Wan Xiao-hua, Li Yu-wen, Luo Xiao-ping
Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Zhonghua Er Ke Za Zhi. 2007 Aug;45(8):604-8.
Hepatolenticular degeneration (Wilson disease, WD) is an autosomal recessive disorder of copper metabolism. The clinical manifestations are dominated by the neuropsychiatric and hepatic symptoms due to copper deposition. Investigation of mechanism of copper injury should be helpful for elucidating the pathogenesis and treatment of WD. Curcumin, a plant-derived polyphenol, exhibits the properties of anti-oxidant, anti-inflammation and has no evident side effects, therefore, today curcumin is studied by more and more researchers in pharmacologic action and clinical application especially for its protective effect on liver diseases. The present study was designed to investigate the lipid peroxidation and apoptotic liver injury in copper-overloaded rats, and to explore the protective effects of curcumin.
Wistar rats, male, were randomly divided by copper-overloaded groups and curcumin treatment groups and control group. Copper-overloaded rat model was established by feeding with forage containing 1 g/kg copper sulfate and water with 0.185% copper sulfate for 8 weeks or 12 weeks. In the treatment groups, curcumin was administered orally either 50 mg/kg or 200 mg/kg for 2 weeks and 4 weeks and 8 weeks and fed with copper sulfate at the same time until the 12th week. Malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) in liver homogenates were measured to reflect the copper induced lipid peroxidation. The apoptosis of liver cell was detected by electron microscope (EM) and TUNEL assay. The expressions of TNF-alpha mRNA and IL-8 mRNA were observed by RT-PCR. Contents of TNF-alpha and IL-8 in liver homogenates were measured by ELISA.
The MDA concentrations were significantly increased and the GSH and SOD levels were decreased in the copper-overloaded rats. The apoptosis index displayed from (2.2 +/- 1.2)% in control rats to (16.7 +/- 2.5)% in the copper treated animals. Expression of TNF-alpha mRNA and IL-8 mRNA were enhanced in the copper-overloaded rats. Curcumin significantly attenuated the increase of MDA concentrations and recovered the GSH and SOD levels. The apoptosis index decreased to (10.4 +/- 1.2)% in the copper-overloaded rats with curcumin treatment. Curcumin down-regulated the expressions of TNF-alpha mRNA and IL-8 mRNA and content of TNF-alpha and IL-8. Histological changes induced by copper in liver, such as mitochondrial swelling and endoplasmic reticulum distention and increased lysosomal granules in the model rats, were also improved significantly by curcumin treatment as evidenced by EM examination.
Copper-overloading caused lipid peroxidatic injury and induced significant apoptosis in liver. TNF-alpha and IL-8 might be involved in liver injury in this model. Curcumin exhibited protective effects and possibly acted through its antioxidant and anti-apoptotic properties.
肝豆状核变性（威尔逊病，WD）是一种常染色体隐性铜代谢紊乱疾病。由于铜沉积，其临床表现以神经精神症状和肝脏症状为主。研究铜损伤机制有助于阐明WD的发病机制和治疗方法。姜黄素是一种植物来源的多酚，具有抗氧化、抗炎特性且无明显副作用，因此，如今越来越多的研究人员对其药理作用和临床应用进行研究，尤其是其对肝脏疾病的保护作用。本研究旨在探讨铜过载大鼠肝脏脂质过氧化和凋亡性肝损伤情况，并探究姜黄素的保护作用。
雄性Wistar大鼠随机分为铜过载组、姜黄素治疗组和对照组。通过给大鼠喂食含1 g/kg硫酸铜的饲料及含0.185%硫酸铜的水8周或12周建立铜过载大鼠模型。在治疗组中，分别以50 mg/kg或200 mg/kg的剂量口服姜黄素2周、4周和8周，并同时喂食硫酸铜直至第12周。检测肝匀浆中丙二醛（MDA）、超氧化物歧化酶（SOD）和谷胱甘肽（GSH）水平以反映铜诱导的脂质过氧化情况。通过电子显微镜（EM）和TUNEL检测法检测肝细胞凋亡情况。通过RT-PCR观察肿瘤坏死因子-α（TNF-α）mRNA和白细胞介素-8（IL-8）mRNA的表达情况。通过ELISA检测肝匀浆中TNF-α和IL-8的含量。
铜过载大鼠的MDA浓度显著升高，GSH和SOD水平降低。凋亡指数从对照大鼠的（2.2±1.2）%升高至铜处理动物的（16.7±2.5）%。铜过载大鼠中TNF-α mRNA和IL-8 mRNA的表达增强。姜黄素显著减轻了MDA浓度的升高，并使GSH和SOD水平恢复。姜黄素治疗的铜过载大鼠凋亡指数降至（10.4±1.2）%。姜黄素下调了TNF-α mRNA和IL-8 mRNA的表达以及TNF-α和IL-8的含量。电子显微镜检查证明，姜黄素治疗还显著改善了模型大鼠肝脏中由铜诱导的组织学变化，如线粒体肿胀、内质网扩张和溶酶体颗粒增加。
铜过载导致肝脏脂质过氧化损伤并诱导显著的肝细胞凋亡。TNF-α和IL-8可能参与了该模型中的肝损伤。姜黄素具有保护作用，可能是通过其抗氧化和抗凋亡特性发挥作用。
