CNS depressant activities of Averrhoa carambola leaves extract in thiopental-sodium model of Swiss albino mice: implication for neuro-modulatory properties

Psychological stress and anxiety have been linked to significant impairments of neurobiological functions. There is a wide range of conditions including neurological disorders such as Alzheimer’s disease and use of certain substances or medications that induce stress and anxiety in humans. Confused state of mind, anxiety and psychological stress have been associated with varying degree of disabilities and poor quality of life in humans. Anxiolytic medications are important modulators of CNS that reduce the anxiety and the related psychological effects in patients. Natural product derived drugs such as galantamine have been shown to possess promising neuro-modulatory properties in neurological disorders. Averrhoa carambola is traditionally used for anti-oxidative, anti-inflammatory, anti-microbial, and anti-ulcerative properties. In this study, we have examined the CNS depressant activity of A. carambola leaves extracts. The neuro-modulatory properties were assessed with the standard protocols that are used to identify such CNS depressant activity and included thiopental sodium-induced sleeping time test, hole cross test, hole board test, and open field test. The extract was found to decrease the motor activity and exploratory behaviour of mice in hole cross, hole board and open field tests. The extract also significantly maximized the duration of sleeping time when administered with thiopental sodium, which also demonstrated the CNS depressant activity. The findings of our study suggest that A. carambola extracts have active CNS depressant and hypnotic properties. However, further studies are warranted for isolation of bioactive constituents and understanding the molecular mechanism and modes of action for such pharmacological effects.