Soaked almonds exhibit vitamin E-dependent memory protective effect in rodent models

Abstract

Background and Objective: It is believed in South-Asian traditions that a small dose of over-night soaked almonds taken in empty stomach have the potential to improve memory. This study aimed to investigate the comparative efficacy of whole and soaked almonds together with vitamin E estimation, given with or without food, for their memory protective effects in different animal models. Methodology: In study 1, different groups of mice (n = 9-10) were fed with three different doses (3, 6 and 12 g kg-1) of almonds (whole, soaked and blanch-control) for 14 days. Memory protection was assessed using Morris water maze (MWM) in scopolamine-induced amnesia. Afterwards, mice were sacrificed and acetylcholinesterase (AChE) inhibition in hippocampus and frontal cortex was estimated. In study 2, High Fat Diet (HFD) was given to rats (n = 8) for 6 weeks for inducing memory impairment, together with different doses (1, 2 and 4 g kg-1) of almonds (whole, soaked and blanch-control). Learning ability was tested through MWM performance in the last week. Besides, HPLC analysis was performed to see the effect of soaking on vitamin-E content of almonds. Results: Almond supplementation prevented scopolamine-induced amnesia in mice and improved learning ability in HFD-fed rats, respectively. Soaking led to an increase in vitamin-E content of almonds. Soaked almonds, consumed without food, protected memory and enhanced learning ability at a lower dose than the whole almonds in both models. With a dose-dependent trend, soaked almonds without food were found to be more effective in improving MWM performance and inhibiting AChE in hippocampus and frontal cortex. Conclusion: It is concluded that overnight soaking which enriches the vitamin-E content of almonds, effectively ameliorates memory impairments at low doses when consumed in empty stomach.