Immunoregulatory activity of polysaccharides from Tanyang Congou black tea on H22 tumor-bearing mice

In this paper, the polysaccharides from Tanyang Congou black tea were extracted, and their preliminary structural characteristics and in vivo antitumor activity were further investigated. Component and monosaccharides analysis showed that the polysaccharides contained 76.26% of total sugar and 30.24% of uronic acid, and were composed of arabinose, galacturonic acid, galactose, rhamnose, glucose and fucose with their ratio of 34.41:29.68:13.23:4.11:13.68:4.89. FTIR results also indicated the presence of carboxylic acid and pyranose rings. The in vivo antitumor results showed that the black tea polysaccharides could significantly inhibit the growth of H22 tumors with the inhibitory ratios of 50.3% (500 mg/kg) and 66.3% (1000 mg/kg), and effectively protect the thymus and spleen of tumor-bearing mice, promote the immunoregulatory activities of macrophagocytes, NK cells and lymphocytes, and improve IL-2, IFN-γ and TNF-α levels, finally leading to the inhibitory effects on the growth of H22 solid tumors. These results support potential uses of black tea polysaccharides as natural anti-tumor agents and provide a theoretical basis for further development and application of Tanyang Congou black tea in functional food and nutra-pharmaceutical industries.