Levosimendan ameliorates the scopolamine induced cognitive impairment via modulating pCREB/BDNF expression, cholinergic neurotransmission and neuroinflammation

Abstract Levosimendan, an inotropic drug that potentiates ATP-dependent K+ channel and sensitise troponin-C for calcium. It has positive effects in neurodegenerative diseases like Parkinson’s disease and mild septic encephalopathy. However, its effect on Alzheimer's disease remains unclear. Hence, in this study, we have investigated the effect of levosimendan against scopolamine induced cognitive impairment in rats via behavioural tests (Y maze, water maze and novel object recognition test), cholinesterase enzymes, oxidative stress markers, amyloid-β plaques, inflammatory mediators, and neurotrophic factors analysis. In this study, rats were divided into five groups. The first and second groups were given with vehicle or levosimendan (100 µg/kg/day i.p.) throughout the study. The remaining groups were pre-treated with vehicle/Donepezil (3mg/kg/day i.p.)/Levosimendan (100 µg/kg/day i.p.) respectively. From day – 8 these groups were given with their respective drugs and Scopolamine (3 mg/kg., i.p.) with 1 hour time interval. Behavioral analysis was carried out to assess the learning and memory functions of rats after 30 min of scopolamine administration from day 8 to day 17. Levosimendan treated group significantly improves in number of spontaneous alterations and recognition ability in Y-maze and NOR test respectively. In addition, levosimendan inhibited scopolamine induced pathological changes such as increased levels of cholinesterase enzymes, Aβ accumulation, neuro inflammation and reduced levels of BDNF. In summary, these findings indicate that pre-treatment with levosimendan mitigates the scopolamine induced behavioural and biochemical changes.