Grape juice concentrate protects reproductive parameters of male rats against cadmium-induced damage: a chronic assay

The aim of the present study was to investigate the effects of long-term grape juice concentrate (GJC) consumption, in two dosages, on the reproductive parameters of cadmium-exposed male rats. The effects of the concentrate on body mass gain, plasma testosterone levels, reproductive organ weights, daily sperm production, sperm morphology, testis histopathological and histomorphometrical parameters, and testicular antioxidant markers were investigated. Wistar rats (n 54) were distributed into six groups: CdCl2; cadmium and grape juice I (1.18 g/kg per d); cadmium and grape juice II (2.36 g/kg per d); grape juice I (1.18 g/kg per d); grape juice II (2.36 g/kg per d); control. A single dose of CdCl2 (1.2 mg/kg body weight (BW)) was injected intraperitoneally and the grape juice was administered orally for 56 d. The results indicated that cadmium changed all reproductive and antioxidant parameters. At dosage I (1.18 g/kg BW), GJC consumption did not show the effects against cadmium-induced damages. In contrast, at dosage II (2.36 g/kg BW), the GJC improved the gonadosomatic index (P=0.003), serum testosterone levels (P=0.001), the relative weight of epididymis (P=0.013) and ventral prostate (P=0.052), the percentage of normal sperm (P=0.001), and histopathological and histomorphometrical parameters. In addition, at this dosage, normalisation of the enzymatic activity of superoxide dismutase (P=0.001) and of testicular levels of glutathione (P=0.03) were observed. The parameters of the non-exposed rats did not depict significant alterations. In conclusion, the product was able to act as a protector of reproductive function against cadmium-induced damage. Such a property was expressed in a dose-dependent manner as the more effective dose was dosage II. The GJC acted possibly by antioxidant mechanisms.