Comparison In Bioactivity Of Polysaccharide Fractions From Fuzhuan Brick-Tea At Different Storage Periods

FuZhuan brick-Tea, is a unique post-fermented tea product in China. Fu Zhuan brick-tea has special flavor because the deliberate fermentation with the fungus, Eurotium cristatum and the beneficial bacterium induced the component contents changed. Tea polysaccharides are polysaccharides-complex with high bioactivity, which can regulate the blood glucose,hypolipidemic, hypotensive and enhance immunity. In this study, we compared the antioxidative and immunomodulatory properties of polysaccharide fractions from Fuzhuan brick-tea(FPS) at different storage periods(from 2009 to 2013).The main contents and results are listed as follows:1. The polysaccharide fractions were isolated from Fuzhuan brick-tea using hot water.The yields of FPS are from 3.2% to 3.9%, and the yields advanced with the storage year increasing.2. Fuzhuan brick-tea polysacchaides have remarkable antioxidant activity to scavenge DPPH and hydroxyl radical were investigated as well as ferric-reducing antioxidant power in a dose-dependent manner.3. According to cell experiment, Fuzhuan brick-tea polysaccharides have no cytotoxicity,and FPS could reduce H2O2-induced PC12 cell apoptotic death through oxidative stress. At the concentration of 25-200μg/m L, FPS increased the cell viability in a dose-dependent manner. At the concentration of 25μg/mL, the cell viability is 14%, while 200μg/Ml, the cell viability of PC12 added to 94%. In reaserch of immunoregulation effects, nitrite concentrations in the supernatant of polysaccharide stimulated macrophages were determined as a reflection of NO production. The results suggested that FPS have observably stimulatory effects on the NO production of RAW 264.7 cells. NO production increased in a dose dependent manner at different concentrations(50, 200, 400 μg/mL).4. It was found in the determination that, while at the sepecific concentration, the properties of FPS which have different storage periods showed regulation by increasing attenuations, and FPS which has been stored for three years emerged better property on antioxidantive and immunomodulatory. From the aspect of antioxidantive andimmunomodulatory, we deduced that the third year during storage period for Fuzhuan brick-tea maybe the best drinking time.