Study On Antioxidant And Weight - Reducing Effects Of Phenolic Compounds

Polyphenol possesses one or more aromatic rings bearing hydroxyl groups, which could scavenge free radicals and protect the body from oxidative stress by donating hydrogen atoms or electron, or chelating metal cations. The antioxidant activity of polyphenol compounds depends on the structure, in particular the number and positions of the hydroxyl groups. In the other way, the polyphenols exhibit both anti-obesity and antiatheroscloresis effect, they possess hydrophobic benzene ring as well as hydrophilic phenolic hydroxyl group, they are both hydrophilic and lipophilic, but the solubility is low in aqueous or oil, so polyphenols could not play their physiological roles very well. Saccharides are responsible for various roles in all living things, most notably in controlling the energy in cells as well as providing biological information. Based on the diversity of glycons and their roles in molecular recognition, polyphenol compounds modified by glycoside with different spatial configurations and physicchemical properties could expand the function of polyphenols. Here polyphenols modified by glycoside or other substituents were studied in vitro and in vivo.This paper involves the following two parts:Part one:Antioxidant activity of polyphenol compounds in vitro and in vivoThe antioxidant experiments in vitro indicate that polyphenol compounds have strong reducing power and free radical-scavenging capacity, A4could protect EVC304cells from oxidative damage. Kunming mice induced by ethanol and KKAy mice induced by hyperglycemia were chosen as oxidative stress models in vivo. A4could inhibit the generation of MDA and protein carbonyl, increase the SOD activity and the content of GSH in Kunming mice, furthermore A4could increase the SOD, GSH-Px activities and decrease the content of MDA, down-regulate the expression of p66Sch in liver in KKAy mice. All the results above show that A4has antioxidant activity in vivo.Part two:Anti-obesity action of polyphenol compounds in vitro and in vivoThe anti-obesity action of polyphenols modified by glycoside or other substituents indicates that A4could effective inhibit the activity of pancreatic lipase. The study in vivo was performed in high fatty diet induced obesity rats. A4reduced the body weight gain, Lees index, fat coefficient and the size of adipocyte, but not influence the amount of food intake, this imply that A4could reduce the fat content not by inhibiting feeding behavior to achieve weight loss. Biochemical indexes show that A4could regulate blood lipid levels, reduce serum triglyceride (TG) levels significantly; increase the LPL+HL activities in serum; down-regulate the expression of TNF-a in liver; and improve the antioxidant capacity. These findings demonstrate that A4could relieve rats’oxidative stress and inflammation reaction, increase the activities of lipid metabolic enzymes, reduce triglyceride (TG) levels, the ensemble research results is anti-obesity.