Ameliorating Effect of Morin Hydrate on Chronic Restraint Stress-induced Biochemical Disruption, Neuronal, and Behavioral Dysfunctions in BALB/c Mice.

Introduction: Morin hydrate (MH) is a bioflavonoid component of many fruits and vegetables. Our previous research demonstrated that MH provides neuroprotection in mouse models of acute restraint stress and sleep deprivation by attenuating hippocampal neuronal damage and enhancing memory. Based on these findings, our study investigated the role of MH in chronic stress-induced neuronal and biochemical perturbations in BALB/c mice.

Methods: Male BALB/c mice were divided into 6 groups (n=6). Groups 1 and 2 received vehicle (10 mL/kg normal saline), groups 3-5 received MH (5, 10, 20 mg/kg IP), while group 6 received ginseng (25 mg/kg) daily and 30 minutes afterward were restrained in a plastic cylindrical restrainer for 14 days.

Results: Immobility time in the forced swim test increased in the MH-treated group, indicating an antidepressant-like effect. Also, a reduction in frequency and duration of open arms exploration was observed in the elevated plus-maze (EPM) test in stressed mice, and administration of MH (5, 10, 20 mg/kg, IP) reversed these effects. An increase in blood levels of glucose, triglycerides, total cholesterol, and brain malondialdehyde and nitrite levels was observed in the stressed groups, which was reversed by MH. Furthermore, MH reversed the stress-induced reduction in HDL cholesterol and glutathione (GSH) levels and attenuated stress-induced alterations in the prefrontal cortex and hippocampus.

Conclusion: Our findings suggest that MH attenuated chronic restraint stress-behavioral and biochemical perturbations, probably due to its capability to decrease oxidative stress and brain neuronal damage.

Highlights: Chronic stress perturbs physiological and psychological homeostasis;Morin hydrate normalized chronic stress-induced biochemical disruptions;Morin hydrate attenuated structural changes in prefrontal cortex and hippocampus.

Plain language summary: Stress is a state of being overwhelmed by demands exceeding the personal and social means of coping. Exposure to excessive stress has resulted in disruption of neurochemical and physiological processes, which sometimes manifest as behavioural abnormalities. Therefore to cope with the stressful life style, there is need to develop a therapeutic agent of plant origin. Morin hydrate is a flavonoid with known antioxidant and neuroprotective properties; however, its effect in a stressful condition has not been studies. The study thus evaluated ameliorating effect of Morin hydrate on chronic restraint stress-induced biochemical disruption, neuronal and behavioral dysfunctions in BALB/c mice. To achieve this, mice were exposed to chronic restraint stress protocol for fourteen days. Behavioural changes were examined using various techniques. The vital parameters like antioxidant, glucose and nitrite levels were also taken. Our findings show that Morin hydrate prevented behavioral abnormalities and damage to the brain cells. It also inhibited stress-induced biochemical disturbance.