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Action of resveratrol on the reproductive and fertility of adult rats treated with cisplatin, etoposide and bleomycin, from peripuberty.

Grant number: 12/05137-1
Support type:Scholarships in Brazil - Doctorate
Effective date (Start): February 01, 2013
Effective date (End): December 31, 2015
Field of knowledge:Biological Sciences - Morphology
Principal Investigator:Sandra Maria Miraglia Valdeolivas
Grantee:Flavia Macedo de Oliveira Neves
Home Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

The incidence of testicular cancer has dramatically increased in the last 50 years. On the other hand, treatments with chemotherapy have also shown an important advance in combating this disease. Thanks to the co-administration of bleomycin, etoposide and cisplatin (BEP), the survival rate of high-risk patients have increased by nearly 90% index achieved; this achievement have contributed to raise the number of studies focusing on the quality of life of these patients after treatment through the evaluation of its impact on fertility and on reproductive function. Patients with testicular tumors usually have already seminal alterations when the disease is diagnosed, a condition that may get even worse after chemotherapy. Thus, in the post-treatment phase a concern arises not only regarding the possible deleterious effects of these therapies to the reproductive health of the survivors, but also the consequences for the development of their progeny. In fact, the action of these drugs is not restricted to tumor cells as they also affect normal cells, such as germ cells. Therefore, following such anti-cancer therapy, there is a reduction in the number and in the motility of spermatozoa produced, along with an increase of morphologically abnormal spermatozoa. There are controversial reports on the quality of sperm chromatin in post-chemotherapy. Moreover, studies have been carried out aiming to evaluate the protective agents, which act to reduce the damage caused by these and other chemotherapeutic agents. Resveratrol (RES), a phytoalexin found in some plants, possesses important and efficient properties against several pathologies, including anti-cancer, anti-apoptotic, anti-inflammatory and antioxidant actions. Hence, the goal of the present study is to determine the deleterious effect of BEP therapy on the reproductive system of Wistar rats (n=144), with or without the prior and concomitant treatment with RES, in the end of the treatment period and after using the adjusted doses based on clinical protocols. Summarizing, we will investigate the potential protection of this phytoalexin against the adverse reproductive effects caused by the administration of BEP to rats, from the peripuberty, based on a corresponding clinical protocol. The RES-treatment will be start at 36 dpp. Initially, RES will be given daily to rats in doses of 90mg/kg by gavage, as a preventive treatment for five days. Subsequently, these animals will be submitted to the co-administration of BEP (n=36), for nine weeks -three cycles of three weeks each, according to the similar clinical protocol and adapted to the age of the animals (3.50mg/kg of etoposide and 0.70mg/kg of cisplatin/ 5 consecutive days with 2 days intervals in each cycle; 0.35mg/kg of bleomycin in the second day of each cycle, all by intraperitoneal injection). One day after the end of the treatments (105-day-old rats), biometric, morphometric, stereological and testicular histopathological (H+PAS method) analyses will be performed; the numerical density of TUNEL-positive germ cells (TUNEL method), the plasma and intratesticular levels of sexual hormones, the mitochondrial activity of sperm and DNA fragmentation/integrity of sperm, produced after the treatments, will also be investigated; moreover, sperm parameters will be evaluated. Three groups will be treated following the same protocols: a) a bleomycin, etoposide, cisplatin-treated group (BEP Group n=36, intraperitoneal injection), b) a resveratrol-treated group (RES Group; n=36, gavage) and c) a sham control group, treated with carboxymethylcellulose and physiological saline 0,9% (SC Group, n=36; gavage and intrapetinoneal injection respectively). Data from the four groups will be compared among them, statistically analyzed, interpreted and discussed.