Isoquercitrin attenuates the progression of non-alcoholic steatohepatitis in mice by modulating galectin-3-mediated insulin resistance and lipid metabolism.

BACKGROUND: Non-alcoholic steatohepatitis (NASH) is a global health problem with no effective treatment. Isoquercitrin (IQ) alters hepatic lipid metabolism and inhibits adipocyte differentiation. The underlying regulatory mechanisms of IQ in regulating insulin resistance (IR) and lipid metabolism remain unclear. PURPOSE: This study was aimed at investigating the effects of IQ on NASH and deciphering whether the underlying mechanisms are via modulation of galectin-3 mediated IR and lipid metabolism. METHODS: IR-HepG2 cell lines were used to demonstrate the ability of IQ to modulate galectin-3-mediated glucose disposal and lipid metabolism. A 20-week high-fat diet (HFD)-induced NASH model was established in C57BL/6J mice, and the protective effect of IQ on lipid disposal in the liver was verified. Further, the mRNA and protein levels of glucose and lipid metabolism were investigated, and lysophosphatidylcholine (LPC) and acylcarnitine (AC) profiling were performed to characterize the changes in endogenous substances associated with mitochondrial function and lipid metabolism in serum and cells. Furthermore, the pharmacokinetic features of IQ were explored in a rat model of NASH. RESULTS: IQ restored liver function and ameliorated inflammation and lipid accumulationin NASH model mice. Notably, significant regulation of the proteins included fatty acid-generating and transporting, cholesterol metabolism enzymes, nuclear transcription factors, mitochondrial metabolism, and IR-related enzymes was noted to be responsible for the therapeutic mechanisms of IQ against experimental NASH. Serum lipid metabolism-related metabolomic assay confirmed that LPC and AC biosynthesis mostly accounted for the therapeutic effect of IQ in mice with NASH and that IQ maintained the homeostasis of LPC and AC levels. CONCLUSION: This is the first study showing that IQ protects against of NASH by modulating galectin-3-mediated IR and lipid metabolism. The mechanisms responsible for liver protection and improved lipid metabolic disorder by IQ may be related to the suppression of IR and regulation of mitochondrial function and lipid metabolism. Galectin-3 down-regulation represents a potentially novel approach for the treatment and prevention of NASH.

Down-regulating Nrf2 by tangeretin reverses multiple drug resistance to both chemotherapy and EGFR tyrosine kinase inhibitors in lung cancer.

Multiple drug resistance (MDR) is the major obstacle for both chemotherapy and molecular-targeted therapy for cancer, which is mainly caused by overexpression of ABC transporters or genetic mutation of drug targets. Based on previous studies, we hypothesized that ROS/Nrf2 is the common target for overcoming acquired drug resistance to both targeted therapy and chemotherapy treatments. In this study, we firstly proved that the levels of ROS and Nrf2 were remarkably up-regulated in both H1975 (Gefitinib-resistant lung cancer cells with T790M) and A549/T (paclitaxel-resistant) cells, which is consistent with the clinical database analysis results of lung cancer patients that Nrf2 expression level is negatively related to survival rate. Nrf2 Knockdown with siRNA or tangeretin (TG, a flavonoid isolated from citrus peels) inhibited the MDR cell growth by suppressing the Nrf2 pathway, and efficiently enhanced the anti-tumor effects of paclitaxel and AZD9291 (the third generation of TKI) in A549/T or H1975, respectively. Moreover, TG sensitized A549/T cells-derived xenografts to paclitaxel via inhibiting Nrf2 and its downstream target P-gp, leading to an increased paclitaxel concentration in tumors. Collectively, targeting Nrf2 to enhance ROS may be a common target for overcoming the acquired drug resistance and enhancing the therapeutic effects of chemotherapy and molecular-targeted therapy.

The combination of Lonicerae Japonicae Flos and Forsythiae Fructus herb-pair alleviated inflammation in liver fibrosis.

Objective: To explore the active components and epigenetic regulation mechanism underlying the anti-inflammatory effects of Lonicerae Japonicae Flos and Forsythiae Fructus herb-pair (LFP) in carbon tetrachloride (CCl4)-induced rat liver fibrosis. Methods: The main active ingredients and disease-related gene targets of LFP were determined using TCMSP and UniProt, and liver fibrosis disease targets were screened in the GeneCards database. A network was constructed with Cytoscape 3.8.0 and the STRING database, and potential protein functions were analyzed using bioinformatics analysis. Based on these analyses, we determined the main active ingredients of LFP and evaluated their effects in a CCl4-induced rat liver fibrosis model. Serum biochemical indices were measured using commercial kits, hepatocyte tissue damage and collagen deposition were evaluated by histopathological studies, and myofibroblast activation and inflammation were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. High-performance liquid chromatography-mass spectrometry was performed to determine the levels of homocysteine, reduced glutathione, and oxidized glutathione, which are involved in inflammation and oxidative stress. Results: The main active components of LFP were quercetin, kaempferol, and luteolin, and its main targets were α-smooth muscle actin, cyclooxygenase-2, formyl-peptide receptor-2, prostaglandin-endoperoxide synthase 1, nuclear receptor coactivator-2, interleukinß, tumor necrosis factor α, CXC motif chemokine ligand 14, and transforming growth factor ß1. A combination of quercetin, kaempferol, and luteolin alleviated the symptoms of liver fibrosis. Conclusion: The results of this study support the role of LFP in the treatment of liver fibrosis, and reveal that LFP reduces collagen formation, inflammation, and oxidative stress. This study suggests a potential mechanism of action of LFP in the treatment of liver fibrosis.

Evaluation of lipid metabolism imbalance in HIV-infected patients with metabolic disorders using high-performance liquid chromatography-tandem mass spectrometry.

Human immunodeficiency virus (HIV) infection and highly active antiretroviral therapy use are associated with the disruption of lipid and glucose metabolism. Herein, a sensitive and robust high-performance liquid chromatography-tandem mass spectrometry method for the quantitation of lysophosphatidylcholines (LPCs) and acylcarnitines (ACs) in human blood serum was developed and validated to investigate them as markers of metabolic disorders in HIV-infected patients. Under optimal extraction and detection conditions, the lower limits of quantification reached 5 ng/mL (LPCs) and 0.1 ng/mL (ACs), and precision and accuracy for both intra- and inter-day analyses were generally below 15%. Serum samples were stable for at least six months when stored at - 80 °C and for at least 12 h when stored at 4 °C or 25 °C. We investigated inter-group differences and associations between the biomarkers and observed a particular volatilitytrend of LPCs and ACs for HIV-infected patients with metabolic disorders. Thus, the developed method can be used for the rapid and sensitive quantitation of LPCs and ACs in vivo to further appraise the process of HIV infection, evaluate interveningmeasures, conduct mechanistic investigations, and further study the utility of LPCs and ACs as biomarkers of HIV infection coupled with metabolic disorders.

Quercetin 7-rhamnoside protects against alpha-naphthylisothiocyanate (ANIT)-induced in cholestatic hepatitis rats by improving biliary excretion and inhibiting inflammatory responses.

Objective: To explore the pharmacological effects and molecular mechanism of quercetin 7-rhamnoside (Q7R) in the treatment of cholestatic hepatitis induced by alpha-naphthylisothiocyanate (ANIT). Methods: ANIT-induced cholestatic hepatitis rat model was used to investigate the hepatoprotective effects of three different doses of Q7R (1.25 mg/kg; 2.5 mg/kg; 5 mg/kg). Serum biochemical indices were detected using commercial kits. H&E and masson staining were used to observe hepatic tissue damage and collagen deposition in hepatocytes. The metabolism of bile acid-related substances was detected via HPLC-MS/MS by 5-(diisopropylamino) amylamine (DIAAA) derivative method. Hepatocyte injury, cholestasis, and inflammation were detected at the mRNA and protein levels using reverse transcription-polymerase chain reaction (RT-PCR) and western blotting, respectively. Results: Q7R can decrease the level of CYP7A1, and increase FXR, CYP27A1 so then improving abnormal bile acid secretion. Furthermore, Q7R can also ameliorating inflammation by reduce TNF-α, IL-1ß, PTGS1, PTGS2, NCOA2, NF-κB level. Therefore, Q7R had an effective therapeutic effect on ANIT-induced cholestatic hepatitis, improving abnormal bile acid secretion, and inhibiting inflammatory responses. Conclusion: The results demonstrated that Q7R treat cholestatic hepatitis by regulating bile acid secretion and alleviating inflammation.

A Network Pharmacology Study of the Molecular Mechanisms of Hypericum japonicum in the Treatment of Cholestatic Hepatitis with Validation in an Alpha-Naphthylisothiocyanate (ANIT) Hepatotoxicity Rat Model.

BACKGROUND This network pharmacology study aimed to identify the active compounds and molecular mechanisms involved in the effects of Hypericum japonicum on cholestatic hepatitis. We validated the findings in an alpha-naphthylisothiocyanate (ANIT) rat model of hepatotoxicity. MATERIAL AND METHODS The chemical constituents and targets of H. japonicum and target genes previously associated with cholestatic hepatitis were retrieved from public databases. A network was constructed using Cytoscape 3.7.2 software and the STRING database and potential protein functions were analyzed based on the public platform of bioinformatics. ANIT was used to induce cholestatic hepatitis in a rat model using 36 Sprague-Dawley rats, and this model was used to investigate intervention with 3 doses of quercetin (low-dose, 50 mg/kg; medium-dose, 100 mg/kg; and high-dose, 200 mg/kg), the main active component of H. japonicum. Levels of serum biochemical indexes were measured by commercial kits, and the messenger RNA (mRNA) levels of markers of liver and mitochondrial function and oxidative stress were detected by real-time reverse transcription-polymerase chain reaction (RT-PCR). RESULTS The main active ingredients of H. japonicum were quercetin, kaempferol, and tetramethoxyluteolin, and their key targets included prostaglandin G/H synthase 2 (PTGS2), B-cell lymphoma-2 (BCL2), cholesterol 7-alpha hydroxylase (CYP7A1), and farnesoid X receptor (FXR). Quercetin intervention promoted recovery from cholestatic hepatitis. CONCLUSIONS The findings from this research provide support for future research on the roles of quercetin, kaempferol, and tetramethoxyluteolin in human liver disease and the roles of the PTGS2, BCL2, CYP7A1, and FXR genes in cholestatic hepatitis.

Suppression of up-regulated LXRα by silybin ameliorates experimental rheumatoid arthritis and abnormal lipid metabolism.

BACKGROUND: As dysregulation of immunometabolism plays a key role in the immunological diseases, dyslipidemia frequently observed in rheumatoid arthritis (RA) patients (60%) is associated with the disease activity and has been considered as the potential target of anti-inflammatory strategy. However, targeting of metabolic events to develop novel anti-inflammatory therapeutics are far from clear as well as the mechanism of dyslipidemia in RA. PURPOSE: To explore the therapeutic potential and mechanisms of silybin again RA through the regulation of lipid metabolism. METHODS: Adjuvant-induced arthritis (AIA) rat model was used to examine the effects of silybin on modulating dysregulated lipid metabolism and arthritis. Metabolomics, docking technology, and biochemical methods such as western blots, qRT-PCR, immunofluorescence staining were performed to understanding the underlying mechanisms. Moreover, knock-down of LXRα and LXRα agonist were used on LO2 cell lines to understand the action of silybin. RESULTS: We are the first to demonstrate that silybin can ameliorate dyslipidemia and arthritis in AIA rats. Overexpression of LXRα and several key lipogenic enzymes regulated by LXRα, including lipoprotein lipase (LPL), cholesterol 7α and 27α hydroxylase (CYP7A, CYP27A), adipocyte fatty acid-binding protein (aP2/FABP4) and fatty acid translocase (CD36/FAT), were observed in AIA rats, which mostly accounted for dyslipidemia during arthritis development. Metabolomics, docking technology, and biochemical results indicated that anti-arthritis effects of silybin related to suppressing the up-regulated LXRα and abnormal lipid metabolism. Notably, activation of LXRα could potentiate cell inflammatory process induced by LPS through the regulation of NF-κB pathway, however, suppression of LXRα agonism by siRNA or silybin reduced the nuclear translocation of NF-κB as well as the induction of downstream cytokines, indicating LXRα agonism is the important factor for the arthritis development and could be a potential target. CONCLUSION: The up-regulation of LXRα can activate lipogenesis enzymes to worsen the inflammatory process in AIA rats as well as the development of dyslipidemia, therefore, rectifying lipid disorder via suppression of LXRα agonism pertains the capacity of drug target, which enables to discover and develop new drugs to treat rheumatoid arthritis with dyslipidaemia.

A multiple-targets alkaloid nuciferine overcomes paclitaxel-induced drug resistance in vitro and in vivo.

OBJECTIVE: Multidrug resistance (MDR) is the major barrier to the successful treatment of chemotherapy. Compounds from nature products working as MDR sensitizers provided new treatment strategies for chemo-resistant cancers patients. METHODS: We investigated the reversal effects of nuciferine (NF), an alkaloid from Nelumbo nucifera and Nymphaea caerulea, on the paclitaxel (PTX) resistance ABCB1-overexpressing cancer in vitro and in vivo, and explored the underlying mechanism by evaluating drug sensitivity, cell cycle perturbations, intracellular accumulation, function and protein expression of efflux transporters as well as molecular signaling involved in governing transporters expression and development of MDR in cancer. RESULTS: NF overcomes the resistance of chemotherapeutic agents included PTX, doxorubicin (DOX), docetaxel, and daunorubicin to HCT-8/T and A549/T cancer cells. Notably, NF suppressed the colony formation of MDR cells in vitro and the tumor growth in A549/T xenograft mice in vivo, which demonstrated a very strong synergetic cytotoxic effect between NF and PTX as combination index (CI) (CI<0.1) indicated. Furthermore, NF increased the intracellular accumulation of P-gp substrates included DOX and Rho123 in the MDR cells and inhibited verapamil-stimulated ATPase activity. Mechanistically, inhibition of PI3K/AKT/ERK pathways by NF suppressed the activation of Nrf2 and HIF-1α, and further reduced the expression of P-gp and BCRP, contributing to the sensitizing effects of NF against MDR in cancer. CONCLUSION: This novel finding provides a promising treatment strategy for overcoming MDR and improving the efficiency of chemotherapy by using a multiple-targets MDR sensitizer NF.

Ginsenoside Rg5 overcomes chemotherapeutic multidrug resistance mediated by ABCB1 transporter: in vitro and in vivo study.

BACKGROUND: Multidrug resistance (MDR) to chemotherapy drugs remains a major challenge in clinical cancer treatment. Here we investigated whether and how ginsenoside Rg5 overcomes the MDR mediated by ABCB1 transporter in vitro and in vivo. METHODS: Cytotoxicity and colon formation as well as the intracellular accumulation of ABCB1 substrates were carried out in MDR cancer cells A2780/T and A549/T for evaluating the reversal effects of Rg5. The expressions of ABCB1 and Nrf2/AKT pathway were determined by Western blotting. An A549/T cell xenograft model was established to investigate the MDR reversal activity of Rg5 in vivo. RESULTS: Rg5 significantly reversed ABCB1-mediated MDR by increasing the intracellular accumulation of ABCB1 substrates without altering protein expression of ABCB1. Moreover, Rg5 activated ABCB1 ATPase and reduced verapamil-stimulated ATPase activity, suggesting a high affinity of Rg5 to ABCB1 binding site which was further demonstrated by molecular docking analysis. In addition, co-treatment of Rg5 and docetaxel (TXT) suppressed the expression of Nrf2 and phosphorylation of AKT, indicating that sensitizing effect of Rg5 associated with AKT/Nrf2 pathway. In nude mice bearing A549/T tumor, Rg5 and TXT treatment significantly suppressed the growth of drug-resistant tumors without increase in toxicity when compared to TXT given alone at same dose. CONCLUSION: Therefore, combination therapy of Rg5 and chemotherapy drugs is a strategy for the adjuvant chemotherapy, which encourages further pharmacokinetic and clinical studies.

Nobiletin potentiates paclitaxel anticancer efficacy in A549/T xenograft model: Pharmacokinetic and pharmacological study.

BACKGROUND: Nobiletin (N), a polymethoxylated flavone from citrus fruits, enhanced anti-cancer effects of paclitaxel (PTX) in multi-drug resistance (MDR) cancer cells via inhibiting P-glycoprotein (P-gp) in our previous report. But the in vivo chemo-sensitizing effect of nobiletin is unknown. Moreover, considering the nonlinear pharmacokinetics and narrow therapeutic window of PTX, drug-drug interaction should be explored for using nobiletin with PTX together. PURPOSE: In this study, we wanted to explore whether nobiletin could affect the pharmacokinetic (PK) behavior of PTX and reverse drug resistance in vivo as well as the corresponding mechanisms. STUDY DESIGN AND METHODS: Accurate and sensitive UPLC-MS/MS method was developed for the detection of PTX, and was applied to the pharmacokinetic study in rats. In vivo anti-MDR tumor study was carried out with A549/T xenograft nude mice model. Immunohistochemistry and western blot analysis were used for evaluating the levels of P-gp, Nrf2, and AKT/ERK pathways in MDR tumors. RESULTS: Nobiletin significantly enhanced the therapeutic effects of PTX, and inhibited the MDR tumor sizes in the A549/T xenograft model, while PTX or nobiletin alone did not. We found that nobiletin increased the PTX concentrations in tumor tissues but did not affect the PK behavior of PTX. Notably, Nrf2 and phosphorylation of AKT/ERK expression in MDR tumor tissues were significantly inhibited by giving nobiletin and PTX together. However, nobiletin did not affect the expression of P-gp. CONCLUSION: Nobiletin reversed PTX resistance in MDR tumor via increasing the PTX content in the MDR tumor and inhibiting AKT/ERK/Nrf2 pathways, but without affecting the systematic exposure of PTX, indicating that nobiletin may be an effective and safe MDR tumor reversal agent.

Role of tangeretin as a potential bioavailability enhancer for silybin: Pharmacokinetic and pharmacological studies.

Biological responses of a variety of naturally occurring compounds in vivo were restrained by their poor oral bioavailability. Silybin, as one of the active ingredients of silymarin, has presented promising bioactivity for the treatment of chronic liver diseases and cancer. However, its exposure in body was limited. In this study, silybin was demonstrated to be substrates of both BCRP and MRP2 by utilizing monolayer Caco-2 cell model and confirmed in MDCK cells overexpressing specific efflux transporter. Of all compounds screened, tangeretin, a potent inhibitor of efflux transporters of BCRP, MRP2 and P-gp, was able to enhance exposure of silybin by inhibiting functions of the barriers mediating transcellular transport. Moreover, study carried out in sandwich-cultured rat hepatocyte (SCH) model showed that the biliary excretion index (BEI) and in vitro biliary clearance of silybin decreased as levels of tangeretin increased, indicating efflux transporters mediating biliary excretion of silybin might be involved. Pharmacokinetic behaviors of silybin in rats were altered by co-administration of tangeretin, in terms of increased AUC and Cmax of silybin by comparing with that of silybin given alone. In addition, results coming from CCl4-induced acute liver injury rat model revealed that protection effect of silybin against liver damage in the presence of tangeretin was significantly enhanced. All these data were evident that efflux transporters play a critical role in transcellular transport of silybin and account for its low bioavailability. Enhanced bioavailability of silybin with co-administration of tangeretin by significantly inhibiting the efflux transporters further boost its bioactivity which is of particular importance in clinical use.

Tangeretin, a citrus pentamethoxyflavone, antagonizes ABCB1-mediated multidrug resistance by inhibiting its transport function.

Multidrug resistance (MDR) and tumor metastasis are the main causes of chemotherapeutic treatment failure and mortality in cancer patients. In this study, at achievable nontoxic plasma concentrations, citrus flavonoid tangeretin has been shown to reverse ABCB1-mediated cancer resistance to a variety of chemotherapeutic agents effectively. Co-treatment of cells with tangeretin and paclitaxel activated apoptosis as well as arrested cell cycle at G2/M-phase. Tangeretin profoundly inhibited the ABCB1 transporter activity since it significantly increased the intracellular accumulation of doxorubicin, and flutax-2 in A2780/T cells and decreased the efflux of ABCB1 substrates in Caco2 cells without altering the expression of ABCB1. Moreover, it stimulated the ATPase activity and inhibited verapamil-stimulated ATPase activity in a concentration-dependent manner, indicating a direct interaction with the transporter. The molecular docking results indicated a favorable binding of tangeretin with the transmemberane region site 1 of homology modeled ABCB1 transporter. The overall results demonstrated that tangeretin could sensitize ABCB1-overexpressing cancer cells to chemotherapeutical agents by directly inhibiting ABCB1 transporter function, which encouraged further animal and clinical studies in the treatment of resistant cancers.