Effects of Crocin on The Pituitary-Gonadal Axis and Hypothalamic Kiss-1 Gene Expression in Female Wistar Rats

Background: Saffron (Crocus sativus L.) is traditionally used as a spice for coloring and flavoring in cooking in some countries. One of the main component of saffron is Crocin. Recent researches have shown Crocin has various pharmacological effects. The aim of this study was to assess the effect of Crocin on the Pituitary-Gonadal Axis and Kiss-1 gene expression in hypothalamus and also ovarian tissue organization in female Wistar rats. Materials and Methods: : In this experimental study, 18 adult female Wistar rats were randomly divided in three groups. Control group received normal saline and experimental groups received two different doses of Crocin, 100 and 200 mg/Kg every two days for 30 days. After treatment period, blood samples were obtained from the heart, then centrifuged and the levels of FSH, LH, estrogen and progesterone hormones were measured by ELISA assay. The ovarian tissues were removed and fixed for histological investigation. The hypothalamic Kiss-1 gene expression using the real-time PCR method was measured. All data were analyzed using one-way ANOVA. Results: The mean number of primordial, primary, growing follicles and corpori lutea did not show differences between the experimental and control groups but a significant reduction (P=0.038) in the number of atretic graffian follicles (0.5±0.31) was observed in rats received 200 mg/Kg Crocin. In addition, estrogen concentration in experimental groups (respectively 35.04±0.85 and 36.18±0.69) compared to control group (38.35±0.64) and progestrone concentration in rats received 200 mg/Kg Crocin (2.06±0.07) compaired to control group (2.16±0.04) significantly decreased. Interestingly, relative expressions of Kiss-1 mRNA decreased in experimental groups (respectively 0.00053± 0.00051 and 0.0011± 0.00066) significantly (P=0.000) compared to control group (1±0). Conclusion: We concluded that Crocin, at hypothalamic level, reduces Kiss-1 gene expression and it can prevents follicular atresia and reduces serum levels of estrogen and progestron.