Investigation of CNS depressant and muscle relaxant effects of the ethnomedicinal plant Macropanax dispermus on Swiss Albino mice and its effect against oxidative stress.

Background and objective: Since plant-based natural drugs are widely accepted in modern times and possess numerous pharmacological effects with an extensive therapeutic range, an ethnomedicinal plant native to Bangladesh was selected to investigate for investigation of its various pharmacological effects. Macropanax dispermus has been traditionally used and has demonstrated numerous pharmacological effects in preclinical investigations. Therefore, this research aimed to assess the central nervous system (CNS) depressant and antioxidant activities of the crude methanol extracts of the stem barks (MDMS), leaves (MDML), and their different fractions.

Methods: The CNS depressant activity was assessed using the hole cross, rota-rod, and elevated plus maze tests on Swiss Albino mice, while the antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl free radical, hydrogen peroxide (H₂O₂) nonradical scavenging, and ferric reducing power assays.

Results: The conducted assays successfully demonstrated that the chloroform fraction of MDML is a significantly (P < 0.001) effective CNS depressant, muscle relaxant, and anxiolytic agent with excellent antioxidative effects compared to standard and control. The aqueous fraction of MDML also acted as a significantly (P < 0.001) active CNS depressant and muscle relaxant, and it was a highly active ferric-reducing agent. All effects were dose and concentration-dependent.

Conclusion: The presence of various phytochemicals might contribute to these activities. However, further research is suggested to isolate their active compounds and evaluate their mechanisms of action.