Green tea and its major components ameliorate immune dysfunction in mice bearing Lewis lung carcinoma and treated with the carcinogen NNK

The protective effects of tea and/or its components on dysfunction of immune functions during tumor growth and carcinogenesis in mice were studied using two experimental models: C-57/BL(6)J mice transplanted with Lewis lung carcinoma (LLC) and Kunming mice treated with a single doss of 4-(methylnitrosamino-)-2-(3-pyridyl)-1-butanone (NNK). in C-57/BL(6)J mice bearing LLC, the weight of the thymus decreased, the proportion of CD4+-positive T lymphocytes and the ratio of CD4+ to CD8+ decreased luminol-enhanced chemiluminescence of white blood cells in peripheral blood stimulated by zymosan increased and plaque-forming cells (PFC) decreased However, in LLC-bearing mice given green tea as drinking water, all immune functions were improved, along with inhibition of tumor growth. in Kunming mice treated with NNK, during the four weeks of observation, their immunologic indicators, such as phagocytosis of macrophages in the abdominal cavity, luminol-enhanced chemiluminescence of white blood cells, plaque-forming cells, and delayed-type hypersensitivity, increased or decreased to various extents compared with normal controls. However, these changes were significantly prevented in the mice given green tea, mixed tea, or tea polyphenol as drinking water. In conclusion, tea and its components ameliorated immune dysfunction in mice bearing LLC or treated with the carcinogen NNK.