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Non-alcoholic fatty liver disease (NAFLD) is characterized by the hepatic manifestation of metabolic syndrome and is the leading cause of chronic liver disease. Steatohepatitis plays a critical role in the process resulting in liver fibrosis and cirrhosis. Puerarin is a herbal product widely used in Asia, and is believed to have therapeutic benefits for alleviating the symptoms of steatohepatitis. The present study was designed to investigate the effects and mechanisms of action of puerarin in reducing lipid accumulation in oleic acid (OA)-treated HepG2 cells. Hepatocytes were treated with OA with or without puerarin to observe lipid accumulation by Oil Red O staining. We also examined hepatic lipid contents (e.g., triacylglycerol and cholesterol) following treatment with puerarin. Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) were used to measure sterol regulatory element binding protein (SREBP)-1, fatty acid synthase (FAS), peroxisome proliferator-activated receptor α (PPARα) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) protein and mRNA expression, respectively. Our results revealed that puerarin suppressed OA-induced lipid accumulation, and reduced the triacylglycerol and cholesterol levels. Furthermore, puerarin decreased the expression levels of lipogenic enzymes, such as FAS and SREBPs, and increased the expression levels of PPARα, which are critical regulators of hepatic lipid metabolism through the AMPK signaling pathway. These results indicate that puerarin has the same ability to activate AMPK, and reduce SREBP-1 and FAS expression, thus inhibiting hepatic lipogenesis and increasing hepatic antioxidant activity. We found that puerarin exerted a regulatory effect on lipid accumulation by decreasing lipogenesis in hepatocytes. Therefore, puerarin extract may have therapeutic benefits in the treatment of fatty liver and lipid-related metabolic disorders.

Quercetin possesses a broad range of pharmacological properties, including protection of LDL from oxidation. However, little is known about the mechanism by which quercetin rescues cardiomyoblasts from oxidative damage. This study was designed to investigate the protective mechanism of quercetin on H(2)O(2)-induced toxicity of H9c2 cardiomyoblasts. Oxidative stress, such as H(2)O(2), ZnCl(2), and menadione, significantly decreased the viability of H9c2 cells, which was accompanied with apparent apoptotic features, including fragmentation of genomic DNA as well as activation of caspase protease. However, quercetin markedly inhibited the apoptotic characteristics via reduction of intracellular reactive oxygen species generation. Also, it prevented the H(2)O(2)-mediated mitochondrial dysfunction, including disruption of mitochondria membrane permeability transition as well as an increase in expression of apoptogenic Bcl-2 proteins, Bcl-2 and Bcl-X(L). Furthermore, pretreatment of quercetin inhibited the activation of caspase-3, thereby both cleavage of poly(ADP-ribose) polymerase and degradation of inhibitor of caspase-activated DNase/DNA fragmentation factor by H(2)O(2) were completely abolished. Taken together, these data suggest that protective effects of quercetin against oxidative injuries of H9c2 cardiomyoblasts may be achieved via modulation of mitochondrial dysfunction and inhibition of caspase activity.

This article investigates the flowing characteristics of the dissociated gas and water from hydrate in porous rock by utilizing the experimental model setup in this study. The apparatus has been validated by comparing the experimentally resulted equilibrium conditions of hydrate against the previously published results. This comparison shows excellent matches. With the developed apparatus, the experiments have been run for the depressurization method as well as the methanol injection method. From the analysis of the measured data of pressure, temperature, and resistance it was found that production and pressure behaviors are quite different from those of conventional gas reservoirs.

This study presents a numerical model for simultaneous flow of gas, water including methanol, and hydrate through methane hydrate reservoirs. The model has been developed to specially investigate the production behavior during injection of methanol with the combination of a depressurization mechanism. The model evaluates the local gas dissociation rate with methanol concentration using the kinetic theory proposed by Kim-Bishinoi and thermodynamics. This kinetic dissociation rate is computed with the aid of the empirical dissociation rate as a function of specific surface area and pressure difference. A number of simulations have been conducted to examine the effect of parameters related to methanol injection on the production behaviors of gas and water, that is, injection rate, time of injection, and methanol content. From the results of numerical studies, it is noted that the effect of methanol injection only appears near the well, rather than whole reservoir, since hydrate reservoirs are extremely low i...

Natural gas hydrates are known to occur in vast quantities at the ocean floor or in permafrost regions. In-situ hydrate contains great volumes of methane gas, which indicates a potential future energy resource. In this study, we have developed a three-dimensional, multi-phase (gas, water, and hydrate) flow finite-difference model by using implicit pressure explicit saturation technique in order to investigate simultaneous flow through ice-liked hydrate reservoir. The developed model is based on the depressurizing method as producing mechanism. The model evaluates local gas generation dissociated from the hydrate with the aid of kinetic dissociation theory proposed by Kim-Bishnoi. The computation of kinetic dissociation uses the empirical dissociation rate as a function of specific surface area between phases and pressure difference. With the developed model, a one-dimensional system has been simulated for analyzing the production performance of a hydrate reservoir and for investigating the effect of hydrate saturation on absolute permeability and relative permeability characteristics. Also, for the three-dimensional field-scaled reservoir system, a number of numerical exercises have been conducted to understand the effect of mass transfer and to characterize the flowing mechanism under the conditions of increased permeability resulting from the dissociation hydrate.

Samultang has been traditionally used for treatment of ischemic heart and brain diseases in oriental medicine. However, little is known about the mechanism by which Samultang rescues the myocardial and neuronal cells from ischemic damage. This study was designed to evaluate whether the water extract of Samultang may modulate the production of nitric oxide (NO) in LPS and PMA treated-C6 glial cells to protect the cells from NO-induced cytotoxicity. C6 glial cells treated with both LPS and PMA significantly produced a large amount of NO compared to untreated, PMA, or LPS-treated cells. In parallel with NO production, cotreatment of LPS and PMA induced the severe apoptotic death of C6 glial cells. However, Samultang significantly reduced both cell death and NO production by LPS/PMA in a dose-dependent manner. In addition, the modulatory effects of Samultang on LPS/PMA-induced cytotoxicity and NO production could be mimicked by exogenous treatments of N(G)MMA, a nitric oxide synthase (NOS) inhibitor, and pyrrolidine dithiocarbamate (PDTC), a strong NF-kappaB inhibitor. Treatment of C6-glial cells with LPS/PMA induced the transcriptional activation of NF-kappaB, which was markedly inhibited by Samultang. Taken together, we suggest that the protective effects of Samultang against LPS/PMA-induced cytotoxicity may be mediated by the suppression of NO synthesis via down-regulation of NF-kappaB activation.

The analysis of hydrate equilibrium condition plays an important role to study pipeline blockage and production procedure of natural gas from in-situ hydrate reservoir. In this study, the experimental study has been performed to investigate hydrate dissociating and forming phenomena and we found out the methane hydrate equilibrium conditions. Also, a thermodynamic numerical model based on the statistical thermodynamics of van der Waals and Platteeuw has been developed for predicting the equilibrium condition of hydrate. This model implements an algorithm developed by Parrish and Prausnitz's method and it evaluates electrostatic interaction between ions in electrolyte solutions using the Debey-Huckel equation. Numerical studies using the model have been conducted for investigating the hydrate forming conditions of binary hydrocarbon mixtures such as methane-ethane, methane-propane, and methane-isobutane. Also, the effects of chemical inhibitors and electrolyte solutions on the hydrate equilibrium ...