Veterans Administration Healthcare System, Long Beach, CA, USA.
Nutr Res. 2013 Nov;33(11):932-41. doi: 10.1016/j.nutres.2013.08.001. Epub 2013 Sep 18.
Mitochondrial abnormalities are suggested to be associated with the development of nonalcoholic fatty liver. Liver mitochondrial content and function have been shown to improve in oral feeding of acetyl-L-carnitine (ALC) to rodents. Carnitine is involved in the transport of acyl-coenzyme A across the mitochondrial membrane to be used in mitochondrial β-oxidation. We hypothesized that oral administration ALC with the antioxidant lipoic acid (ALC + LA) would benefit nonalcoholic fatty liver. To test our hypothesis, we fed Balb/C mice a standard diet (SF) or SF with ALC + LA or high-fat diet (HF) or HF with ALC + LA for 6 months. Acetyl-L-carnitine and LA were dissolved at 0.2:0.1% (wt/vol) in drinking water, and mice were allowed free access to food and water. Along with physical parameters, insulin resistance (blood glucose, insulin, glucose tolerance), liver function (alanine transaminase [ALT], aspartate transaminase [AST]), liver histology (hematoxylin and eosin), oxidative stress (malondialdehyde), and mitochondrial abnormalities (carbamoyl phosphate synthase 1 and electron microscopy) were done. Compared with SF, HF had higher body, liver, liver-to-body weight ratio, white adipose tissue, ALT, AST, liver fat, oxidative stress, and insulin resistance. Coadministration of ALC + LA to HF animals significantly improved the mitochondrial marker carbamoyl phosphate synthase 1 and the size of the mitochondria in liver. Alanine transaminase and AST levels were decreased. In a nonalcoholic fatty liver mice model, ALC + LA combination improved liver mitochondrial content, size, serum ALT, and AST without significant changes in oxidative stress, insulin resistance, and liver fat accumulation.
线粒体异常被认为与非酒精性脂肪肝的发生有关。已经表明,在给啮齿动物口服乙酰左旋肉碱(ALC)时,肝脏线粒体的含量和功能得到改善。肉碱参与酰基辅酶 A 通过线粒体膜的转运,以便在线粒体β-氧化中使用。我们假设口服 ALC 与抗氧化剂硫辛酸(ALC+LA)的联合治疗会有益于非酒精性脂肪肝。为了验证我们的假设,我们给 Balb/C 小鼠喂食标准饮食(SF)或 SF+ALC+LA 或高脂肪饮食(HF)或 HF+ALC+LA 长达 6 个月。ALC 和 LA 溶解在饮用水中,浓度为 0.2:0.1%(wt/vol),并允许小鼠自由摄取食物和水。除了生理参数外,我们还检测了胰岛素抵抗(血糖、胰岛素、葡萄糖耐量)、肝功能(丙氨酸转氨酶[ALT]、天冬氨酸转氨酶[AST])、肝脏组织学(苏木精和伊红)、氧化应激(丙二醛)和线粒体异常(氨基甲酰磷酸合成酶 1 和电子显微镜)。与 SF 相比,HF 组的体重、肝脏、肝重比、白色脂肪组织、ALT、AST、肝脂肪、氧化应激和胰岛素抵抗更高。将 ALC+LA 联合给予 HF 动物可显著改善肝脏线粒体标志物氨基甲酰磷酸合成酶 1 和肝脏线粒体的大小。丙氨酸转氨酶和天冬氨酸转氨酶水平降低。在非酒精性脂肪肝小鼠模型中,ALC+LA 联合治疗可改善肝脏线粒体含量、大小、血清 ALT 和 AST,而氧化应激、胰岛素抵抗和肝脂肪堆积无明显变化。