICV)-Streptozocin-(STZ)- and high-fat diet (HFD)-induced amnesia served as interoceptive memory models where as, Morris water-maze served as an exteroceptive model in the present study. A total of 13 groups, comprising seven mice in each group were used in this investigation. Day 4 Escape latency time (ELT) recorded during acquisition trials conducted from day 1 to day 4, in water-maze was taken as an index of acquisition, where as mean time spent in target quadrant during retrieval trial on day 5, was taken as an index of retrieval (memory). ICV-STZ-(3 mg kg -1 i.p.), and HFD-treated (for 90 days) mice showed an impairment of acquisition as well as retention on water maze task as reflected by significant increase in ELT on day 4 and decrease in time spent in target quadrant on day 5. Pitavastatin (5 mg kg -1 ), atorvastatin (5 mg kg -1 ) and simvastatin (5 mg kg -1 ) significantly attenuated ICV-STZ- and HFD-induced amnesia. These results highlight the ameliorative role of statins in experimental amnesia with possible involvement of their cholesterol-dependent as well as cholesterol independent actions.