Immunomodulatory Effect of Fennel in Animal Model of Polycystic Ovarian Syndrome

Fennel with phytoestrogenic, antioxidant and anti-diabetic properties is used in traditional Iranian medicine to treat Polycystic Ovarian Syndrome (PCOS). Chronic inflammation is a new proposed mechanism in PCOS pathogenesis that suggests the role of immune system in this disease. Due to the main role of Treg cells in maintaining immune homeostasis, their impaired function, along with increased production of inflammatory compounds such as nitric oxide, can lead to persistent inflammation.

In this experimental study, 18 BALB/c mice were randomly divided into three groups including control group, untreated PCOS-induced group, and fennel-treated group. The control group received 0.1 ml sesame oil for 21 days. PCOS was induced by subcutaneous injection of Dehydroepiandrosterone (60 mg/kg/day) plus 0.1 mL sesame oil for 21 days. Mice in third group were treated by intraperitoneal injection of 500 mg/kg/day fennel extract after 21 days. The regulatory of T cells (Tregs) were analyzed by flow cytometry method and nitric oxide level determination was performed by Griess Reaction method. Ferric Reducing/Antioxidant Power (FRAP) assay was used to measure the total antioxidant power.

This study was approved by the Ethical Committee of Arak University of Medical Sciences (Code: IR.ARAKMU.REC.1397.312).

 The estrous cycle was normalized after treatment with fennel. Fennel significantly reduced the number of ovarian cysts. Nitric oxide concentration decreased significantly while FRAP concentrations did not significantly alter. The number of Treg cells was also increased significantly.

 Due to the role of immune system in the incidence of inflammation, concurrent modulation of both immune and endocrine systems may open new horizons in the design of new therapeutic interventions for PCOS.