双环醇对大鼠黄曲霉毒素B1代谢和肝毒性的影响

目的:研究抗肝炎新药双环醇对大鼠黄曲霉毒素B_1(AFB_1)代谢和肝毒性的影响.方法:大鼠灌胃双环醇300 mg·kg~(-1)·d~(-1),连服三日后腹腔注射黄曲霉毒素B_1 1.5 mg·kg~(-1).给黄曲霉毒素B_1 16小时后观察双环醇对黄曲霉毒素B_1引起肝损伤的防护作用以及对体外代谢的影响.结果:双环醇(300 mg·kg~(-1)·d~(-1),连服三日)可明显降低黄曲霉毒素B_1引起的大鼠血清转氨酶和肝脏MDA的升高,增加低毒代谢产物AFQ_1的生成.双环醇还可增加大鼠肝脏细胞色素P450总量和胞浆谷胱甘肽含量,诱导P450 CYP2B1介导的7-戊氧基香豆素脱烃酶和谷胱甘肽疏基转移酶的活性.此外,双环醇对P450 CYP3A介导的红霉素脱甲基酶和 P450 CYP1A介导的7-乙氧基香豆素脱烃酶也有诱导作用.结论:双环醇可通过增加大鼠肝脏对AFB_1代谢的解毒功能起到肝保护作用.     

双环醇通过抑制线粒体凋亡途径缓解TNF-α/D-GalN诱导的爆发性肝损伤

目的探讨双环醇对肿瘤坏死因子-α/D-半乳糖胺(TNF-α/D-GalN)诱导肝损伤的保护作用及可能机制。方法雄性C57小鼠灌胃给予双环醇50、100及200 mg·kg-1·d-1,连续5 d,末次给药2 h后,腹腔注射TNF-α及D-GalN建立爆发性肝炎模型。观察小鼠生存率,评价血清ALT、AST水平,肝组织病理损伤及细胞凋亡情况。Western blot方法检测肝组织Bax、Bcl-2和激活型caspase-3/-9蛋白表达水平。根据离体线粒体膜通透性转换孔(mPTP)开放程度及线粒体细胞色素C的胞质释放情况评价双环醇抗凋亡效应与线粒体保护作用的相关性。结果双环醇明显提高TNF-α/D-GalN所致肝损伤小鼠的生存率,降低血清ALT、AST水平,减轻肝组织病理损伤和肝细胞凋亡。机制研究显示双环醇降低Bax并升高抗凋亡蛋白Bcl-2水平,减轻TNF-α/D-GalN诱导的线粒体mPTP开放及细胞色素C的胞质释放,进而抑制caspase-3/-9的活性及蛋白激活水平。结论双环醇对TNF-α/D-GalN诱导的爆发性肝损伤具有明显的保护作用,其机制与减轻线粒体损伤,进而抑制线粒体凋亡途径有关。     

双环醇对四环素诱发小鼠急性脂肪肝的保护作用

研究双环醇对四环素诱发小鼠急性脂肪肝的影响。小鼠一次腹腔注射四环素(180 mg·kg^-1) 24 h后，收集血样和肝组织，采用生化法测定肝脏甘油三酯(triglyceride，TG)、胆固醇(cholesterol，CHO)、谷胱甘肽(glutathione，GSH)含量，以及血清脂质和转氨酶水平；光谱法测定小鼠线粒体脂肪酸β-氧化速率以及肝脏极低密度脂蛋白(very low density lipoprotein，VLDL，TG)分泌速率。结果表明，双环醇(150及300 mg·kg^-1)连续灌胃给药3次可以不同程度地保护四环素引起的小鼠肝脏TG和CHO升高以及血清谷丙转氨酶(alanine aminotransferase，ALT)、谷草转氨酶(aspartate aminotransferase，AST)升高和脂质异常。双环醇(300 mg·kg^-1)还可减轻四环素诱发小鼠肝脏丙二醛(malondialdehyde，MDA)生成增加和GSH水平降低，并能抑制肝线粒体脂肪酸β-氧化速率下降。双环醇(300 mg·kg^-1)可部分逆转四环素所致小鼠肝脏VLDL(TG)分泌速率的减少。由此可见，双环醇对四环素诱发小鼠急性脂肪肝具有明显的保护作用，其作用机制与保护肝线粒体β-氧化功能、改善肝脂蛋白分泌及转运以及抑制肝脏脂质过氧化密切相关。     

双环醇对肝脏部分切除大鼠CYP450酶活性和表达的影响(英文)

本研究考察双环醇对肝脏部分切除(PH)后大鼠肝脏微粒体细胞色素P450(CYP)活性、基因和蛋白表达的影响及相关机制。大鼠PH前灌胃给予双环醇(300 mg.kg-1)3次,PH后处死大鼠,取其血清和肝组织进行检测,依次测定血清谷丙转氨酶(ALT)、肝微粒体丙二醛(MDA)和肝脏总CYP含量、4种CYP同工酶活性、基因和蛋白表达。结果显示,双环醇可显著抑制PH大鼠血清ALT和肝微粒体MDA的升高,抑制肝脏总CYP含量的减少,抑制CYP2C6、2C11活性和mRNA表达的下降,明显抑制CYP3A1/2活性的下降,并上调CYP3A1和2E1的mRNA和蛋白表达。结果表明,双环醇对PH大鼠肝脏CYP450酶及部分同工酶活性和表达的改变有明显改善作用,其作用机制可能与其抗氧化作用和酶诱导作用密切相关。     

双环醇对脂多糖诱导巨噬细胞iNOS蛋白的表达和NF-κB活化的抑制作用

目的炎症是肝炎病毒或其它因素所致的肝损伤的一个共同特征,该文目的系研究抗肝炎新药双环醇对与炎症反应相关分子的调节作用。方法以无毒性浓度双环醇预先与巨噬细胞株RAW264.7和小鼠腹腔巨噬细胞温孵1h后,加入一定量脂多糖(LPS)共同培养适当时间以诱导上述细胞的活化,培养上清中NO2-的含量和TNF-α的水平分别用Griess试剂及L929细胞株生物法测定,用Westernblot方法测定iNOS蛋白的表达和NF-κB的活化。结果双环醇在0.1～0.5mmol.L-1剂量依赖性降低1mg.L-1LPS引起的RAW264.7和小鼠腹腔巨噬细胞NO的释放以及TNF-α的分泌,双环醇0.5mmol.L-1能够明显抑制1mg.L-1LPS引起的iNOS蛋白的表达和NF-κB的活化。结论双环醇对与炎症相关的调控因子iNOS蛋白的表达和NF-     

Tectoridin,an isoflavone glycoside from the flower of Pueraria lobata,prevents acute ethanol-induced liver steatosis in mice

In traditional Chinese medicine, the flower of Pueraria lobata (Puerariae Flos) has been used in therapy to counteract the problems associated with alcohol drinking and liver injury. In this study, we investigated the hepatoprotective effects and its mechanisms of tectoridin, an isoflavone glycoside from the flower of P. lobata (Willd.) Ohwi. Ethanol (5 g/kg) was given orally every 12 h for a total of three doses. 1 h after the last dose of ethanol, tectoridin (25, 50 and 100 mg/kg) was given intragastrically five times in three consecutive days. The mice were sacrificed at 4 h after tectoridin treatment. Peroxisome proliferators-activated receptor α (PPARα), sterol regulatory element-binding protein (SREBP)-1c and their target genes were evaluated by biochemical analysis and quantitative real-time polymerase chain reaction (qPCR). Mitochondria were isolated for the mitochondrial permeability transition (MPT) and membrane potential (ΔΨ_m) assay. Acute ethanol exposure resulted in the significant increase of the alanine aminotransferase (ALT), aspartate aminotransferase (AST) and triglyceride (TG) levels and hepatic mitochondria dysfunction shown as the increase of MPT and the decrease of ΔΨ_m. However, tectoridin treatment dramatically attenuated these effects. In addition, tectoridin remarkably alleviated the over-production of thiobarbituric acid-reactive substance. Furthermore, tectoridin inhibited the decrease of PPARα expression and its target genes, including medium-chain acyl-CoA dehydrogenase (MCAD), acyl-CoA oxidase (ACO) and cytochrome P450 4A (CYP 4A) at mRNA and enzyme activity levels. These data showed that tectoridin protected against ethanol-induced liver steatosis mainly through modulating the disturbance of PPARα pathway and ameliorating mitochondrial function.     

双环醇在大鼠和人肝微粒体的代谢

目的研究参与双环醇代谢的主要药物代谢酶及代谢动力学参数，分离鉴定双环醇代谢产物。方法双环醇与大鼠和人肝微粒体进行温孵，以高效液相色谱、质谱、核磁共振技术检测并分离鉴定双环醇及其代谢产物。结果双环醇在地塞米松诱导大鼠肝微粒体中的代谢速率显著高于正常大鼠肝微粒体，酮康唑可显著抑制双环醇的代谢。双环醇主要代谢产物为:4-羟基-4′-甲氧基-6-羟甲基-6′-甲氧羰基-2，3，2′，3′-双亚甲二氧基联苯和4-甲氧基-4′-羟基-6-羟甲基-6′-甲氧羰基-2，3，2′，3′-双亚甲二氧基联苯。结论双环醇在大鼠和人肝微粒体的主要代谢产物为4-羟基-4′-甲氧基-6-羟甲基-6′-甲氧羰基-2，3，2′，3′-双亚甲二氧基联苯和4-甲氧基-4′-羟基-6-羟甲基-6′-甲氧羰基-2，3，2′，3′-双亚甲二氧基联苯，细胞色素P450 3A主要参与双环醇代谢。     

The antiepileptic drug topiramate preserves metabolism-secretion coupling in insulin secreting cells chronically exposed to the fatty acid oleate

Topiramate (Topamax), primarily prescribed against epilepsy, was reported to reduce body weight and to ameliorate glycemic control in obese patients with diabetes. In rodent models of obesity and diabetes, topiramate treatment counteracts hyperglycemia and increases insulin levels upon glucose tolerance test. These observations suggest that topiramate might exert direct action on insulin secreting cells, in particular regarding obesity associated β-cell dysfunction. In this study, INS-1E β-cells were exposed for 3 days to the fatty acid oleate (0.4 mM) and concomitantly treated with therapeutic concentrations of topiramate before measurements of insulin secretion and metabolic parameters. In healthy cells, topiramate had no acute or chronic effects on insulin release. Exposure of INS-1E cells to oleate for 3 days increased insulin release at basal 2.5 mM glucose and blunted the response to stimulatory glucose concentration (15 mM). Such lipotoxic effects were associated with impaired mitochondrial function, as evidenced by partial loss of resting mitochondrial membrane potential and reduced hyperpolarization in response to glucose. Oil-red-O staining and triglyceride measurements revealed lipid accumulation in oleate treated cells. Topiramate treatment counteracted oleate-induced lipid load and partially protected against mitochondrial membrane dysfunction. In particular, topiramate restored glucose stimulated insulin secretion, essentially by maintaining low insulin release at basal glucose. Topiramate increased expression of the nutrient sensor PPARα and of the mitochondrial fatty acid carrier CPT-1, correlating with enhancement of β-oxidation rate. The data demonstrate that a drug originally used as mood stabilizer exerts a direct action on β-cells, protecting against lipid-induced dysfunction.     

Pharmacological characterization of a human-specific peroxisome proliferater-activated receptor alpha (PPARalpha) agonist in dogs

Peroxisome proliferator-activated receptor α (PPARα) is a key regulator in lipid metabolism and a potential therapeutic target for lipid-related metabolic diseases. It has been shown that there are species differences between human and mouse in response to several PPARα agonists in a transactivation assay. In the present study, we cloned a full length of dog PPARα and investigated the effects of a novel and potent agonist (KCL) for human PPARα. In a transactivation assay using the full length of PPARα, agonistic activity of KCL for dog PPARα (EC₅₀: 0.007 μM) was comparable to that for human PPARα (EC₅₀: 0.003 μM), but not that for rat PPARα (EC₅₀: 11.49 μM). Similar results were obtained from a transactivation assay using a GAL4/PPARα ligand-binding domain (LBD) chimera. A point-mutation study showed that I272 on PPARαLBD is a major contributor to species differences in response to KCL between human, dog, and rat PPARα. KCL also induced mRNA levels of HMG-CoA synthase in dog hepatocytes. When administered orally to dogs and rats, KCL significantly decreased plasma triglyceride levels in a dose-dependent manner. The triglyceride-lowering effects of KCL in dogs were >100-fold more potent than those in rats. These results suggest that KCL may induce activation of highly potent PPARα in humans as well as dogs, and that dog is a suitable animal model for studying and predicting the biological actions of potent agonists for human PPARα.     

双环醇片联合肌苷片治疗老年脂肪肝的疗效观察

目的探讨双环醇片联合肌苷片治疗老年脂肪肝的疗效,并观察对患者肝功能、血脂的影响。方法将在我院接受治疗的120例老年脂肪肝患者,分成对照组和观察组,患者接受常规治疗的同时,对照组口服肌苷片,观察组联合双环醇片治疗。结果治疗后,观察组患者TG、CHOL、LDL-C水平低于对照组、而观察组患者HDL-C水平高于对照组(P<0.05)。治疗后,观察组患者AST、TBil、ALT、GGT水平低于对照组(P<0.01)。观察组患者的治疗总有效率为95.00%,高于对照组(78.33%),(P<0.01)。结论双环醇片联合肌苷片治疗老年脂肪肝疗效佳,能够有效调节患者血脂、促进患者肝功能的恢复,有利于患者症状体征的改善。     

酒精性脂肪肝脂质代谢研究进展

酒精性脂肪肝(AFL)是长期大量饮用酒精引发的肝脏损害性病变,可逆转也可进一步发展为肝纤维化和肝硬化。众多的脂肪细胞因子如瘦素(Leptin)、抵抗素(Resistin)和肿瘤坏死因子-α(TNF-α)在脂肪肝的发病中起到一定的促进作用,脂联素(Adiponectin)能改善脂质代谢,延缓脂肪肝的发生;脂联素通过腺苷酸活化蛋白激酶(AMPK)调节糖脂代谢、改善胰岛素敏感性。脂联素/AMPK信号通路是酒精在肝脏的作用靶点、也是调节PPARγ作用的重要信号通路;脂肪分化相关蛋白(ADRP)调节脂质代谢、促进酒精性脂肪肝的形成;过氧化物酶增殖体激活受体γ(PPARγ)参与机体脂质稳态的调节,脂肪肝时PPARγ表达增高,肝纤维化时PPARγ表达减少。对酒精性脂肪肝脂质代谢的深入研究,有助于阐明酒精性脂肪肝发病机制并为临床防治ALD及脂质代谢相关疾病提供新策略。     

双环醇片防治肿瘤化疗药物性肝损害的研究

目的：评价双环醇片对肿瘤化疗药物所致肝损害的治疗和预防作用。方法：随机选取62例初次肿瘤化疗后出现药物性肝损害的患者,开始口服双环醇片50mg每日3次。待肝功能恢复正常后再次按照原方案化疗时,继续口服双环醇片50mg每日3次,持续14d,前后进行自身对照。观察口服双环醇片对肿瘤患者化疗后肝损害所致谷丙转氨酶（ALT）、谷草转氨酶（AST）、总胆红素（TBiL）等肝功能的影响。同时,观察口服双环醇片治疗肿瘤化疗药物所致肝损害恢复正常后,化疗同时联合双环醇片预防性保肝治疗,比较该次与单纯化疗前后的ALT、AST、TBiL差值。结果：口服双环醇片治疗化疗后肝损害,肝功能ALT、AST等指标明显降低,在中位时间8.5d恢复正常。在预防化疗所致肝损害上,化疗与双环醇片联合治疗前后的ALT、AST差值明显减小,与单纯化疗前后比较,差异有统计学意义（P〈0.01）。结论：双环醇片可以有效治疗和预防化疗药物对肝脏的损害。     

双环醇的抗病毒与肝细胞保护作用及其作用机制

双环醇是人工合成的一类抗慢性病毒性肝炎新药,具有显著的保肝作用和一定抗肝炎病毒活性。该药50,100,200mg.kg^-1ig对CCl4,D-氨基半乳糖,对乙酰氨基酚引起的小鼠肝损伤以及卡介苗＋脂多糖（LPS）诱导的小鼠免疫性肝炎均有明显降ALT和AST作用,并能减轻肝组织病理损伤。双环醇体外药对2．2．15细胞株分泌HBeAg和HBsAg有抑制作用,该药0．4和0．6g.kg^-1ig对鸭病毒性肝炎血清和肝脏的DHBV－DNA有显著抑制作用,对该药作用的机制进行多方面的研究的结果表明,双环醇不是转氨酶抑制剂,而是有清除自由基作用以保护细胞膜,并且能保护肝细胞核DNA免受损伤和减少细胞凋亡的发生。     

Activated peroxisomal fatty acid metabolism improves cardiac recovery in ischemia-reperfusion

Depressed oxidation of long chain fatty acids (LCFA) in heart ischemia leads to acute accumulation of LCFA metabolites that impair the functioning of the mitochondria. We hypothesized that reduced activity of carnitine palmitoyltransferase-I (CPT-I) might activate peroxisomal LCFA oxidation and protect mitochondrial function in ischemia and reperfusion. In the present study, despite the long-term threefold reduction in L-carnitine content by 3-(2,2,2-trimethylhydrazinium)-propionate, the uptake and oxidation rates of LCFA in the heart in normoxia were not significantly influenced. The significant increase in PPARα and PGC1α nuclear content, observed in this study, were followed by increased expression of genes involved in peroxisomal fatty acid oxidation (FAO) which compensated for the limited CPT-I-dependent FA transport into the mitochondria. In ischemia followed by reperfusion, the redirection of LCFA oxidation from mitochondria to peroxisomes protected the mitochondria from the accumulation of LCFA. In turn, the recovery of FAO resulted in significant reduction of myocardial infarct size. In conclusion, the decreased L-carnitine content in the heart preserves its peroxisomal and mitochondrial function after ischemia and improves cardiac recovery during reperfusion. The functional interplay between the decrease in L-carnitine and the PPARα/PGC1α pathway-induced redirection of FA metabolism protects the mitochondria against LCFA overload and provides a foundation for novel cardioprotective mechanisms.     

Evaluation of hepatic and thyroid responses in male Sprague Dawley rats for up to eighty-four days following seven days of dietary exposure to potassium perfluorooctanesulfonate

In a prior 28-day dietary study in rats with 20 and 100 ppm K? PFOS, activation of PPARα and CAR/PXR were concluded to be etiological factors in K? PFOS-induced hepatomegaly and hepatic tumorigenesis. The objective of this study was to evaluate persistence/resolution of K? PFOS-induced, liver-related effects in male Sprague Dawley rats following a 7-day dietary exposure to K? PFOS at 20 or 100 ppm. Groups of 10 rats per treatment were observed on recovery Day(s) 1, 28, 56, and 84 following treatment. Changes consistent with hepatic PPARα and CAR/PXR activation noted on recovery Day 1 included: increased liver weight; decreased plasma cholesterol, alanine aminotransferase, and triglycerides; decreased liver DNA concentration and increased hepatocellular cytosolic CYP450 concentration; increased liver activity of acyl CoA oxidase, CYP4A, CYP2B, and CYP3A; increased liver proliferative index and decreased liver apoptotic index; decreased hepatocellular glycogen-induced vacuoles; increased centrilobular hepatocellular hypertrophy. Most effects resolved to control levels during recovery. Effects on plasma cholesterol, hepatocellular cytosolic CYP450 concentrations, liver apoptotic index, CYP3A, and centrilobular hepatocellular hypertrophy persisted through the end of the recovery period. Thyroid parameters (histology, apoptosis, and proliferation) were unaffected at all time points. Mean serum PFOS concentrations on recovery Day 1 were 39 and 140 μg/mL (20 ppm and 100 ppm K? PFOS, respectively), decreasing to 4 and 26 μg/mL by recovery Day 84. Thus, hepatic effects in male rats resulting from K? PFOS-induced activation of PPARα and CAR/PXR resolved slowly or were still present after 84-days following a 7-day dietary treatment, consistent with the slow elimination rate of PFOS.     

Therapeutic role of Artemether in the prevention of hepatic steatosis through miR-34a-5p/PPARα pathway

Artemether (ATM) is a natural antimalarial drug that can also regulate glucose and lipid metabolism. However, little is known regarding its pharmacological action in metabolic dysfunction-associated fatty liver disease (MAFLD), and the underlying mechanisms remain undetermined. The aim of this study was to explore the therapeutic effects of ATM against hepatic steatosis and the possible mechanisms. ATM significantly decreased blood glucose levels, improved glucose tolerance, reduced inflammatory response, and alleviated hepatic steatosis in the ob/ob mouse model as well as the high-fat diet-fed mice. ATM also inhibited lipid accumulation in murine hepatocytes in vitro. Using RNA sequencing, miR-34a-5p and peroxisome proliferator-activated receptor-α (PPARα) were identified as important regulators during ATM treatment. ATM administration downregulated miR-34a-5p expression and miR-34a-5p abrogated the inhibitory effects of ATM on PO (palmitate + oleate)-induced lipid accumulation as well as triglycerides levels in murine hepatocytes. Furthermore, the expression of PPARα, a target gene of miR-34a-5p, was upregulated by ATM and PPARα inhibitor MK-886 abolished the positive effect of ATM. Consequently, PPARα agonist fenofibrate reversed the decreased mitochondrial fatty acid β-oxidation induced by miR-34a-5p mimics after ATM treatment, thereby leading to attenuation of intracellular lipid accumulation. Taken together, ATM is a promising therapeutic agent against MAFLD that reduces lipid deposition by suppressing miR-34a-5p and upregulating PPARα.     

壳聚糖复方制剂对脂肪肝大鼠的治疗作用及其机制的探讨

目的 :进一步研究壳聚糖复方制剂对实验性脂肪肝大鼠的治疗作用及其机制。方法 :采用小剂量CCl4 致肝损伤并高脂饮食建立大鼠脂肪肝模型 ,给予模型大鼠壳聚糖复方制剂 0 .7g·kg- 1·d- 1灌服 8wk ,检测肝脏三酰甘油 (TG )、总胆固醇(TC)、血清及肝脏游离脂肪酸 (FFA)含量 ,检测肝脂变面积及肝脏过氧化物酶体增殖物激活受体α(PPARα)mRNA的表达情况。结果 :CCl4 损伤并高脂饮食可引起实验性大鼠肝脏明显脂肪变性 ,肝脏TG ,TC ,FFA及血清FFA含量升高 ,肝细胞PPARαmRNA表达减少。与模型组比较 ,壳聚糖复方制剂能明显降低肝脏TG ,TC ,FFA及血清FFA含量(P <0 .0 1) ,提高肝细胞PPARαmRNA的表达(P <0 .0 1)。结论 :壳聚糖复方制剂对实验性脂肪肝大鼠具有一定的治疗作用 ,其作用机制可能与其诱导PPARα表达 ,促进肝脏摄取、氧化脂肪酸有关。