Dietary supplementation with high dose of epigallocatechin-3-gallate promotes inflammatory response in mice

• Published in: The Journal of nutritional biochemistry Vol. 23; no. 6; pp. 526 - 531
• Main Authors: Pae, Munkyong, Ren, Zhihong, Meydani, Mohsen, Shang, Fu, Smith, Donald, Meydani, Simin Nikbin, Wu, Dayong
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.06.2012; Elsevier
• Subjects: administration & dosage; analogs & derivatives; analysis; animal models; Animals; anti-inflammatory activity; Biological and medical sciences; Biomarkers; Biomarkers - analysis; Biomarkers - metabolism; Catechin; Catechin - administration & dosage; Catechin - analogs & derivatives; chemically induced; chemistry; cytology; Dietary Supplements; Dinoprostone; Dinoprostone - analysis; Dinoprostone - metabolism; drug effects; EGCG; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Green tea; homeostasis; in vitro studies; in vivo studies; Inflammation; Inflammation - chemically induced; Inflammation - physiopathology; interleukin-1; Interleukin-1beta; Interleukin-1beta - analysis; Interleukin-1beta - metabolism; interleukin-4; Interleukin-6; Interleukin-6 - analysis; Interleukin-6 - metabolism; Killer Cells, Natural; Killer Cells, Natural - drug effects; Killer Cells, Natural - metabolism; Macrophages; Male; metabolism; Mice; Mice, Inbred C57BL; Natural Killer T-Cells; Natural Killer T-Cells - drug effects; Natural Killer T-Cells - metabolism; physiopathology; Plant Extracts; Plant Extracts - administration & dosage; prostaglandins; Spleen; Spleen - cytology; Spleen - drug effects; Spleen - metabolism; Splenocytes; T-lymphocytes; Tea; Tea - chemistry; tumor necrosis factor-alpha; Tumor Necrosis Factor-alpha - analysis; Tumor Necrosis Factor-alpha - metabolism; Vertebrates: anatomy and physiology, studies on body, several organs or systems; IL; EGCG; Con A; Inflammation; Macrophages; TNF; LPS; IFN; FITC; APC; Th; PE; Splenocytes; PG; MΦ; Green tea; Rodentia; Epigallocatechin-3-gallate; Splenocyte; Vertebrata; Mammalia; Mouse; Animal; Supplementation; High dose; Macrophage
• ISSN: 0955-2863; 1873-4847; 1873-4847
• DOI: 10.1016/j.jnutbio.2011.02.006

Epigallocatechin-3-gallate (EGCG) from green tea has been indicated to have anti-inflammatory activity. However, most of the evidence is in vitro studies in which EGCG is often added at levels unachievable by oral intake. With few exceptions, in vivo studies along this line have been conducted in animal models of diseases, and the results are inconclusive. In this study, we fed C57BL/6 mice a diet containing 0%, 0.15%, 0.3% or 1% (w/w) EGCG for 6 weeks. Contrary to the assumption that EGCG would reduce inflammatory response, mice fed 0.15% and 0.3% EGCG diet exhibited no change while those fed 1% EGCG diet produced more proinflammatory cytokines tumor necrosis factor-α, interleukin (IL)-6, and IL-1β and lipid inflammatory mediator prostaglandin E2 in their splenocytes and macrophages (MΦ) and less IL-4 in splenocytes. Spleens from the mice fed 1% EGCG diet also had higher proportions of regulatory T cells, MΦ, natural killer (NK) cells and NKT cells compared to those from mice fed the other diets. These results suggest that high intake of EGCG may induce a proinflammatory response, and this change may be associated with a disturbed homeostasis of immune cells involving changes in both function and number of specific immune cell populations. While the mechanisms and clinical significance for this effect of EGCG remain to be investigated further, these data suggest the need for defining accurate EGCG dose limits to induce an anti-inflammatory effect since current data indicate that higher doses would produce an inflammatory response.