Neuroprotective effects of naringenin on nicotine-induced anxiety and depression: Involvement of monoaminergic systems, oxidative stress, and neuroinflammation on male rats

Introduction: Nicotine withdrawal during adolescence induces severe neurobehavioral disturbances and neurochemical alterations, including anxiety, depression, affective dysregulation, oxidative stress, and neuroinflammation. Current therapeutic options for managing nicotine dependence remain suboptimal. This study investigated the neuroprotective potential of naringenin (NG) in alleviating behavioral and biochemical sequelae of nicotine withdrawal in adolescent rats. Materials and methods: Male adolescent Wistar rats were allocated into eight groups and subjected to nicotine exposure (1 mg/kg) and NG treatment (50 or 100 mg/kg) across nicotine exposure and withdrawal phases. Behavioral assays (OFT, EPM, FST) were employed to evaluate anxiety- and depression-like behaviors. Neurochemical assessments of dopamine, serotonin, their metabolites (DOPAC, 5-HIAA), MAO-A activity, oxidative stress markers (MDA, Nit), antioxidant enzymes (SOD, CAT, TT), and neuroinflammatory/neurodegenerative biomarkers (GFAP, IL-10, BDNF, NSE) were conducted in prefrontal cortex (PFC) homogenates. Results: Nicotine withdrawal significantly induced anxiety- and depression-like behaviors, disrupted monoaminergic balance, elevated MAO-A activity, and triggered oxidative and neuroinflammatory responses in the PFC. NG administration, particularly at 100 mg/kg across both phases, significantly ameliorated behavioral impairments, restored neurotransmitter homeostasis, inhibited MAO-A, suppressed lipid peroxidation and nitrosative stress, enhanced antioxidant defenses, reduced GFAP and NSE expression, and restored IL-10 and BDNF levels. Conclusion: NG exerts anxiolytic, antidepressant, antioxidant, and anti-inflammatory effects, likely via modulation of monoaminergic pathways and suppression of neuroinflammation and oxidative stress. These findings underscore the potential of NG as a promising candidate for mitigating neuropathological effects associated with nicotine withdrawal-induced neuropathology, particularly during adolescence.