Copper and resveratrol attenuates serum catalase, glutathione peroxidase, and element values in rats with DMBA-induced mammary carcinogenesis

Abstract

In this paper, a hypothesis was assessed whether or not the intoxication with copper and supplementation with copper plus resveratrol would result in changes in the activities of catalase and glutathione peroxidase and moreover if the characteristic changes would appear in concentrations of copper, iron, calcium, magnesium, and zinc in the serum of rats with chemically induced carcinogenesis. Female Sprague-Dawley rats were divided into study groups which, apart from the standard diet, were treated with copper (42.6 mg Cu/kg food as CuSO4·5H2O) or copper plus resveratrol (0.2 mg/kg body) via gavage for a period from 40 days until 20 weeks of age. In cancer groups, the rats were treated with a dose of 80 mg/body weight of 7,12-dimethyl-1,2-benz[a]anthracene (DMBA) given in rapeseed oil at 50 and 80 days of age to induce mammary carcinogenesis. The control groups included the rats kept in the same conditions and fed with the same diet as the animals from the study groups, but not DMBA-treated. The activity of catalase significantly decreased in groups of rats with mammary carcinogenesis that were supplemented with copper (p < 0.05) or copper plus resveratrol (p < 0.001) in comparison with the control groups that received the same diets. In cancer groups of nonsupplemented rats, the increase of glutathione peroxidase activity was observed. The process of carcinogenesis and the applied supplementation significantly altered the concentrations of trace elements in serum, in particular as concerns iron and copper. The mean serum iron levels in rats with breast cancer were significantly lower than those in the control groups (p < 0.001). The mean serum copper levels significantly decreased in the groups of rats with mammary carcinogenesis that were supplemented with copper or copper plus resveratrol in comparison with the control groups that received the same diets (p < 0.001). The characteristic changes in iron content and the zinc/copper and zinc/iron ratios in blood may be used as one of the prognostic factors in breast cancer research.

Fig. 1

A comparison of catalase activity (μmol/min/mL) and peroxidase activity (nmol/min/mL) in the serum of the examined rats with mammary cancer with respect to the control rats fed with the same diet. Numbers 0–20 refer to the serum evaluated at 20 weeks of the animals’ age (decapitation time). DMBA 7,12-dimethyl-1,2-benz[a]anthracene. a statistically significant results of a comparison of the activities of enzymes in the serum of the DMBA+ and DMBA− groups of rats receiving the same diet (p < 0.05). b statistically significant results of a comparison of the activities of enzymes in the serum of the DMBA+ and DMBA− groups of rats receiving the same diet (p < 0.001). (n) test number

Fig. 2

Comparison of the changes in mineral ratio composition: Zn/Cu and Zn/Fe in the serum of rats with mammary cancer against the control rats. Numbers 0–8 refer to the serum evaluated at 20 weeks of the animals’ age (decapitation time). DMBA 7,12-dimethyl-1,2-benz[a]anthracene. a statistically significant results of a comparison of the ratio of minerals in the serum of the DMBA+ and DMBA− groups of rats receiving the same diet (p < 0.05). b statistically significant results of a comparison of the ratio of minerals in the serum of the DMBA+ and DMBA− groups of rats receiving the same diet (p < 0.001). (n) test number