The flavonoid 4,4'-dimethoxychalcone promotes autophagy-dependent longevity across species.

Ageing constitutes the most important risk factor for all major chronic ailments, including malignant, cardiovascular and neurodegenerative diseases. However, behavioural and pharmacological interventions with feasible potential to promote health upon ageing remain rare. Here we report the identification of the flavonoid 4,4'-dimethoxychalcone (DMC) as a natural compound with anti-ageing properties. External DMC administration extends the lifespan of yeast, worms and flies, decelerates senescence of human cell cultures, and protects mice from prolonged myocardial ischaemia. Concomitantly, DMC induces autophagy, which is essential for its cytoprotective effects from yeast to mice. This pro-autophagic response induces a conserved systemic change in metabolism, operates independently of TORC1 signalling and depends on specific GATA transcription factors. Notably, we identify DMC in the plant Angelica keiskei koidzumi, to which longevity- and health-promoting effects are ascribed in Asian traditional medicine. In summary, we have identified and mechanistically characterised the conserved longevity-promoting effects of a natural anti-ageing drug.

Prominent role of NF-kappaB in the induction of endothelial activation by endogenous nitric oxide inhibition.

Decreased endothelial nitric oxide (NO) production and increased expression of vascular cell adhesion molecule-1 (VCAM-1) are early features of atherosclerosis. We investigated the effects of suppressing endogenous NO production by the NO synthase inhibitor l-mono-methyl-arginine (L-NMMA), given alone or in combination with interleukin(IL)-1alpha, on VCAM-1 expression by human umbilical vein endothelial cells (HUVEC). VCAM-1 expression (by enzyme immunoassay), barely detectable at baseline, was significantly increased by L-NMMA (by no more than 20% over control compared with IL-1alpha induction). This was paralleled by an increase in U937 monocytoid cell adhesion. When HUVEC incubated with L-NMMA were stimulated with low concentrations of IL-1alpha (0.05-0.5ng/mL), these determined a higher VCAM-1 expression than in the presence of L-NMMA or IL-1alpha alone. Northern analysis indicated that VCAM-1 mRNA was induced by L-NMMA alone, and that the effects of L-NMMA and IL-1alpha were, again, at least additive. Nuclear factor-kappaB (NF-kappaB), GATA, activator protein-1 (AP-1) and interferon regulatory factor-1 (IRF-1), transcription factors all involved in VCAM-1 gene expression, were all activated at electrophoretic mobility shift assay and at chromatin immunoprecipitation assay by L-NMMA, but additive effects with the combined administration of L-NMMA and IL-1alpha only occurred for NF-kappaB. These results support the view that endogenous NO mantains a normal endothelial non-reactivity towards circulating monocytes, and that suppression of this endogenous brake for endothelial activation results in the activation of multiple transcription factors even in the absence of other endothelial activators, with a prominent role of NF-kappaB in the presence or absence of other inflammatory mediators.

Does k-11706 enhance performance and why?

Erythropoietin gene expression is stimulated by hypoxia-inducible factor 1 and inhibited by GATA. Thus, drugs that attenuate the action of GATA and/or potentiate the action of HIF-1 may increase Epo production and hemoglobin concentration. The effects of such drugs on endurance performance and the potential mechanisms by which they may exert effects are unclear. In Hep3B cells, we showed that K-11706 inhibits GATA binding activity, but enhances HIF-1 binding activity. However, the expression levels of GATA and HIF-1 protein were not changed by the addition of K-11706. We investigated the effects of K-11706 on Epo and Hb concentrations, hematocrit and endurance performance of mice (total number of mice = 40). K-11706 was dissolved in polyethylene glycol and administered via oral tube feeding to mice for either five or eight days. Endurance performance was assessed using a treadmill. Muscle fibers from the quadriceps muscles of mice were stained with ATPase. Administration of 3 mg/kg K-11706 for five or eight days significantly increased erythropoietin concentrations, hemoglobin concentrations, hematocrit and endurance performance, but the diameters of cross-sections and ratios of type I, IIA and IIB muscle fibers were not affected.