Green tea polyphenol extract attenuates inflammation in interleukin-2-deficient mice, a model of autoimmunity

Green tea polyphenols (GrTP) have been previously shown to decrease endotox in-induced tumor necrosis factor-ct production and lethality in mice. Our p resent studies demonstrate that GrTP inhibit inflammatory responses and may be useful in treating chronic inflammatory stales, such as inflammatory bo wel disease. In this preliminary study, we examined whether GrTP decrease d isease activity in interleukin-2-deficient (IL-2(-/-) mice. Eight-week old IL-2(-/-) C57BL/6J mice who were fed nonpurified diet were randomly assigne d to receive water with GrTP (5 g/L) or water alone (control) for up to 6 w k. After 1 wk, explant colon and lamina propria lymphocyte (LPL) cultures w ere established from a subgroup of mice and supernatants collected. Culture supernatants from GrTP-treated mice showed decreased spontaneous interfero n-gamma and tumor necrosis factor-alpha secretion compared with that of con trols. At 6 wk, the GrTP group had less severe colitis as demonstrated by l ower histologic scores and wet colon weights. This was associated with lowe r plasma levels of serum amyloid A, increased weight gain and improved hema tocrits. These results show that GrTP attenuated inflammation in 11-2(-/-) mice and suggest a role for GrTP in treating chronic inflammatory diseases such as inflammatory bowel disease.