Experimental endometriosis reduction in rats treated with Uncaria tomentosa (cat’s claw) extract

Objective: The aim of this study was to analyze the macroscopic and histological changes that occur in experimental endometriosis after treatment with Uncaria tomentosa. 

Study design: Experimental endometriosis was induced in twenty-five female Wistar rats. After three weeks, 24 animals developed grade III experimental endometriosis and were divided into two groups. Group ‘‘U’’ received U. tomentosa extract orally (32 mg/day), and group ‘‘C’’ (control group) received a 0.9% sodium chloride solution orally (1 ml/100 g of body weight/day). Both groups were treated with gavage for 14 days. At the surgical intervention and after the animal was euthanized, the implant volume was calculated with the following formula: [4p (length/2)  (width/2)  (height/2)/3]. The autotransplants were removed, dyed with hematoxylin–eosin, and analyzed by light microscopy. The Mann– Whitney test was used for the independent samples, and the Wilcoxon test analyzed the related samples, with a significance level of 5%. 

Results: The difference between the initial average volumes of the autotransplants was not significant between the groups (p = 0.18). However, the final average volumes were significantly different between the groups (p = 0.001). There was a significant increase (p = 0.01) between the initial and final average volumes in the control group, and treatment with the U. tomentosa caused a marked reduction in the growth over time (p = 0.009). Histologically, in the experimental group (n = 10) six rats had a well preserved epithelial layer, three had mildly preserved epithelium, and one had poorly preserved epithelium. The epithelial layer occasionally presented sporadic epithelial cells. The control group (n = 12) presented seven cases (58.3%) of well-preserved epithelial cells and five cases (41.7%) of mildly preserved epithelial cells.