Objective: Endometriosis is an estrogen-dependent chronic inflammatory disease observed in reproductive period. The aim of the present study is to assess the efficacy of colchicine, widely used to treat many inflammatory diseases, in an experimental rat endometriosis model.

Study Design: Experimental endometriosis was constituted with implantation of autogenous endometrial tissue. Rats were divided randomly into 2 groups as colchicine group (n = 8) and control group (n =8). Although oral 0.1 mg/kg colchicine was administered 4 weeks to the colchicine group, the same amount of saline solution was administered to the control group. Before and after 30 days of treatment period, peritoneal and tissue tumor necrosis factor α (TNF-α), the volumes and histopathological properties of the implants were evaluated.

Results: Although the implant volume decreased significantly in the colchicine group (89.2 ± 13.4 mm³ to 35.2 ± 4.5 mm³, P < .05), the implant volume increased in the control group (85.1 ± 14.2 mm3 to 110.3 ± 10.5 mm³, P < .05). When compared to the control group, the colchicine group had significantly lower histopathologic sores (1.4 ± 0.2 vs 2.6 ± 0.4, P < .001). Although peritoneal fluid TNF-α levels were significantly decreased in the colchicine group (45.2 ± 5.3 pg/mL vs 12.1 ± 5.2 pg/mL, P < .001), the peritoneal fluid TNF-α levels were significantly increased in the control group after the treatment (44.2 ± 3.5 pg/mL vs 61.3 ± 12.2 pg/mL; P < .001). Tissue TNF-α levels were significantly lower in the colchicine group when compared to the control group (45.4 ± 8.6 pg/mL vs 71.3 ± 11.2 pg/mL; P < .001).

Conclusion: Colchicine resulted in regression of endometrial implant volumes in experimental rat endometriosis model and decreased peritoneal and tissue TNF-α levels.