Metformin regresses endometriotic implants in rats by improving implant levels of superoxide dismutase, vascular endothelial growth factor, tissue inhibitor of metalloproteinase-2, and matrix metalloproteinase-9.

Abstract

OBJECTIVE: We sought to test if metformin could regress endometriotic explants in rats. STUDY DESIGN: After inducing endometriotic implants and randomization of female Wistar albino rats, they were given 25 and 50 mg/kg/day of oral metformin in group A (n = 9) and B (n = 8), respectively, for 28 days. Group C (n = 9) was given saline as placebo. RESULTS: Mean volume, weight, and histologic score of implants in groups A (P < .01, P < .05, and P < .05, respectively) and B (P < .01, P < .05, and P < .05, respectively) were significantly lower than in group C. The activity of superoxide dismutase and tissue inhibitor of metalloproteinase-2 staining in groups A (P < .05 and P < .01, respectively) and B (P < .01 and P < .01, respectively) was significantly higher than in the control group. Moreover, there were more significant reductions in implant levels of vascular endothelial growth factor and matrix metalloproteinase-9 in groups A (both P < .001) and B (both P < .001) than in group C. CONCLUSION: Metformin causes regression of endometriotic implants in rats.