Characterization of the Synergistic Antioxidant Activity of Epigallocatechin Gallate (EGCG) and Kaempferol

Molecules. 2023 Jul 7;28(13):5265. doi: 10.3390/molecules28135265.

Abstract

Epigallocatechin gallate (EGCG) and kaempferol exhibit cellular antioxidant activity; however, their interactive effects in terms of antioxidant actions and underlying mechanisms remain unclear. In this study, their cytoprotective effects were examined against 2,2-azobis (2-amidinopropane) dihydrochloride solution (ABAP)-induced oxidative stress in HepG2 cells. The results showed that the median effective dose (EC50) of the EGCG and kaempferol (6:1.5, c/c) combination was 3.4 ± 0.1 μg/mL, with a combination index (CIavg) value of 0.54, which represented a significant synergistic effect. Further experiments proved that the combined pretreatment with EGCG and kaempferol exerted protective effects by suppressing reactive oxygen species (ROS) generation, upregulating cellular antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px)) in a dose-dependent manner. The mechanism of synergistic antioxidant effects of EGCG combined with kaempferol may be due to the up-regulation of higher antioxidant enzyme activities that improve the antioxidant capacities and balance the cell oxidative stress. The synergistic antioxidant effect of EGCG and kaempferol can provide a theoretical basis for the development of formulas of functional food ingredients.

Keywords: EGCG; antioxidant enzymes; cellular antioxidant activity; kaempferol; synergistic effect.

MeSH terms

  • Antioxidants* / metabolism
  • Antioxidants* / pharmacology
  • Catechin* / pharmacology
  • Kaempferols / pharmacology
  • Oxidative Stress
  • Reactive Oxygen Species / pharmacology

Substances

  • Antioxidants
  • epigallocatechin gallate
  • Kaempferols
  • Catechin
  • Reactive Oxygen Species

Grants and funding

This work was supported by The National Key Research and Development Program (2022YFD1600700), the Natural Science Foundation of Henan (No. 222300420383), the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS-ASTIP-ZFRI), and the Strategic Co-operation Project between Chongqing Municipal People’s Government and Chinese Academy of Agricultural Sciences (CQ-CAAS-08).