Turmeric is traditionally used as a spice and coloring in foods. It is an important ingredient in curry and gives curry powder its characteristic yellow color. As a consequence of its intense yellow color, turmeric, or curcumin (food additive E100), is used as a food coloring (e.g. mustard). Turmeric contains the curcuminoids curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Recently, the health properties (neuroprotection, chemo-, and cancer prevention) of curcuminoids have gained increasing attention. Curcuminoids induce endogenous antioxidant defense mechanisms in the organism and have anti-inflammatory activity. Curcuminoids influence gene expression as well as epigenetic mechanisms. Synthetic curcumin analogues also exhibit biological activity. This Review describes the development of curcumin from a "traditional" spice and food coloring to a "modern" biological regulator.

Regular consumption of flavonoids may reduce the risk for CVD. However, the effects of individual flavonoids, for example, quercetin, remain unclear. The present study was undertaken to examine the effects of quercetin supplementation on blood pressure, lipid metabolism, markers of oxidative stress, inflammation, and body composition in an at-risk population of ninety-three overweight or obese subjects aged 25-65 years with metabolic syndrome traits. Subjects were randomised to receive 150 mg quercetin/d in a double-blinded, placebo-controlled cross-over trial with 6-week treatment periods separated by a 5-week washout period. Mean fasting plasma quercetin concentrations increased from 71 to 269 nmol/l (P,0·001) during quercetin treatment. In contrast to placebo, quercetin decreased systolic blood pressure (SBP) by 2·6 mmHg (P,0·01) in the entire study group, by 2·9 mmHg (P,0·01) in the subgroup of hypertensive subjects and by 3·7 mmHg (P,0·001) in the subgroup of younger adults aged 25 -50 years. Quercetin decreased serum HDL-cholesterol concentrations (P,0·001), while total cholesterol, TAG and the LDL:HDL-cholesterol and TAG:HDL-cholesterol ratios were unaltered. Quercetin significantly decreased plasma concentrations of atherogenic oxidised LDL, but did not affect TNF-a and C-reactive protein when compared with placebo. Quercetin supplementation had no effects on nutritional status. Blood parameters of liver and kidney function, haematology and serum electrolytes did not reveal any adverse effects of quercetin. In conclusion, quercetin reduced SBP and plasma oxidised LDL concentrations in overweight subjects with a high-CVD risk phenotype. Our findings provide further evidence that quercetin may provide protection against CVD.Quercetin: Blood pressure: Inflammation: Oxidised LDL: CVD Flavonoids in general and quercetin in particular have been associated with a decreased risk for CVD (1) . Furthermore, there was a trend towards a reduction in the incidence of type 2 diabetes mellitus at higher quercetin intakes (2) . In Western populations, the primary dietary sources of quercetin are tea, red wine, fruits and vegetables (3,4) . Quercetin is one of the major flavonoids, ubiquitously distributed in (edible) plants, and one of the most potent antioxidants of plant origin (1) . Numerous biological effects of quercetin, including antioxidant, anti-inflammatory, anti-thrombotic and vasodilatory actions, have been described in vitro (1) . However, quercetin intervention trials in human subjects have so far shown inconclusive and even conflicting results (5) . Quercetin supplementation increased plasma antioxidant capacity, ex vivo resistance of LDL to oxidation and resistance of lymphocyte DNA to strand breakage, but decreased urinary 8-hydroxy-2 0 -deoxyguanosine concentrations (5) . Other human studies, however, failed to confirm effects on these biomarkers (5) . A recent meta-analysis of 133 controlled flavonoid trials (6) suggested that there may be clinically relevant effects of some flavonoids or flavonoid-ri...

Our aim was to investigate the effects of an oral supplementation of quercetin at 3 different doses on plasma concentrations of quercetin, parameters of oxidant/antioxidant status, inflammation, and metabolism. To this end, 35 healthy volunteers were randomly assigned to take 50, 100, or 150 mg/d (group Q50-Q150) quercetin for 2 wk. Fasting blood samples were collected at the beginning and end of the supplementation period. Compared with baseline, quercetin supplementation significantly increased plasma concentrations of quercetin by 178% (Q50), 359% (Q100), and 570% (Q150; P , 0.01 for all).High interindividual variation was found for plasma quercetin concentrations (36-57%). Quercetin did not affect concentrations of serum uric acid or plasma a-and g-tocopherols, oxidized LDL, and tumor necrosis factor-a, or plasma antioxidative capacity as assessed by the ferric-reducing antioxidant potential and oxygen radical absorbance capacity assays. In addition,

Hypoxia-inducible factor-1 (HIF-1) is a dimeric transcriptional complex that has been recognized primarily for its role in the maintenance of oxygen and energy homoeostasis. The HIF-1alpha subunit is O(2) labile and is degraded by the proteasome following prolyl-hydroxylation and ubiquitination in normoxic cells. The present review summarizes evidence that HIF-1 is also involved in immune reactions. Immunomodulatory peptides, including interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha), stimulate HIF-1 dependent gene expression even in normoxic cells. Both the hypoxic and the cytokine-induced activation of HIF-1 involve the phosphatidylinositol- 3-kinase (PI3K) and the mitogen-activated protein kinase (MAPK) signaling pathways. In addition, heat shock proteins (HSP) and other cofactors interact with HIF-1 subunits. HIF-1 increases the transcription of several genes for proteins that promote blood flow and inflammation, including vascular endothelial growth factor (VEGF), heme oxygenase-1, endothelial and inducible nitric oxide synthase (NOS) and cyclooxygenase-2 (COX-2). The pharmacologic activation of the HIF-1 complex can be desirable in ischemic and inflammatory disorders. In contrast, HIF-1 blockade may be beneficial to prevent tumor angiogenesis and tumor growth.

Betalains are water-soluble nitrogen-containing pigments that are subdivided in red-violet betacyanins and yellow-orange betaxanthins. Due to glycosylation and acylation betalains exhibit a huge structural diversity. Betanin (betanidin-5-O-β-glucoside) is the most common betacyanin in the plant kingdom. According to the regulation on food additives betanin is permitted quantum satis as a natural red food colorant (E162). Moreover, betanin is used as colorant in cosmetics and pharmaceuticals. Recently, potential health benefits of betalains and betalain-rich foods (e.g. red beet, Opuntia sp.) have been discussed. Betanin is a scavenger of reactive oxygen species and exhibits gene-regulatory activity partly via nuclear factor (erythroid-derived 2)-like 2-(Nrf2) dependent signaling pathways. Betanin may induce phase II enzymes and antioxidant defense mechanisms. Furthermore, betanin possibly prevents LDL oxidation and DNA damage. Potential blood pressure lowering effects of red beet seem to be mainly mediated by dietary nitrate rather than by betanin per se.

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In this study, the underlying mechanisms of the potential anti-inflammatory properties of allyl-isothiocyanate (AITC) were analysed in vitro and in vivo. Murine RAW264.7 macrophages stimulated with lipopolysaccharide (LPS) were supplemented with increasing concentrations of AITC. In addition, C57BL/6 mice (n= 10 per group) were fed a pro-inflammatory high-fat diet and AITC was administered orally via gavage for 7 days. Biomarkers of inflammation were determined both in cultured cells and in mice. AITC significantly decreased tumour necrosis factor α mRNA levels and its secretion in LPS stimulated RAW264.7 macrophages. Furthermore, gene expression of other pro-inflammatory markers including interleukin-1β and inducible nitric oxide synthase were down-regulated following AITC treatment. AITC decreased nuclear p65 protein levels, a subunit of the transcription factor NF-κB. Importantly, our data indicate that AITC significantly attenuated microRNA-155 levels in LPS-stimulated RAW264.7 macrophages in a dose-dependent manner. The anti-inflammatory effects of AITC were accompanied by an increase in Nrf2 nuclear translocation and consequently by an increase of mRNA and protein levels of the Nrf2 target gene heme-oxygenase 1. AITC was slightly less potent than sulforaphane (used as a positive control) in down-regulating inflammation in LPS-stimulated macrophages. A significant increase in nuclear Nrf2 and heme-oxygenase 1 gene expression and only a moderate down-regulation of interleukin-1β and microRNA-155 levels due to AITC was found in mouse liver. Present data suggest that AITC exhibits potent anti-inflammatory activity in cultured macrophages in vitro but has only little anti-inflammatory activity in mice in vivo.