Safety evaluation of long term oral treatment of methanol sub-fraction of the seeds of Carica papaya as a male contraceptive in albino rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The manuscript is one of the series of attempts in authenticating scientific documentation of the seeds of Carica papaya being traditionally used for contraception. AIMS OF THE STUDY: To establish safety of the methanol sub-fraction (MSF) of the seeds of Carica papaya as a male contraceptive following long term oral treatment. MATERIALS AND METHODS: MSF was administered orally to albino rats at multiples of contraceptive dose (CD) at 50 (1x), 100 (2x), 250 (5x) and 500 (10x)mg/kg body weight daily for 52 weeks. Body weight, organs weight, morbidity, mortality, clinical chemistry, sperm analysis, histopathology and serum testosterone were evaluated to assess the safety and contraceptive efficacy. RESULTS: MSF treatment at various dose regimens, daily for 52 weeks did not show significant changes in body weight, organs weight, food and water intake and pre-terminal deaths compared to those of control animals. Sperm count and viability in 50mg/kg body weight treated animals and the weight of epididymis, seminal vesicle and prostate of all the treated animals showed significant reduction compared to control. Cauda epididymal spermatozoa of 50mg/kg body weight treated animals were immotile. Azoospermia was observed in 100, 250 and 500 mg/kg body weight treated animals. Serum clinical parameters, serum testosterone and histopathology of vital organs were comparable to those of control animals. Histology of testis revealed adverse effects on the process of spermatogenesis, while the histology of epididymis, seminal vesicles and ventral prostate showed no changes compared to control. CONCLUSION: The long term daily oral administration of MSF affects sperm parameters without adverse side effects and is clinically safe as a male contraceptive.