Effect of fat ingestion on postprandial oxidative status in healthy young women: a pilot study.

Reactive oxygen species (ROS) and highly reactive oxygen species (hROS) secreted by leukocytes are crucial to innate immunity; however, they pose a risk of oxidative stress. To monitor their balance in daily health check-ups, optical technologies for the simultaneous measurement of ROS (superoxide radicals) and hROS (hypochlorite ions) that utilize only a few microliters of whole blood have been developed. The aim of this study was to clarify whether this system could assess the effects of fat ingestion on postprandial oxidative status. Eight healthy young Japanese women ingested a beverage containing oral fat tolerance test cream. Blood samples were collected before and 0.5, 1, 2, 4, and 6 h after fat ingestion. Blood ROS and hROS levels, oxidative stress markers, and biochemical markers were monitored. Consistent with previous studies, triglyceride levels significantly increased at 4 h (p<0.01) and returned to near-baseline levels 6 h after ingestion. ROS levels peaked significantly at 2 h (p<0.05), and hROS levels peaked significantly at 1 (p<0.05) and 2 h (p<0.01) after ingestion. This study offers an insight into the acute effects of fat ingestion on leukocyte activity and provides a methodology for monitoring postprandial oxidative status.

Comparison of the oxidative profiles before and after revascularization in peripheral arterial disease: a pilot study.

Reactive and highly reactive oxygen species (ROS and hROS) produced by white blood cells are essential for innate immunity; however, they may cause oxidative stress in the host. We developed systems for simultaneously monitoring ROS and hROS, i.e., superoxide radicals (O2•-) and hypochlorite ions (OCl-) secreted from stimulated white blood cells in a few microliters of whole blood. We previously reported on the evaluation of healthy volunteers' blood using the developed system; however, whether patients' blood can be assessed remains unclear. Here, we report a pilot study of 30 cases (28 patients) with peripheral arterial disease, in whom we measured the ROS and hROS levels before and approximately one month after endovascular treatment (EVT) using the system (CFL-H2200) that we developed. At approximately the same time points, physiological indices of blood vessels, oxidative stress markers, and standard clinical parameters in the blood were also monitored. The ankle-brachial index, a diagnostic tool for peripheral arterial disease, was significantly improved after EVT (p<0.001). The ROS-hROS ratio, low-density lipoprotein cholesterol, and hematocrit levels were decreased after EVT (p<0.05), while triglyceride and lymphocyte levels were increased after EVT (p<0.05). The correlations between the study parameters were also analyzed.

A novel quinone derived from 5-hydroxyindoleacetic acid reacts with protein: Possible participation of oxidation of serotonin and its metabolite in the development of atherosclerosis.

The modification of 5-hydroxyindoleacetic acid (5HIAA) by myeloperoxidase with a xanthine oxidase system was investigated by chromatographic analyses. Two major products were identified as a dimer and quinone (indoleacetate dione) of 5HIAA. The formation of a quinone moiety was also confirmed by chemical trapping with o-phenylenediamine. In the presence of N-acetyl-cysteine (NAC), a quinone-NAC adduct was formed. When glyceraldehyde 3-phosphate dehydrogenase was exposed to the myeloperoxidase system with 5HIAA, quinone adducts were formed on the protein molecule. A monoclonal antibody was prepared using a quinone-modified protein as an immunogen to immunochemically detect the quinone on a protein. The established antibody recognized the quinone-NAC adduct, quinone-modified poly-L-lysine, and quinone-modified low-density lipoprotein. Quinone-modified proteins in human atherosclerotic lesions were immunohistochemically observed using the established antibody to the quinone and also a monoclonal antibody to tryptamine dione-modified protein, suggesting an occurrence of in vivo oxidation of serotonin and 5HIAA, accompanied by covalent adduction to biomolecules.

Effects of Aerobic Exercise on Postprandial Carbohydrate and Lipoprotein Metabolism Following Cookie Ingestion in Healthy Young Women.

We examined the acute effects of postprandial aerobic exercise on glucose and lipid metabolism following cookie ingestion. Fifteen healthy young women with a sedentary lifestyle, normal weight and apolipoprotein E3/3 participated. After a 12-h overnight fast, each subject ingested a cookie (1.53 g/kg, Meal Test C) and then performed two trials, one with postprandial exercise (E trial) and one without exercise (C trial), in a randomized crossover design. A single 30-min bout of walking exercise was performed 20 min after the cookie intake. Venous blood samples were drawn before (0 h) and 20 min and 1, 2, 4, and 6 h after cookie ingestion. The Δglucose concentration was not significantly different between the two trials, but the Δinsulin concentration at 1 h and the incremental area under the curve (IAUC) (0-2 h)-insulin in the E trial were significantly lower than in the C trial. The ratio of glucose/insulin at 1 h was significantly higher in the E trial than in the C trial. The ΔTG, ΔRLP-TG, ΔapoB48 and ΔRemL-C concentrations at 1 h in the E trial were significantly higher than in the C trial. The IAUC (0-2 h)-apoB48 in the E trial was significantly larger than in the C trial. Postprandial exercise showed an insulin-sparing effect following the cookie ingestion by increasing insulin sensitivity. However, postprandial exercise transiently stimulated the secretion of exogenous apoB48-containing lipoprotein during the early period, and no further effects were observed. These results suggest that postprandial aerobic exercise is effective for the promotion of postprandial carbohydrate metabolism, but not lipidemia.

The Ingestion of a Fructose-Containing Beverage Combined with Fat Cream Exacerbates Postprandial Lipidemia in Young Healthy Women.

AIM: To investigate the acute effects of the ingestion of a fructose-containing beverage combinedwith fat on postprandial lipoprotein metabolism. METHODS: Twelve young healthy Japanese women with apolipoprotein E phenotype 3/3 were enrolled in this study. At each of four sessions, the subjects ingested one of four sugar beverages containing fructose and/or glucose (total: 0.5g/kg body weight) combined with OFTT cream (1g/kg, 0.35g/kg as fat) in a randomized crossover design. The four sugar beverages were as follows: 100% (w/w) fructose (F100), 90% fructose+10% glucose (F90G10), 55% fructose+45% glucose (F55G45) and 100% glucose (G100). Venous blood samples were obtained at baseline and 0.5, one, two, four and six hours after ingestion. RESULTS: The serum concentrations of TG in the F100, F90G10 and F55G45 trials were significantlyhigher than each fasting value at two and four hours, and returned to baseline at six hours, except inthe F100 trial. The concentrations at four hours and the incremental areas under the curve for thehepatic triglyceride-rich lipoprotein-triglyceride (VLDL-TG(TM)) levels in the F100 and F90G10 trialswere significantly higher and larger, respectively, than those observed in the G100 trial. Meanwhile,the concentrations of RLP-TG and apolipoprotein B-48 peaked at two hours in the G100 trial, versusfour hours in the other trials, and did not return to baseline at six hours, except in the G100 trial.At four hours, the ⊿apoB48 tended to be higher in the F100 trial than in the G100 trial. CONCLUSIONS: The ingestion of a high-fructose-containing beverage with fat cream delays the clearance of chylomicron and its remnant derived from the intestine and enhances the secretion of triglyceride-rich lipoprotein particles from the liver, thereby inducing postprandial lipidemia, even in young healthy women.

The ingestion of a fructose-containing beverage combined with fat cream exacerbates postprandial lipidemia in young healthy women.

AIM: To investigate the acute effects of the ingestion of a fructose-containing beverage combined with fat on postprandial lipoprotein metabolism. METHODS: Twelve young healthy Japanese women with apolipoprotein E phenotype 3/3 were enrolled in this study. At each of four sessions, the subjects ingested one of four sugar beverages containing fructose and/or glucose (total: 0.5 g/kg body weight) combined with OFTT cream (1 g/kg, 0.35 g/kg as fat) in a randomized crossover design. The four sugar beverages were as follows: 100% (w/w) fructose (F100), 90% fructose + 10% glucose (F90G10), 55% fructose + 45% glucose (F55G45) and 100% glucose (G100). Venous blood samples were obtained at baseline and 0.5, one, two, four and six hours after ingestion. RESULTS: The serum concentrations of TG in the F100, F90G10 and F55G45 trials were significantly higher than each fasting value at two and four hours, and returned to baseline at six hours, except in the F100 trial. The concentrations at four hours and the incremental areas under the curve for the hepatic triglyceride-rich lipoprotein-triglyceride (VLDL-TG(TM)) levels in the F100 and F90G10 trials were significantly higher and larger, respectively, than those observed in the G100 trial. Meanwhile, the concentrations of RLP-TG and apolipoprotein B-48 peaked at two hours in the G100 trial, versus four hours in the other trials, and did not return to baseline at six hours, except in the G100 trial. At four hours, the ⊿apoB48 tended to be higher in the F100 trial than in the G100 trial. CONCLUSIONS: The ingestion of a high-fructose-containing beverage with fat cream delays the clearance of chylomicron and its remnant derived from the intestine and enhances the secretion of triglyceride-rich lipoprotein particles from the liver, thereby inducing postprandial lipidemia, even in young healthy women.

Amide-adducts in atherosclerosis.

Too many hypotheses in the etiology of atherosclerosis have been proposed. Classically, lipid insudation hypothesis by Virchow and thrombogenic hypothesis by Rokitansky are famous. However, in the recent progress in the area of atherosclerosis, the response-to-injury hypothesis by Ross (Ross R Glomset JA, N Engl J Med 295:369-377, 420-425, 1976; Ross R, Arteriosclerosis 1:293-311, 1981; Ross R, N Engl J Med 314:488-500, 1986; Ross R, Nature 362:801-809, 1993; Ross R, N Engl J Med 340:115-126, 1999) has been the leading one. In this review, however, the author focuses to the recent debate on the role of oxidative modification of atherogenic lipoproteins.

Simultaneous ingestion of fructose and fat exacerbates postprandial exogenous lipidemia in young healthy Japanese women.

AIM: To investigate the acute effects of the simultaneous ingestion of fructose and fat on postprandial lipoprotein metabolism in healthy young women. METHODS: Nine young healthy Japanese women with a normal weight (body mass index: 18.5≤-< 25 kg/m(2)), a normal ovarian cycle and an apolipoprotein E 3/3 phenotype were enrolled as participants and studied on four occasions. At each session, the subjects ingested one of four beverages containing either glucose or fructose (0.5 g/kg body weight each) with or without OFTT cream (1 g/kg, 0.35 g/ kg as fat) in a randomized crossover design. Blood samples were collected at baseline and at 0.5, 1, 2, 4 and 6 hours after ingestion. RESULTS: The ingestion of fructose combined with fat led to significantly higher rises in the serum triglyceride (TG), remnant-like particle (RLP)-TG, remnant lipoprotein-cholesterol (RemL-C) and apolipoprotein B-48 (apoB48) concentrations with delayed peaks compared with that observed following ingestion of the other three types of beverages. The incremental area under the curve (ΔAUC)-TG and ΔAUC-apoB48 were larger than those observed for the ingestion of fat only. The serum RLP-TG and apoB48 concentrations returned to the fasting levels (0 hours) at the end of the test (6 hours) following the ingestion of fat only; however, these concentrations did not return to the fasting levels following the intake of fructose combined with fat. CONCLUSIONS: These findings suggest a delay in the clearance of intestinal TG-rich lipoproteins, namely chylomicron and its remnant, following the ingestion of fructose combined with fat. The simultaneous ingestion of fructose and fat markedly enhances postprandial exogenous lipidemia in young healthy Japanese women.

Acute effects of postprandial aerobic exercise on glucose and lipoprotein metabolism in healthy young women.

AIM: To investigate the acute effects of postprandial exercise on glucose and lipoprotein metabolism after the intake of glucose with or without fat cream in healthy but sedentary young women. METHODS: Healthy young Japanese women with a sedentary lifestyle, normal weight (18.5≤BMI<25), normal ovarian cycle, and apolipoprotein (apo) E3/3 were enrolled as participants. They ingested 1 g/kg body weight of glucose only or glucose supplemented with 1 g/kg oral fat tolerance test (OFTT) cream 4 (0.35 g/kg as fat) with or without postprandial walking exercise on a motorized treadmill (ca. 50%V(·)o(2)max for 30 min) 20 min after intake of the beverage. Each subject performed 4 trials in a randomized, cross-over design. Venous blood was drawn before (0 h), and 20 min, 1, 2, 4, and 6 h after ingestion. RESULTS: Postprandial exercise alleviated the sharp rise of serum glucose and insulin, and transiently mitigated the decrease of free fatty acids (FFA) after ingestion of the glucose-only beverage. Although no fat was contained in the glucose beverage, transient apoB48 secretion was observed without the rise of serum triglyceride (TG) and remnant-like particle (RLP)-TG, suggesting that apoB48-containing lipoprotein particles with little TG were released by the exercise. Serum apoB48 concentrations at 6 h had decreased to levels lower than the baseline (0 h, after 12-h overnight fast) with or without exercise, suggesting that the 12-h overnight fast may not have been a 'true' fast. Similarly, postprandial exercise suppressed the sharp rise of serum glucose and insulin, and transiently mitigated the decrease of FFA after the ingestion of glucose with OFTT cream. Postprandial exercise stimulated the transient secretion of apoB48-containing TG-rich lipoproteins (TRL) with a rapid rise of serum apoB48, TG, and RLP-TG; however, the subsequent course of lipemia was not significantly changed. Serum apoB48 and RLP-TG values did not return to the baseline even after 6 h, suggesting that postprandial lipoprotein metabolism was not finished at the end of the experiment. CONCLUSION: Postprandial aerobic exercise alleviated the glycemic peak at 1 h associated with insulin 'sparing'. The effect of exercise on fat metabolism was transient, enhancing the secretion of intestinal TRL at an early phase, but no further significant effects were observed. Postprandial exercise transiently stimulated the secretion of apoB48 after glucose intake without a fat load.

Acute effects of shortly pre- versus postprandial aerobic exercise on postprandial lipoprotein metabolism in healthy but sedentary young women.

AIM: To compare the acute effects of shortly pre- vs. postprandial exercise on postprandial lipid metabolism in healthy but sedentary young Japanese women. METHODS: Healthy young Japanese women with a sedentary lifestyle, normal weight (18.5 ≤ BMI < 25), normal ovarian cycle, and apolipoprotein E3/3 were selected as participants. A single bout of walking exercise was performed 20 min after (Exp. 1) or 50 min before (Exp. 2) the intake of oral fat tolerance test (OFTT) cream (1 g/kg body weight) at about 50% Vo(2)max for 30 min on a motorized treadmill. A control trial without exercise was also performed in each experiment. Each subject performed 2 trials in a randomized, cross-over design. Venous blood samples were drawn before the preprandial exercise (-1 h, Exp. 2 only) [corrected] and before (0 h) and 1, 2, 4 and 6 h after the fat intake for the determination of triglyceride (TG), apolipoprotein B-48 (apoB48), remnant-like particle-TG (RLP-TG), lactate, free fatty acid (FFA), insulin, and glucose. RESULTS: In both experiments, postprandial serum TG concentrations in the exercise group were lower, but not significantly, than those in the control. In Exp. 1, incremental areas under the curve (IAUC) for TG and RLP-TG were slightly, but not significantly, smaller in the postprandial exercise group than the control. The values of apoB48, a marker of the chylomicron particle number, at 2, 4, and 6 h after the fat intake and IAUC for apoB48 were significantly lower in the postprandial exercise group than the control. In Exp. 2, IAUC for TG, RLP-TG, and apoB48 were not significantly different between the two groups. CONCLUSION: The present findings suggest that postprandial, but not preprandial, exercise may reduce the number of chylomicrons and chylomicron remnants and improve exogenous lipoprotein metabolism. Postprandial exercise is more effective for improving postprandial lipoprotein metabolism than preprandial exercise.

Delayed postprandial metabolism of triglyceride-rich lipoproteins in obese young men compared to lean young men.

BACKGROUND: Obesity, especially visceral obesity, has been known to affect lipoprotein metabolism, but it is not clear whether obesity in young, apparently healthy men is associated with postprandial triglyceride-rich lipoprotein (TRL) metabolism. METHODS: Ten young normolipidemic, normoglycemic obese men (20.6 ± 0.5 y, BMI 27.5 ± 1.0 kg/m(2)) and 11 lean healthy men (22.1 ± 0.4 y, 21.2 ± 0.4 kg/m(2)) ingested OFTT cream (1g/kg body weight). Fasting and postprandial blood samples were obtained for up to 6h, and serum lipids and lipoproteins were analyzed. RESULTS: The obese men with a fasting triglyceride (TG) in the normal range and not different from the fasting value of lean controls had a prolonged postprandial response, indicated by a significantly greater incremental areas under the curve in serum TG, TRL-TG, and remnant-like particle-cholesterol (RLP-C) compared with controls. Plasma glucose levels did not change during the test. Differences in serum insulin levels and homeostasis model assessment-insulin resistance (HOMA-IR) were not statistically significant between the two groups; however, trends toward higher levels were shown in obese young men. CONCLUSIONS: The obese young men showed significantly delayed TRL metabolism compared to the lean young men after fat loading, even though the obese men were normolipidemic. These results suggest the possibility that early insulin resistance in the obese young men may have caused the decrease of lipoprotein lipase activity and induced delayed TRL metabolism. A fat loading test without carbohydrate may provide a useful tool for the detection of delayed postprandial TRL metabolism and early insulin resistance.

Chemical and immunochemical identification of propanoyllysine derived from oxidized n-3 polyunsaturated fatty acid.

It is known that n-3 polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid and eicosapentaenoic acid, are rapidly oxidized in vitro. Nvarepsilon-(propanoyl)lysine (propionyllysine, or PRL) is formed from the reaction of the oxidized products of n-3 PUFAs and lysine. To evaluate the oxidized n-3 PUFA-derived protein modifications in vivo, we have developed detection methods using a novel monoclonal antibody against PRL as well as liquid chromatography-mass spectrometry (LC/MS/MS). The antibody obtained specifically recognized PRL. A strong positive staining in atherosclerotic lesions of hypercholesterolemic rabbits was observed. We have also simultaneously identified and quantified both urinary PRL and urinary Nvarepsilon-(hexanoyl)lysine, using LC/MS/MS using isotope dilution methods. The level of urinary PRL (21.6+/-10.6 micromol/mol of creatinine) significantly correlated with the other oxidative stress markers, 8-oxo-deoxyguanosine, dityrosine, and isoprostanes. The increase in the excretion of amide adducts into the urine of diabetic patients was also confirmed compared to healthy subjects. These results suggest that PRL may be good marker for n-3 PUFA-derived oxidative stress in vivo.

Quantification of Modified Tyrosines in Healthy and Diabetic Human Urine using Liquid Chromatography/Tandem Mass Spectrometry.

The quantification of urinary oxidized tyrosines, dityrosine (DiY), nitrotyrosine (NY), bromotyrosine (BrY), and dibromotyrosine (DiBrY), was accomplished by quadruple liquid chromatography-tandem mass spectrometry (LC/MS/MS). The sample was partially purified by solid phase extraction, and was then applied to the LC/MS/MS using multiple-reaction monitoring (MRM) methods. The analysis for the DiY quantification was done first. The residual samples were further butylated with n-butanol/HCl, and the other modified tyrosines were then quantified with isotopic dilution methods. MRM peaks of the modified tyrosines (DiY, NY, BrY, and DiBrY) from human urine were measured and the elution times coincided with the authentic and isotopic standards. The amounts of modified tyrosines in healthy human urine (n = 23) were 8.8 +/- 0.6 (DiY), 1.4 +/- 0.4 (NY), 3.8 +/- 0.3 (BrY), and 0.7 +/- 0.1 (DiBrY) micromol/mol of creatinine, respectively. A comparison of the modified tyrosines with urinary 8-oxo-deoxyguanosine, pentosidine, and N(epsilon)-(hexanoyl)lysine was also performed. Almost all products, except for NY, showed good correlations with each other. The amounts of the modified tyrosines (NY, BrY, and DiBrY) in the diabetic urine were higher than those in the urine from healthy people.

Lemon Polyphenols Suppress Diet-induced Obesity by Up-Regulation of mRNA Levels of the Enzymes Involved in beta-Oxidation in Mouse White Adipose Tissue.

The aim of this study was to investigate the effect of dietary lemon polyphenols on high-fat diet-induced obesity in mice, and on the regulation of the expression of the genes involved in lipid metabolism to elucidate the mechanisms. Mice were divided into three groups and fed either a low fat diet (LF) or a high fat diet (HF) or a high fat diet supplemented with 0.5% w/w lemon polyphenols (LP) extracted from lemon peel for 12 weeks. Body weight gain, fat pad accumulation, the development of hyperlipidemia, hyperglycemia, and insulin resistance were significantly suppressed by lemon polyphenols. Supplementation with lemon polyphenols also significantly up-regulated the mRNA level of the peroxisome proliferator activated receptor-alpha (PPARalpha) compared to the LF and HF groups in the liver. Furthermore, the mRNA level of acyl-CoA oxidase (ACO) was up-regulated in the LP group compared to the LF group, but not HF group in the liver, and was also significantly increased in the epididymal white adipose tissue. Thus, feeding with lemon polyphenols suppressed body weight gain and body fat accumulation by increasing peroxisomal beta-oxidation through up-regulation of the mRNA level of ACO in the liver and white adipose tissue, which was likely mediated via up-regulation of the mRNA levels of PPARalpha.

Immunohistochemical detection of oxidative stress biomarkers, dityrosine and N(epsilon)-(hexanoyl)lysine, and C-reactive protein in rabbit atherosclerotic lesions.

UNLABELLED: Several lines of evidence have demonstrated that C-reactive protein (CRP) is associated with oxidative stress; however, the precise co-localization between CRP and oxidative stress markers in atherosclerotic lesions is not fully established. In this study, we focused on two oxidative stress markers, dityrosine (DY) and N(epsilon)-(hexanoyl)lysine (HEL), which had not previously been investigated in relation to CRP in atherosclerotic lesions. AIM: We investigated the production and localization of DY, HEL, and CRP in early-stage and moderately progressed fatty lesions of cholesterol-fed rabbits by immunohistochemistry using specific monoclonal antibodies to examine the co-localization between CRP and oxidative stress in atherosclerotic lesions. METHODS: Rabbit atherosclerotic specimens were obtained from New Zealand White rabbits fed a diet containing 1.0% cholesterol for 12 weeks. All specimens were fixed in formalin for histological examinations. RESULTS: CRP-positive cells in rabbit early-stage and moderately progressed fatty lesions were detected mostly in the macrophage-derived foam cell-rich areas. Both DY and HEL were also detected in foam cell-rich areas in both lesions, where they were primarily co-localized with CRP-positive cells. CONCLUSION: Our results suggest that the generation of oxidative stress markers, DY and HEL, may be mediated by CRP in atherosclerotic lesions, and that CRP may be associated with oxidative stress in rabbit atherosclerotic lesions.

(-)-Epicatechin gallate accumulates in foamy macrophages in human atherosclerotic aorta: implication in the anti-atherosclerotic actions of tea catechins.

The localization and target sites of tea catechins underlying their biological activity including anti-atherosclerotic activity have not yet been fully understood. To identify the target sites of catechins in vivo, we have developed a novel monoclonal antibody (mAb5A3) specific for (-)-epicatechin-3-gallate (ECg), one of the major tea catechins. The immunoreactive materials with mAb5A3 were detected in the human atherosclerotic lesions but not in the normal aorta, and were specifically localized in the macrophage-derived foam cells. In vitro experiments using macrophage-like cell lines also showed the significant accumulation of ECg in the cells. We also demonstrated that ECg could suppress the gene expression of a scavenger receptor CD36, a key molecule for foam cell formation, in macrophage cells. These results, for the first time, showed the target site of a tea component ECg in the aorta and might provide a mechanism for the anti-atherosclerotic actions of the catechins.

Flavonoids as substrates and inhibitors of myeloperoxidase: molecular actions of aglycone and metabolites.

Myeloperoxidase (MPO), secreted by activated neutrophils and macrophages at the site of inflammation, may be implicated in the oxidation of protein/lipoprotein during the development of cardiovascular diseases. Flavonoids have been suggested to act as antioxidative and anti-inflammatory agents in vivo; however, their molecular actions have not yet been fully understood. In this study, we examined the molecular basis of the inhibitory effects of dietary flavonoids, such as quercetin, and their metabolites on the catalytic reaction of MPO using a combination of biological assays and theoretical calculation studies. Immunohistochemical staining showed that a quercetin metabolite was colocalized with macrophages, MPO, and dityrosine, an MPO-derived oxidation product of tyrosine, in human atherosclerotic aorta. Quercetin and the plasma metabolites inhibited the formation of dityrosine catalyzed by the MPO enzyme and HL-60 cells in a dose-dependent manner. Spectrometric analysis indicated that quercetin might act as a cosubstrate of MPO resulting in the formation of the oxidized quercetin. Quantitative structure-activity relationship studies showed that the inhibitory actions of flavonoids strongly depended not only on radical scavenging activity but also on hydrophobicity (log P). The requirement of a set of hydroxyl groups at the 3, 5, and 4'-positions and C2-C3 double bond was suggested for the inhibitory effect. The binding of quercetin and the metabolites to a hydrophobic region at the entrance to the distal heme pocket of MPO was also proposed by a computer docking simulation. The current study provides the structure-activity relationships for flavonoids as the anti-inflammatory dietary constituents targeting the MPO-derived oxidative reactions in vivo.

Immunochemical detection of flavonoid glycosides: development, specificity, and application of novel monoclonal antibodies.

Flavonoid-rich diets are expected to decrease the risk of cardiovascular diseases. The localization and target sites of flavonoids underlying the protective mechanism in vivo have not been fully investigated because the methods for detection of flavonoids have been limited to chemical analysis such as high-performance liquid chromatography. To further understand the actions of flavonoids in vivo, we developed a novel methodology that immunochemically evaluates flavonoids using specific antibodies. Quercetin-3-glucuronide (Q3GA), a major metabolite in human plasma, was coupled with keyhole limpet hemocyanin. Alternatively, the sugar moiety of quercetin-3-glucoside (Q3G) was succinylated and then coupled with a carrier protein. Using these two immunogens, we finally obtained two monoclonal antibodies, mAb14A2 and mAb11G6, from the immunogen using Q3GA and Q3G, respectively. Competitive enzyme-linked immunosorbent assay showed the unique difference in the specificity between the two similar antibodies: mAb14A2 recognized several quercetin-3-glycosides including Q3G and rutin but mAb11G6 was highly specific to the Q3G structure. The macrophage-derived foam cells in human atherosclerotic lesions were significantly stained with mAb14A2 but scarcely with mAb11G6. These results showed that the anti-flavonoid glycoside antibodies are useful tools for evaluating their localization in tissues and that the specificities strongly depend on the immunogen design for synthesizing the hapten-protein conjugates.

Influence of aging and menopause on postprandial lipoprotein responses in healthy adult women.

AIM: To analyze the influence of menopause and age on postprandial lipoprotein responses in healthy adult women. METHOD: Twenty-seven healthy young and middle-aged pre- and postmenopausal female volunteers aged 21-53 y were enrolled. They ingested OFTT cream(Jomo, Takasaki, Japan). Fasting and postprandial blood samples were obtained for up to 6 h, and serum concentrations of lipoproteins were analyzed. RESULTS: In the postprandial phase, serum triglycerides(TG), remnant-like particle(RLP)-TG(RLP-TG), RLP-cholesterol(RLP-C), and TG-rich lipoprotein-TG(TRL-TG)concentrations in all groups peaked after 2 h. After 4 h, the TG, RLP-C, RLP-TG and TRL-TG concentrations in the young women returned to the fasting concentrations. However, at 6 h, these parameters in the pre- and postmenopausal women had barely returned to the fasting concentrations. CONCLUSION: The present results suggest that:(1)the magnitude of postprandial TG concentrations is dependent on age, but not on menopause;(2)clearance of remnant lipoproteins is delayed with age in pre- and postmenopausal women compared to young women, and(3)menopause is associated with an increase of RLP-C, but may not influence LDL particle size.

Analysis of the factors contributing to serum retinol binding protein and transthyretin levels in Japanese adults.

OBJECTIVE: We examined various factors possibly related to metabolic syndrome, particularly focusing on nutritional assessment proteins such as retinol binding protein (RBP) and transthyretin (TTR), and remnant lipoproteins. MATERIALS AND METHODS: Fasting serum lipid was analyzed in 58 Japanese adult volunteers (33 men and 25 women, 42.5 +/- 10.1 years old). RESULTS: The lipid profiles of the subjects were classified by lipoprotein polyacrylamide gel electrophoretic patterns into Types S (n = 10), A (n = 37), and N (n = 11), according to the method described in Internal Medicine 42: 244, 2003. RBP and TTR were significantly higher in Type N than in Types S and A. In multivariate analysis, RBP was accounted for by remnant-like particle-triglyceride (RLP-TG), interleukin 6, body mass index and low-density lipoprotein (LDL)-cholesterol (adjusted R2 = 0.621). TTR was accounted for by lipoprotein(a), adiponectin and RLP-TG (adjusted R2 = 0.415). Malondialdehyde-LDL was significantly accounted for by LDL-cholesterol and RLP-cholesterol (adjusted R2 = 0.601). Lipoprotein(a) and LDL-cholesterol were independent variables for oxidized LDL antigen (adjusted R2 = 0.620). High-sensitivity C-reactive protein was accounted for by interleukin 6, immunoreactive insulin and oxidized LDL antigen (adjusted R2 = 0.361). Uric acid and body mass index were independent variables for adiponectin (adjusted R2 = 0.429). CONCLUSION: RBP and TTR may be useful as convenient and simple clinical markers of overnutrition and possibly of metabolic syndrome.