RESUMEN
Background: Morinda lucida leaves and fruits of Capsicum frutescens are used locally in the management of fever in Nigeria. No scientific credence has been lent to this claim. Objective: To investigate the antipyretic effect and potency of aqueous extracts of Morinda lucida leaves and fruits of Capsicum frutescens in albino rats. Method: Brewer's yeast was used to induce pyrexia. Thirty animals were divided into six groups. Group A was orally administered normal saline (103 mg/kg). Group B was served indomethacin (5 mg/kg), while groups C and D received aqueous extract of Capsicum frutescens at 100mg/kg and 200mg/kg, 17 hours post induction of pyrexia. Groups E and F were administered extract of Morinda lucida at the same doses. Rectal temperature of the animals was taken at 60-, 90- and 120-minutes post-treatment. Results: Both C. frutescens and M. lucida produced significant reduction (p<0.05) in rectal temperature after 120 minutes in the rats compared with animals in the control group. Also, the antipyretic activities of the two extracts at 100mg/kg and 200mg/kg were comparable to 5mg/kg of indomethacin, with apparent dose dependence in the antipyretic activities of both extracts. Conclusion: Morinda lucida leaves and fruits of Capsicum frutescens exhibit dose-dependent antipyretic activities.