Anti-amnesic activity of ascophyllum nodosum polyphenols on trihexyphenidyl induced amnesia

Abstract

Amongst the foremost studied classes of antioxidants, dietary polyphenols and alternative natural antioxidants have gained attention as viable candidates for clinical testing in chronic diseases. The multiple modes of action of polyphenols to mitigate oxidative stress and promote neural survival signals probably underlie their effectiveness in such a big amount of in-vitro and in-vivo models of neuronic injury and chronic diseases. Considering these facts, our study was aimed toward evaluating psychological feature enhancing properties of Ascophyllum nodosum and comparison of cognitive enhancing properties with resveratrol. Trihexyphenidyl (THP), a selective M1 muscarinic blocker was used for induction of amnesia. The study was conducted into two regimens, i.e. prophylactic and curative regimens. Learning and memory behavior was assessed using Morris water maze and elevated plus maze. Mice treated with Ascophyllum nodosum were found to forestall as well as restore activity alterations provoked by THP. Prophylactic regimen: There was no significant difference found among the ELT of various groups, the group treated with highest dose of A. nodosum extract (200 mg/kg). Although various treatments didn't found significantly different, A. nodosum (highest dose, i.e. 200 mg/kg) extract treated animals were found to score highest TSTQ., A. nodosum high dose (200 mg/kg) was found to be most preventive (p = 0.001) towards THP induced amnesia. Curative regimen: significantly prevented the decrease in day 4 ELT when compared with the respective sham. Combination (DPZ + RVT & DPZ + ASCO) on day 5, after administration of THP (1mg/kg, i.p. for 5 days); attenuated the decrease in TSTQ. prior to retention trial, caused a significant decrease in fifth day TL as compared to TL of fourth day reflecting reversal of memory impairment caused by THP. Cognitive enhancing property of Ascophyllum nodosum might function a predictive index of its clinical efficaciousness to guard and cure against Alzheimer's disease. The combination of donepezil plus resveratrol and donepezil plus A. nodosum extract was also found effective but the effectiveness was not significantly different from the monotherapy of all three compounds.