The effects of thalidomide in a rat model of surgically-induced endometriosis

OBJECTIVE: The aim of the study was to analyze the anti-angiogenic role of thalidomide and to assess whether thalidomide had any influence on a rat model of surgically-induced endometriosis. MATERIALS AND METHODS: Endometriosis was induced through surgical induction and homologous transplantation in 16 rats. The rats were randomly separated into two groups as thalidomide (n=8) and control (n=8) groups. Using oral gavage, 100 mg/kg thalidomide 0.5 ml was administered to the first group and saline 0.5 ml to the control group. Histopathologic findings and volume analysis of implants were evaluated after 4 weeks. Vascular endothelial growth factor-A (VEGF-A) and oxidative markers were run from the fluid through peritoneal lavage. RESULTS: The average implant volume decreased significantly in the thalidomide administrated group after treatment (53.3 and 22.9 mm(3) respectively, p=0.012). Significant differences observed in the histopathologic scores of the thalidomide group (3 and 1 respectively, p=0.012) were not observed in the control group. Significant decreases were observed in the levels of VEGF-A and myeloperoxidase (MPO) from oxidative markers (p=0.004, p=0.037, respectively). CONCLUSION: Thalidomide provides volumetric and histopathologic recovery in implants particularly because the VEGF inhibition and anti-angiogenic effect, which suggests that it could be effective in the treatment of endometriosis.