3,4-Dicaffeoylquinic Acid, a Major Constituent of Brazilian Propolis, Increases TRAIL Expression and Extends the Lifetimes of Mice Infected with the Influenza A Virus.

Brazilian green propolis water extract (PWE) and its chemical components, caffeoylquinic acids, such as 3,4-dicaffeoylquinic acid (3,4-diCQA), act against the influenza A virus (IAV) without influencing the viral components. Here, we evaluated the anti-IAV activities of these compounds in vivo. PWE or PEE (Brazilian green propolis ethanol extract) at a dose of 200 mg/kg was orally administered to Balb/c mice that had been inoculated with IAV strain A/WSN/33. The lifetimes of the PWE-treated mice were significantly extended compared to the untreated mice. Moreover, oral administration of 3,4-diCQA, a constituent of PWE, at a dose of 50 mg/kg had a stronger effect than PWE itself. We found that the amount of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mRNA in the mice that were administered 3,4-diCQA was significantly increased compared to the control group, while H1N1 hemagglutinin (HA) mRNA was slightly decreased. These data indicate that PWE, PEE or 3,4-diCQA possesses a novel and unique mechanism of anti-influenza viral activity, that is, enhancing viral clearance by increasing TRAIL.

Novel anti-cancer compounds: structure-based discovery of chemical chaperons for p53.

Thermal stability of p53 is crucial in preventing cancer proliferation. Critical mutations which significantly destabilize p53 conformation prevent normal interaction between p53 and DNA and consequently interfere with its inhibitory function against cancer proliferation. The purpose of this study was to discover the small compounds called 'chemical chaperons' that can efficiently stabilize the functional p53 conformation and restore the anti-cancer activity. To search for such compounds, we performed a docking simulation using the AutoDock program and the ZINC database. Simply based on the docking energy, we extracted 70 compounds (GJC1-GJC70) and examined their anti-cancer activity using the MTT assay of the human colon cancer cells, HCT116. We found that two compounds, GJC29 and GJC30, significantly inhibited the proliferation of cancer cells compared to the positive control staurosporine. Interaction between p53 and novel anti-cancer compounds were confirmed using SPR measurements. Intriguingly, in the simulated binding mode, both compounds bind to the pocket in the vicinity of the residue V143, one of the mutation hot-spots in p53. Finally, we injected each compound subcutaneously into the nude mice implanted with HCT116 and found that GJC29 has a strong suppressive effect against cancer proliferation in vivo. In conclusion, p53 is an appropriate target for the rational design of the chemical chaperon for cancer treatment.

Critical role of CD44 in hepatotoxin-mediated liver injury.

BACKGROUND/AIMS: Blocking of adhesion molecules is considered to be one of the therapeutic strategies inflammatory diseases, although it remains unclear whether this strategy is beneficial. METHODS: We used CD44-deficient mice to assess whether inhibition of CD44 could control liver injury caused by carbon tetrachloride (CCl(4)). RESULTS: CD44-deficient mice exhibited suppressed liver inflammation during the early phase (within 6h) after CCl(4) injection due to reduced inflammatory cell infiltration and cytokine production, but showed severe liver inflammation with increased numbers of apoptotic hepatocytes at the late phase (after 12h). The induction of hepatocyte apoptosis was triggered by reduced NF-kappaB activity, which was induced by the low inflammatory cytokine concentrations. Furthermore, macrophages contributed to the induction of hepatocyte apoptosis, since neutralization by an anti-CD11b antibody significantly protected against hepatocyte apoptosis. Finally, we found that blocking of MIP-2 and TNF-alpha reduced hepatocyte apoptosis with decreased numbers of intrahepatic leukocytes and reduced inflammatory cytokine production. CONCLUSIONS: These findings suggest that targeting of CD44 as a therapeutic approach for inflammatory liver diseases may require caution for particular immune systems in the liver.