Analgesic and Anti-Inflammatory Activity of Ambroxol in the Treatment of Endometriosis: An Experimental Study in Wistar Rats

Background/Objective: This study evaluated the analgesic and anti-inflammatory effects of ambroxol in an experimental model of endometriosis. Methods: Ambroxol was administered at doses of 10, 50, and 100 mg/kg (Abx 10, Abx 50, and Abx 100) by daily gavage for 21 days. A medroxyprogesterone-treated group (Progesterone) was included as a positive control. Pain was assessed using validated behavioral tests, including the Rat Grimace Scale (RGS), the von Frey test, and the rotarod test. Additionally, interleukin-1β (IL-1β) levels and total leukocyte counts were measured in peritoneal lavage fluid. The volumetric reduction in endometriotic implants was evaluated by ultrasonography, while histopathological analysis characterized inflammatory infiltrate and epithelial layer integrity using a standardized scoring system. Results: All ambroxol doses reduced spontaneous pain manifestations throughout the treatment. The mechanical withdrawal threshold significantly increased from the second week onward, and motor quality improved over the course of the study. A significant reduction in IL-1β levels compared with the negative control (Control(−)) was observed on day 21. Abx 50 and Abx 100 significantly reduced implant volumes (48.2% and 56.2%, respectively) and promoted marked disruption of the endometriotic epithelial layer. When compared with Progesterone, higher doses—particularly 100 mg/kg—demonstrated comparable efficacy. Conclusions: Taken together, these pleiotropic effects support the potential for drug repurposing in endometriosis.