Effect of Tea Polysaccharide-Tea Polyphenol on Improving D-Galactose-Induced Oxidative Damage of Brain in Mice

Objective: To explore the synergistic effect of tea polysaccharide-tea polyphenol on the improvement of oxidative stress damage in brain induced by D-galactose (D-Gal) in mice, and to provide a basic for the development of functional food. Methods: The oxidative stress model was induced by D-Gal, and 12 mice were retained as the normal control group. The mice that were successfully modeled were randomly divided into a model control group and a positive drug group (reduced glutathione, 200 mg/kg·bw), tea polyphenol group (50 mg/kg·bw), and low-dose, medium-dose and high-dose tea polysaccharide-tea polyphenol groups (40, 100, 250 mg/kg·bw). Gavage for 45 days to determine the content of biomacromolecule oxidative damage markers and enzyme antioxidant system related indicators in the brain of homogenate mice. Results: Compared with the model control group, the levels of the high-dose tea polysaccharide-tea polyphenol group of the biomacromolecule oxidative damage markers including protein carbonyl (PCO), advanced oxidation (AOPP), 3-nitrotyrosine (3-NT), malondialdehyde (MDA), 8-iso-prostaglandin(8-iso-PG), 8-hydroxy-2'-desoxyguanosine (8-OHdG), 5- hydroxy-2' -desoxyguanosine (5-OH-DG) were significantly decreased by 22.95%, 15.23%, 15.29%, 25.23%, 23.15%, 32.36%, 28.63%, respectively (P<0.05). The levels of antioxidants including SOD and GPX were significantly increased by 71.15% (P<0.05) and 36.90% (P<0.05), all of which reached the normal levels (P>0.05). Compared with the tea polyphenol group, the levels of PCO, AOPP, 3-NT, MDA, 8-iso-PG, 8-OHdG, 5-OH-DG of the high-dose tea polysaccharide-tea polyphenol group were decreased by 4.06%, 1.81%, 4.96%, 10.12%, 3.40%, 12.50%(P>0.05), respectively and the level of 8-OHdG was significantly decreased by 21.19% (P<0.05). The level of SOD was increased by 15.63% (P>0.05) and the level of GPX was significantly increased by 5.84% (P<0.05). Conclusion: The tea polysaccharide-tea polyphenol mixture could effectively improve the oxidative damage of the brain of mice, and the effect of the tea polysaccharide-tea polyphenol mixture was better than that of the same dose of tea polyphenol.