Study of inhibiting effects of genistein on mice endometriosis

Objective:To explore the inhibiting effects of genistein on experimentally induced endometriosis(EM) in rat model and its mechanism..Methods:Seventy adult female ICR mice were divided into control and endometriosis groups,ten rats that underwent a sham operation were used as control(group A).Endometriosis model was surgically induced in 60 rats by transplanting an autologous fragment of endometrial tissue onto the inner surface of the abdominal wall.Meanwhile,the estradiol-17βwas administered for 3 weeks at 0.5 μg/kg s.c.every 3 days.Three weeks later 20 rats were killed to assess the implants volume and for pathological examination.The remaining rats were randomly divided into group B(model group,n=10);group C(Low-dose genistein group,0.35 mg/kg/d,n=10),group D(Middle-dose genistein group,3.5 mg/kg/d,n=10) and group E(High-dose genistein group,35 mg/kg/d,n=10).Genistein group rats continued to receive the three different doses(s.c.)for 12 weeks.Group A and group B were injected sesame oil 0.05 ml daily for 12 weeks.At end of 12 weeks,after collecting blood sample from eyeball all rats were killed to reassess the implants' size and for histological analysis,blood sample was also taken to determine anti endometrial antibody(EMAb),interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) in serum by ELISA..Results:The rate of induced EM model in mice was 68.3%.Before and after treatment,there was no significant implants volume change group C(P0.05),and the volume was significantly reduced between group D((135.6±15.1)mm3,(61.4±9)mm3))and group E((137.8±15.6)mm3,(11.6±3.3) mm3)(P﹤0.05)(P﹤0.01).In the B group,the contents of EMAb,IL-6 and TNF-α were significantly increased than those of group A(P﹤0.05),and was no difference between group C and B(P﹥0.05),but it was significantly decreased in group D((137.8±15.6)mm3,(11.6±3.3)mm3)) and E((31.18±2.97)pg/ml,(19.34±2.85)pg/ml) than that of group B((125.04±3.23)pg/ml,(49±5.15)pg/ml)(P﹤0.05),it was also significant difference between group D and E(P﹤0.01).Conclusion:Transplanting an autologous fragment of endometrial tissue onto the inner surface of the abdominal wall and meanwhile administered the 17β-estradiol is simple method to induce EM model in rat,and it is an ideal animal model to study EMS..Genistein could cause a satisfically significant regression of endometriotic implants,and may be related with competitive binding with ER,decreasing the estrogenic level,and some cytokines..