Structure-effect Relationship Of Anti-free Radical Effects Of Quercetin And Its Monoglycoside Isoquercetin And Diglycoside Rutin

ObjectiveTo study comparatively anti-free radical effects of three flavonids: Quercetin(Q), and its monoglucoside isoquerectin(I),diglucoside rutin(R) using different free radical injury models,and thereby find out structure-effect relationship of three flavonoids in anti-free radical activity .Methods1. Oxygen free radical scavenging-effect in vitro by Q,I,R Hydroxyl free radical(·OH) was generated using H₂O₂/Fe²⁺ system via Fenton reaction;Superoxide anion (O₂·^-) was generated using pyrogallol auto-oxidation method.Hepatocellular lipid peroxidation and the rupture of RBC membrane were caused by·OH.Clearance and inhibitory rate of three flavonoids at four concentration levels were calculated based on optical density which was measured by UV-754 spectrophotometer,and thereby SC₅₀ and IC₅₀ were calculated according to established formula.2. Protective effects of Q,I,R on in vitro free-radical induced cell injury HEK293 cells were damaged by using H₂O₂ and anoxia/hypoglycemia cell culture fluid.MTT method was used to examine cell survival rate.SOD ,LDH and TAC levels in cell culture fluid were determined to observe the cyto-protective effect and anti-free radical effect of three flavonoids at cell level. 3. Protective effect of Q,I,R on in vivo free-radical induced brain and liver injuries Persistent cerebral ischemia model and liver injury model were caused by tightening bilateral arteria carotis communis and injecting CCl4 intraperitoneally.SOD and MDA levels in mice brain homogenate as well as mean survival time were determined to observe the cerebral ischemia-induced injury and its protection by Q,I,R;...