STUDY TO FIND THE BEST EXTRACTION SOLVENT FOR USE WITH CUCUMBER PEEL (CUCUMIS SATIVUS) FOR HIGH NEUROPROTECTIVE ACTIVITY IN COGNITIVE IMPAIRED RATS

ABSTRACT Objective: The present study was designed to investigate the best extraction solvent for cucumber (Cucumis sativus) peel neuroprotective effects on bilateral common carotid artery occlusion (BCCAO) induced cognitive impairment rats. Methods: To study the activity, rats weighing 250-300g were pretreated with successive extracts of n-hexane fraction (HF), ethyl acetate fraction (EAF), ethanol fraction (EE) and aqueous fraction (AF) of 400 mg/kg, 200 mg/kg, p.o of each for 10 days and the treatment was continued for another 7 days after cerebral ischemia. Cognitive impairment was induced by BCCAO for 30 minutes, followed by 7 days reperfusion of male wistar rats. The neuroprotective capability was assessed based on memory performance tasks by morris water maze and rectangular maze performance tests and locomotor activity. Various biochemical parameters like lipid peroxidation, Catalase, DPPH and AchE were also estimated in the brain after the treatment. Results: The results demonstrated that the neuroprotective ability of cucumber peel extracts of EE was higher than AF due to having more phenolic compound and flavonoids content. The animals treated with donepezil, EE and AF prevented the biochemical changes significantly (p<0.001) and there was significant (p<0.001) improvement in cognitive parameters in dose dependent manner compared to BCCAO treated rats. However there was no significant improvement in cognitive parameters of HF and EAF extractions of cucumber peel. Conclusion: Thus present study indicates Neuroprotective effect of cucumber peel extracts (EE > AF) against BCCAO induced cognitive impairment. The ethanolic extract was observed to be the most effective solvent showing high neuroprotective ability than aqueous fraction. Key words: Bilateral common carotid artery occlusion, Cucumis sativus, Cognitive impairment, Flavonoids, Neuroprotective