Irbesartan, an angiotensin II receptor antagonist, with selective PPAR-gamma-modulating activity improves function and structure of chemotherapy-damaged ovaries in rats

Cyclophosphamide (CYP) is a chemotherapeutic agent with a potent ovarian toxic effect. CYP induces granulosa cell apoptosis and oxidative stress. Irbesartan (IRB) is a unique ARB with a peroxisome proliferator-activated receptor-gamma (PPAR-) agonistic activity. As PPAR-? activation exerts anti-inflammatory effects and reduces ROS production, IRB may further reduce inflammatory chemokine expression and suppress apoptotic cell death. Therefore, this study aimed to evaluate the effects of IRB on the development of CYP-induced ovarian damage. Rats were divided into four groups: control group, IRB group (100mg/kg, orally), CYP group (100mg/kg, i.p. single injection), and IRB+CYP group (IRB administered 9days before and 6days after CYP administration). Rats sacrificed on day16 of experiment; estradiol (E2), FSH, and TNF- levels were estimated in serum. Reduced glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD) and caspase-3 activities, myeloperoxidase (MPO), and IL-10 levels were determined in ovarian tissues. Protein expressions of p53, caspase-3, Ki-67, and Rad-51 were estimated by immunohistochemical and Western blot techniques. CYP produced ovarian damage as indicated from the decline in serum E2; elevation in FSH; unbalance in tissue oxidative stress parameters; increase in MPO, TNF- levels, caspase-3 activity/expression, p53, and Rad-51 expression; and decrease in IL-10 contents, without effect on Ki-67. On the other hand, IRB, significantly reduced the toxic effects of CYP as indicted from normalization of E2, FSH, oxidative stress, apoptotic, and inflammatory mediators. These data were further supported by histopathological studies. Thus, co-administration of IRB may be promising in alleviating the ovarian toxic effects of CYP.