The in Vivo Antioxidant Effects of (-)-Epigallocatechin-3-Gallate Consumption in Healthy Postmenopausal Women Measured by Urinary Excretion of Secondary Lipid Peroxidation Products.

Chelsey Fiecke,A Saari Csallany,Chi Chen,Mindy Kurzer

doi:10.4236/fns.2019.101002

Abstract

The present study was carried out to determine whether the consumption of epigallocatechin (EGCG), the major bioactive green tea catechin, exerts a positive effect on lowering in vivo lipid peroxidation, a measure of oxidative stress, in healthy postmenopausal women. Urinary excretion of secondary lipid peroxidation products, a measure of in vivo lipid peroxidation, was determined in 40 participants randomly assigned to consume a green tea catechin extract (843.0 ± 44.0 mg EGCG/d) or placebo capsules for 12 months. Urine samples were analyzed for individual polar and nonpolar lipophilic aldehydes and related carbonyl compounds by high-performance liquid chromatography (HPLC) at the beginning and at the end of the 12-month intervention period. Results show that two nonpolar aldehydes, nonanal and decatrienal, were both 48% lower (p < 0.005) following consumption of EGCG. These results indicate that a modest degree of in vivo antioxidant activity exists with long-term EGCG consumption, which could slightly limit oxidative damage associated with lipid peroxidation and the onset and progression of chronic diseases.

Highlights

IntroductionIn aging 14-month-old mice, 0.05% green tea catechins (71% epigallocatechin gallate [Epigallocatechin gallate (EGCG)]) were administered in the drinking water for 6 months, which is equivalent to about 250 mg EGCG/day or 2 cups of Green tea (GT)/day for humans
These results indicate that a modest degree of in vivo antioxidant activity exists with long-term Epigallocatechin gallate (EGCG) consumption, which could slightly limit oxidative damage associated with lipid peroxidation and the onset and progression of chronic diseases
The minor compound represented 10% of the original high-performance liquid chromatography (HPLC) fraction and was identified as decatrienal (a 10-carbon tri-unsaturated aldehyde). These two nonpolar aldehydes were significantly lower following green tea extract (GTE) supplementation for 12 months when compared to both groups at 0 months (p < 0.005) and the placebo group at 12 months (p < 0.05), as shown in Table 3 and Figure 4

Summary

Introduction

In aging 14-month-old mice, 0.05% green tea catechins (71% epigallocatechin gallate [EGCG]) were administered in the drinking water for 6 months, which is equivalent to about 250 mg EGCG/day or 2 cups of GT/day for humans. In this mouse model, EGCG supplementation resulted in reduced levels of several oxidative stress markers in the hippocampus, including thiobarbituric acid reactive substances, a measure of aldehydic degradation products from lipid peroxidation, and protein carbonyls, superoxide dismutase, and glutathione peroxidase [9]. GT caused a tendency towards increased HDL levels [8] These studies indicate the beneficial effects of GT and, certain catechins such as EGCG

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