Evaluation of the protective role of the seed coat of Caesalpinia bonduc L.Roxb. against chronic fatigue syndrome induced by forced swimming in rats

Introduction: Chronic Fatigue Syndrome (CFS), also known as myalgic encephalomyelitis, is a complex, multi system disorder characterized by persistent and unexplained fatigue, cognitive impairment, sleep disturbances, autonomic dysfunction, and post-exertional malaise. These symptoms markedly reduce patients’ functional capacity and quality of life. Early diagnosis and effective intervention are crucial to minimizing morbidity and long-term disability. Objective: The present study aimed to evaluate the therapeutic potential of the ethanolic extract of the seed coat of Caesalpinia bonduc L. Roxb. (EESCB) against forced swimming-induced CFS in experimental rats and to investigate its possible underlying mechanisms, with particular emphasis on behavioral and oxidative stress parameters. Methods: CFS was induced in Wistar rats by subjecting them to a forced swimming protocol—continuous swimming for 15 minutes daily for 28 consecutive days. Animals were divided into five groups (n = 6): Group I (naïve control), Group II (stress control), Group III (standard, treated with Imipramine HCl), Group IV (EESCB 250 mg/kg), and Group V (EESCB 500 mg/kg). Fatigue severity was assessed by recording immobility duration on days 1, 7, 14, 21, and 28. Twenty-four hours after the final swimming session, behavioral assessments were conducted, including anxiety evaluation using the Elevated Plus Maze, muscle strength via the rota-rod test, and locomotor activity using an actophotometer. Oxidative stress markers, including catalase activity and malondialdehyde (MDA) levels, were measured to assess antioxidant status. Results: Imipramine- and EESCB-treated groups (both doses) exhibited a significant reduction in immobility duration and anxiety-like behaviour compared with the stress control group (p < 0.05). These groups also demonstrated a significant improvement in locomotor activity and muscle grip strength. Biochemically, EESCB administration led to a marked decrease in MDA levels and a significant elevation in catalase activity, indicating attenuation of oxidative stress. The higher dose (500 mg/kg) showed a more pronounced effect, approaching the efficacy of the standard drug. Conclusion: Therefore, the results highlighted that, EESCB has a prominent protection against experimentally induced CFS which is considered as beneficial for alleviating exercise- induced fatigue. The dose-dependent activity was observed with EESCB due to presence of enormous phytoconstituents.