Neuroprotective effect of Celastrus paniculatus on chronic stress-induced cognitive impairment

Abstract

Objective:Several studies report that chronic stress results in impaired spatial learning and working memory and enhanced anxiety-like behavior. However, not many studies have looked into the possible ways of reversing stress-induced deficits. Celastrus paniculatus (CP), a traditional ayurvedic herbal medicine, was used to treat cognitive deficits in mentally retarded children. CP oil has been reported to have neuroprotective and antioxidant activities. However, the effects of CP oil on chronic stress-induced cognitive deficits are unclear. In the present study, we intended to analyze the neuroprotective effects of CP oil on stress-associated cognitive dysfunctions.Materials and Methods:Chronic stress was induced by subjecting rats to restrainers for 6 h a day for 21 days. CP oil (400, 600 mg/kg) or vehicle was administered intraperitoneally (i.p.) after stress protocol once a day over the next 14 days. Groups used in the present study: normal control, stress, stress + vehicle, stress + CP oil at 2 different doses (400 and 600 mg/kg, i.p.). After the drug treatment, open field and elevated plus maze (EPM) were used to analyze anxiety-like behavior, and partially baited radial arm maze (RAM) and T-maze were used to evaluate spatial learning and memory capabilities. Analysis has been done using two-way ANOVA followed by Bonferroni's post hoc test and one-way ANOVA followed by Tukey's post hoc test.Results:Stressed rats showed enhanced anxiety-like behavior in EPM (P < 0.001) and impaired performance in RAM (P < 0.001) and T-maze tasks (P < 0.001) compared to normal animals. In contrast, CP oil treatment to these rats improved their performance in both RAM (P < 0.001) and T-maze (P < 0.001). In addition, CP oil significantly reduced stress-induced anxiety behavior (P < 0.001).Conclusion:Chronic treatment with CP oil is to improve cognitive abilities in chronically stressed rats. The current study provides a novel perspective on beneficial effect of herbal therapy on stress-induced cognitive dysfunctions.

Short‐term exposure to enriched environment rescues chronic stress‐induced impaired hippocampal synaptic plasticity, anxiety, and memory deficits

“…In the current study, chronic restraint stress enhanced anxiety‐like behavior in the EPM. Previous studies have confirmed enhanced anxiety in different chronic stress models (Anuradha et al, ; Chiba et al, ; Bhagya et al, ). Stress + EE rats showed increased time and entries in the open arms, thus indicating an anxiolytic effect of EE in chronically stressed rats.…”

“…We observed impaired spatial working memory in rats exposed to chronic restraint stress. Previous studies from our lab showed that chronic restraint stress impairs spatial learning and memory in T‐maze and partially baited radial arm maze tasks (Sunanda et al, ; Srikumar et al, ; Ramkumar et al, ; Veena et al, ; Bhagya et al, ). We also observed decreased hippocampal LTP in response to restraint stress, which is in accordance with previous studies (Shors et al, ; Cui et al, ).…”

“…Chronic restraint stress is a reliable animal model of depression with good replicability (Veena et al, , ; Bhagya et al, ; Liu et al, ). Previous studies from our lab show that there was no spontaneous recovery in the spatial learning capabilities and hippocampal neurogenesis of chronically stressed rats after cessation of stress for a 10‐day period (Veena et al, ).…”

“…Recorded video files were coded for behavioral analysis. Data were expressed as the percentage time spent in the open arms [100 × (time in the open arms/total time spent in both arms)] as an index of anxiety‐like behavior and the total number of closed‐arm entries as an index of locomotion (Anuradha et al, ; Bhagya et al, ; Mahati et al, ).…”

“…Working memory was assessed by T‐maze rewarded alternation task. The test was performed as previously described (Sunanda et al, ; Ramkumar et al, ; Bhagya et al, ). An acclimatization session was used to familiarize the rats with the T‐maze.…”