Neuropharmacological effects of an ethanolic fruit extract of Xylopia aethiopica and xylopic acid, a kaurene diterpene isolate, in mice.

Abstract

Background: Even though the central analgesic effects of Xylopia aethiopica (XAE) and xylopic acid (XA) have been reported, XAE and XA have however not been evaluated for their effects on other neurological functions. Objectives: To determine the effects of XAE and XA on spontaneous activity, neuromuscular function, convulsive threshold and sedation as well as their interaction with hepatic enzymes Methods: The activity meter, rota rod, PTZ-induced convulsion and pentobarbitone-induced sleep tests were used to evaluate spontaneous activity, neuromuscular function, convulsive threshold and sedation respectively in mice. Effects of hepatic enzyme inhibition and induction were estimated using duration of pentobarbitone induced sleep. Results: XAE and XA showed significant central nervous system depressant effects in pentobarbitone-induced hypnosis and spontaneous activity test. Both XAE and XA showed neuromuscular coordination impairment tendency above 300 mg/kg. Whereas XAE significantly increased seizure threshold at all doses tested, XA had no effect on PTZ-induced convulsion. XAE may induce hepatic enzymes at lower doses whereas XA showed a bidirectional effect by inhibiting hepatic enzymes at lower doses and inducing hepatic enzymes at higher doses. Both XAE and XA may however be metabolized by hepatic enzymes. Conclusion: Xylopic acid and the fruit extract of Xylopia aethiopica have significant central nervous system depressant effects in mice