Tanshinone IIA alleviates tri-ortho-cresyl phosphate-induced ovarian damage through Hippo signaling pathway activation in mice.

BACKGROUND: Tri-ortho-cresyl phosphate (TOCP), a widely used plasticizer, has been shown to impair ovarian function. While tanshinone IIA exhibits ovarian protective effects in aging models, its potential to counteract TOCP-induced ovarian damage and associated signaling mechanisms remains unexplored. This study investigates the therapeutic effects of tanshinone IIA on TOCP-damaged ovaries in mice, with focus on Hippo, AKT, and MAPK pathways. RESULTS: TOCP exposure (200 mg/kg/d for 28 days) significantly reduced ovarian follicle counts (primordial, preovulatory, and mature follicles) and disrupted hormone levels (elevated Estrogen(E2), decreased Follicle stimulating hormone(FSH)/ Anti-Mueller tube hormone(AMH)) in mice. Treatment with high-dose tanshinone IIA restored ovarian structure and function: growing follicle counts increased significantly (p < 0.001), FSH (p < 0.001) and AMH (p < 0.001) levels surged to marked degrees, while E2 (p < 0.001) levels decreased significantly. All changes were statistically significant. Immunohistochemistry and Western blot analysis revealed that tanshinone IIA restored ovarian AMH and Follicle-Stimulating Hormone Receptor (FSHR) protein expression, which were suppressed by TOCP. In vitro experiments further demonstrated that TOCP dose-dependently inhibited granulosa cell viability (p < 0.001) and proliferation (p < 0.001). Co-treatment with tanshinone IIA (0.01 mM) rescued cell viability (p < 0.01) and proliferation (p < 0.05). Mechanistically, tanshinone IIA suppressed ovarian apoptosis (p < 0.01) and modulated multiple signaling pathways: it attenuated Hippo signaling (p < 0.05) and reactivated PI3K/AKT (p < 0.05), p38 (p < 0.05), and ERK1/2 (p < 0.01) pathways. CONCLUSIONS: Tanshinone IIA alleviates TOCP-induced ovarian dysfunction primarily through coordinated modulation of Hippo signaling and AKT/MAPK pathway activities, offering a potential therapeutic strategy for chemical-induced ovarian injury.