Vitamin C Alleviates Neurobehavioral Deficits, IGF1 Expression, and Neuronal Damage Induced by Chronic Social Isolation Stress in the Hippocampus of Adult Male Rats

Social isolation stress (SIS) is associated with emotional and cognitive deficits. Here, we examined the impact of prolonged treatment with vitamin C on memory work and anxiety-like actions in chronic SIS rats and its possible hippocampal protective mechanism. Thirty-two male Wistar rats were grouped into control, vitamin C, SIS, vitamin C + SIS groups (n = 8 for each). Individual housing was designed as a model of SIS. Rats received vitamin C (500 mg/kg/day) or saline by gavage for 4 weeks. Memory and anxiety-like behavior were assessed in the passive avoidance and elevated-plus maze tests, respectively. Moreover, Nissl staining and western blotting were conducted to evaluate neuronal cells number and IGF1 level in the hippocampus, respectively. SIS significantly enhanced anxiety and impaired memory retention compared to control rats, while these impacts were reversed by vitamin C. SIS also decreased CA3neuronal number compared to control group, while vitamin C restored CA3 neuronal number to control levels. Finally, SIS decreased the hippocampal IGF1, and vitamin C restored the hippocampal IGF1 to control values. Our results show anxiolytic effects of vitamin C followed by the restoration of cognitive function and hippocampal neurons and suggest that hippocampal IGF1 may be one of the main components underlying these anxiolytic and improved memory effects.