Neuroprotective Effects of Citrus reticulata in Scopolamine-Induced Dementia Oxidative Stress in Rats

Abstract

The purpose of the study was to evaluate the potential effects of Citrus reticulate (mandarin) peel methanolic extract (MPME) on memory dysfunction in rats. Memory impairment was produced by scopolamine (1.4 mg/kg, intraperitoneally injected). Brain acetylcholinesterase enzyme (AChE) activity was measured to assess the central cholinergic activity. This study also investigated the effect of scopolamine on norepinephrine, dopamine and serotonin content in rat hippocampus, striatum and cerebral cortex. In addition, the levels of brain lipid peroxidation (LPO), nitric oxide (NO) and glutathione (GSH) were estimated to assess the degree of oxidative stress. Scopolamine administration induced a significant impairment of central cholinergic activity in rats, as indicated by a marked increase in AChE activity. The impairment of the cholinergic system was associated with a significant alternation in brain monoamines. Scopolamine administration also caused oxidant damage (elevation in LPO and NO and reduction in GSH levels). Pretreatment of MPME (250 mg/kg, orally administered) significantly reduced scopolamine-induced alternation in brain monoamines with an attenuation of scopolamine-induced rise in brain AChE activity and brain oxidative stress. It is concluded that administration of mandarin peel extract, demonstrating antioxidant activity, may be of value for dementia exhibiting elevated brain oxidative status.

Green leafy vegetables from two Solanum spp. (Solanum nigrum L and Solanum macrocarpon L) ameliorate scopolamine‐induced cognitive and neurochemical impairments in rats

“…Nevertheless, El‐Khadragy et al. () reported significant alterations in brain monoamines in rats administered 1.4 mg/kg SCOP. Thus, we hypothesize that the significant reduction in MAO activity induced by SCOP in this study could be as a result of the higher dose used (2 mg/kg).…”

“…It is noteworthy that previous reports show no significant effect of SCOP on brain MAO activity (Bihaqi, Singh, & Tiwari, 2011;Liu et al, 2017;Rubio et al, 2017); we, however, observed that these studies reported administration of 1 mg/kg SCOP. Nevertheless, El-Khadragy et al (2014) reported significant alterations in brain monoamines in rats administered 1.4 mg/kg SCOP. Thus, we hypothesize that the significant reduction in MAO activity induced by SCOP in this study could be as a result of the higher dose used (2 mg/kg).…”

“…The use of the muscarinic cholinergic receptor antagonist scopolamine to induce animal models of amnesia and cognitive dysfunctions has been widely accepted (Akinyemi, Oboh, Oyeleye, & Ogunsuyi, ; El‐Khadragy, Al‐Olayan, & Abdel Moneim, ; Marisco et al., ). The ability of scopolamine to impair memory is characterized by dysfunction of the central cholinergic system of neurotransmission, impaired neuronal antioxidant status, and alteration in functional neurochemistry (Akinyemi et al., ; El‐Khadragy et al., ; Goverdhan, Sravanthi, & Mamatha, ). This has therefore made scopolamine a useful drug in simulating human dementia and AD (Akinyemi et al., ; Kwon, Kim, Lee, & Jang, ; Sadek, Khan, Darras, Pockes, & Decker, ).…”

“…The use of the muscarinic cholinergic receptor antagonist scopolamine to induce animal models of amnesia and cognitive dysfunctions has been widely accepted El-Khadragy, Al-Olayan, & Abdel Moneim, 2014;Marisco et al, 2013). The ability of scopolamine to impair memory is characterized by dysfunction of the central cholinergic system of neurotransmission, impaired neuronal antioxidant status, and alteration in functional neurochemistry El-Khadragy et al, 2014;Goverdhan, Sravanthi, & Mamatha, 2012).…”

Oxidant/Antioxidant Imbalance and the Risk of Alzheimer's Disease

“…Increased concentration of acetylcholine leads to improve the communication between the nerve cells that use acetylcholine as a neurotransmitter, which may in turn temporarily improve or stabilize the symptoms of Alzheimer's disease [13-14]. This class of medications may be used for three years, possibly longer.…”