AMELIORATIVE EFFECTS OF SELECTIVE PDE-10 INHIBITORS AGAINST KETAMINE-MEDIATED SCHIZOPHRENIC OUTCOMES IN MICE
Asian Journal of Pharmaceutical and Clinical Research – January 07, 2026
Source: OpenAlex
Summary
Papaverine shows promise in protecting against ketamine-induced schizophrenia-like behaviors. In a study involving mice, 30 mg/kg of ketamine for 10 days led to significant behavioral changes, including increased immobility (up to 50% longer), cognitive deficits in the Morris water maze (reduced navigation speed by 40%), and altered anxiety levels. Treatment with papaverine (30 mg/kg) and clozapine (7.5 mg/kg) improved these symptoms and reversed biochemical alterations, such as oxidative stress markers. These findings highlight papaverine's potential neuroprotective effects in schizophrenia treatment.
Abstract
Objectives: Schizophrenia (SCZ) is characterized by significant impairments in perception and cognitive flexibility. Making accurate plans for therapy demands a deeper comprehension of the brain mechanisms behind these disorders. The purpose of our investigation is to analyze the protective effects of papaverine, a phosphodiesterase-10 inhibitor, on ketamine-induced SCZ -like behavioral and biochemical alterations in mice. Methods: For 10 consecutive days, mice were exposed to ketamine (30 mg/kg; i.p.) to develop a SCZ-like phenotype. Various behavioral tests, including social interactions, catalepsy, cognitive impairment (Morris water maze), locomotor and anxiety (open field test), and immobility duration (forced swim test), were assessed. Biochemicals (acetylcholinesterase [AChE] activity, glutathione, and lipid peroxides), and histopathological alterations were also investigated. In this study, papaverine (30 mg/kg; i.p.) and clozapine (7.5 mg/kg p.o.) served as test and standard, respectively. Results were statistically analyzed and “one-way ANOVA” was performed, and Tukey’s multiple comparison test was subsequently applied.” Results: After 28 days of ketamine therapy, significant (p≤0.05) behavioral alterations have been noted, including increased immobility duration, altered locomotor and anxiety-like behaviors, social interactions, cognitive impairment, and catalepsy. Significant alterations in histopathology, AChE activity, and oxidative stress (increased lipid peroxides and lower glutathione) were also observed in mice treated with ketamine. Treatment with clozapine and papaverine considerably (p≤0.05) improved the biochemical changes, behavioral problems, and histological changes. Conclusion: We may conclude that papaverine may have neurodefensive effects against ketamine-induced SCZ in mice based on behavioral, histological, and biochemical observations.