ObjectiveThe present study was conducted to investigate the protective effects of fennel and flaxseed during pre- and post-natal period until puberty and menopause on ovarian follicular reserve (OFR).MethodsPregnant NMRI mice received fennel (FV, 500 mg/kg/day), flaxseed (LU, 500 mg/kg/day), LU + FV (500 mg/kg/day) and no treatment was given to the controls. Female pups were studied on post-natal-days 1, 56 and 240 (PND1, 56, 240). Ovary weight and diameters, the number of primordial (PF), atretic (AF) and apoptotic (APF) follicles were determined. The expression of Bcl2 and STAT3 (apoptosis-related-genes), micoRNA-125a-5p, and also serum levels of sex hormones were measured. Data were analyzed using one-way ANOVA test.ResultsFV and FV + LU groups showed a marked rise in body and ovary weights and diameters as compared to the control group. The number of PF at PND1, PND56, and PND240 increased significantly in the FV and FV + LU groups but decreased in the LU group compared to the control mice. There was a significant reduction in the mean of AF in the FV and FV + LU group and a marked increase in the LU group compared to the controls. Also, more APF were observed in the LU group, whereas less apoptotic follicles were present in the FV group. FSH and estradiol serum levels increased significantly while LH decreased in the FV group. The anti-apoptotic-genes expression and pro-apoptotic microRNA, respectively, increased and decreased in the FV group versus control group.ConclusionsIt can be concluded that fennel alone and in combination with flaxseed could improve OFR during pregnancy, lactation, and afterwards until puberty and menopause.