Regulation of Curcumin on Follicle Initiation Rate in Diminished Ovarian Reserve

Aim: To study the mechanism by which curcumin regulates ovarian primordial follicle initiation in rats with triptolide-induced diminished ovarian reserve (DOR). Methods: An in vitro gelatin sponge culture was performed on 3-day-old rat ovaries. After the establishment of the DOR model with triptolide, curcumin was administered for 3 days. Histological analysis and follicle counts were performed using H&E staining. ELISA detection of ovarian hormones in the culture medium (E2, FSH and LH), western blotting and Q-PCR for protein and mRNA expression (LTCONS-00011173, TGF-β1, Smad1, AMH, PTEN and GDF-9). Results: Ovarian primordial and growing follicles increased significantly after curcumin intervention (p < 0.05), FSH/LH and E2 levels were increased significantly (p < 0.05). Curcumin also significantly decreased the expression of LTCONS-00011173. Meanwhile, curcumin increased the expression of TGF-β, AMH, and GDF-9 (p < 0.05). In addition, curcumin increased Smad1 gene expression and protein phosphorylation in the ovary on the one hand (p < 0.05), but inhibited Smad1 and p-Smad1 protein expression on the other hand (p < 0.05). Moreover, curcumin decreased PTEN protein and mRNA expression (p < 0.05). Conclusion: Curcumin activates primordial follicles in DOR model rats through TGF-β1 and downstream AMH signaling pathways and may limit follicle exhaustion through LncRNA.