Anti-Inflammatory Activity of Dehydroandrographolide by TLR4/NF-κB Signaling Pathway Inhibition in Bile Duct-Ligated Mice.

BACKGROUND/AIMS: Clinically, biliary obstruction is often accompanied by progressive inflammation. Dehydroandrographolide (DA) possesses anti-inflammatory properties. However, the anti-inflammatory activities of DA in cholestatic liver injury remain unclear. METHODS: Mice were administered with DA by intraperitoneal injection after bile duct ligation (BDL) on day 1. Then mice were subjected to an ileocecal vein injection of lipopolysaccharide (LPS). Liver function markers, histology, pro-inflammatory cytokine levels, NF-κB activation and fibrosis formation were evaluated in BDL mice with LPS. LPS binding to primary Kupffer cells was examined by high-content cytometers. RESULTS: DA was shown to greatly lower initially higher than normal levels of alanine aminotransferase (ALT) and total bilirubin (TBIL) in the serum and liver of BDL mice with LPS. DA exerted hepatic protective effects that were also confirmed by prolonged survival of BDL mice with LPS. Liver histopathology showed reduced inflammatory cellular infiltration, bile duct proliferation, and biliary necrosis with DA treatment. Furthermore, DA reduced the expression levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in liver tissue and plasma and showed decreased NF-κB activation in BDL mice with LPS. DA could prevent LPS binding to primary Kupffer cells in the normal liver and BDL mice liver. DA also suppressed LPS-stimulated inflammatory responses by blocking the interaction between LPS and TLR4 in primary Kupffer cells and human LX-2 cells, thereby inhibiting NF-κB activation. CONCLUSION: DA inhibition of inflammation against liver damage following BDL with LPS may be a promising agent for the treatment of cholestatic liver injury.

Protective effect of dehydroandrographolide on obstructive cholestasis in bile duct-ligated mice.

BACKGROUND: Dehydroandrographolide (DA) is the main contributor to the therapeutic properties of the medicinal plant Andrographis paniculata (AP). However, it is unknown whether DA has a hepatoprotective effect on obstructive cholestasis in mice and humans. METHODS: We administered DA to mice for 5 days prior to bile duct ligation (BDL) and for the 7 days. Liver function markers, liver histology and necrosis, compensatory responses of hepatocytes, liver fibrosis and the expression of hepatic fibrogenesis markers were evaluated in BDL mice and/or human LX-2 cells. RESULTS: Mice treated with DA demonstrated lower levels of serum alanine transarninase (ALT), milder liver damage, liver necrosis and fibrosis formation than in vehicle control with carboxymethylcellulose (CMC) mice after BDL. DA treatment also enhanced the Mrp3 expression of hepatocytes but not Mrp4 following BDL. Further, DA treatment in BDL mice significantly reduced liver mRNA and/or protein expression of Tgf-ß, Col1a1, α-Sma and Mmp2. This result was also supported by hydroxyproline analysis. The molecular mechanisms of DA treatment were also assessed in human hepatic stellate cell line (LX-2 cell). DA treatment significantly inhibited Tgf-ß-induced Col1a1, Mmp2 and α-Sma expression in human LX-2 cells. These data suggested that DA treatment reduced liver damage through development of a hepatic adaptive response and inhibition of the activation of HSCs, which led to a reduction in liver fibrosis formation in BDL mice. CONCLUSIONS: DA treatment protected against liver damage and fibrosis following BDL and might be an effective therapy for extrahepatic cholestasis due to bile duct obstruction.

Isoalantolactone induces autophagic cell death in SKOV3 human ovarian carcinoma cells via upregulation of PEA-15.

We investigated the effects of isoalantolactone on cell growth inhibition and underlying cell death mechanisms in SKOV3 human ovarian cancer cells. The effects of isoalantolactone on cell proliferation and cell cycle were examined by EdU incorporation assay and DNA content assay. Western blotting was performed to determine the protein expression effects of isoalantolactone on cell cycle­related proteins, autophagic regulators and PEA­15. Autophagic vacuoles were observed by acridine orange staining. PEA­15 knockdown by siRNA was used to confirm that PEA­15 was involved in isoalantolactone­induced autophagy of SKOV3 cells. Isoalantolactone inhibited the viability and proliferation of SKOV3 cells in a dose­ and time­dependent fashion. Isoalantolactone induced cell cycle arrest at G2/M phase and decreased the expression of cell cycle­related proteins cyclin B1 and CDK1 in SKOV3 cells. Accordingly, isoalantolactone also induced SKOV3 cell autophagy via accumulation of autophagic vacuoles in the cytoplasm, increased Beclin1 protein expression, and increased LC3 cleavage. Furthermore, we observed that isoalantolactone­induced autophagy was through increased PEA­15 expression and the phosphorylation of ERK, whereas less change was observed to autophagy on SKOV3 cells through PEA­15 knockdown by siRNA. Isoalantolactone­induced autophagic cell death was further confirmed by pretreatment with the autophagy inhibitor 3­methyladenine (3­MA). In conclusion, isoalantolactone induced cell cycle arrest and autophagy and inhibited cell proliferation of SKOV3 cells via the upregulated PEA­15 expression and the phosphorylation of ERK.

Isoalantolactone Enhances the Radiosensitivity of UMSCC-10A Cells via Specific Inhibition of Erk1/2 Phosphorylation.

BACKGROUND: Although radiotherapy is one of the mainstream approaches for the treatment of head and neck squamous cell carcinoma (HNSCC), this cancer is always associated with resistance to radiation. In this study, the mechanism of action of isoalantolactone as well as its radiosensitizing effect was investigated in UMSCC-10A cells. METHODS: The radiosensitization of UMSCC-10A cells treated with isoalantolactone was analyzed by colony formation assay. The radiosensitization effects of isoalantolactone on cell proliferation, cell cycle and apoptosis regulation were examined by BrdU incorporation assay, DNA content assay and flow cytometry, respectively. Western blotting was performed to determine the effects of isoalantolactone combined with radiation on the protein expression of Mek, extracellular signal-regulated kinase (Erk1/2) as well as phosphorylated Mek and Erk1/2. Erk1/2 knockdown by siRNA was used to confirm that isoalantolactone specifically inhibited the activation of Erk1/2 signaling pathway in UMSCC-10A cells. RESULTS: Isoalantolactone enhanced the radiosensitivity of UMSCC-10A cells; the sensitivity enhanced ratios (SERs) were 1.44 and 1.63, respectively, for 2.5 and 5 µM. Moreover, isoalantolactone enhanced radiation-induced cell proliferation and apoptosis and cell cycle arrested at G2/M phase. Furthermore, no marked changes were observed in the expression of total Erk1/2 and Mek protein after radiation treatment. However, isoalantolactone was significantly reduced radiation-induced the phosphorylation of Erk1/2, whereas it altered the phosphorylation of Mek to a lesser extent. In addition, the radiosensitivity of UMSCC-10A cells with Erk1/2 knockdown was increased. Isoalantolactone cannot further prevent the proliferation of UMSCC-10A cells with Erk1/2 knockdown which other mechanism regulated cell proliferation. CONCLUSION: Our results suggested that isoalantolactone enhanced radiation-induced apoptosis, cell cycle arrested and reduced the cell proliferation of UMSCC-10A cells via specifically inhibited the phosphorylation of Erk1/2. Thus a low concentration of isoalantolactone may be used to overcome the resistance of UMSCC-10A cells to radiation and may be a promising radiosensitizer in cancer therapy.

Aquaporin-1 Deficiency Protects Against Myocardial Infarction by Reducing Both Edema and Apoptosis in Mice.

Many studies have determined that AQP1 plays an important role in edema formation and resolution in various tissues via water transport across the cell membrane. The aim of this research was to determine both if and how AQP1 is associated with cardiac ischemic injury, particularly the development of edema following myocardial infarction (MI). AQP1+/+ and AQP1-/- mice were used to create the MI model. Under physiological conditions, AQP1-/- mice develop normally; however, in the setting of MI, they exhibit cardioprotective properties, as shown by reduced cardiac infarct size determined via NBT staining, improved cardiac function determined via left ventricular catheter measurements, decreased AQP1-dependent myocardial edema determined via water content assays, and decreased apoptosis determined via TUNEL analysis. Cardiac ischemia caused by hypoxia secondary to AQP1 deficiency stabilized the expression of HIF-1α in endothelial cells and subsequently decreased microvascular permeability, resulting in the development of edema. The AQP1-dependent myocardial edema and apoptosis contributed to the development of MI. AQP1 deficiency protected cardiac function from ischemic injury following MI. Furthermore, AQP1 deficiency reduced microvascular permeability via the stabilization of HIF-1α levels in endothelial cells and decreased cellular apoptosis following MI.

Design, synthesis, and biological evaluation of novel piperidine-4-carboxamide derivatives as potent CCR5 inhibitors.

Based on a putative 'Y shape' pharmacophore model of CCR5 inhibitors, a series of novel piperidine-4-carboxamide derivatives were designed and synthesized using a group-reverse strategy. Among synthesized target compounds, 16g (IC50 = 25.73 nM) and 16i (IC50 = 25.53 nM) showed equivalent inhibitory activity against CCR5 to that of the positive control maraviroc (IC50 = 25.43 nM) in calcium mobilization assay. Selected compounds were further tested for their antiviral activity in HIV-1 single cycle assay. Two compounds, 16g and 16i, displayed antiviral activity with IC50 values of 73.01 nM and 94.10 nM, respectively. Additionally, the pharmacokinetic properties and inhibitory potency against hERG of 16g were evaluated, providing a foundation for ongoing optimization.

Isoalantolactone inhibits UM-SCC-10A cell growth via cell cycle arrest and apoptosis induction.

Isoalantolactone is a sesquiterpene lactone compound isolated from the roots of Inula helenium L. Previous studies have demonstrated that isoalantolactone possesses antifungal, anti-bacterial, anti-helminthic and anti-proliferative properties in a variety of cells, but there are no studies concerning its effects on head and neck squamous cell carcinoma (HNSCC). In the present study, an MTT assay demonstrated that isoalantolactone has anti-proliferative activity against the HNSCC cell line (UM-SCC-10A). Immunostaining identified that this compound induced UM-SCC-10A cell apoptosis but not necrosis. To explain the molecular mechanisms underlying its effects, flow cytometry and western blot analysis showed that the apoptosis was associated with cell cycle arrest during the G1 phase, up-regulation of p53 and p21, and down-regulation of cyclin D. Furthermore, our results revealed that induction of apoptosis through a mitochondrial pathway led to up-regulation of pro-apoptotic protein expression (Bax), down-regulation of anti-apoptotic protein expression (Bcl-2), mitochondrial release of cytochrome c (Cyto c), reduction of mitochondrial membrane potential (MMP) and activation of caspase-3 (Casp-3). Involvement of the caspase apoptosis pathway was confirmed using caspase inhibitor Z-VAD-FMK pretreatment. Together, our findings suggest that isoalantolactone induced caspase-dependent apoptosis via a mitochondrial pathway and was associated with cell cycle arrest in the G1 phase in UM-SCC-10A cells. Therefore, isoalantolactone may become a potential drug for treating HNSCC.

Design, synthesis and biological evaluation of novel piperazine derivatives as CCR5 antagonists.

By using a fragment-assembly strategy and bioisosteric-replacement principle, a series of novel piperazine derivatives were designed, synthesized, and evaluated for their cellular target-effector fusion activities and in vitro antiviral activities against HIV-1. Preliminary structure-activity relationships (SARs) of target compounds were concluded in this study, and five compounds were found to exhibited medium to potent CCR5 fusion activities with IC(50) values in low micromolar level. Among evaluated compounds, 23 h was found to be a CCR5 antagonist with an IC(50) value of 6.29 µM and an anti-HIV-1 inhibitor with an IC(50) value of 0.44 µM.

Recent advances in the development of small-molecule CCR5 inhibitors for HIV.

CCR5 (C-C chemokine receptor type 5) is a chemokine receptor that has been identified as a major HIV co-receptor in viral entry and therefore is a highly validated target for the development of new anti-HIV drugs. Here, we discuss the insights gained so far relevant to the development of small-molecule CCR5 inhibitors for the treatment of HIV, and highlight small-molecule CCR5 inhibitors that are currently under preclinical and clinical trials.