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Dietary supplementation with green tea EGCG at high dose promotes inflammatory response
Author(s) -
Pae Munkyong,
Ren Zhihong,
Meydani Mohsen,
Shang Fu,
Meydani Simin Nikbin,
Wu Dayong
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.925.1
Subject(s) - proinflammatory cytokine , splenocyte , inflammation , immune system , cytokine , endocrinology , immunology , epigallocatechin gallate , mediator , in vivo , chemistry , medicine , pharmacology , biology , biochemistry , polyphenol , antioxidant , microbiology and biotechnology
Epigallocatechin‐3‐gallate (EGCG) has been shown to have anti‐inflammatory activity. The majority of supporting evidence is from cell‐based in vitro studies in which EGCG is added at levels often unachievable by oral intake. The in vivo studies utilizing disease model animals have shown inconsistent findings. To determine the anti‐inflammation efficacy of and the body's tolerance to dietary EGCG, we fed C57BL/6 mice a diet containing 0, 0.15, 0.3, or 1% (w/w) EGCG for 6 wk. EGCG supplementation dose‐dependently reduced weight gain. Contrary to the assumption that EGCG would reduce the inflammatory response, mice fed 0.15 and 0.3% EGCG diet showed no change, whereas those fed 1% EGCG diet had even higher levels of inflammatory response. Splenocytes and macrophages (MΦ) showed a higher capacity to produce proinflammatory cytokines TNF‐α, IL‐6, and IL‐1β and lipid inflammatory mediator prostaglandin E 2 , and splenocytes showed a lower capacity to produce anti‐inflammatory cytokine IL‐4. Furthermore, spleens from mice fed 1% EGCG diet had higher proportions of regulatory T cells, MΦ, natural killer (NK) cells, and NKT cells compared to those from mice fed other diets. These results suggest that high intake of EGCG may induce an inflammatory response, and this change may be associated with a disturbed homeostasis of immune cells involving the change in both function and number of specific populations. While the mechanisms and clinical significance for this effect of EGCG require further investigation, our results suggest that taking high doses of EGCG may cause an inflammatory effect rather than inhibit it. Supported by USDA #58‐1950‐7‐707.