Comparison of the Effects of Etanercept and Dienogest in a Rat Endometriosis Model: An Experimental Study

This study aimed to explore a potential alternative to dienogest for endometriosis treatment by comparing the effects of dienogest, etanercept, and placebo in a rat model. Endometriosis was experimentally induced in 28 healthy, non-pregnant adult female Wistar-Albino rats. After one month, laparotomy was performed to evaluate the ectopic endometrial implants, and rats were randomly assigned to four groups: control, saline (placebo), dienogest, and etanercept. Dienogest was administered via oral gavage at a dose of 0.3 mg/kg/day, and etanercept was administered subcutaneously at 0.4 mg/kg twice weekly. After a one-month treatment period, laparotomy was repeated to assess treatment response. The implants were excised, and their spherical volumes were calculated using the ellipsoid volume formula. Histopathological analysis evaluated the integrity of the epithelial layer on a semi-quantitative scale from 0 to 3. Both the dienogest and etanercept groups demonstrated a statistically significant reduction in implant volume compared to the control and saline groups. Histopathological scoring showed significantly lower epithelial integrity in these groups as well (P < 0.05). Although implants in the etanercept group appeared more cystic and organized and had lower epithelial scores than those in the dienogest group, this difference was not statistically significant. These findings suggest that both dienogest and etanercept are effective in reducing endometriotic implant volume and epithelial integrity in a rat model, with etanercept showing a non-significant trend toward greater efficacy.