Nagababu E, Lakshmaiah N
Department of Biochemistry, National Institute of Nutrition, Indian Council of Medical Research, Jamai Osmania, India.
Mol Cell Biochem. 1997 Jan;166(1-2):65-71. doi: 10.1023/a:1006878315029.
The effect of eugenol on xanthine oxidase (XO) xanthine(X)-Fe+3-ADP mediated lipid peroxidation was studied in liver microsomal lipid liposomes. Eugenol inhibited the lipid peroxidation in a dose dependent manner as assessed by formation of thiobarbituric acid reactive substances. When tested for its effect on XO activity per se, (by measuring uric acid formation) eugenol inhibited the enzyme to an extent of 85% at 10 microm concentration and hence formation of O2.- also. However, the concentration of eugenol required for XO inhibition was more in presence of metal chelators such as EDTA, EGTA and DETAPAC, but not in presence of deferoxamine, ADP and citrate. The antiperoxidative effect of eugenol was about 35 times more and inhibition of XO was about 5 times higher as compared to the effect of allopurinol. Eugenol did not scavenge O2.- generated by phenazine methosulfate and NAD but inhibited propagation of peroxidation catalyzed by Fe2+ EDTA and lipid hydroperoxide containing liposomes. Eugenol inhibits XO-X-Fe+3 ADP mediated peroxidation by inhibiting the XO activity per se in addition to quenching various radical species.
在肝微粒体脂质脂质体中研究了丁香酚对黄嘌呤氧化酶（XO）-黄嘌呤（X）-Fe³⁺-ADP介导的脂质过氧化的影响。通过硫代巴比妥酸反应性物质的形成评估，丁香酚以剂量依赖性方式抑制脂质过氧化。当测试其对XO本身活性的影响（通过测量尿酸形成）时，丁香酚在10微摩尔浓度下可将该酶抑制85%，因此也抑制了超氧阴离子（O₂⁻）的形成。然而，在存在金属螯合剂如EDTA、EGTA和DETAPAC时，抑制XO所需的丁香酚浓度更高，但在存在去铁胺、ADP和柠檬酸盐时则不然。与别嘌呤醇的作用相比，丁香酚的抗过氧化作用约强35倍，对XO的抑制作用约高5倍。丁香酚不能清除由吩嗪硫酸甲酯和NAD产生的O₂⁻，但能抑制由Fe²⁺-EDTA和含脂质过氧化氢的脂质体催化的过氧化反应的传播。丁香酚除了淬灭各种自由基外，还通过抑制XO本身的活性来抑制XO-X-Fe³⁺-ADP介导的过氧化。
