Contraceptive effect of Uncaria tomentosa (cat's claw) in rats with experimental endometriosis.

PURPOSE Evaluate the histological changes in parenchyma's epithelial layer of the uterus and ovarian of rats with induced endometriosis, treated with Uncaria tomentosa extract. METHODS 29 rats with experimental endometriosis, were selected and divided in three groups: The uncaria group received 32 mg/ml of Uncaria tomentosa extract, 1 ml administered daily and the placebo group received 1 ml of saline 0.9% per day, during for 14 days (both groups); the leuprolide group received leuprolide acetate 1mg/kg body weight applied single subcutaneous dose. In the 15th day of treatment the uterine horn and ovaries were removed for histopathological analysis. RESULTS The uncaria group presented nine samples (90%) with immature ovarian follicles, whereas the placebo group did not present any case and in the leuprolide group there were eight rats (88%) with the same change. The placebo group showed mature corpus luteum in all animals, occurring less frequent in uncaria (10%) and leuprolide (22%) groups. The uterine epithelium showed weak proliferative in nine (90%) samples of the uncaria group, in two (20%) animals in the placebo group and seven (77.8%) rats in the leuprolide group. CONCLUSIONS The findings suggest that Uncaria tomentosa has contraceptive effect.