Regulating the Age-Related Oxidative Damage, Mitochondrial Integrity, and Antioxidative Enzyme Activity in Fischer 344 Rats by Supplementation of the Antioxidant Epigallocatechin-3-Gallate

Abstract

In this study, epigallocatechin-3-gallate (EGCG) was examined for the first time for its anti-aging effect on middle-aged male Fischer 344 rats as a dietary supplement at 50 (low dose) and 500 (high dose) mg/kg/day over a 6-month period. Such levels of EGCG concentration were well-tolerated by rats without causing tissue damage or dysfunction in the liver and kidney, as evaluated by histopathological and biochemical observations. Compared to the rats in the low-dose and control groups, rats fed with high-dose EGCG showed a significant decline in the concentration of 8-hydroxy-2'-deoxyguanosine in the plasma while maintaining a better mitochondrial potential in the peripheral lymphocytes and preventing the deletion of ND4 region from mitochondrial DNA in the liver. The protective effects of high-dose EGCG against oxidative stress were comparable with the effects of caloric restriction, a well-established dietary intervention that retards aging. However, the supplementation of EGCG influenced merely the antioxidative enzyme activities and their gene expressions in rats, suggesting that EGCG may either function as an antioxidant itself or regulate other bioprocesses, including energy metabolism, biosynthesis, and stress response, as shown in the gene profiling analysis of microarray data. Thus, the present study provides preliminary information on the anti-aging property of EGCG in male Fischer 344 rats.

Supplementation with Essential Amino Acids in Middle Age Maintains the Health of Rat Kidney

“…Together, the upregulation of cyt-c-ox, Hsp-60, and Grp-75 observed after EAA supplementation strongly suggests the restoration of mitochondrial function to a level similar to that seen in juvenile rats. Nutritional approaches other than CR have been reported to limit renal aging and to maintain healthy mitochondrial activity (42). As noted above, the efficacy of low-protein diets against hypertension and proteinuria in CDK is controversial, occasionally it has been considered dangerous (43)(44), even if EAA supplementation has been recently shown to improve anabolism and suggested to be adopted as an integral part of the therapeutical approach in chronic hemodialysis patients (22).…”

Polyphenols: Benefits to the Cardiovascular System in Health and in Aging

“…The P13-Akt pathway is implicated along with estrogen receptor (ER) mediated pathways but no receptor for tea catechins or polyphenols have been identified in the cardiovascular system. Moreover, dietary intervention of aged Fischer 344 rats with EGCG was also found to lower the age-related oxidative damage in these animals by reducing oxidative stress, maintaining mitochondrial integrity while significantly declining the plasma level of 8-hydroxy-2′ deoxyguanosine, a critical biomarker of oxidative stress [143]. Most of the evidence of EGCG’s antithrombotic activity comes from in vitro evidence.…”

The Use of Transcriptomics to Unveil the Role of Nutrients in Mammalian Liver

“…In this sense, catechin-rich green tea downregulated expression of genes for glucose-6-phosphatase and fatty acid synthase and upregulated expression of peroxisome proliferator activated receptor alpha in the rats, suggesting an antidiabetic activity [150]. An analogue, epigallocatechin-3-gallate as dietary supplement, influenced the antioxidative enzyme activities and their gene expressions in male Fischer 344 rats, suggesting that it may either function as an antioxidant by itself or regulate other bioprocesses, including energy metabolism, biosynthesis, and stress response [151]. Tomato and paprika beverages were also highly active in modifying gene expressions, both promoted glycogen accumulation and fatty acid oxidation [152].…”