Methanolic extract of Jasminum humile L. leaves possess anxiolytic activity mediated via the gabaergic system in the central nervous system of mice

Abstract

Background: Jasminum humile L. is one of the traditional medicinal plants from Oleaceae family. It is abundantly available in Afghanistan, Pakistan, Nepal, Burma, the Himalayas, and southwest China. The tea of leaves and barks are used conventionally in the treatment of various diseases such as central nervous system disorder, anti-inflammatory, and antiseptic. Aim: The present study was undertaken to investigate the anxiolytic effect of methanolic extract of J. humile L. leaves (MEJHL). Materials and Methods: Anxiolytic activity of J. humile L. leaves extracts were evaluated using Elevated Plus-Maze (EPM) and light/dark exploration models. The motor coordination and sedative effect were also observed using Rota Rod apparatus, actophotometer, and ketamine-induced sleeping time, respectively. Brain neurotransmitters like GABA level were estimated by validated methods. Results: From the acute toxicity studies, extracts of J. humile L. leaves were found to be nontoxic. Among all extracts, the only methanolic extract showed significant (P < 0.05) anxiolytic activity. Preliminary phytochemical screening revealed the presence of carbohydrates, flavonoids, and alkaloids in the MEJHL. The results of anxiolytic models clearly depicted that MEJHL at the dose of 200 mg/kg significantly (P < 0.05) increased the number of entries and the average time spent in the open arms and light compartment of the EPM and light/dark models, respectively. In the case of motor coordination activity, the MEJHL does not cause any significant effect (at any dose) on the latency to fall off from the Rota Rod bar compared to the control group. Moreover, no remarkable effects in actophotometer and on ketamine-induced sleep latency and total sleeping time induced by ketamine was observed. Results of neurotransmitter estimation in the whole brain and the cerebellum revealed the increased concentration of GABA was similar to standard drug diazepam. Conclusions: The presence of alkaloids in the methanolic extract of this plant can serve as a potential resource for natural psychotherapeutic agents against anxiety with less sedation.