50 research outputs found
Pyrrolizidine alkaloids enhance alcohol-induced hepatocytotoxicity in vitro in normal human hepatocytes
OBJECTIVE : Herbal remedies containing
pyrrilidozine alkaloids (PA)s can induce liver
damage, including hepato-sinusoidal obstruction
syndrome (HSOS) or veno-occlusive liver disease
(VOD). Some individuals misusing alcohol consume
also teas and/or herbal remedies containing
PA. The interaction or additive toxicity of alcohol to
PA toxicity needs to be addressed. The objectives
of this study are 1) to review the scientific literature
on the PA-induced liver toxicity; 2) identify possible
mechanism(s) involved in PA-induced hepatocytotoxicity
in the presence or absence of ethanol
(EtOH) in vitro in normal human hepatocytes (NHH)
in primary culture. To respond to the first objective,
we systematically search all the literature engines
(PubMed, Google Scholar) for liver induced damage
due to PAs and summarize the results in an introductory
systematic review.
ORIGINAL ARTICLE EXPERIMENTAL DESIGN
AND METHODS : Cells were exposed to one
dose of 100 mmol/L EtOH for 24 hrs and to 2 doses
of 100 mmol/L EtOH for consecutive 24 hrs
periods, in the presence or absence of PAs (10
mg/mL), or the caspase-3 inhibitor IDN-1965 (50
μmol/L). Cells were analyzed for apoptosis by
light microscopy, immuno-histochemistry, measuring
cytokeratin-18 fragmentation, and transmission
electron microscopy (TEM) (6000 cells/
treatment). Cytotoxicity was determined using succinate dehydrogenase (SDH) activity, an enzyme
specific to the mitochondria.
RESULTS : In NHH cells, a 100 mmol/L dose of
Et-OH resulted in 22±2.5 apoptosis (p<0.001 vs.
control). Two consecutive doses of 100 mmol/L
Et-OH for 24 hrs each caused 36±3.0% apoptosis
(p<0.001 vs. control and p<0.05 vs. one dose Et-
OH). Pre-treatment with 50 μmol/L caspase inhibitor
significantly reduced Et-OH-induced apoptosis
[12±1.5% in 100 mmol/L (p<0.05) and 20±4.0%
in 2×100 mmol/L (p<0.001)]. In addition, pre-treatment
with 50 μmol caspase inhibitor in cells treated
with PA + EtOH reduced apoptosis significantly
(vs. non-exposed to caspase-inhibitor): Δ -22±3.0 % (p<0.05). HPC significantly decreased apoptosis
compared to conditions lacking this supplementation
in cells treated with EtOH-exposed
cells present ballooning, Mallory bodies, changes
in mitochondrial cristae and apoptosis by TEM.
Pre-treatment with 50 μmol caspase inhibitor significantly
reduced 100 mmol/L EtOH-induced (one
dose) in NHH by 14±0.5% (p<0.05) compared to
cells not exposed to the caspase-inhibitor. In cells
treated concomitantly with PA and EtOH 100 mM
Mallory-bodies and apo-necrotic cells have been
observed. Pre-treatment with 50 μmol caspase inhibitor
reduced the mitochondrial damage. A significant
depletion in glutathione (GSH) was observed
in Et-OH treated cells after 1 and 2 treatments
(p<0.001 vs. control). Treatment with E t-OH enhanced
PA-induced GSH-depletion and resulted
in a significant increase in PA-induced cytotoxicity
(p<0.001 vs. Et-untreated cells). Exposure to EtOH
increased the cell culture media levels of the pro-inflammatory
cytokine TNF. PA + EtOH-treated cells
increased TNF-α levels in media compared to EtOH
alone [86±8 vs. 53±5 pg/mL in cells exposed to 100
mmol/L EtOH (p<0.05) and 218±14 vs. 179±8 pg/mL
in cells exposed to 2×100 mmol/L EtOH (p<0.05)].
CONCLUSIONS : PA up-regulates EtOH-induced
hepatocytotoxicity by inducing the inflammatory
cytokines and enhancing the apoptotic effects
of ethanol. There is a need for monitoring herbal medicine in order to optimize traditional medicine
use and maximize the clinical benefits. Additionally,
there is necessary to communicate to physicians
the possible negative results of herbal remedies
use. Also, the interactions between herbal
remedies and drugs of misuse should be communicated
to consumers.The
work was funded by In Vitro Drug Safety and Biotechnology.
We are thankful for the financial contribution to Mahaffy
-Gastroenterology Fund, Sunnybrook HSC, Toronto,
ON, Canada.http://www.europeanreview.orgam2017Pharmacolog
Recommended from our members
Instrumentation and Measurement Strategy for the NOAA SENEX Aircraft Campaign as Part of the Southeast Atmosphere Study 2013
Natural emissions of ozone-and-aerosol-precursor gases such as isoprene and monoterpenes are high in the southeast of the US. In addition, anthropogenic emissions are significant in the Southeast US and summertime photochemistry is rapid. The NOAA-led SENEX (Southeast Nexus) aircraft campaign was one of the major components of the Southeast Atmosphere Study (SAS) and was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. Here we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign. The aircraft, its capabilities and standard measurements are described. The instrument payload is summarized including detection limits, accuracy, precision and time resolutions for all gas-and-aerosol phase instruments. The inter-comparisons of compounds measured with multiple instruments on the NOAA WP-3D are presented and were all within the stated uncertainties, except two of the three NO2 measurements. The SENEX flights included day- and nighttime flights in the Southeast as well as flights over areas with intense shale gas extraction (Marcellus, Fayetteville and Haynesville shale). We present one example flight on 16 June 2013, which was a daytime flight over the Atlanta region, where several crosswind transects of plumes from the city and nearby point sources, such as power plants, paper mills and landfills, were flown. The area around Atlanta has large biogenic isoprene emissions, which provided an excellent case for studying the interactions between biogenic and anthropogenic emissions. In this example flight, chemistry in and outside the Atlanta plumes was observed for several hours after emission. The analysis of this flight showcases the strategies implemented to answer some of the main SENEX science questions
Statistical and scaling analyses of neural network soil property inputs/outputs at an Arizona field site.
Analyses of flow and transport in the shallow subsurface require information about spatial and statistical distributions of soil hydraulic properties (water content and permeability, their dependence on capillary pressure) as functions of scale and direction. Measuring these properties is relatively difficult, time consuming and costly. It is generally much easier, faster and less expensive to collect and describe the makeup of soil samples in terms of textural composition (e.g. per cent sand, silt, clay and organic matter), bulk density and other such pedological attributes. Over the last two decades soil scientists have developed a set of tools, known collectively as pedotransfer functions (PTFs), to help translate information about the spatial distribution of pedological indicators into corresponding information about soil hydraulic properties. One of the most successful PTFs is the nonlinear Rosetta neural network model developed by one of us. Among remaining open questions are the extents to which spatial and statistical distributions of Rosetta hydraulic property outputs, and their scaling behavior, reflect those of Rosetta pedological inputs. We address the last question by applying Rosetta, coupled with a novel statistical scaling analysis recently proposed by three of us, to soil sample data from an experimental site in southern Arizona, USA
Frequency distribution and scaling of soil texture and hydraulic properties in a stratified deep vadose zone near Maricopa, Arizona.
We analyze the distributional and scaling properties of soil texture data measured to a depth of 15 meters over an area of 3600 m^2 in a vadose zone near Maricopa, Arizona, and of hydraulic properties estimated on the basis of these data with the Rosetta neural network pedotransfer model. We find that vertical and horizontal spatial increments of all variables exhibit Gaussian or symmetric heavy-tailed distributions, nonlinear power-law scaling in a midrange of separation distances (lags), breakdown in power law scaling at small and large lags, extended power-law scaling at all lags, and various degrees of vertical to horizontal anisotropy. Both sets of variables are amenable to interpretation by viewing them as stationary and anisotropic samples from spatially correlated sub-Gaussian random fields subordinated to truncated fractional Brownian motion (tfBm) or truncated fractional Gaussian noise (tfGn)