Abstract

Exposure to chronic stress results in anxiety, depression, and impaired cognitive functions. Previously it was shown that prolonged stress associated memory impairment and behavioural abnormalities are connected with neuroinflammation. Studies in the preclinical and clinical stages have revealed that herbal medicines have exceptional protective characteristics. This study aims to investigate the beneficial effects of Celastrus paniculatus (CP) and Tribulus terrestris (TT) in an experimental model of depression. Wistar rats were subjected to stress for 2h/day for 10 days in immolisation bags. After the stress induction, these rats were orally administered with Celastrus paniculatus oil (CP) (400 mg/kg/day) and ethanolic extract of Tribulus terrestris (TT) (250 mg/kg/day) for 14 days. In the elevated plus maze (EPM) and open field (OFT) tests, CIS rats displayed increased anxiety-like behaviour. In the forced swim test (FST) and the sucrose preference test, stressed mice displayed behavioural despair and anhedonia, respectively. Recognition and working memory was impaired in stressed condition. Behavioural deficits was associated with decreased BDNF level and increased IL-6, TNF-α levels in the hippocampus and prefrontal cortex. Interestingly, CP and TT treatment for 2 weeks completely ameliorated anxiety, depression and memory in stressed rats. Treatment also restored BDNF, IL-6 and TNF-α levels in the hippocampus and prefrontal cortex. In summary, our results demonstrate that both CP and TT can be beneficial against chronic stress induced neurocognitive deficits and neuroinflammation.

Key words: Tribulus terrestris, Celastrus paniculatus, Chronic Immobilization stress, BDNF, Cytokines, Hippocampus, and Frontal Cortex.