Flavan 3-ols, a type of polyphenolic substance, are distributed in a number of plant foods. Of these foods, chocolate is very rich in flavan 3-ols as flavan 3-ol monomers, (+)-catechin and (−)-epicatechin, and the oligomers as procyanidins. There is evidence that cacao products containing flavan 3-ols have the potential to contribute to the risk reduction of cardiometabolic disorders according to recent epidemiological or intervention studies. This review focuses on recent advances in research on the ability of flavan 3-ols to reduce the risk of cardiovascular disease as a result of improving metabolic syndrome risk factors and these mechanisms.
Several dietary phytochemicals exhibit anti-oxidative, anti-inflammatory and anti-osteoporotic activities relevant to prevention of chronic diseases, including lifestyle-related diseases. Soybean isoflavones are similar in structure to estrogen and have received considerable attention as potential alternatives to hormone replacement therapy. Daidzein, a major isoflavone found in soybean, is metabolized to equol by intestinal microflora; this metabolite exhibits stronger estrogenic activity than daidzein. Recent studies suggest that the clinical effectiveness of isoflavones might be due to their ability to produce equol in the gut. This review focused on the metabolic pathway of equol and possible bioactivities of equol and O-desmethylangolensin, another metabolite of daidzein, with regard to bone metabolism and the status of intestinal microflora. Furthermore, we considered risk-benefit analyses of isoflavones and their metabolites.
Mushrooms are distinguished as important food containing immunomodulating and anticancer agents. These compounds belong mostly to polysaccharides especially β-d-glucans. Among them, β-1,3-glucan with side chain β-1,6-glucose residues have more important roles in immunomodulating and antitumor activities. In this review, we have introduced polysaccharide mainly from Lentinula edodes and Agaricus blazei Murill with immunomodulating and antitumor activities. In addition, the mechanism of activation of immune response and signal cascade are also reviewed.
In the past few decades, many types of functional factors have been identified in dietary foods; for example, flavonoids are major groups widely distributed in the plant kingdom. However, the absorption rates of the functional food factors are usually low, and many of these are difficult to be absorbed in the intact forms because of metabolization by biological processes during absorption. To gain adequate beneficial effects, it is therefore mandatory to know whether functional food factors are absorbed in sufficient quantity, and then reach target organs while maintaining beneficial effects. These are the reasons why the bioavailability of functional food factors has been well investigated using rodent models. Recently, many of the biological processes have been reported to follow diurnal rhythms recurring every 24 h. Therefore, absorption and metabolism of functional food factors influenced by the biological processes may vary with time of day. Consequently, the evaluation of the bioavailability of functional food factors using rodent models should take into consideration the timing of consumption. In this review, we provide a perspective overview of the diurnal rhythm of biological processes involved in the bioavailability of functional food factors, particularly flavonoids.
There is compelling evidence showing that dietary phytochemicals have exhibited pronounced bioactivities in a number of experimental models. In addition, a variety of epidemiological surveys have demonstrated that frequent ingestion of vegetables and fruits, which contain abundant phytochemicals, lowers the risk of onset of some diseases. However, the action mechanisms by which dietary phytochemicals show bioactivity remain to be fully elucidated and a fundamental question is why this class of chemicals has great potential for regulating health. Meanwhile, maintenance and repair of biological proteins by molecular chaperones, such as heat shock proteins, and clearance of abnormal proteins by the ubiquitin-proteasome system and autophagy play central roles in health, some disease prevention, and longevity. Interestingly, several recent studies have revealed that phytochemicals, including curcumin (yellow pigment in turmeric), resveratrol (phytoalexin in grapes), quercetin (general flavonol in onions and others), and isothiocyanates (preferentially present in cruciferous vegetables, such as broccoli and cabbage), are remarkable regulators of protein quality control systems, suggesting that their physiological and biological functions are exerted, at least in part, through activation of such unique mechanisms. This review article highlights recent findings regarding the effects of representative phytochemicals on protein quality control systems and their possible molecular mechanisms.
Lipid peroxidation products are known to cause toxicity by reacting with biologically significant proteins, but the inducing role of peroxidation products has been not noted to produce degenerative disease-related eicosanoids. Here, 9-oxononanoic acid (9-ONA), one of the major products of peroxidized fatty acids, was found to stimulate the activity of phospholipase A2 (PLA2), the key enzyme to initiate arachidonate cascade and eicosanoid production. An exposure of fresh human blood to the atmosphere at 37°C accumulated 9-ONA, increasing peroxide value and thiobarbituric acid reactive substances in the blood. The lipid peroxidation was accompanied by significant increases of PLA2 activity and thromboxane B2 (TxB2) production, which is a stable metabolite of thromboxane A2 (TxA2) and a potent agonist of platelet aggregation. These events were abolished by standing the blood under nitrogen. The addition of organically synthesized 9-ONA resumed the activity of PLA2 and the production of TxB2. Also, 9-ONA induced platelet aggregation dose-dependently. These results indicated that 9-ONA is the primary inducer of PLA2 activity and TxA2 production, and is probably followed by the development of diseases such as thrombus formation. This is the first report to find that a lipid peroxidation product, 9-ONA, stimulates the activity of PLA2.
In this study, to study the effect of aging and Apolipoprotein E (ApoE) deficiency on antioxidant ability in mice, we examined whether lipid peroxidation is promoted by aging in ApoE deficient (ApoE−/−) mice, which have a shorter lifespan than normal mice. The levels of thiobarbituric acid-reactive substances (TBARS), a biomarker of lipid peroxidation, were measured in plasma and liver in ApoE−/− mice aged 12 weeks (young) and 52 weeks (early stage of senescence). TBARS in plasma and liver were significantly increased by aging. Next, we examined the reasons why lipid peroxidation was promoted by aging, based on measurement of protein and mRNA levels for antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) in liver in ApoE−/− mice aged 12 and 52 weeks. The levels of superoxide dismutase 1 and 2 in liver were significantly decreased by aging. The mRNA level of catalase was also significantly decreased and the mRNA levels of superoxide dismutase 1, superoxide dismutase 2 and glutathione peroxidase 1 all showed a tendency to decrease with age. These results suggest that lipid peroxidation is caused by reduction of antioxidant activity with aging and that this promotes senescence and shortens lifespan in ApoE−/− mice.
Hepatocellular carcinoma (HCC) and liver cirrhosis are fatal diseases. This study aimed to investigate survival time and palliative care in terminal HCC and/or liver cirrhosis compared with lung cancer. Between January 2004 and December 2010, we enrolled 116 patients with terminal cirrhosis and/or HCC or lung cancer admitted to a municipal hospital in Japan; 48 had liver cirrhosis, 35 HCC and 33 lung cancer. By retrospective chart review, we evaluated: (i) rate of usage of narcotic analgesics and (ii) survival time from onset of coma (Glasgow Coma Scale less than 8). Time between coma and death was significantly shorter in the liver disease patients (cirrhosis and/or HCC: 7.0 h) than in lung cancer (44.0 h, p = 0.045). Total bilirubin was higher in HCC compared with cirrhosis (p<0.01). Rate of usage of narcotic analgesics was higher in lung cancer (20/33: 60.6%) than in liver disease (17/83: 20.5%, p<0.01); analgesics were used more frequently in HCC than in liver cirrhosis (p<0.01). These results suggest that liver cirrhosis and HCC patients do not always require palliative care and that survival time from onset of coma due to liver disease was not prolonged compared with lung cancer.
The purpose of this study was to investigate the protective effect of polysaccharides from Boschniakia rossica against hepatotoxicity induced by carbon tetrachloride (CCl4). Boschniakia rossica polysaccharides was administered intragastrically once daily for 7 days. One hour after the final treatment, mice were treated intraperitoneally with 80 mg/kg of CCl4. CCl4-induced hepatotoxicity was manifested by increased levels of serum marker enzymes and hepatic lipid peroxidation, and by decreased potential of hepatic antioxidative defense system. CCl4 challenge also resulted in elevated serum tumor necrosis factor-α and hepatic nitric oxide level, and up-regulation of inducible nitric oxide synthase and cyclooxygenase-2 proteins of liver tissue. Pretreatment of mice with Boschniakia rossica polysaccharides reversed these altered parameters of mice with liver injury induced by CCl4. Furthermore, caspase-3 cleavage and activities, and DNA fragmentation of liver in mice treated with Boschniakia rossica polysaccharides were decreased than mice treated with CCl4 alone. Hepatoprotective effect of Boschniakia rossica polysaccharides was further demonstrated by histopathological examination of liver sections. The results indicate that Boschniakia rossica polysaccharides play a protective role in CCl4-induced acute liver injury and the hepatoprotective effect of Boschniakia rossica polysaccharides may be due to elevated antioxidative defense potentials, suppressed inflammatory responses and apoptosis of liver tissue.