Ketamine induces schizophrenia-like condition in rats via amendment of neurotransmitters and behavior: antipsychotic effect of silkworm pupae

Abstract

Background The pupae of mulberry silkworms, family Bombycidae, possess a great number of proteins that cover all of the necessary amino acids obligatory for well-being. Objective In this study, we aimed to evaluate the probable antipsychotic effect of pupae of mulberry silkworms in a rat model of schizophrenia prompted by ketamine on the cerebral cortex, hippocampus, and striatum, the brain areas involved in neuropsychiatric complaints. Materials and methods To this end, male albino rats were classified as follows: group 1 was the control group; group 2 animals were administered 135 mg/kg, p.o. silkworm pupae for 3 weeks; group 3 animals received vehicle for 3 weeks, and ketamine (30 mg/kg, i.p.) for the last 5 consecutive days of the experiment; and group 4 was the silkworm pupae and ketamine-treated group. Results The results revealed that treatment with silkworm pupae improved the exploration of schizophrenic rats in the novel object test and almost normalized their locomotor activity in the open field test. Additionally, silkworm pupae modulated the content of catecholamines and oxidative state in the cerebral cortex, hippocampus, and striatum of schizophrenic rats; however, the acetylcholine esterase activity was restored in the hippocampus only. Histopathological damages caused by ketamine are partially reduced by silkworm pupae. Conclusion Our data suggest that silkworm pupae, via neurobehavioral modulatory pathway, exhibit beneficial effects against psychomimetic influence of ketamine.