Comparison of Effects of High-Fat, High-Protein and Low-Calorie Diets on Klotho Gene Expression and TGF-β Level in Serum and Liver of Old Male Wistar Rats

Different diets have important roles in human health and aging. In the current study, we aimed to characterize the Klotho, an anti-aging protein, gene expression and protein level in the serum and assess the protein levels of Transforming growth factor-β and Platelet-derived growth factor in old rats which treated with different diets (high-fat, high-protein, low calorie, high-protein and low calorie).

Twenty-five old and five adult rats were treated with high-fat, high-protein, low calorie, high-protein and low-calorie diets for ten weeks. Then, serum protein levels of Klotho, transforming growth factor-β and platelet-derived growth factor and gene expression of Klotho in the liver were assessed using enzyme-linked immunosorbent assay.

Protein level of Klotho in the blood serum and expression level of Klotho gene in the liver were increased in high-protein, low-calorie and low-calorie high-protein diets in comparison to control old group (p = 0.000). The levels of transforming growth factor-β and platelet-derived growth factor were increased in low-calorie high-protein group, compared to old group in the liver (p = 0.000).

Results revealed that expression of Klotho decreased in old rats while low-calorie high-protein and particularly low-calorie high-protein diets increased this protein. Moreover, these protective diets could enhance transforming growth factor-β and platelet-derived growth factor in liver of rats,veryfieing improvement of the liver function.