Water extract of Vitis coignetiae Pulliat leaves attenuates oxidative stress and inflammation in progressive NASH rats.

This study aimed to investigate the therapeutic effects of the water extract of leaves of Vitis coignetiae Pulliat (VCPL) on nonalcoholic steatohepatitis (NASH) with advanced fibrosis, as our previous study exhibited its preventive effect on NASH. The NASH animal model [PCT/JP2007/52477] was prepared by loading recurrent and intermittent hypoxemia stress to a rat with fatty liver, which resembled the condition occurring in patients with obstructive sleep apnea (OSA) and fatty liver, who have a high incidence of NASH. Intermittent hypoxemia stress is regarded as a condition similar to warm ischemia followed by re-oxygenation, which induces oxidative stress (OS). The daily 100 or 300 mg/kg VCPL administrations were performed for 3 weeks perorally beginning at the time of detection of advanced liver fibrosis. The therapeutic efficacy of VCPL on NASH was demonstrated by the reduction of the leakage of hepato-biliary enzymes and the amelioration of liver fibrosis. The OS elevation in NASH rats was measured based on the derivation of reactive oxygen species from liver mitochondrial energy metabolism and on the decrease in plasma SOD-like activity. The aggravation of inflammatory responses was demonstrated by the neutrophil infiltration (elevated myeloperoxidase activity) and the progression of fibrosis in the livers of NASH rats. In addition, the NASH rats without VCPL treatment also exhibited activation of nuclear factor-κB, a key factor in the link between oxidative stress and inflammation. All of these changes were reduced dose-dependently by the VCPL administration. These findings indicate that VCPL may improve hepatic fibrosis or at least suppress the progression of NASH, by breaking the crosstalk between OS and inflammation.

Beneficial effects of Vitis coignetiae Pulliat leaves on nonalcoholic steatohepatitis in a rat model.

Vitis coignetiae Pulliat (Yamabudo) is used as a health juice and wine based on the abundant polyphenols and anthocyanins in its fruit. However, it is not known whether the leaves of this plant confer similar benefits. This study investigated the hepatoprotective effects of aqueous extracts from Vitis coignetiae Pulliat leaves (VCPL) in an animal model of nonalcoholic steatohepatitis (NASH). Rats were fed a choline-deficient high-fat diet for four weeks to generate fatty livers. NASH was induced by oxidative stress loading. Ten weeks later, blood and liver samples were collected from anesthetized animals and assessed biochemically, histologically, and histochemically to determine the extent of oxidative stress injury and the overall effects of VCPL. Six-week VCPL extract supplementation reduced serum levels of liver enzymes, decreased CYP2E1 induction, increased plasma antioxidant activities and delayed the progression of liver fibrosis. The findings suggested that VCPL has strong radical-scavenging activity and may be beneficial in preventing NASH progression.

In vitro pharmacologic testing using human induced pluripotent stem cell-derived cardiomyocytes.

The lethal ventricular arrhythmia Torsade de pointes (TdP) is the most common reason for the withdrawal or restricted use of many cardiovascular and non-cardiovascular drugs. The lack of an in vitro model to detect pro-arrhythmic effects on human heart cells hinders the development of new drugs. We hypothesized that recently established human induced pluripotent stem (hiPS) cells could be used in an in vitro drug screening model. In this study, hiPS cells were driven to differentiate into functional cardiomyocytes, which expressed cardiac markers including Nkx2.5, GATA4, and atrial natriuretic peptide. The hiPS-derived cardiomyocytes (hiPS-CMs) were analyzed using a multi electrode assay. The application of ion channel inhibitors resulted in dose-dependent changes to the field potential waveform, and these changes were identical to those induced in the native cardiomyocytes. This study shows that hiPS-CMs represent a promising in vitro model for cardiac electrophysiologic studies and drug screening.

Changes of materials that scavenge 1,1-diphenyl-2-picrylhydrazyl radicals in plasma by per-oral administration of Kampo medicine, Ninjin-yoei-to in rats.

The Kampo medicine, Ninjin-yoei-to, scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent fashion as did ascorbic acid and alpha-tocopherol. Ninjin-yoei-to, which is composed of 12 herbs, had a potent DPPH radical scavenging ability. We investigated the transition of the materials that scavenge DPPH radicals in plasma after oral administration of Ninjin-yoei-to to rats. When 1.0 g kg(-1) Ninjin-yoei-to was administered, the DPPH radical scavenging ability increased at 30 min and biphasic peaks were observed at 2 h and at 10 h. From the response-time profile, kinetic parameters including values for K(a) (absorption rate constant), t(max) (peak concentration time), t(1/2) (half-life) and MRT (mean residence time) of the radical scavenging ability in plasma could be calculated for DPPH radicals. K(a) values were 0.53 +/- 0.03 and 0.36 +/- 0.07 h, t(max) values were 2.1 +/- 1.04 and 8.56 +/- 2.69 h, t(1/2) values were 1.60 +/- 0.12 and 3.39 +/- 1.72 h, and MRT values were 4.14 +/- 1.59 and 8.18 +/- 2.55 h, respectively. These parameters calculated from the antioxidation dynamics were considered to offer a very meaningful procedure for examining the effects of Ninjin-yoei-to.

Expression and functional analyses of novel mutations of ATP-binding cassette transporter-1 in Japanese patients with high-density lipoprotein deficiency.

ATP-binding cassette transporter-1 (ABCA1) gene is mutated in patients with familial high-density lipoprotein deficiency (FHD). In order to know the molecular basis for FHD, we characterized three different ABCA1 mutations associated with FHD (G1158A/A255T, C5946T/R1851X, and A5226G/N1611D) with respect to their expression in the passaged fibroblasts from the patients and in the cells transfected with the mutated cDNAs. Fibroblasts from the all patients showed markedly decreased cholesterol efflux to apolipoprotein (apo)-Al. In the fibroblasts homozygous for G1158A/A255T, the immunoreactive mass of ABCA1 could not be detected, even when stimulated by 9-cis-retinoic acid and 22-R-hydroxycholesterol. In the fibroblasts homozygous for C5946T/R1851X, ABCA1 mRNA was comparable. Because the mutant ABCA1 protein (R1851X) was predicted to lack the epitope for the antibody used, we transfected FLAG-tagged truncated mutant (R1851X/ABCA1-FLAG) cDNA into Cos-7 cells, showing that the mutant protein expression was markedly reduced. The expression of N1611D ABCA1 protein was comparable in both fibroblasts and overexpressing cells, although cholesterol efflux from the cells was markedly reduced. These data indicated that, in the three patients investigated, the abnormalities and dysfunction of ABCA1 occurred at the different levels, providing important information about the expression, regulation, and function of ABCA1.