The Impact of Coenzyme Q10 on Cognitive Dysfunction, Antioxidant Defense, Cholinergic Activity, and Hippocampal Neuronal Damage in Monosodium Glutamate-Induced Obesity

Abstract

Background: Obesity, a rising global health issue, is linked to numerous disorders, including cognitive impairment. Objectives: This study investigates the effects of coenzyme Q10 (Co-Q10) on cognitive performance, antioxidant defense, cholinergic activity, and hippocampal neuron damage in rats rendered obese by monosodium glutamate (MSG) exposure. Methods: Forty-eight neonatal male Wistar rats were randomly assigned to one of four groups: Control, MSG, MSG + Q10-10, and MSG + Q10-20. Monosodium glutamate (4 g/kg BW) was administered subcutaneously into the cervical region from postnatal day (PND) 2 to PND 10. Coenzyme Q10 (10 mg/kg BW and 20 mg/kg BW) was administered intraperitoneally from PND 30 to PND 42. At the end of the treatment period, working memory and avoidance learning tests were conducted. Anthropometric data were collected, followed by evaluations of hippocampal catalase (CAT), superoxide dismutase (SOD), acetylcholinesterase (AChE), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels. The density of apoptotic/dark neurons (DN) in the CA₁ and CA₃ regions of the hippocampus was also assessed. Results: Monosodium glutamate treatment increased Body Mass Index (BMI) and Lee Index, impaired working memory and avoidance learning, and reduced CAT, SOD, and GPx activities. Additionally, MSG exposure led to elevated MDA levels, increased AChE activity, and higher DN density in the CA₁ and CA₃ hippocampal regions. Treatment with Co-Q10 resulted in a decrease in BMI, enhanced memory and learning, noteworthy increases in CAT, SOD, and GPx activities in the hippocampus, and reductions in MDA levels, AChE activity, and DN density in the CA₁ and CA₃ regions. Conclusions: Coenzyme Q10 mitigates hippocampal neuronal damage and improves cognitive function in MSG-induced obesity, primarily through its antioxidant and AChE inhibitory properties.