Silymarin Reverses Seizure-Precipitating Effects of Alcohol and Associated Psychiatric Comorbidities, and Neurotoxicity in Pentylenetetrazol Pre-Kindled Mice.

Heavy alcohol consumption has multiple negative cognitive, psychological, and neurobiological consequences for people with epilepsy. However, the psychopharmacological interactions remain unclear with limited therapeutic interventions. In this study, we investigated the diverse impact of alcohol on experimental simulated pentylenetetrazol-induced seizures and alcohol-use disorder, and the effects of silymarin, a polyphenolic compound with neuroprotective properties. Following seven days of ethanol binge exposure (2 g/kg, oral gavage) in mice, maximal and sub-convulsive pentylenetetrazol-induced seizures were administered from days 8 to 14, alongside silymarin (50 and 100 mg/kg) or diazepam (3 mg/kg) oral administration. This study evaluated the interplay between ethanol and pentylenetetrazol-induced seizures, assessing behavioural comorbidities, dysregulation of the hypothalamic-pituitary-adrenal (HPA)-axis, neurochemical and neurotrophic alterations, oxidative stress, and neuroinflammation in the hippocampus, prefrontal-cortex, and striatum, which are involved in the disease. Ethanol increased seizure severity and frequency caused by pentylenetetrazol, and worsened anxiety-like and depressive behaviours, along with spatial working memory deficits linked to higher alcohol preference. These effects were reduced by silymarin. Ethanol also increased corticosterone release and reduced GABA-dependent glutamic acid decarboxylase activity, raising glutamate levels, while decreasing serotonin and brain-derived neurotrophic factor across the studied brain regions. Silymarin significantly reduced neuroinflammatory markers such as myeloperoxidase, TNF-α, IL-6, nitrite, and malondialdehyde, while enhancing IL-10 levels and antioxidant defenses, including catalase, superoxide dismutase and glutathione in the brain regions. These findings suggest alcoholism with alcohol-use disorders worsens epilepsy, notably involving neurochemical imbalance, neurotropic, HPA-axis upregulation, oxidative stress, and neuroinflammation, which were reversed by silymarin.