Baitouweng Tang ameliorates DSS-induced ulcerative colitis through the regulation of the gut microbiota and bile acids via pathways involving FXR and TGR5.

In China, Baitouweng Tang (BTWT) is a commonly prescribed remedy for the treatment of ulcerative colitis (UC). Herein, the present study aims to assess the anti-colitis activity of BTWT and its underlying mechanisms in UC BALB/c mice. Induction of UC in BALB/c mice was carried out by adding 3.5% DSS in the drinking water of underlined mice. After UC induction, the mice were administrated with BTWT for 7 days. Clinical symptoms were assessed, followed by analyzing the bile acids (BAs) in serum, liver, colon, bile, and feces of UC mice through UPLC-MS/MS. The modified 16S rDNA high-throughput sequencing was carried out to examine the gut microbiota of feces. BTWT significantly improved the clinical symptoms such as and histological injury and colon shortening in UC induced mice. Furthermore, BTWT remarkably ameliorated colonic inflammatory response. After BTWT treatment, the increased concentrations of UDCA, HDCA, αMCA, ßMCA, CA, and GLCA in UC were decreased, and the levels of some BAs, especially CA, αMCA, and ßMCA were normalized. Moreover, the relative species abundance and gut microbiota diversity in the BTWT-exposed groups were found to be considerably elevated than those in the DSS-treated group. BTWT increased the relative abundance of Firmicutes, Proteobacteria, Actinobacteria, Tenericutes, and TM7, which were statistically lower in the fecal microbiota of UC mice. The relative abundance of Bacteroidetes was found to be elevated in the DSS group and normalized after BTWT treatment. BTWT increased the expression of FXR and TGR5 in the liver. BTWT administration improved DSS-induced mice signs by increasing the TGR5 and FXR expression levels. This result was achieved by the regulation of the BAs and gut microbiota.

Targeting eIF5A Hypusination Prevents Anoxic Cell Death through Mitochondrial Silencing and Improves Kidney Transplant Outcome.

The eukaryotic initiation factor 5A (eIF5A), which is highly conserved throughout evolution, has the unique characteristic of post-translational activation through hypusination. This modification is catalyzed by two enzymatic steps involving deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase (DOHH). Notably, eIF5A may be involved in regulating the lifespan of Drosophila during long-term hypoxia. Therefore, we investigated the possibility of a link between eIF5A hypusination and cellular resistance to hypoxia/anoxia. Pharmacologic targeting of DHPS by N1-guanyl-1,7-diaminoheptane (GC7) or RNA interference-mediated inhibition of DHPS or DOHH induced tolerance to anoxia in immortalized mouse renal proximal cells. Furthermore, GC7 treatment of cells reversibly induced a metabolic shift toward glycolysis as well as mitochondrial remodeling and led to downregulated expression and activity of respiratory chain complexes, features characteristic of mitochondrial silencing. GC7 treatment also attenuated anoxia-induced generation of reactive oxygen species in these cells and in normoxic conditions, decreased the mitochondrial oxygen consumption rate of cultured cells and mice. In rats, intraperitoneal injection of GC7 substantially reduced renal levels of hypusinated eIF5A and protected against ischemia-reperfusion-induced renal injury. Finally, in the preclinical pig kidney transplant model, intravenous injection of GC7 before kidney removal significantly improved graft function recovery and late graft function and reduced interstitial fibrosis after transplant. This unconventional signaling pathway offers an innovative therapeutic target for treating hypoxic-ischemic human diseases and organ transplantation.

Phragmalin limonoids from the stem barks of Chukrasia tabularis var. velutina.

Seven new phragmalin limonoids, chukvelutilides I-O (1-7), were isolated from the stem barks of Chukrasia tabularis var. velutina. Their structures were elucidated by extensive spectroscopic analysis. Among them, compound 1 showed moderate lethal activity against brine shrimp larvae, with an LC50 value of 84.1 µM.

Dietary supplementation of krill oil attenuates inflammation and oxidative stress in experimental ulcerative colitis in rats.

OBJECTIVE: To evaluate the effects of krill oil (KO) on inflammation and redox status in dextran sulfate sodium (DSS)-induced colitis in rats. MATERIALS AND METHODS: Thirty male Wistar rats were divided into three groups: Control, DSS, and DSS + KO 5% in a 4-week diet study. Colitis was induced by 5% DSS in the drinking water the last week of the experiment. Weight and disease activity index (DAI), colon length, histological combined score (HCS), colon levels of selected cytokines and prostaglandins, markers of protein oxidative damage, fatty acid profile, and expression of selected genes were measured. RESULTS: Rats in the DSS group increased their DAI and HCS compared with healthy controls. The colon length was significantly preserved after KO diet. Tumor necrosis factor (TNF)-α and interleukin (IL)-1ß were elevated in the DSS group compared with controls. Cytokines and HCS were nonsignificantly lower in the KO versus the DSS group. Prostaglandin (PG)E(3) increased significantly in the KO versus the other groups. Peroxisome proliferator-activated receptor (PPAR)-γ expression was nonsignificantly increased while PPAR-γ coactivator 1α (Pparg1α) expression increased significantly after KO. The levels of protein oxidation markers decreased significantly. CONCLUSIONS: KO showed protective potential against DSS colitis based on the preservation of colon length, reduction of oxidative markers and the consistent beneficial changes of HCS, cytokine, and (PG)E(3) levels, as well as PPAR-γ and Pparg1α expression compared with DSS alone. These findings indicate an anti-inflammatory and a protein antioxidant effect of KO.

Structure-based drug design: from nucleic acid to membrane protein targets.

The in silico methods for drug discovery are becoming increasingly powerful and useful. That, in combination with increasing computer processor power, in our case using a novel distributed computing grid, has enabled us to greatly enhance our virtual screening efforts. Herein we review some of these efforts using both receptor and ligand-based virtual screening, with the goal of finding new anti-cancer agents. In particular, nucleic acids are a neglected set of targets, especially the different morphologies of duplex, triplex, and quadruplex DNA, many of which have increasing biological relevance. We also review examples of molecular modeling to understand receptors and using virtual screening against G-protein coupled receptor membrane proteins.

Morpholino oligomers targeting the PB1 and NP genes enhance the survival of mice infected with highly pathogenic influenza A H7N7 virus.

Peptide-conjugated phosphorodiamidate morpholino oligomers (PPMO) are single-stranded nucleic acid-analogue antisense agents that enter cells readily and can reduce gene expression by steric blocking of complementary RNA (cRNA) sequences. Here, we tested a panel of PPMO designed to target conserved sequences in the RNA genome segments encoding polymerase subunits of a highly pathogenic mouse-adapted influenza A virus (SC35M; H7N7). Three PPMO, targeting the translation start site region of PB1 or NP mRNA or the 3'-terminal region of NP viral RNA (vRNA), potently inhibited virus replication in MDCK cells. Primer extension assays showed that treatment with any of the effective PPMO led to markedly reduced levels of mRNA, cRNA and vRNA. Initially, the potential toxicity of a range of intranasally administered PPMO doses was evaluated, by measuring their effect on body weight of uninfected mice. Subsequently, a non-toxic dosing regimen was used to investigate the effect of various PPMO on SC35M infection in a mouse model. Mice administered intranasal treatment of PPMO targeting the PB1-AUG region or NP vRNA, at 3 mug per dose, given once 3 h before and once 2 days after intranasal infection with 10xLD(50) of SC35M, showed a 2 log(10) reduction of viral titre in the lungs and 50 % survival for the 16 day duration of the experiment, whereas the NP-AUG-targeted PPMO treatment resulted in 30 % survival of an otherwise lethal infection. These data suggest that PPMO provide a useful reagent to investigate influenza virus molecular biology and may constitute a therapeutic strategy against highly pathogenic influenza viruses.

Suppression of influenza A virus nuclear antigen production and neuraminidase activity by a nutrient mixture containing ascorbic acid, green tea extract and amino acids.

Influenza, one of the oldest and most common infections, poses a serious health problem causing significant morbidity and mortality, and imposing substantial economic costs. The efficacy of current drugs is limited and improved therapies are needed. A unique nutrient mixture (NM), containing ascorbic acid, green tea extract, lysine, proline, N-acetyl cysteine, selenium among other micronutrients, has been shown to exert anti-carcinogenic and anti-atherogenic activity both in vitro and in vivo. Many of the constituents of NM have been shown to have an inhibitory effect on replication of influenza virus and HIV. This prompted us to study the effect of NM on influenza A virus multiplication in infected cells and neuraminidase activity (NA) in virus particles. Addition of NM to Vero or MDCK cells post infection resulted in dose-dependent inhibition of viral nucleoprotein (NP) production in infected cells. NM-mediated inhibition of viral NP was selective and not due to cytotoxicity towards host cells. This antiviral effect was enhanced by pretreatment of virus with the nutrient mixture. Individual components of NM, namely ascorbic acid and green tea extract, also blocked viral NP production, conferring enhanced inhibition when tested in combination. Incubation of cell-free virus with NM resulted in dose-dependent inhibition of associated NA enzyme activity. In conclusion, the nutrient mixture exerts an antiviral effect against influenza A virus by lowering viral protein production in infected cells and diminishing viral enzymatic activity in cell-free particles.

Partially folded states of the capsid protein of cowpea severe mosaic virus in the disassembly pathway.

The different partially folded states of the capsid protein that appear in the disassembly pathway of cowpea severe mosaic virus (CPSMV) were investigated by examining the effects of hydrostatic pressure, sub-zero temperatures and urea. The conformational states of the coat protein were analyzed by their intrinsic fluorescence, binding of bis(8-anilinonaphthalene-1-sulfonate) (bis-ANS) and susceptibility to trypsin digestion. CPSMV could be disassembled by pressure at 2.5 kbar. Intrinsic fluorescence and hydrodynamic measurements showed that pressure-induced dissociation was completely reversible. Virus pressurization in the presence of ribonuclease revealed that viral RNA was not exposed, since it was not digested by the enzyme, suggesting the maintenance of protein-nucleic acid interactions under pressure. When the temperature was decreased to -10 degrees C under pressure, CPSMV disassembly became an irreversible process and in this condition, viral RNA was completely digested by ribonuclease. These results suggest a relationship between protein-RNA interactions and CPSMV assembly. Bis-ANS binding and trypsin digestion of coat proteins revealed that they assume a different conformation when they are denatured by low temperatures under pressure or than when they are denatured by urea at atmospheric pressure. The results indicate that the coat proteins can exist in at least four states: (1) The native conformation in the virus capsid; (2) bound to RNA when the virus is dissociated by pressure at room temperature, assuming a conformation that retains the information for reassembly; (3) free subunits in a molten-globule conformation when the virus is dissociated by low temperature under pressure; and (4) free subunits completely unfolded by high concentrations of urea.