Effect of Tea Extracts and Phenolic Components on Immunoglobulin Production by Mesenteric Lymph Node Lymphocytes of Sprague-Dawley Rats.

Abstract

We examined the effect of tea extracts on Ig (Ig) production of mesenteric lymph node lymphocytes of Sprague-Dawley rats and found that various extracts suppressed the production of IgA, IgG, and IgM. In addition, the original extracts of green and black teas strongly enhanced IgE production, and their 102 or 103 times diluted samples exerted an inhibitory effect. Similarly, tea polyphenols having a triphenol group enhanced IgE production at 1 mM and inhibited it at concentrations below 100 μM. On the contrary, diphenolic epicatechin did not affect IgE production Though all tea polyphenols exerted inhibitory effect on the production of IgA and IgG at concentrations above 10 μM, triphenolic compounds, such as epigallocatechin gallate, gallic acid and pyrogallol, exerted an enhancing tendency on IgA production at 0.1 μM. These results suggest that the Ig production-regulating activity of tea extract is partly due to tea polyphenols, especially those having a triphenol group.