Nanomedicines based on trace elements for intervention of diabetes mellitus.

Epidemiology shows that the incidence of diabetes mellitus (DM) is increasing year by year globally. Proper interventions are highly aspired for diabetics to improve the quality of life and prevent development of chronic complications. Trace elements, also known as microelements, are chemical substances that are present in our body in minute amounts. They are necessitated by the body for growth, development and functional metabolism. For the past few years, trace element nanoparticles have aroused considerable interest as a burgeoning form of nanomedicines in antidiabetic applications. These microelement-based nanomedicines can regulate glucose metabolism in several ways, showing great potential for diabetes management. Starting from the pathophysiology of diabetes, the state-of-the-art of diabetes treatment, the physiological roles of trace elements, various emerging trace element nanoparticles specific for diabetes were comprehensively reviewed in this work. Our findings disclose that trace element nanoparticles can fight against diabetes by lowering blood glucose, promoting insulin secretion, alleviating glucose intolerance, improving insulin sensitivity, ameliorating lipid profile, anti-inflammation and anti-oxidant stress, and other mechanisms. In conclusion, trace element nanoparticles can be applied as nanomedicines or dietary modifiers for effective intervention for diabetes.

Dysregulated hepatic UDP-glucuronosyltransferases and flavonoids glucuronidation in experimental colitis.

Glucuronidation catalyzed by UDP-glucuronosyltransferases (UGTs) is one of the most important phase II mechanisms, facilitating drug clearance via conjugation of glucuronic acid with polar groups of xenobiotics. Accumulating evidence suggests that IBDs impact drug disposition, but whether and how IBDs regulate UGTs and drug glucuronidation remains undefined. In this study, we aim to investigate the expression of UGTs and drug glucuronidation in experimental colitis. Given that glucuronidation occurs primarily in the liver, we analyzed the mRNA changes in hepatic UGTs with a DSS-induced mouse colitis model. Twelve UGTs were downregulated in the liver of colitis mice including UGT1A1 and UGT1A9 (two representative UGTs). Colitis in mice downregulated UGT1A1 and UGT1A9 in the liver but not in small intestine, colon, and kidney. We also established that the downregulation of UGTs was attributed to the disease itself rather than the DSS compound. Moreover, colitis-reduced UGT1A1 and UGT1A9 lead to dampened baicalein and puerarin glucuronidation. PXR was the only UGT regulator significantly downregulated in colitis mice, suggesting dysregulation of PXR is associated with the downregulation of UGT1A1 and UGT1A9, thereby potentially resulting in dysfunction of baicalein and puerarin glucuronidation. Collectively, we establish that UGTs and glucuronidation are dysregulated in colitis, and this effect may cause variation in drug responsiveness in IBDs.

Chronotoxicity of Semen Strychni is associated with circadian metabolism and transport in mice.

OBJECTIVES: We aimed to determine the circadian responses of mice to Semen Strychni and to investigate the role of pharmacokinetics in generating chronotoxicity. METHODS: Total extract of Semen Strychni was administered by oral gavage to wild-type (WT) and Bmal1-/- (a circadian clock-deficient model) mice at different circadian time points for toxicity (including survival) and pharmacokinetic characterization. Nephrotoxicity and neurotoxicity were evaluated by measuring plasma creatinine and creatine kinase BB (CK-BB), respectively. Drug metabolism and transport assays were performed using liver/intestine microsomes and everted gut sacs, respectively. KEY FINDINGS: Semen Strychni nephrotoxicity and neurotoxicity as well as animal survival displayed significant circadian rhythms (the highest level of toxicity was observed at ZT18 and the lowest level at ZT2 to ZT6). According to pharmacokinetic experiments, herb dosing at ZT18 generated higher plasma concentrations (and systemic exposure) of strychnine and brucine (two toxic constituents) compared with ZT6 dosing. This was accompanied by reduced formation of both dihydroxystrychnine and strychnine glucuronide (two strychnine metabolites) at ZT18. Bmal1 ablation sensitized mice to Semen Strychni-induced toxicity (with increased levels of plasma creatinine and CK-BB) and abolished the time dependency of toxicity. Metabolism of Semen Strychni (strychnine and brucine) in the liver and intestine microsomes of WT mice was more extensive at ZT6 than at ZT18. These time differences in hepatic and intestinal metabolism were lost in Bmal1-/- mice. Additionally, the intestinal efflux transport of Semen Strychni (strychnine and brucine) was more extensive at ZT6 than ZT18 in WT mice. However, the time-varying transport difference was abolished in Bmal1-/- mice. CONCLUSIONS: Circadian responses of mice to Semen Strychni are associated with time-varying efflux transport and metabolism regulated by the circadian clock (Bmal1). Our findings may have implications for optimizing phytotherapy with Semen Strychni via timed delivery.

Oscillating lncRNA Platr4 regulates NLRP3 inflammasome to ameliorate nonalcoholic steatohepatitis in mice.

Background: Understanding the molecular events and mechanisms underlying development and progression of nonalcoholic steatohepatitis is essential in an attempt to formulating a specific treatment. Here, we uncover Platr4 as an oscillating and NF-κB driven lncRNA that is critical to the pathological conditions in experimental steatohepatitis Methods: RNA-sequencing of liver samples was used to identify differentially expressed lncRNAs. RNA levels were analyzed by qPCR and FISH assays. Proteins were detected by immunoblotting and ELISA. Luciferase reporter, ChIP-sequencing and ChIP assays were used to investigate transcriptional gene regulation. Protein interactions were evaluated by Co-IP experiments. The protein-RNA interactions were studied using FISH, RNA pull-down and RNA immunoprecipitation analyses Results: Cyclic expression of Platr4 is generated by the core clock component Rev-erbα via two RevRE elements (i.e., -1354/-1345 and -462/-453 bp). NF-κB transcriptionally drives Platr4 through direct binding to two κB sites (i.e., -1066/-1056 and -526/-516 bp), potentially accounting for up-regulation of Platr4 in experimental steatohepatitis. Intriguingly, Platr4 serves as a circadian repressor of Nlrp3 inflammasome pathway by inhibiting NF-κB-dependent transcription of the inflammasome components Nlrp3 and Asc. Loss of Platr4 down-regulates Nlrp3 inflammasome activity in the liver, blunts its diurnal rhythm, and sensitizes mice to experimental steatohepatitis, whereas overexpression of Platr4 ameliorates the pathological conditions in an Nlrp3-dependent manner. Mechanistically, Platr4 prevents binding of the NF-κB/Rxrα complex to the κB sites via a physical interaction, thereby inhibiting the transactivation of Nlrp3 and Asc by NF-κB. Conclusions:Platr4 functions to inactivate Nlrp3 inflammasome via intercepting NF-κB signaling. This lncRNA might be an attractive target that can be modulated to ameliorate the pathological conditions of steatohepatitis.

Circadian clock-controlled drug metabolism and transport.

Metabolism and transport of many drugs oscillate with times of the day (solar time), resulting in circadian time-dependent drug exposure and pharmacokinetics.Time-dependent pharmacokinetics (also known as chronopharmacokinetics) is associated with time-varying drug effects and toxicity.This review summarizes drug-metabolizing enzymes and transporters with rhythmic expressions in the liver, intestine and/or kidney. Correlations of these diurnal proteins with circadian variations in drug exposure and effects/toxicity are covered. We also discuss the molecular mechanisms for circadian control of enzymes and transporters.Mechanism-based chronopharmacokinetics would facilitate a better understanding of chronopharmacology and the design of time-specific drug delivery systems, ultimately leading to improved drug efficacy and minimized toxicity.

Chinese tree shrews as a primate experimental animal eligible for the study of alcoholic liver disease: characterization and confirmation by MRI.

There has been a lack of suitable fatty liver models and characterization techniques for histopathological evaluation of alcoholic fatty liver (AFL). This work aimed to exploit an magnetic resonance imaging (MRI) technique for characterizing an alcohol-induced fatty liver model established in tree shrews (Tupaia belangeri chinese). The animals were treated with 15% alcohol for two weeks instead of drinking water to induce AFL. Blood alanine aminotransferase (ALT), aspartate aminotransferase (AST), alcohol, and liver malondialdehyde (MDA) concentrations were determined, and the histopathology of the liver was checked by hematoxylin & eosin (HE) and Oil red O staining on day 0 and on the 4th, 7th and 14th days after alcohol feeding. MRI was used to trace the histopathological changes in the liver of tree shrews in real time. Compared with the control group, the levels of ALT, AST, and MDA significantly increased in the alcohol-induced group and were positively correlated with the induction time. HE and Oil red O staining revealed that a moderate fatty lesion occurred in the liver on the 4th day and that a serious AFL was successfully induced on the 14th day. MRI further confirmed the formation of AFL. MRI, as noninvasive examination technique, provides an alternative tool for accurate characterization of AFL in live subjects. It is comparable to HE or Oil red O staining for histopathological examination, but is more suitable by virtue of its high flexibility and compliance. The AFL model of tree shrews combined with MRI characterization can work as a platform for studying fatty liver diseases and medications for their treatment.

Identification of UGTs and BCRP as potential pharmacokinetic determinants of the natural flavonoid alpinetin.

Alpinetin is a natural flavonoid showing a variety of pharmacological effects such as anti-inflammatory, anti-tumor and hypolipidemic activities. Here, we aim to determine the roles of UDP-glucuronosyltransferases (UGTs) and breast cancer resistance protein (BCRP) in disposition of alpinetin. Glucuronidation potential of alpinetin was evaluated using pooled human liver microsomes (pHLM), pooled human intestine microsomes (pHIM) and expressed UGT enzymes supplemented with the cofactor UDPGA. Activity correlation analyses with a bank of individual HLMs were performed to identify the main contributing UGT isozymes in hepatic glucuronidation of alpinetin. The effect of BCRP on alpinetin disposition was assessed using HeLa cells overexpressing UGT1A1 (HeLa1A1) cells. Alpinetin underwent extensive glucuronidation in pHLM and pHIM, generating one glucuronide metabolite. Of 12 test UGT enzymes, UGT1A3 was the most active one toward alpinetin with an intrinsic clearance (CLint = Vmax/Km) value of 66.5 µl/min/nmol, followed by UGT1A1 (CLint = 48.6 µl/min/nmol), UGT1A9 (CLint = 21.0 µl/min/nmol), UGT2B15 (CLint = 16.7 µl/min/nmol) and UGT1A10 (CLint = 1.60 µl/min/nmol). Glucuronidation of alpinetin was significantly correlated with glucuronidation of estradiol (an activity marker of UGT1A1), chenodeoxycholic acid (an activity marker of UGT1A3), propofol (an activity marker of UGT1A9) and 5-hydroxyrofecoxib (an activity marker of UGT2B15), confirming the important roles of UGT1A1, UGT1A3, UGT1A9 and UGT2B15 in alpinetin glucuronidation. Inhibition of BCRP by its specific inhibitor Ko143 significantly reduced excretion of alpinetin glucuronide, leading to a significant decrease in cellular glucuronidation of alpinetin. Our data suggest UGTs and BCRP as two important determinants of alpinetin pharmacokinetics.

Pharmaceutical Dispersion Techniques for Dissolution and Bioavailability Enhancement of Poorly Water-Soluble Drugs.

Over the past decades, a large number of drugs as well as drug candidates with poor dissolution characteristics have been witnessed, which invokes great interest in enabling formulation of these active ingredients. Poorly water-soluble drugs, especially biopharmaceutical classification system (BCS) II ones, are preferably designed as oral dosage forms if the dissolution limit can be broken through. Minimizing a drug’s size is an effective means to increase its dissolution and hence the bioavailability, which can be achieved by specialized dispersion techniques. This article reviews the most commonly used dispersion techniques for pharmaceutical processing that can practically enhance the dissolution and bioavailability of poorly water-soluble drugs. Major interests focus on solid dispersion, lipid-based dispersion (nanoencapsulation), and liquisolid dispersion (drug solubilized in a non-volatile solvent and dispersed in suitable solid excipients for tableting or capsulizing), covering the formulation development, preparative technique and potential applications for oral drug delivery. Otherwise, some other techniques that can increase the dispersibility of a drug such as co-precipitation, concomitant crystallization and inclusion complexation are also discussed. Various dispersion techniques provide a productive platform for addressing the formulation challenge of poorly water-soluble drugs. Solid dispersion and liquisolid dispersion are most likely to be successful in developing oral dosage forms. Lipid-based dispersion represents a promising approach to surmounting the bioavailability of low-permeable drugs, though the technique needs to traverse the obstacle from liquid to solid transformation. Novel dispersion techniques are highly encouraged to develop for formulation of poorly water-soluble drugs.

[Long-term high-fat diet inhibits hippocampal expression of insulin receptor substrates and accelerates cognitive deterioration in obese rats].

OBJECTIVE: To assess the effect of long-term high-fat diet on the expressions of insulin receptor substrates in the hippocampus and spatial learning and memory ability of obese rats. METHODS: A total of 100 4-week-old male SD rats were randomly divided into two groups and fed with common diet (CD group, n=40) or high-fat diet (HFD group, n=60) for 16 weeks. At 4, 8, 12, 16 and 20 weeks, 8 rats were randomly selected from each group for testing their spatial learning and memory function using Morris water maze. After the tests, the rats were sacrificed for measurement of the metabolic parameters and detection of the expressions of insulin receptor substrate-1 (IRS-1) and IRS-2 mRNAs in the CA1 region of the hippocampus. RESULTS: Compared with those in CD group, the rats in HFD group showed a prolonged escape latency, longer swimming distance, faster average swimming speed, and shorter stay in the platformat 12 weeks. In HFD group, the serum levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, and fasting insulin were all significantly increased (P<0.05) and the level of high-density lipoprotein cholesterol decreased (P<0.01) in comparison with those in CD group at each of the time points. No significant difference was found in fast glucose levels between the two groups (P>0.05), but the expressions of IRS-1 and IRS-2 mRNAs were significantly decreased in HFD group at 12 weeks (P<0.05). CONCLUSION: In obese rats, long-term feeding with high-fat diet leads to insulin resistance, which interferes with hippocampal expression of insulin receptor substrates and insulin metabolism to cause impairment of the cognitive function and accelerate cognitive deterioration.

Lipid nanoparticles for the delivery of active natural medicines.

BACKGROUND: Thousands of bioactive compounds are identified and isolated from the medicinal plants every year, of which many possess significant health benefits. However, the overwhelming majority of entities suffer from poor water solubility and membrane permeability that impedes them approaching the clinical stage. METHODS: Lipid nanoparticles have shown to be a versatile platform for advanced delivery of various therapeuticals, including the oral, topical and systemic routes. Lipid nanoparticles are able to significantly improve the oral bioavailability, pharmacokinetic profile, skin permeability, and ocular residence time of drugs, demonstrating considerable potential in pharmaceutical or medical practice. RESULTS: This article profoundly reviews important applications of lipid nanoparticles in active natural medicines. Special concerns focus on solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) for their training in the oral, intravenous, percutaneous and ocular drug delivery. CONCLUSION: The survey shows that lipid nanoparticles are promising vehicles for the delivery of various natural actives and may address some intractable problems associated with delivery thereof.

Recent Advances in Understanding of Kinetic Interplay Between Phase II Metabolism and Efflux Transport.

BACKGROUND: Mechanistic understanding of the metabolism-transport interplay assumes great importance in pharmaceutical fields because the knowledge can help to interpret drug/xenobiotic metabolism and disposition studies as well as the drug-drug interactions in vivo. About 10 years ago, it started to recognize that cellular phase II metabolism is strongly influenced by the excretion (efflux transport) of generated metabolites, a kinetic phenomenon termed "phase II metabolism-transport interplay". This interplay is believed to have significant effects on the pharmacokinetics (bioavailability) of drugs/chemicals undergoing phase II metabolism. METHODS: In this article, we review the studies investigating the phase II metabolism-transport interplay using cell models, perfused rat intestine, and intact rats. The potential confounding factors in exploring such interplay is also summarized. Moreover, the mechanism underlying the phase II metabolism-transport interplay is discussed. RESULTS: Various studies with engineered cells and rodents have demonstrated that there is an interaction (interplay) between phase II enzymes and efflux transporters. This type of interplay mainly refers to the dependence of phase II (conjugative) metabolism on the activities of efflux transporters. In general, inhibiting efflux transporters or decreasing their expression causes the reductions in metabolite excretion, apparent excretion clearance (CLapp) and total metabolism (fmet), as well as an increase in the intracellular level of metabolite (Ci). The deconjugation mediated by hydrolase (acting as a "bridge") is essential for the interplay to play out based on pharmacokinetic modeling/simulations, cell and animal studies. The hydrolases bridge the two processes (i.e., metabolite formation and excretion) and enable the interplay thereof (a bridging effect). Without the bridge, metabolite formation is independent on its downstream process excretion, thus impact of metabolite excretion on its formation is impossible. CONCLUSION: Deconjugation (mediated by hydrolases) plays an essential role in the conjugation-transport interplay.

Comparison of miRNA expression profiles in pituitary-adrenal axis between Beagle and Chinese Field dogs after chronic stress exposure.

MicoRNAs (miRNAs), usually as gene regulators, participate in various biological processes, including stress responses. The hypothalamus-pituitary-adrenal axis (HPA axis) is an important pathway in regulating stress response. Although the mechanism that HPA axis regulates stress response has been basically revealed, the knowledge that miRNAs regulate stress response within HPA axis, still remains poor. The object of this study was to investigate the miRNAs in the pituitary and adrenal cortex that regulate chronic stress response with high-throughput sequencing. The pituitary and adrenal cortex of beagles and Chinese Field dogs (CFD) from a stress exposure group (including beagle pituitary 1 (BP1), CFD pituitary 1 (CFDP1), beagle adrenal cortex 1 (BAC1), CFD adrenal cortex 1 (CFDAC1)) and a control group (including beagle pituitary 2 (BP2), CFD pituitary 2 (CFDP2), beagle adrenal cortex 2 (BAC2), CFD adrenal cortex 2 (CFDAC2)), were selected for miRNA-seq comparisons. Comparisons, that were made in pituitary (including BP1 vs. BP2, CFDP1 vs. CFDP2, BP1 vs. CFDP1 and BP2 vs. CFDP2) and adrenal cortex (including BAC1 vs. BAC2, CFDAC1 vs. CFDAC2, BAC1 vs. CFDAC1 and BAC2 vs. CFDAC2), showed that a total of 39 and 18 common differentially expressed miRNAs (DE-miRNAs) (Total read counts > 1,000, Fold change > 2 & p-value < 0.001), that shared in at least two pituitary comparisons and at least two adrenal cortex comparisons, were detected separately. These identified DE-miRNAs were predicted for target genes, thus resulting in 3,959 and 4,010 target genes in pituitary and adrenal cortex, respectively. Further, 105 and 10 differentially expressed genes (DEGs) (Fold change > 2 & p-value < 0.05) from those target genes in pituitary and adrenal cortex were obtained separately, in combination with our previous corresponding transcriptome study. Meanwhile, in line with that miRNAs usually negatively regulated their target genes and the dual luciferase reporter assay, we finally identified cfa-miR-205 might play an important role by upregulating MMD in pituitary and hippocampus, thus enhancing the immune response, under chronic stress exposure. Our results shed light on the miRNA expression profiles in the pituitary and adrenal cortex with and without chronic stress exposure, and provide a new insight into miR-205 with its feasible role in regulating chronic stress in the pituitary and hippocampus through targeting MMD.

Transcriptome comparison in the pituitary-adrenal axis between Beagle and Chinese Field dogs after chronic stress exposure.

Chronic stress can induce a series of maladjustments, and the response to stress is partly regulated by the hypothalamus-pituitary-adrenal axis. The aim of this study was to investigate the genetic mechanisms of this axis regulating stress responsiveness. The pituitary and adrenal cortex of Beagle and Chinese Field Dog (CFD) from a stress exposure group [including Beagle pituitary 1 (BP1), CFD pituitary 1 (CFDP1), Beagle adrenal cortex 1 (BAC1), CFD adrenal cortex 1 (CFDAC1)] and a control group [including Beagle pituitary 2 (BP2), CFD pituitary 2 (CFDP2), Beagle adrenal cortex 2 (BAC2), CFD adrenal cortex 2 (CFDAC2)], selected to perform RNA-seq transcriptome comparisons, showed that 40, 346, 376, 69, 70, 38, 57 and 71 differentially expressed genes were detected in BP1 vs. BP2, CFDP1 vs. CFDP2, BP1 vs. CFDP1, BP2 vs. CFDP2, BAC1 vs. BAC2, CFDAC1 vs. CFDAC2, BAC1 vs. CFDAC1 and BAC2 vs. CFDAC2 respectively. NPB was a gene common to BAC1 vs. BAC2 and CFDAC1 vs. CFDAC2, indicating it was a potential gene affecting response to chronic stress, regardless of the extent of chronic stress induced. PLP1 was a gene common to BP1 vs. CFDP1 and BP2 vs. CFDP2, suggesting its important roles in affecting the stress-tolerance difference between the two breeds, regardless of whether there was stress exposure or not. Pathway analysis found 12, 4, 11 and 1 enriched pathway in the comparisons of BP1 vs. CFDP1, BP2 vs. CFDP2, CFDP1 vs. CFDP2 and BAC1 vs. BAC2 respectively. Glutamatergic synapse, neuroactive ligand-receptor interaction, retrograde endocannabinoid signaling, GABAergic synapse, calcium signaling pathway and dopaminergic synapse were the most significantly enriched pathways in both CFDP1 vs. CFDP2 and BP1 vs. CFDP1. GO, KEGG pathway and gene network analysis demonstrated that GRIA3, GRIN2A, GRIN2B and NPY were important in regulating the stress response in CFD. Nevertheless, ADORA1, CAMK2A, GRM1, GRM7 and NR4A1 might be critical genes contributing to the stress-tolerance difference between CFD and Beagle when subjected to stress exposure. In addition, RGS4 and SYN1 might play important roles both in regulating the stress response in CFD and in affecting the stress-tolerance difference in different breeds. These observations clearly showed that some genes in the adrenal cortex and pituitary could regulate the stress response in Beagle and CFDs, whereas some others could affect the stress-tolerance difference between these two breeds. Our results can contribute to a more comprehensive understanding of the genetic mechanisms of response to chronic stress.

Establishment of the tree shrew as an alcohol-induced Fatty liver model for the study of alcoholic liver diseases.

Currently, the pathogenesis of alcoholic liver diseases (ALDs) is not clear. As a result, there is no effective treatment for ALDs. One limitation is the lack of a suitable animal model for use in studying ALDs. The tree shrew is a lower primate animal, characterized by a high-alcohol diet. This work aimed to establish a fatty liver model using tree shrews and to assess the animals' suitability for the study of ALDs. Tree shrews were treated with alcohol solutions (10% and 20%) for two weeks. Hemophysiology, blood alcohol concentrations (BACs), oxidative stress factors, alcohol metabolic enzymes and hepatic pathology were checked and assayed with an automatic biochemical analyzer, enzyme-linked immunosorbent assay (ELISA), western blot, hematoxylin-eosin (HE) staining and oil red O staining, and magnetic resonance imaging (MRI). Compared with the normal group, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), total cholesterol (TC), triglyceride (TG), reactive oxygen species (ROS), and malondialdehyde (MDA) were significantly enhanced in alcohol-treated tree shrews. However, the activity of reduced glutathione hormone (GSH) and superoxide dismutase (SOD) declined. Notable changes in alcohol dehydrogenase(ADH1), aldehyde dehydrogenase(ALDH2), CYP2E1, UDP-glucuronosyl transferase 1A1 (UGT1A1) and nuclear factor erythroid-related factor 2 (Nrf2) were observed. HE and oil red O staining showed that hepatocyte swelling, hydropic degeneration, and adipohepatic syndrome occurred in the tree shrews. Alcohol can induce fatty liver-like pathological changes and result in alterations in liver function, oxidative stress factors, alcohol metabolism enzymes and Nrf2. Therefore, the established fatty liver model of tree shrews induced by alcohol should be a promising tool for the study of ALDs.

Comparative analysis of glucuronidation of ethanol in treeshrews, rats and humans.

1. The treeshrews consume food-derived alcohol (ethanol) at a dose that would intoxicate humans, highlighting a marked difference in detoxification of ethanol between the animal species and humans. 2. In this study, we reported that the treeshrews and rats exhibited considerably high glucuronidation capacity for ethanol. Ethanol glucuronidation was 7.1-fold (for the liver microsomes) or 29.2-fold (for the intestine microsomes) more efficient in treeshrews than in humans. Similar to treeshrews, rats also showed a high efficiency in glucuronidating ethanol. 3. In the single-pass perfused intestinal model, significant amount of ethyl glucuronide (EtG) was excreted into the perfusate (for both treeshrews and rats) and bile (for rats). Biliary excretion of EtG was 8.8-13.4 times of intestinal excretion of EtG, suggesting that the liver played a determinant role in glucuronidation of ethanol. In vivo pharmacokinetics showed that EtG production was rapid in the animals with a Tmax value of ≤ 1.75 h. The excreted EtG into urine was 0.11-0.13% of dosed ethanol, a value increased by a 5.5- to 6.6-fold compared to that in humans. 4. This was the first report that the glucuronidation activity toward ethanol was much higher in treeshrews and rats than that in humans, revealing a marked species difference in ethanol glucuronidation.

Effects of Chaihu-Shugan-San and Shen-Ling-Bai-Zhu-San on p38 MAPK Pathway in Kupffer Cells of Nonalcoholic Steatohepatitis.

This study aimed to investigate the effects of Chaihu-Shugan-San (CSS), Shen-Ling-Bai-Zhu-San (SLBZS), and integrated recipe of the above two recipes on inflammatory markers and proteins involved in p38 MAPK pathway in Kupffer cells of NASH rats induced by high fat diet (HFD). Rats were administered at low or high dose of CSS, SLBZS, and integrated recipe except normal group and model group for 16 weeks. The levels of hepatic lipid, TNF- α , IL-1, and IL-6 in liver tissues were measured. Kupffer cells were isolated from livers to evaluate expressions of TLR4, p-p38 MAPK, and p38 MAPK by Western blotting. The results showed that the NASH model rats successfully reproduced typical pathogenetic and histopathological features. Levels of hepatic lipid and liver tissues inflammatory factors in high-dose SLBZS group and integrated recipe group were all lower than that of model group decreased observably. Expressions of TLR4, p-p38 MAPK, and p38 MAPK in Kupffer cells were decreased in all treatment groups, but there was no significant difference between treatment groups. The high-dose SLBZS group had the lowest expression levels of TLR4, and the most visible downtrend in the expression levels of p-p38 MAPK and p38 MAPK was found in the high-dose integrated recipe group. The ratio of p-p38 MAPK to total p38 MAPK protein was obviously increased in all treatment groups. Therefore, our study showed that the activation of p38 MAPK pathway in Kupffer cells might be related to the release of inflammatory factors such as TNF- α , IL-1, and IL-6 in NASH rats. High dose of SLBZS and integrated recipe might work as a significant anti-inflammatory effect in Kupffer cells of NASH rats induced by HFD through suppression of p38 MAPK pathway. It indicated that p38 MAPK pathway may be the possible effective target for the recipes.

Effects of low-level autonomic stimulation on prevention of atrial fibrillation induced by acute electrical remodeling.

BACKGROUND: Rapid atrial pacing (RAP) can induce electrical and autonomic remodeling and facilitate atrial fibrillation (AF). Recent reports showed that low-level vagosympathetic nerve stimulation (LLVNS) can suppress AF, as an antiarrhythmic effect. We hypothesized that LLVNS can reverse substrate heterogeneity induced by RAP. METHODS AND RESULTS: Mongrel dogs were divided into (LLVNS+RAP) and RAP groups. Electrode catheters were sutured to multiple atrial sites, and LLVNS was applied to cervical vagosympathetic trunks with voltage 50% below the threshold slowing sinus rate by ≤ 30 msec. RAP induced a significant decrease in effective refractory period (ERP) and increase in the window of vulnerability at all sites, characterized by descending and elevated gradient differences towards the ganglionic plexi (GP) sites, respectively. The ERP dispersion was obviously enlarged by RAP and more significant when the ERP of GP-related sites was considered. Recovery time from AF was also prolonged significantly as a result of RAP. LLVNS could reverse all these changes induced by RAP and recover the heterogeneous substrate to baseline. Conclusions. LLVNS can reverse the electrical and autonomic remodeling and abolish the GP-central gradient differences induced by RAP, and thus it can recover the homogeneous substrate, which may be the underlying mechanism of its antiarrhythmic effect.