Vitamin E can compensate the density of M1 receptors in the hippocampus of scopolamine-treated rats

Abstract

M1 muscarinic receptor plays a fundamental role in memory and is closely associated with Alzheimer's disease (AD); it has long been assumed as a therapeutic goal. By activating of the cholinergic receptor vitamin E helps with memory retention. But effects of vitamin E on density of M1 muscarinic receptor-immunoreactive (ir) neurons remain poorly understood. The present research aimed to examine the chronic administration effect of vitamin E against scopolamine-induced memory loss and the number of M1 muscarinic receptor-ir neurons of the hippocampus in male rats. Randomly, 42 adult male Wistar rats were divided to six groups: control, Sham-saline: receiving scopolamine + saline, Sham-sesame oil: receiving scopolamine + sesame oil and three experimental groups: receiving scopolamine + vitamin E with different doses (25, 50, and 100 mg/kg/day, i.p.) for 14 days. The passive avoidance task was used for the memory test. Twenty-four hours after behavioral tests, rats' brains were taken and fixed, and after tissue processing, sections were stained using the immunohistochemical technique for M1 muscarinic receptor-ir neurons and cresyl violet for neurons. The injection of scopolamine to rats caused memory impairment and vitamin E treatment could ameliorate it. In the scopolamine-treated groups, the number of CA1 and CA3 pyramidal and dentate gyrus (DG) granular neurons was decreased significantly as compared to the control group. Vitamin E treatment significantly increased neuron numbers in the CA1 and CA3 areas of the hippocampus and DG area. Treatment with vitamin E for 14 days could compensate the loss of M1 muscarinic receptor-immunoreactive neuron numbers induced by scopolamine in the hippocampus. The most effective vitamin E dose was 50 mg/kg/day in this study. In conclusion, vitamin E can compensate the neuronal loss in the hippocampal formation and also it can raise the density of M1 receptor-ir muscarinic neurons after an injection of scopolamine.

Effects of Sesamin, the Major Furofuran Lignan of Sesame Oil, on the Amplitude and Gating of Voltage-Gated Na+ and K+ Currents

“…Similar to the ranolazine or perampanel action on I Na described previously [23,25], the inhibitory effect of SSM on ion currents seen herein may be responsible for its wide spectrum of effects observed in vivo [3,54]. Additionally, caution needs to be taken in the interpretation of sesame oil as a fat-soluble vehicle [55][56][57].…”

Anti-Amnesic and Neuroprotective Effects of Ziziphus Jujuba Aqueous Extract on Scopolamine-Induced Cognitive Impairments in Rats

“…Analysis of the histological sections of scopolamine-treated rats showed a reduction in the number of neuronal cells in the CA1 and CA3 regions of the hippocampus. These results support those of Sayyahi et al [62]. The extract protected the hippocampus from neuronal degeneration in the CA1 and CA3 regions of the hippocampus.…”

Effect of buscopan, a compound that alleviates cramps, on the developing nervous system of the chick embryo

“…Campbell et al exposed female rats at doses of 1.2 and 2.5 mg/kg buscopan in the prenatal period (Campbell & Ramirez, 1980). Apart from these two studies, there were experimental animal studies on buscopan doses varying between 0.15 and 3 mg/kg in the literature (Luyten, Nuyts, & Beckers, 2017; Parrott, 1986; Sayyahi, Jahanshahi, Amini, & Sepehri, 2018). Considering the clinical use and experimental study doses of buscopan in the literature, five different dose adjustments were made according to the fertilized chicken egg weight.…”