Effect of Icariin on the Number of Follicles and Endometrium Thickness in Mice with Premature Ovarian Failure

Background: This study explored icariin’s effects on endometrial thickness and follicle numbers in mouse models of premature ovarian failure (POF). Methods: We divided 8-week-old C57BL/6J female mice into five groups: NC (control), CTX (cyclophosphamide-induced POF), CTX-ICA (CTX-induced POF with icariin), OVX (ovariectomy-induced POF), and OVX-ICA (ovariectomy-induced POF with icariin). We monitored estrous cycles and assessed endometrial thickness and follicle counts using Hematoxylin & Eosin (H&E) staining. Results: CTX and OVX reduced estrous activity, and the CTX-ICA group exhibited higher activity. Compared with NC, the primary follicles were decreased in the CTX group (p = 0.005) but not in the CTX-ICA group (p = 0.272). Endometrial thickness was respectively thinner in the OVX and OVX-ICA vs. CTX-ICA, CTX, and NC groups (p < 0.001); the CTX vs. NC (p < 0.001) groups; and the CTX vs. CTX-ICA groups (p < 0.001). No significant differences were found between the CTX-ICA and NC groups (p = 0.972). Conclusions: In conclusion, CTX and OVX induce POF in mice, causing endometrial thinning and decreased follicles (CTX). Icariin may partly restore endometrial thickness.