Prevention of in vivo oxidation by anthocyanins and its molecular biological function mechanism

多酚类物质，特别是黄酮类化合物对多种疾病的预防作用已被许多学者所研究。然而，红紫色果皮果蔬中所含的多酚类物质花青素的生理功能尚未得到充分研究。本课题研究了红甘蓝中主要的三种酰化花色苷在体内的生理功能及其作用机制，发现红甘蓝中主要的三种酰化花色苷均能抑制百草枯诱导的体内氧化反应，产生活性氧。抑制肝脏NADPH-细胞色素P450还原酶喂养的酰化花青素表明，这些花青素部分可以通过抑制这种酶的活性，防止氧化应激。另一方面，在喂食这些花色苷的大鼠中，血液和肝脏的脂质过氧化、伴随DNA损伤产生的肝脏氧化型谷胱甘肽和8-羟基脱氧鸟苷（8-OH dG）的增加以及链脲霉素诱导的糖尿病大鼠从肝脏向血液释放α-生育酚的抑制被缓解，表明这些花色苷有效地防止氧化应激。在腹腔注射D-氨基半乳糖诱发大鼠肝损伤前，给大鼠喂饲茄子花色素苷和茄子花色素苷，可抑制血浆GOT和GPT活性的升高，抑制α-生育酚从肝脏向血液的释放，抑制肝脏8-OH dG的升高，抑制肝脏抗坏血酸的氧化。在注射D-氨基半乳糖之前喂食花色苷的大鼠肝匀浆的抵抗力更强，这表明这些可能从肠道吸收的花色苷或其氧化产物部分地充当自由基清除剂。

Preventive effects of polyphenols, especially of flavonoids which a kind of polyphenols, against diseases were investigated by many researchers. However, physiological functions of anthocyanins, which is a kind of polyphenols and contained in fruits and vegetables with red - purple color peels, have not yet been fully investigated. In this project, the physiological functions of anthocyanins in vivo and function mechanism were investigated.Major three acylated anthocyanins contained in red cabbage suppressed in vivo oxidation induced by paraquat which generate active oxygen species in vivo. Suppression of liver NADPH-cytochrome P450 reductase by feeding the acylated anthocyanins suggested that these anthocyanins partly could prevent oxidative stress by inhibiting the activity of this enzyme. On the other hands, Increases in lipid peroxidation of blood and liver, liver oxidized glutathione and 8-hydroxydeoxyguanosine (8-OH dG) generated with DNA damage, and suppression for release of α-tocopherol from the liver to blood by streptozotocin-induced diabetic rats were relieved in rats fed these anthocyanins, indicating that these anthocyanins were effective to prevent oxidative stress.Anthocyanins contained in boysenberry , and Nasunin in egg plant suppressed increases in plasma GOT and GPT activities and release of α-tocopherol from liver to blood, increase in liver 8-OH dG, and oxidation of the liver ascorbic acid when those anthocyanins were fed to rats before induction of liver injury by the intraperitoneal injection of D-galactosamine. Stronger resistance of liver homogenate of rats fed anthocyanins before the injection of D-galactosamine, suggested that these anthocyanins or their oxidation products, which might be absorbed from intestine, partly acted as radical scavengers.