Thalidomide affects experimental endometriosis: a randomized controlled study in the rat

Abstract

Aim: This study aimed to assess the efficacy of thalidomide for treatment of experimental endometriosis.

Methods: This study was a parallel-group, double-blind, stratified, randomized controlled animal trial with 1:1 allocation ratio. Endometriosis was induced experimentally in 23 mature, nulligravid, female Sprague-Dawley rats, weighing approximately 200 g and aged 2 months. A checkpoint surgery was performed 6 weeks later. Then, the rats were randomly allocated into the thalidomide (22 mg/day p.o.) and control (0.5 mL saline 0.9%/day p.o.) groups of nine. After 6 weeks, they were killed. Before each laparotomy, blood for leukocyte and lymphocyte counts and during them, implants for histopathology and peritoneal fluid for interleukin (IL)-6, tumor necrosis factor-α and vascular endothelial growth factor (VEGF)-A concentrations (by enzyme-linked immunoassay) were collected. Allocation and stratified randomization were done using a computer, based on the obtained histopathology scores of the implants of the checkpoint surgery.

Results: The histopathology scores (the main outcome measure) were 2.00 ± 1.55 versus 0.44 ± 1.01 (P = 0.035). The comparisons of after-treatment counts of leukocytes, lymphocytes, VEGF-A and IL-6 between the two groups were statistically significant.

Conclusion: The results of this study are in favor of therapeutic implication of thalidomide in experimental endometriosis in rats. This is the first time thalidomide has been evaluated on endometriosis in an animal model.

Keywords: animal model; endometriosis; immunology; randomized controlled trial; thalidomide.