Screening of Neuropharmacological Activities of Naringi crenulata (Roxb.) Nicolson Leaves

Purpose: Although the global prevalence of psychological disorders is increasing continually, the efficacies of therapeutic strategies are still very limited. Oxidative stress has been implicated in the pathogenesis of psychiatric disorders and substances possessing antioxidant activity can alleviate the mentioned conditions. Therefore, we hypothesized that Naringi crenulata (Roxb.) Nicolson leaves, a medicinal plant claimed for nerve tonic, also possess neuropharmacological activities which provide an advantage for psychiatric disorders.

Methods: The present study was carried out to perform neuropharmacological screening methods on sedatives and hypnotics (Phenobarbitone sodium-induced sleep latency and sleep time and Motor coordination activity), anxiolytics (elevated plus maze and open field test), anti-depressants (forced swim test and L-dopa induced hyperactive aggressive behaviour in mice) and anticonvulsants activities (PTZ and MES induced convulsions) in Swiss Albino mice and Sprague Dawley rats.

Results: The methanolic extract of a higher dose of Phenobarbitone sodium in Naringi crenulata induced sleep latency and sleep time significant results. The extracts of Naringi crenulata showed a significant dose-dependent increase in muscle relaxation in motor coordination activity. In the experiment of PTZ-induced convulsions, the latency of seizures was prolonged by the extracts in a dose-dependent manner. Even in MES-induced convulsion, the results were extremely significant for the 400mg/kg of MENC. The depressant effect was observed to be significant to the extracts of the herb in the Open Field test and also for the Elevated Plus Maze apparatus. In the Forced Swim Test, MENC (400 mg/kg) significantly lengthened the time spent immobile (p <0.01), indicating a CNS depressive impact. Lastly in L-dopa-induced hyperactive aggressive behaviour in mice, results suggest that NC has antidepressant efficacy due to its influence on the serotonergic, noradrenergic, and dopaminergic systems.

Conclusion: The methanolic extract of Naringi crenulata (Roxb.) Nicolson leaves showed significant neuroprotective activity. So, the extracts of Naringi crenulata can be used for the treatment of a wide variety of neurological ailments in humans.