Avaliação do tempo de tratamento com resveratrol sobre o tecido ósseo de ratas ovariectomizadas

Abstract

Resveratrol (3,5,4 'trihydroxystilbene) is a polyphenol found in some plants and fruits that has been suggested as a preventive agent for the bone damage characteristic of osteoporosis. Studies indicate the effects on only a few bone parameters, besides diverging regarding the minimum protocol duration required to observe such effects. The objective of this study was to evaluate the effects of the treatment with resveratrol on femurs and vertebrae of ovariectomized young adult female rats during 60 and 90 days. Fifty-nine Wistar female rats at 3 months of age at the beginning of the experiment have been utilized, which were divided into 6 groups: groups maintained Intact for 60 and 90 days (INT 60 and INT 90) with 11 and 9 animals each, respectively; Ovariectomized control groups treated with 60 and 90 days (OVX 60 and OVX 90) with 10 and 9 animals each, respectively, ovariectomized and treated via gastric gavage with saline 0.9% [0.1ml / 100g Body Weight (BW)]; Ovariectomized groups + Resveratrol treated for 60 and 90 days (OVX + RES 60 and OVX + RES 90) with 11 and 9 animals each, respectively, ovariectomized and treated via gastric gavage with a solution of resveratrol in 95% ethanol diluted in distilled water (10 mg / kg BW). Biometric, physical, and biomechanical parameters of bones from the animals with greater quantities cortical (femur) and cancellous (vertebrae) contingent were analyzed, as well as the areal bone density of the vertebrae via DEXA, and the body weight of the animals. The biomechanical properties of the femurs were obtained by the three point bending test, and the lumbar vertebrae’s by the bone compression test. The experimental protocol of 60 days was able to remark the increase of the corporal weight of the rats after the castration, as well as the decrease of the vertebrae bone and mineral densities with the surgery and the protective effect of the resveratrol on these parameters of these same bones. In the 90-day protocol, these effects on the physical parameters were also extended to the femurs and the treatment, in this case, also able to prevent the greater corporal weight due to the castration as well. In the biomechanical parameters, it was possible to observe only a tendency of reduction of the maximum load with the surgery and protection with the treatment in the vertebrae of the longer experimental protocol. Therefore, the results indicate resveratrol, in the dose and route of administration used, as a potential protector of the bone tissue, both with greater cortical contingent and with greater cancellous contingent. In addition, the experimental protocol of 90 days showed be able to present more clearly the effects of castration and treatment with resveratrol on bone and body weight parameters.