抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Epidemiological studies have clearly shown that whole-grain cereals can protect against obesity, diabetes, CVD and cancers. The specific effects of food structure (increased satiety, reduced transit time and glycaemic response), fibre (improved faecal bulking and satiety, viscosity and SCFA production, and/or reduced glycaemic response) and Mg (better glycaemic homeostasis through increased insulin secretion), together with the antioxidant and anti-carcinogenic properties of numerous bioactive compounds, especially those in the bran and germ (minerals, trace elements, vitamins, carotenoids, polyphenols and alkylresorcinols), are today well-recognised mechanisms in this protection. Recent findings, the exhaustive listing of bioactive compounds found in whole-grain wheat, their content in whole-grain, bran and germ fractions and their estimated bioavailability, have led to new hypotheses. The involvement of polyphenols in cell signalling and gene regulation, and of sulfur compounds, lignin and phytic acid should be considered in antioxidant protection. Whole-grain wheat is also a rich source of methyl donors and lipotropes (methionine, betaine, choline, inositol and folates) that may be involved in cardiovascular and/or hepatic protection, lipid metabolism and DNA methylation. Potential protective effects of bound phenolic acids within the colon, of the B-complex vitamins on the nervous system and mental health, of oligosaccharides as prebiotics, of compounds associated with skeleton health, and of other compounds such as alpha-linolenic acid, policosanol, melatonin, phytosterols and para-aminobenzoic acid also deserve to be studied in more depth. Finally, benefits of nutrigenomics to study complex physiological effects of the 'whole-grain package', and the most promising ways for improving the nutritional quality of cereal products are discussed.

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New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre?

Nutraceuticals: facts and fiction.

Interest in anthocyanins has increased immensely during the past decade. From these studies, it is clear that anthocyanins have unique properties: Anthocyanins are absorbed intact and absorption can be saturated; acylation of anthocyanins lowers their apparent absorption; anthocyanidin diglycosides in the form of sambubioside or rutinoside impart increased stability to the anthocyanin molecule; and the quantities excreted in urine are less than 0.1% of intake. However, 60–90% of the anthocyanins may disappear from the gastrointestinal tract within 4 h after a meal. What happens to the bulk of the anthocyanins that disappear is not clear. Degradation accounts for a part of this disappearance, but differs for the various aglycones and may be modified further by the nature of the aglycone glycosylation, which further complicates our understanding of this process. Anthocyanins may play an important role in health promotion in terms of obesity prevention, cardiovascular health, anti-inflammatory and anti-cance...

Anthocyanins: Structural characteristics that result in unique metabolic patterns and biological activities

Natural products have potential for inducing apoptosis, inhibiting adipogenesis and stimulating lipolysis in adipocytes. The objective of this review is to discuss the adipocyte life cycle and various dietary bioactives that target different stages of adipocyte life cycle. Different stages of adipocyte development include preadipocytes, maturing preadipocytes and mature adipocytes. Various dietary bioactives like genistein, conjugated linoleic acid (CLA), docosahexaenoic acid, epigallocatechin gallate, quercetin, resveratrol and ajoene affect adipocytes during specific stages of development, resulting in either inhibition of adipogenesis or induction of apoptosis. Although numerous molecular targets that can be used for both treatment and prevention of obesity have been identified, targeted monotherapy has resulted in lack of success. Thus, targeting several signal transduction pathways simultaneously with multiple natural products to achieve additive or synergistic effects might be an appropriate approach to address obesity. We have previously reported two such combinations, namely, ajoene+CLA and vitamin D+genistein. CLA enhanced ajoene-induced apoptosis in mature 3T3-L1 adipocytes by synergistically increasing the expression of several proapoptotic factors. Similarly, genistein potentiated vitamin D's inhibition of adipogenesis and induction of apoptosis in maturing preadipocytes by an enhanced expression of VDR (vitamin D receptor) protein. These two examples indicate that combination therapy employing compounds that target different stages of the adipocyte life cycle might prove beneficial for decreasing adipose tissue volume by inducing apoptosis or by inhibiting adipogenesis or both.

Phytochemicals and regulation of the adipocyte life cycle.

Black rice and its pigment fraction may have antiatherogenic activity, but the exact component contributing to the beneficial effect remains unclear. The aim of the present study was to investigate the influence of the anthocyanin-rich extract from black rice on the vulnerability of advanced plaques in apolipoprotein (apo) E-deficient mice. Using LC-MS, the anthocyanin-rich extract from black rice was identified as containing cyanidin-3-glucoside and peonidin-3-glucoside. ApoE-deficient mice (n = 30; 30 wk old) were randomly divided into 3 groups: a control group (fed the AIN-93G diet), the simvastin group [simva; fed the AIN-93G diet containing simvastatin, 50 mg/(kg.d)], or the anthocyanin-rich extract group [antho; fed the AIN-93G diet supplemented with anthocyanin-rich extract from black rice, 300 mg/(kg.d)]. After 20 wk of intervention, the plaque area that developed in the brachiocephalic artery of mice in the antho group was smaller than that of the control mice. Both the antho and simva groups had lower frequencies of the large necrotic core and thin fibrous cap in plaques than the control group. Collagen I was increased and matrix metalloproteinase-1 contents were reduced in the brachiocephalic lesion of both the antho and simva groups compared with the control group. Furthermore, mRNA levels of tissue factor and inducible nitric oxide synthase in aortae were decreased in the antho and simva groups. Supplementation of anthocyanin-rich extract improved the lipid profile by decreasing serum triglyceride, total cholesterol, and non-HDL cholesterol. These results suggest that chronic diet intake of anthocyanin-rich extract from black rice may enhance plaque stabilization in old apoE-deficient mice. The underlying mechanism is related mainly to inhibiting proinflammatory factors and improving the serum lipid profile.

An Anthocyanin-Rich Extract from Black Rice Enhances Atherosclerotic Plaque Stabilization in Apolipoprotein E–Deficient Mice

This study was designed to evaluate the effect of an anthocyanin-rich extract from black rice on hyperlipidemia and insulin resistance in fructose-fed rats. Rats fed fructose diet for 4 weeks exhibited significantly higher plasma insulin levels and lower insulin sensitivity than the control rats fed AIN-93G diet. Dietary supplementation with the anthocyanin-rich extract (5 g/kg of high-fructose diet) prevented the development of fructose-induced insulin resistance. After fructose-induced insulin resistance had been established, 4-week treatment with the anthocyanin-rich extract (5 g/kg of high-fructose diet) or pioglitazone (270 mg/kg of high-fructose diet) ameliorated the glucose intolerance and hyperlipidemia, but the extract failed to reverse the fructose-induced hyperinsulinemia as pioglitazone did. In addition, rats supplemented by the extract exhibited lower oxidative stress than the fructose-fed controls, as indicated by the lower concentrations of plasma thiobarbituric acid reactive substances and blood oxidized glutathione. Overall, these results suggest that the anthocyanin-rich extract from black rice improves certain metabolic abnormalities associated with diets high in fructose.

Effect of anthocyanin-rich extract from black rice (Oryza sativa L. indica) on hyperlipidemia and insulin resistance in fructose-fed rats.

Anthocyanins Induce Cholesterol Efflux from Mouse Peritoneal Macrophages THE ROLE OF THE PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR γ-LIVER X RECEPTOR α-ABCA1 PATHWAY

Xiaodong Xia

Papers

An Anthocyanin-Rich Extract from Black Rice Enhances Atherosclerotic Plaque Stabilization in Apolipoprotein E–Deficient Mice

Effect of anthocyanin-rich extract from black rice (Oryza sativa L. indica) on hyperlipidemia and insulin resistance in fructose-fed rats.

Anthocyanins Induce Cholesterol Efflux from Mouse Peritoneal Macrophages THE ROLE OF THE PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR γ-LIVER X RECEPTOR α-ABCA1 PATHWAY