Carica papaya leaf extract ameliorates catalepsy and depression but not convulsion in mice

Abstract

Carica papaya is a common herbaceous plant consumed as food and used as a therapeutic agent. This study examined the effect of the aqueous extract of C. papaya leaves on catalepsy, depression and convulsion. Phytochemical screening and determination of the mean lethal dose were carried out. Haloperidol-induced catalepsy, the forced swim test, the tail suspension, pentylene tetrazole (PTZ)-induced seizures and maximal electroshock (MES) tests were used to evaluate the effects of C. papaya on catalepsy, depression and convulsion at 3 dose levels -100, 200 and 400 mg/kg. Carbohydrates, flavonoids, saponins, steroids and tannins were detected and the mean lethal dose was determined to be greater than 5000 mg/kg. The extract significantly (p<0.05) reduced mean cataleptic score in haloperidol - induced catalepsy at higher doses. C. papaya also significantly (p<0.05) reduced periods of immobility in both the forced swim and tail suspension tests at all doses used but was not seizure-protective in both the PTZ- and MES-induced tests. C. papaya possesses central nervous system modifying activity.