Luteolin Supplementation Modulates Mammary Tumor Growth in C3H Mice Fed Diet with High- and Low-Fat Content

In this study we investigated the effects of luteolin supplementation (0.05% w/w) on mammary tumor growth in C3H mice, a strain of mouse mammary tumor virus negative, fed either high-fat (45% fat of energy) or low-fat diet (15% fat of energy). Animals (n = 12/group) were allocated into 4 experimental groups (low-fat diet, low-fat diet + luteolin supplementation, high-fat diet, high-fat diet + luteolin supplementation). Experimental diet were fed for 13 wk and 7,12-dimethylbenz[a]anthracene was administered once a week for 6 wk starting at Week 1 to induce mammary tumors. Study results showed that animals on low-fat diet supplemented with luteolin exhibited longer tumor latency and lower tumor weights and sizes compared to the other groups. Animals fed high-fat diet showed increased serum IGF-1 levels and the elevated mammary tissue expression of Ki-67, IRS-1, pp38, Cdk4, and Cdk6. Luteolin inhibited IRS-1, Cdk4, and Cdk6 expression in high-fat fed animals. The expression of pp38, cyclinD1, and Bcl-xL was ...