| Safflower, a common blood circulation drugsthe, was the dried flower of safflower (Carthamus tinctorius L.). The ingredient of safflower was mixed chalcone glycosides. With the pharmacological activity of the treatment of a variety of cardiovascular and cerebrovascular diseases, safflower can treat many cycle disorders. The mechanism of cardiovascular and cerebrovascular disease was caused by free radicals which processed by myocardial ischemia and reperfusion, inflammation, etc. The free radicals could damage of biological macromolecules,lead to lipid peroxidation and protein cross-linking. So inhibition of free radical reactions, is an important way to mitigate such damage.Studies showed that the water extract of safflower not only could scavenge hydroxyl radicals, but also could inhibite the hyaluronic acid depolymerization induced by lipid peroxidation of mouse liver homogenate and free radical.The flavonoids was the most important ingredients in safflower, however, rare researches focus on antioxidant components of safflower. In this paper, we studied the three main ingredients in safflower(hydroxyl safflower yellow A, safflower yellow B and6-hydroxykaempferol--3-O-β-glucoside). We studied their antioxidant activity and preliminary action mechanism, which designed to provide the basis pharmacological effects for safflower research.This paper is divided into the following areas:1. Three flavonoid compounds(hydroxyl safflower yellow A (HSYA) safflower yellow B(SYB) and6-hydroxykaempferol-3-O-β-glucoside (6-HK-3-O-G) were separated from safflower, using Chromatographic separation method.2. In this chapter, we used the experiments of2-deoxyribose degradation to study the ability of three flavonoids in safflower protecting2-deoxyribose oxidative damage. This chapter also studied the ability of protecting2-deoxyribose oxidative damage of3',4'-dihydroxyflavone;5,7-dihydroxyflavone;3-hydroxyflavone and6-hydroxyflavone.The result showed that the6-HK-3-O-G has strong ability of protecting2-deoxyribose oxidative damage.3. In this chapter, we used the DPPH-scavenging experiments to study the ability of scavenging the hydroxyl radicals about the there flavonoid constituents in safflower. This chapter also studied the ability of scavenging the hydroxyl radicals of3',4'-dihydroxyflavone;5,7-dihydroxyflavone;3-hydroxyflavone and6-hydroxyflavone.The result showed that the6-HK-3-O-G had strong ability of scavenging the hydroxyl radicals.4. In this chapter, we used the electron spin resonance (EPR) to study the ability of6-HK-3-O-G scavenging the hydroxyl radicals, and then detect the EPR signals of Fe3+influenced by flavonoids and EDTA. The results:(1)Flavonoids could reduced the EPR signal of Fe3+, the reason might be that flavonoids had reduced Fe3+to Fe2+;(2)Fe3+potential change was likely related to the phenolic hydroxyl number of flavonoids, the more phenolic hydroxyl number,the more reduced ability for Fe3+to Fe2+(3)Flavonoids could block the Fenton reaction by chelation of Fe2+, therefore, it reduced the amount of hydroxyl radicals which generated in Fenton system;(4) Flavonoids not only could weak the EPR signal of Fe3+which generated in the Fenton reaction by chelation of Fe2+, but also could further reduce Fe3+to Fe2+5.We studied the preliminary mechanism of flavonoids for inhibiting oxidative damage by studing the mechanism of6-HK-3-O-G's. The impact of EDTA on the hydroxyl radical which generated by the Fenton reaction had been studied. The formation of an iron complex with6-HK-3-O-G was demonstrated by UV/vis absorbance spectroscopic, EPR, electrochemical and so on. The result indicated that there were two reasons for6-HK-3-O-G protecting2-deoxyribose oxidative damage, one of the reasons is the strong ability of6-HK-3-O-G scavenging hydroxyl radical, and more important reasons is the chelation of6-HK-3-O-G with Fe2+, which can block the Fenton reaction. |
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