Niacin Inhibits Apoptosis and Rescues Premature Ovarian Failure

Background/Aims: Over 99% of mouse and human ovarian follicles will undergo specialized cell death including atresia and apoptosis. Reduction of apoptosis may help reduce infertility and maintain the reproductive ability in women. Methods: 3-day B6D2F1 mice were used to culture small follicle and ovary tissue with niacin and 18-day mice were intraperitoneal injected with niacin to determine its effect on follicle development. Then establish 8-weeks POF animal model with cytoxan (CTX) or radiation. Treatment group was given 0.1 mL of 100 mM niacin by an intraperitoneal injection twice before ovulation. The ovaries were collected and the follicles were counted and categorized, and ovarian histologic sections were stained for TUNEL. Ovarian function was then evaluated by monitoring ovulation. Microarray analyses, Western blot, immunofluorescence and real-time quantitative PCR were used to assess the mechanism of ovarian injury and repair. Results: We found that niacin promotes follicle growth in the immature oocyte and it increased the levels of a germ-line cell marker DDX4, and a cell proliferation marker PCNA in the ovary. Addition of niacin to the cell culture reduced oocyte apoptosis in vitro. Administration of niacin to treat premature ovarian failure (POF) in mouse models showed inhibition of follicular apoptosis under harmful conditions, such as radiation and chemotherapy damage, by markedly reducing cumulus cell apoptosis. Additionally, the number of developing follicles increased after administration of niacin. Conclusion: Niacin may have an important function in treating POF by reducing apoptosis in clinical applications.