Yarrow (Achillea millefolium L.) Extract Produces Beneficial effects on Reproductive Parameters in Estradiol Valerate-Induced Polycystic Ovarian Syndrome in Rats

 Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders with a spread of around 10% in the world. Yarrow (Achillea millefolium L.) is a medicinal plant with essential oils, steroids, flavonoids and phenolic compounds. The aim of this study was to investigate the effects of yarrow extract on blood hormones and ovarian histology in rat model of PCOS. Seventy rats were equally allocated into seven groups: control; control+1.2g/kg body weight (BW) yarrow extract; PCOS, induced by single-dose intramuscular injection of estradiol valerate (EV, 1 mg/100g BW); PCOS+2 mg/kg BW clomiphene citrate (CC); PCOS+1.2, 2.5 and 5g/kg BW of yarrow extract for a period of 30 days. Vaginal smear was performed for 60 days after the EV injection. Hormone assays for LH, FSH, progesterone, testosterone and estradiol, and ovarian histology were also performed.  CC could moderate serum levels of FSH, estrogen and progesterone and concentrations of LH, LH/FSH and testosterone became normal, whereas CC did not have a significant effect on body and ovary weights, and number of ovarian cysts. Yarrow extract could ameliorate the body and ovary weights, cystic follicles and sex hormones in PCOS induced by EV in a dose-dependent manner. High dose of yarrow extract improved the detrimental effects of PCOS on body and ovary weights, and number of ovarian cysts, and caused them to reach normal levels.  Yarrow extract in 5mg/kg BW may be used as a nutritional supplement for adjunct therapy of PCOS patients.