Green Tea Compound, Hypermethylation and Tregs In Allergy and Chemical Sensitivity!

Recent studies propose that environmental illnesses are caused from "loss of tolerance" and that alterations in T regulatory cells (Tregs) may be a important factor. A number of studies demonstrate health benefits from epigallocatechin gallate (EGCG) which is a compound found in green tea. Yun shows EGCG can enhance Tregs production and enhance expression of histone deacetylases while decreasing expression of NF-kappaB. It also has been shown to reactivate genes that have been silenced by hypermethylation and prevent these changes to subsequent passage to daughter cells by DNA methyltransferases. (Fang) Interestingly, CCL18 is a chemokine that is elevated in allergic patients and may contribute to the "loss of tolerance" because in normal patients it promotes the generation of normal normal Tregs but in allergic patients it does not and may
an increased prevalence for symptoms that are common with chemical sensitivity in allergic patients. In addition, other factors including the proper expression of the Nrf2 system and other pathways for antioxidant expression may mitigate the effects while impairments may exacerbate them. EGCG has been shown to act through Nrf2, although this may not be its only mode of action. In any event, EGCG may provide some therapeutic effects for these kinds of conditions.


Yun, J.-M. and Jialal, I. Effects of epigallocatechin gallate on regulatory t cell number and function in obese versus lean volunteers. FASEB.http://www.citeulike.org/user/HEIRS/article/7651808
Fang, M. Z. Z., Wang, Y., Ai, N., Hou, Z., Sun, Y., Lu, H., Welsh, W., and Yang, C. S. (2003). Tea polyphenol (-)-epigallocatechin-3-gallate inhibits dna methyltransferase and reactivates methylation-silenced genes in cancer cell lines. Cancer research, 63(22):7563-7570.
http://www.citeulike.org/user/HEIRS/article/3326104
Chang, Y., de Nadai, P., Azzaoui, I., Morales, O., Delhem, N., Vorng, H., Tomavo, S., Ait Yahia, S., Zhang, G., Wallaert, B., Chenivesse, C., and Tsicopoulos, A. (2010). The chemokine ccl18 generates adaptive regulatory t cells from memory cd4+ t cells of healthy but not allergic subjects. The FASEB journal. http://www.citeulike.org/user/HEIRS/article/7651843