Effects of oil extracts from Arachis hypogea on stem cell factors for follicular maturation and implantation in the superovulated rat

Abstract

Oil extracts from Arachis hypogea is often used clinically for the administration of exogenous hormone during assisted reproduction. But its capacity to induce follicular growth after fertilisation to maintain the formation of progesterone has not yet been clarified. We assessed the effects of peanut oil on stem cell factors (SCFs) for follicular maturation and meiotic activities in the superovulated rat. Female rats were superovulated and treated with peanut oil (S + Pn), while the controls were either superovulated and treated with saline solution (S + N), or non-superovulated and treated with saline solution (N) or peanut oil (Pn). After mating, uterine horns and ovaries were obtained and a morphometry of granulosa cells and theca interna (TI) was carried out. The mitotic index (MI) of the granulosa cells and the protein expression of SCF on ovarian stromal cells were evaluated, as well as the ultramorphology of the endometrium. Results showed a successful implantation in S + Pn, N and Pn groups. The MI was high in the Pn group, moderate in the S + Pn and N groups, and poor in the S + N group. However, both follicular size and TI levels varied significantly (p < 0.05) across intervention groups. In multiple comparisons, both follicular size and TI values in the experimental group were the highest (p < 0.0001). Protein expressions of SFC were high on ovarian stromal cells in both the S + Pn and N groups, while decidualisation was observed in the experimental groups. We conclude that peanut oil may be implicated in mitotic activities of granolusa cells, induce the release of SCF and sustain implantation.