Neuromodulatory effects of hydro-ethanol extract of Parinari curatellifolia leaf in mice

Purpose: To investigate the neuromodulatory activities of the hydro-ethanolic extract of Parinari curatellifolia (HEPC) leaves of the family Chrysobalanaceae in mice. Method: The open field, hole cross, hole board, climbing, elevated plus-maze, tail suspension and ketamine-induced sleeping time tests were conducted on mice groups (n = 3) to which HEPC 200, 400, and 800 mg/kg (per os) or standard central nervous system drugs (20 mg/kg imipramine and 20 mg/kg fluoxetine) intramuscularly were administered 30 min earlier. Results: Imipramine, HEPC, and fluoxetine significantly decreased (p < 0.05) the frequency of hole crossing, head dipping and locomotory activities in the animals. The immobility period during tail suspension was significantly increased (p < 0.05) in the group treated with 400 and 800 mg/kg HEPC but was significantly decreased (p < 0.05) in the imipramine group. The duration of chain climbing significantly increased (p < 0.05) after treatment with 400 and 800 mg/kg HEPC in comparison to the climbing time observed in the imipramine group. The frequency of open arm entry was significantly higher (p < 0.05) in the imipramine group compared to open arm entries in the 400 and 800 mg/kg HEPC-treated groups. Ketamine-induced sleep time was not prolonged with 200, 400 and 800 mg/kg HEPC, when compared with the standard drugs used. Conclusion: P. curatellifolia extract causes sedation and muscle relaxation but does not abolish anxiety behaviour in mice. The findings, therefore, provide some scientific evidence validating the use of Parinari curatellifolia extract in the folkloric management of insomnia.