| The Ziyang green tea is famous for the richness of trace element selenium. It enjoys a good reputation of "the king of anticancer treatment" and "the anti-senile star" in the medicine domain. Being honored as the new century nutrition health products by the nutrition circles, it has the prospects for the development of health care products, particularly, and benefits the supplement of the content of body selenium.Therefore, in this research we selected Ziyang selenium-enriched green tea which was grown in the specific region of the tea, and used our laboratory mature separation and analysis of polysaccharide. The separation and analysis of9monosaccharides in Ziyang selenium-enriched green tea were accomplished for the first time on the basis of established HPLC technique with PMP precolumn derivatization. It was indicated that the Ziyang selenium-enriched green tea polysaccharide’s (TPS) main monosaccharide composition are Rib, Rha, Xyl, GlcUA, GalUA, Man, Glc, Gal and the Ara, its correspondence’s mole of percentage are4.3%,1.4%,4.1%,2.6%,3.0%,31.4%,4.6%,21.8%and23.5%, and the main contents are Glc, Gal and Ara, which take up the percentage of76.7%. In addition, determination of the uronic acid content is16.3%in samples, the protein content is5.1%, the selenium content is1.5μg/g. Based on the experimental data, TPS is a typical acidic protein polysaccharide containing selenium. At the same time, qualitative and quantitative analysis carried out using HPLC coupled with UV detection revealed that four predominantly polyphenolic compounds present in tea polyphenol (TP) were epigallocatechin gallate (EGCG,28.2%, w/w), epigallocatechin (EGC,5.7%, w/w), epicatechin gallate (ECG,5.6%, w/w) and caffeine (CAF,42.9%, w/w).Study on antioxidant activity in vitro results showed that TPS and TP have the strong antioxidant activity, and taken on a good dose-effect relationship. TP has the highly strengthened antioxidant activity and reducing ability, and its antioxidant activity obviously is higher than that of the same concentrations of positive drug, while reducing ability is close to the same concentrations of positive drug (BHT). However, TPS’s antioxidant activity is slightly lower than that of the same concentrations of positive drug. In brief, TPS and TP are the effective natural oxidation inhibitor, particularly the TP. Its antioxidant activity obviously is the higher than the partial positive drugs.At the same time, it was discovered in the study that the TPS and TP to the growth of the breast cancer MCF-7cell, the adenocarcinoma of lung A549cell and the colon cancer LoVo cell has certain inhibitory action. Among them, the MCF-7cell’s function of proliferation inhibition is surppressed most, and then is the LoVo cell, and A549last. Therefore, this topic only concentrates on MCF-7cell in-depth mechanism research. Through the further research found that the Ziyang selenium-enriched green tea polysaccharide can keep breast cancer MCF-7cell cycle from growing in the G2/M phase, and it contributes to the promotion of apoptosis. While the TP can retard cell cycle in the G1phase, and has a strong induction of apoptosis, and the rate of apoptosis achieves37.79%at0.5mg/mL. Meanwhile, western blot analysis showed that the TPS and TP may cause the Bax and the p53protein expression up-regulation as well as the Bcl-2protein expression down-regulation. Finally, the kit’s method analysis examination revealed that the TPS and TP can cause the caspase-3/9activeness to increase, and the TP’s function is much stronger. Based on the experimental results, we can be preliminarily assess that the TPS and TP are involved in MCF-7cell mitochondrial apoptotic pathway.In this research we have prepared and separated TPS and TP which contain the selenium, from Ziyang selenium-enriched green tea. We also carried out the TPS and TP composition analysis and the physicochemical properties. On the basis of systematic studies of TPS and TP antitumor mechanism and dose-effect relationship, for the development of independent intellectual property of the new functional food factors or drugs to provide the theory basis, to play its great potential economic and social benefits. |
