Study On Composition Of Proanthocyanidins In Pyracantha Fortuneana Fruit And Their Effects On Cellular Antioxidant Activity Of Quercetin

The Pyracantha Fortuneana is a edible and medicinal plant belonged to the Maloideae of Rosaceae, which is rich in polyphenol like flavonoid and proanthocyanidins(PCs). Proanthocyanidins was reported as functional component of many natural health protection foods with physiological activities of anti-cancer, metabolic regulation and anti-oxidation. Due to it`s poor bioavailability especially macromolecule proanthocyanidins uptake by cells, the mechanism of physiological activities of proanthocyanidins is still unclear. As the research object of this article, the interactions between proanthocyanidins and small molecules were focused on to study pharmacological mechanism. Through extraction and separation to get different degrees of polymerization proanthocyanidins, the structure of proanthocyanidins can be analysised by LC-MS.After the identification of structure, it`s easy for us to explore the interactions between small molecule quercetin and proanthocyanidins, to providing a theoretical support antioxidant activity mechanism of proanthocyanidins. The results are as follows.(1)Extraction by Sephadex LH-20 column to obtain different degrees of polymerization of water soluble-proanthocyanidins, eight components have been harvested when based on mobile phase polarity difference which the yield can reach 99%. After LC-MS identification analysis, the degree of Pyracantha fortuneana soluble proanthocyanidins have been identifyed as follows: 6.2±0.4,5±0.2, 8.3±0.3, 8.9±0.4, 9.5±0.3, 10.7±0.3, 13.9±0.3, 15.8±0.4. The monomers of proanthocyanidins are catechin(C), epicatechin(EC), gallocatechin(GC), epigallocatechin(EGC).(2)Dichlorofluorescin and 2, 2`-azobis(2-amidinopropane) dihydrochloride-(ABAP) have been used to detect the free radical in Hep G 2. In order to analysis the fluorescence intensity attenuation of group Q(quercetin) when is coexistence of PCs, some assays was done. The regularity of the fluorescence decay in each groups has been found. As for group Q, fluorescence intensity of group F+Q was notably attenuation along with the polymerization degree of PCs, like group Q(EC50) 5.97 and group F8+Q(EC50) 2.91. And the effect has positive correlation with degrees of PCs. Compared to group Q, the fluorescence decay intensity variation of group Pyracantha fortuneana was non-significant, and group PCs undetected.(3)Both stability and solubility have been discussed to uncover the mechanism how PCs improves the antioxidant activity of Q. PCs can significantly increase the solubility of Q in the intestinal simulate fluid(Fasted State Simulated Intestinal Fluid, FASIF) along with the polymerization degrees of PCs, and the maximum can reach 97.4%. Also, procyanidin B2 can significantly inhibit the oxidation of Q, like the content of group Q+B2 and Q after 20 d, 49.02 μg/ml, 4.92 μg/ml, respective.In summary, it was found that PCs can improve the solubility of Q and reduce oxidative stress in the environmental, which can maintain Q stability to improve its bioavailability, and better exert antioxidant activity of Q.