Effect of the Supplementation with Different Selenium Dietary Sources on the Evolution of Mammary Tumor Induced by 4T1 Cells Inoculation in Mice

RESUMO

We investigated the effects of dietary selenium (Se) supplementation on 4T1 mammary tumor growth, blood total Se concentration, and hepatic glutathione peroxidase (GPx) antioxidant activity in Balb/c mice. Initially, 30 female mice were randomly assigned into three groups a control group (Se-adequate) receiving diet containing 0.15 ppm of total Se (n = 10) and two supplemented groups with diet containing 1.4 ppm of total Se derived either from Brazilian nuts (n = 10) or from SeMet (n = 10). Animals received diets for 29 days, starting six days after subcutaneous inoculation of 4T1/GFP cells. Tumors were measured periodically in each mouse to estimate tumor volume. On the 29th day, animals were killed and blood and hepatic samples were collected. Data was analyzed by means of Variance analysis (ANOVA) followed by post hoc Tukeys HSD test. Se-supplemented diets affected tumor growth only at the first seven days feeding. Total blood Se concentration for SeMet group was higher than Se-adequate group (p < 0.05), while hepatic GPx activity was similar for all groups. More studies are necessary to determine the utility of Brazilian nuts in preventing growth or treating breast cancer.

ABSTRACT

We investigated the effects of dietary selenium (Se) supplementation on 4T1 mammary tumor growth, blood total Se concentration, and hepatic glutathione peroxidase (GPx) antioxidant activity in Balb/c mice. Initially, 30 female mice were randomly assigned into three groups a control group (Se-adequate) receiving diet containing 0.15 ppm of total Se (n = 10) and two supplemented groups with diet containing 1.4 ppm of total Se derived either from Brazilian nuts (n = 10) or from SeMet (n = 10). Animals received diets for 29 days, starting six days after subcutaneous inoculation of 4T1/GFP cells. Tumors were measured periodically in each mouse to estimate tumor volume. On the 29th day, animals were killed and blood and hepatic samples were collected. Data was analyzed by means of Variance analysis (ANOVA) followed by post hoc Tukeys HSD test. Se-supplemented diets affected tumor growth only at the first seven days feeding. Total blood Se concentration for SeMet group was higher than Se-adequate group (p < 0.05), while hepatic GPx activity was similar for all groups. More studies are necessary to determine the utility of Brazilian nuts in preventing growth or treating breast cancer.