AQUEOUS LEAF EXTRACT OF CARICA PAPAYA (CARICACEAE) LINN. CAUSES LIVER INJURY AND REDUCED FERTILITY IN RATS

Objective: Dried Carica papaya (Caricaceae) leaves have been used in traditional medicine as a contraceptive. The objective of the present study was to evaluate the safety of the aqueous leaf extract of Carica papaya and study its effects on fertility in rats.Methods: The aqueous extract of Carica papaya was administered as single doses to Sprague Dawley rats in an acute study. Animals were observed over a 24 h period for various signs of toxicity. In a separate experiment, the extract was administered to different groups of rats daily for 14 d in a sub-acute study. Animals were observed each day and sacrificed on the 15th day. Organs were then harvested for histopathology. Reproductive studies were also carried out in both male and female rats by administration of the extract at different doses. Markers for fertility were assessed in the rats by determination of fertility indices in the female and sperm analysis in the males. Hormonal assays were also performed.Results: In the acute toxicity study, the LD50 (lethal dose) of the aqueous extract was above 5000 mg/kg with no signs of autonomic or other symptoms of toxicity. In the sub-acute study, treatment of rats with extract (10-500 mg/kg; p. o) for 14 d had no effect on the formed elements of blood or haemoglobin. However, the levels of alkaline phosphatase (AP), gamma glutamyl transferase (GGT) and bilirubin (BIL) increased dose-dependently, suggesting a possible damage to the hepato-billiary system. In the reproductive studies in adult male and female rats, administration of the aqueous leaf extract (10-500 mg/kg; p. o) for 14 d to male rats resulted in significant reduction in sperm count, sperm motility, sperm viability and testosterone. Transverse sections of testes exhibited mild to moderate atrophy. Treatment of female rats with the extract also showed reduction in fertility and increases in maternal mortality and embryolethality.Conclusion: The study shows that the aqueous extract of Carica papaya has the potential to cause liver injury and adversely affect reproduction in rats. Keywords; Carica papaya, Fertility, Toxicity, Sperm count, Testosteron