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Pumpkin Center, NC, United States

Knab A.M.,Appalachian State University | Bowen R.S.,Truett-McConnell College | Hamilton A.T.,Cannon Research Center | Lightfoot J.T.,Texas A&M University
Journal of Biological Regulators and Homeostatic Agents | Year: 2012

The genetic factors involved in the regulation of physical activity are not well understood. The dopamine system has been implicated in the control of voluntary locomotion and wheel running (WR) in mice and is thus a likely candidate as a genetic/biological system important to the regulation of physical activity. This study evaluated the effects of four different dopaminergic acting drugs on WR in differentially active inbred strains of mice. High active C57L/J (n=7, 3 controls, 4 experimental) and low active C3H/HeJ (n=8, 3 controls, 5 experimental) were analyzed for baseline wheel-running indices of distance (km/day), duration (mins/day), and speed (m/min) for 21 days. Experimental mice received increasing doses over four days of each of the following drugs: SKF 81297 (Dl agonist), SCH 23390 (Dl antagonist), GBR 12783 (DAT inhibitor), and AMPT (tyrosine hydroxylase inhibitor). Each drug dose response treatment was separated by three days of recovery (no drug injections). WR indices were monitored during drug treatments and during drug wash-out phases. SKF 81297 significantly reduced (p=0.0004) WR in the C57L/J mice, but did not affect WR in the C3H/HeJ mice. GBR 12783 significantly increased (p=0.0005) WR in C3H/HeJ mice, but did not affect WR in C57L/J mice. Only duration (not overall WR) was significantly reduced in C57L/J mice in response to SCH 23390 (p=0.003) and AMPT (p=0.043). SCH 23390 (p=0.44) and AMPT (p=0.98) did not significantly affect WR in C3H/HeJ mice. These results suggest that genetic differences in dopamine signaling may play a role in the WR response to dopaminergic-acting drugs in inbred strains of mice. The high activity in the C57L/J strain appears most responsive to D1-like receptor acting drugs, while in the C3H/HeJ strain, dopamine re-uptake appears to have an influence on activity level. Copyright © by BIOLIFE, s.a.s. Source


Navarro V.J.,Albert Einstein Medical Center | Bonkovsky H.L.,Medicine and Research | Hwang S.-I.,Cannon Research Center | Vega M.,Albert Einstein Medical Center | And 2 more authors.
Digestive Diseases and Sciences | Year: 2013

Background: Many herbal dietary supplements (HDS) contain green tea extract (GTE) and its component catechins, although their presence may not always be indicated on the product label. Purpose: Because GTE and catechins have been implicated in human hepatotoxicity in several case reports, our objective was to determine whether catechins were present in HDS that were implicated in hepatotoxicity, even if not identified among the labeled ingredients, and whether these compounds could be associated with liver injury. Methods: We assayed 97 HDS implicated in human hepatotoxicity for catechins. Results: We found that 29 of 73 HDS (39.7 %) that did not identify GTE or any of its component catechins on their label contained catechins. Among patients with confirmed hepatotoxicity, there was no statistically significant association between the presence of catechin or the dose consumed and liver injury causality score, severity, or pattern of liver injury. Catechin levels tended to be highest in products used for weight loss, although catechin concentrations were low in most products. Conclusions: Many HDS commonly contain catechins that are implicated in hepatotoxicity, although their presence may not be indicated on the product label. Although our results did not establish an association between GTE or catechins with hepatotoxicity, they highlight some of the many complexities and uncertainties that surround the attribution of drug-induced liver injury (DILI) to HDS. © 2013 Springer Science+Business Media New York. Source


Lambrecht R.W.,University of Connecticut Health Center | Sterling R.K.,Virginia Commonwealth University | Naishadham D.,New England Research Institutes, Inc. | Stoddard A.M.,New England Research Institutes, Inc. | And 6 more authors.
Gastroenterology | Year: 2011

Background & Aims: Iron may influence severity and progression of non-hemochromatotic liver diseases. Our aim was to assess the relationship of iron and HFE genetic variations to progression and outcomes in the HALT-C Trial and whether PegIFN therapy influenced iron variables. Methods: Participants were randomized to receive long-term PegIFN [n = 400] or no therapy [n = 413] for 3.5 y, with follow-up for up to 8.7 y [median 6.0 y]. Associations of patient characteristics with iron variables at baseline and over time were carried out using Kaplan-Meier analyses, Cox regression models, and repeated measures analysis of covariance. Results: Participants who developed clinical outcomes [CTP > 7, ascites, encephalopathy, variceal bleeding, SBP, HCC, death] had significantly higher baseline scores for stainable iron in hepatocytes and in portal tract cells than those without. There were significant direct correlations between stainable iron in portal triads and lobular and total Ishak inflammatory and fibrosis scores [P < 0.0001]. Iron in triads at baseline increased risk of outcomes (HR = 1.35, P = 0.02). Stainable iron in hepatocytes decreased, whereas that in portal stromal cells increased significantly [P < 0.0001] over time. Serum iron and TIBC fell significantly over time [P < 0.0001], as did serum ferritin [P = 0.0003]. Chronic PegIFN treatment did not affect stainable iron. HFE genetic variations did not correlate with outcomes, including development of hepatocellular carcinoma. Conclusions: Stainable iron in hepatocytes and portal tract cells is a predictor of progression and clinical and histological outcomes in advanced chronic hepatitis C. Chronic low-dose PegIFN therapy did not improve outcomes, nor iron variables. © 2011 AGA Institute. Source


Chalasani N.,Indiana University | Vuppalanchi R.,Indiana University | Navarro V.,Thomas Jefferson University | Fontana R.,Alfred University | And 4 more authors.
Annals of Internal Medicine | Year: 2012

Background: Flavocoxid is a prescription medical food that is used to treat osteoarthritis. It is a proprietary blend of 2 flavonoids, baicalin and catechins, which are derived from the botanicals Scutellaria baicalensis and Acacia catechu, respectively. Objective: To describe characteristics of patients with acute liver injury suspected of being caused by flavocoxid. Design: Case series. Setting: Drug-Induced Liver Injury Network Prospective Study ongoing at multiple academic medical centers since 2004. Patients: Four adults with liver injury. Measurements: Clinical characteristics, liver biochemistry values, and outcomes. Results: Among 877 patients enrolled in the prospective study, 4 had liver injury suspected to have been caused by flavocoxid. All were women; ages ranged from 57 to 68 years. All developed symptoms and signs of liver injury within 1 to 3 months after initiating flavocoxid. Liver injury was characterized by marked elevations in levels of alanine aminotransferase (mean peak, 1268 U/L; range, 741 to 1540 U/L), alkaline phosphatase (mean peak, 510 U/L; range, 286 to 770 U/L), and serum bilirubin (mean peak, 160.7 μmol/L [9.4 mg/dL]; range, 34.2 to 356 μmol/L [2.0 to 20.8 mg/dL]). Liver biochemistry values decreased to the normal range within 3 to 12 weeks after flavocoxid was stopped, and all patients recovered without experiencing acute liver failure or chronic liver injury. Causality was adjudicated as highly likely in 3 patients and as possible in 1 patient. Limitation: The frequency and mechanism of liver injury could not be assessed. Conclusion: Flavocoxid can cause clinically significant liver injury, which seems to resolve within weeks after cessation. Primary Funding Source: National Institute of Diabetes and Digestive and Kidney Diseases. © 2012 American College of Physicians. Source


Yan J.,University of Manitoba | Gong Y.,University of Manitoba | Wang G.,Cannon Research Center | Gang Y.,University of Manitoba | Burczynski F.J.,University of Manitoba
Biochemistry and Cell Biology | Year: 2010

Peroxisome proliferator-activated receptor (PPAR) agonists such as clofibrate are known to affect liver fatty acid binding protein (L-FABP) levels, which in turn influence hepatocellular oxidant status. The mechanism of clofibrate's modulation of L-FABP levels is not clear. In this study we used clofibrate (PPARα agonist), MK886 (PPARα antagonist), and GW9662 (PPARγ antagonist) in determining the regulating mechanism of L-FABP expression and its antioxidant activity in CRL-1548 hepatoma cells. Antioxidant activity was assessed by determining intracellular reactive oxygen species (ROS) using dichlorofluorescein (DCF) fluorescence. The effect of clofibrate on cytosolic activity of the intracellular antioxidant enzymes was also assessed. RT-PCR and mRNA stability assay showed that clofibrate treatment enhanced L-FABP mRNA stability, which resulted in increased L-FABP levels. A nuclear run-off assay and RT-PCR measurements of L-FABP mRNA revealed that clofibrate increased the L-FABP gene transcription rate. The increased L-FABP was associated with reduced cytosolic ROS. Levels of superoxide dismutase, glutathione peroxidase, and catalase were not affected by clofibrate treatment. L-FABP siRNA knockdown studies showed that a reduction in L-FABP expression was associated with increased DCF fluorescence. We conclude that clofibrate enhanced L-FABP gene transcription and mRNA stability, thus affecting L-FABP expression and ultimately cellular antioxidant activity. Source

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