Molecular mechanisms involved in the prevention and reversal of ketamine-induced schizophrenia-like behavior by rutin: the role of glutamic acid decarboxylase isoform-67, cholinergic, Nox-2-oxidative stress pathways in mice

Mounting evidences have shown that nicotinamide adenine dinucleotide phosphate oxidase-2 (Nox-2) pathway modifies glutamic-acid decarboxylase-67 (GAD67) (GABAergic enzyme) and cholinergic systems via oxidative-nitrergic mechanisms in schizophrenia pathology. Rutin, a neuroactive antioxidant compound, with proven neuroprotective property has been shown to reduce schizophrenic-like behavior in mice. This study sought to investigate the mechanisms of action of the psychopharmacological activity of rutin in the preventive and reversal effects of ketamine-induced schizophrenic-like behavior, oxidative-nitrergic stress, cholinergic and GABAergic derangements in mice. In the preventive treatment, male mice were given rutin (0.1, 0.2 and 0.4 mg/kg) or risperidone (0.5 mg/kg) orally for 14 days prior to ketamine (20 mg/kg, i.p.) treatment from the 8 to 14th day. However, in the reversal treatment, ketamine was given for 14 days prior to rutin and risperidone. Behavioral (open-field, social-interaction and Y-maze tests), biochemical (oxidative/nitrergic stress markers, acetylcholinesterase activity), immunohistochemical (GAD67, Nox-2) and neuronal cell deaths in the striatum, prefrontal cortex, and hippocampus were evaluated. Ketamine-induced behavioral impairments were prevented and reversed by rutin. Exposure of mice to ketamine increased malondialdehyde, nitrite contents, acetylcholinesterase activity, neuronal cell death and Nox-2 expressions in the striatum, prefrontal cortex and hippocampus. Conversely, these derangements were prevented and reversed by rutin. The decreased glutathione levels due to ketamine were marked increased by rutin. Rutin only prevented ketamine-induced decrease in GAD67 expression in the striatal-hippocampal region. Altogether, the study showed that the prevention and reversal treatments of mice with rutin attenuated ketamine-induced schizophrenic-like behaviors via reduction of Nox-2 expression, oxidative/nitrergic stresses, acetylcholinesterase activity, and increased GAD67 enzyme.