Neuropharmacological Assessment of the Hydroethanolic Leaf Extract of Calotropis procera (Ait). R. Br. (Apocynaceae) in Mice

BACKGROUND: Calotropis procera has been widely used traditionally for its analgesic and anti-inflammatory effects. It is also reportedly used in ethnomedicine for mental health disorders including epilepsy even in the absence of supporting scientific data. Thus, the potential of the plant to affect neurological functions was evaluated. METHODS: Irwin's test was performed to determine the effect of the oral administration of the extract (30–3000 mg kg(−1)) on gross behaviour and physiological function. The activity meter, rotarod, pentylenetetrazol- (PTZ-) induced convulsion, pentobarbitone-induced sleep test, and the tail immersion tests were used to evaluate the spontaneous activity, neuromuscular function, convulsive threshold, sedation, and analgesic effects of the Calotropis procera extract (30–1000 mg/kg), respectively, in mice. RESULTS: Calotropis procera extract (CPE) exhibited significant (p < 0.0001) anticonvulsant and analgesic effects. There was a significant increase in withdrawal latency of the CPE-treated animals in the tail immersion test for analgesia (p < 0.0001), while latency and duration of PTZ-induced convulsions were positively modulated. Calotropis procera extract showed significant (p < 0.0001) central nervous system depressant effects in pentobarbitone-induced hypnosis at 100–1000 mg/kg and spontaneous activity test (30–1000 mg/kg). The extract also depicted impaired motor coordination at 100–1000 mg/kg dose levels. LD(50) was estimated to be above 1000 mg kg(−1). CONCLUSIONS: Calotropis procera extract has significant central nervous system depressant and analgesic effects in mice.