Endothelial dysfunction is now widely recognized as an early marker of cardiovascular disease, making its treatment, or complete avoidance, an emerging, interesting therapeutic target. This study investigated the ability of the highly intriguing amino acid L-arginine to influence endothelial function. Its therapeutic potential is also compared to that of known cardiovascular medications, namely nitroglycerin [a nitric oxide (NO) donor] and enalapril [an angiotensin-converting enzyme (ACE) inhibitor]. Fifty male New Zealand rabbits were included in the study, divided into 5 equal groups: control, hypercholesterolemia (untreated), hypercholesterolemia (+L-arginine), hypercholesterolemia (+enalapril), and hypercholesterolemia (+nitroglycerin). Biochemical investigations included measurement of circulating NOx, malondialdehyde (MDA), and lipid profile markers, as well as dimethylarginine dimethylaminohydrolase (DDAH) and ACE activities. Furthermore, aortic ACE activity and blood platelet aggregation were estimated. A histopathological examination and intimal thickness measurement were also conducted. Compared to the untreated hypercholesterolemic group, all agents were capable of positively influencing MDA levels, platelet aggregation and intimal thickness; however, only the L-arginine group was capable of beneficially and significantly altering both NOx levels and serum and aortic ACE activities. No agents were capable of modulating serum DDAH activity inhibited by hypercholesterolemia. Based on the results of this study, L-arginine appears to be a novel cardio-protective agent, illustrated by its ability to ameliorate the deleterious effects of hypercholesterolemia on endothelial function, in a manner comparable to, and sometimes more potent than, commonly used cardiovascular medications.

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It has not yet been examined whether salivary calcium levels reflect changes in bone mass. The purpose of this study was to investigate the relationship between salivary calcium concentration and differences in bone mineral density due to estrogen deficiency and/or different calcium intake levels in female rats. In Experiment 1, the animals (n=14) were divided into an ovariectomized group (OVX) (n=8, 0.6% calcium diet) and a sham-operated group (Sham) (n=6, 0.6% calcium diet). The bone mineral density (BMD) levels of the tibia and lumbar spine were significantly lower in the OVX group than in the Sham group (p<0.001 and p<0.01, respectively), whereas there was no significant difference in the salivary calcium concentration between the two groups. In Experiment 2, after an ovariectomy operation, the animals (n=42) were randomized into five groups that received 0.01%, 0.1%, 0.6%, 1.2%, and 2.4% calcium diets (n=10, 10, 6, 8, and 8, respectively). The BMD levels of the tibia and lumbar spine were significantly lower in the 0.01% or 0.1% calcium diet intake groups than in the 0.6%, 1.2%, 2.4% calcium diet intake groups (all p<0.001), whereas there were no differences in the salivary calcium concentration among the groups. In conclusion, the salivary calcium level did not change during periods of decreasing BMD and bone strength induced by estrogen deficiency and/or calcium intake restrictions in female rats.

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Declining renal function is commonly observed with age. Obesity induced by a high-fat diet (HFD) may reduce renal function. Korean red ginseng (KRG) has been reported to ameliorate oxidative tissue injury and have an anti-aging effect. This study was designed to investigate whether HFD would accelerate the D-galactose-induced aging process in the rat kidney and to examine the preventive effect of KRG on HFD and D-galactose-induced aging-related renal injury. When rats with D-galactose-induced aging were fed an HFD for 9 wk, enhanced oxidative DNA damage, renal cell apoptosis, protein glycation, and extracellular high mobility group box 1 protein (HMGB1), a signal of tissue damage, were observed in renal glomerular cells and tubular epithelial cells. However, treatment of rats with HFD- plus D-galactose-induced aging with KRG restored all of these renal changes. Our data suggested that a long-term HFD may enhance D-galactose-induced oxidative renal injury in rats and that this age-related renal injury could be suppressed by KRG through the repression of oxidative injury.

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The aim of this study was to evaluate the effect of an infant formula supplemented with short-chain fructooligosaccharides (scFOS) on faecal concentration of bifidobacteria. Sixty-one healthy formula-fed infants participated in this double-blind controlled trial and were randomized to receive either the scFOS-supplemented formula (4 g/L scFOS) or the placebo-supplemented formula (4 g/L maltodextrins) until the age of 4 mo. Stool samples were analyzed for bifidobacteria at enrolment and at the age of 2 and 3 mo and for antipoliovirus IgA at the age of 4 mo. Parents completed a questionnaire to assess digestive tolerance. Change in faecal bifidobacteria after 2 mo were higher with scFOS compared to the placebo. At 4 mo, specific IgA tended to be higher with the scFOS group than with the placebo. Somatic growth and digestive tolerance were similar between groups. This study confirms that scFOS-supplemented formula can increase the concentration of faecal bifidobacteria while being well tolerated.

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To compare incorporations of acetate and glucose in tissue total lipids and triacylglycerols (TAG), incorporations of labeled acetate and glucose in livers and epididymal adipose tissues (adipose tissue) were followed after their intravenous injection in the tail vein of individual rat fed a fat-free or 10% corn oil diet. The incorporation of acetate into total lipids (mostly TAG) in the liver reached maximum 2 h after the injection, while the incorporation of glucose decreased more quickly. Incorporation of glucose into total lipids and TAG was more greatly suppressed by dietary corn oil than that of acetate in the liver. In the adipose tissues, the incorporation of labeled acetate or glucose into total lipids was maximum 2-8 h after the injection, while the incorporation of glucose was very low, especially in rats fed the corn oil diet. Moreover, the time courses for labeled acetate and glucose incorporations into total lipids in the liver were parallel to those in plasma, but opposite to those in adipose tissue. TAG synthesized from acetate and glucose in the liver appeared to be mostly transported to adipose tissue. Thus, it is suggested that as the labeled glucose rapidly decreased in the liver, plasma and adipose tissue, TAG should be less derived from dietary carbohydrate than from dietary fat.

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We have reported that newly diagnosed type 2 diabetes mellitus (DM) patients in Vietnam have a low body mass index (BMI) of around 23 and that the major factor for this is high white rice (WR) intake. Brown rice (BR) is known to be beneficial in the control of blood glucose levels; however, it has the property of unpleasant palatability. Pre-germinated brown rice (PGBR) is slightly germinated by soaking BR in water as this reduces the hardness of BR and makes it easier to eat. This study was designed to evaluate the effect of a 4-mo PGBR administration on various parameters in Vietnamese women aged 45-65 y with impaired glucose tolerance (IGT). Sixty subjects were divided into a WR or PGBR group. For the first 2 wk, WR was replaced by 50% PGBR, then for 2 wk by 75% PGBR and from the second month 100%. Before the beginning of the study and at the end of the study, 1) anthropometric measurements, 2) a nutrition survey for 3 nonconsecutive days by the 24 h recall method and 3) blood biochemical examinations were conducted. Fasting plasma concentrations of glucose and lipids and the obesity-related measurements and blood pressure were favorably improved only in the PGBR diet group. The present results suggest that replacing WR with PGBR for 4 mo may be useful in controlling body weight as well as blood glucose and lipid levels in Vietnamese women with IGT.

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Carbohydrate supplementation is extremely important during prolonged exercise because it maintains blood glucose levels during later stages of exercise. In this study, we examined whether maintaining blood glucose levels by carbohydrate supplementation could be enhanced during long-term exercise by combining this supplementation with alanine and proline, which are gluconeogenic amino acids, and whether such a combination would affect exercise endurance performance. Male C57BL/6J mice were orally administered either maltodextrin (1.25 g/kg) or maltodextrin (1.0 g/kg) with alanine (0.225 g/kg) and proline (0.025 g/kg) 15 min before running for 170 min. Combined supplementation of maltodextrin, alanine, and proline induced higher blood glucose levels than isocaloric maltodextrin alone during the late exercise phase (100-170 min). The hepatic glycogen content of mice administered maltodextrin, alanine, and proline was higher than that of mice ingesting maltodextrin alone 60 min after beginning exercise, but the glycogen content of the gastrocnemius muscle showed no difference. We conducted a treadmill running test to determine the effect of alanine and proline on endurance performance. The test showed that running time to exhaustion of mice that were supplemented with maltodextrin (2.0 g/kg) was longer than that of mice that were supplemented with water alone. Maltodextrin supplementation (1.0 g/kg) with alanine (0.9 g/kg) and proline (0.1 g/kg) further increased running time to exhaustion compared to maltodextrin alone (2.0 g/kg). These results indicate that combined supplementation of carbohydrate, alanine, and proline is effective for maintaining blood glucose and hepatic glycogen levels and increasing endurance performance during long-term exercise in mice.

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It has been suggested that vitamin E alone or combined with other vitamins or minerals can prevent oxidative stress and slow oxidative injury-related diseases, such as cardiovascular disease and cancer. A comprehensive search of PubMed/MEDLINE, EMBASE and the Cochrane Library was performed. Relative risk was used as an effect measure to compare the intervention and control groups. A total of 33 trials were included in the meta-analysis. Neither vitamin E intake alone (RR=1.01; 95% CI, 0.97 to 1.04; p=0.77) nor vitamin E intake combined with other agents (RR=0.97; 95% CI, 0.89 to 1.06; p=0.55) was correlated with all-cause mortality. Subgroup analyses revealed that low-dose vitamin E supplementation combined with other agents is associated with a statistically significant reduction in all-cause mortality (RR=0.92; 95% CI, 0.86 to 0.98; p=0.01), and vitamin E intake combined with other agents is associated with a statistically significant reduction in mortality rates among individuals without probable or confirmed diseases (RR=0.92; 95% CI, 0.86 to 0.99; p=0.02). Neither vitamin E intake alone nor combined with other agents is associated with a reduction in all-cause mortality. But a low dose (<400 IU/d) of vitamin E combined with other agents is correlated with a reduction in all-cause mortality, and vitamin E intake combined with other agents is correlated with a reduction in the mortality rate among individuals without probable or confirmed diseases.

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The effects of inulin with three different degrees of polymerization (DP) on microbial dietary fiber fermentation were compared in an in vitro simulator of the porcine large bowel. The three inulin isolates had a DP of 15 (from chicory grown in Hokkaido, Japan), and 10 and 24 (from Orafti, Belgium), while cellulose was used as a control. The Lactobacillus level in the DP 10 group at 48 h and bifidobacteria levels in the DP 15 and DP 24 groups at 24 and 48 h were significantly higher than in the carbohydrate-free and cellulose groups. The SCFA concentrations in all the inulin groups were significantly higher than in the carbohydrate-free and cellulose groups at 24 and 48 h. Ammonia nitrogen concentrations in all the inulin groups were significantly lower than those in the carbohydrate-free and cellulose groups at 24 and 48 h. The three different inulin types were fermentable by gut microbiota as indicated by substantial increases in SCFA. In particular, inulin DP 15 exhibited a clear potential to be used as a prebiotic with significant increases in Lactobacillus and Bifidobacterium populations, and concomitantly propionate and butyrate productions than cellulose at the early incubation time. There was a negative correlation between SCFA and ammonia nitrogen concentrations. These results indicate DP 15 product has similar potential as a prebiotic to DP 10 or DP 24 product and showed substantial equivalence to DP 10 and DP 24 products.

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Alterations in gut microbiota composition offer insights that may be relevant for several chronic conditions, including obesity. This study aimed to evaluate the effect of (−)-epigallocatechin gallate (EGCG) on the modulation of gut microbiota and biomarkers of colonic fermentation end-products in rats. Rats were fed an assigned diet of either a control diet, a 0.3% (w/w) EGCG diet, or a 0.6% (w/w) EGCG diet for 4 wk. Compared to the control group, the addition of 0.6% EGCG to the diet brought about a significant increase in the starch and protein contents in the feces collected in the fourth week of feeding, but the relative weights of abdominal adipose tissues of rats were inversely suppressed. Host-specific bacterial community composition, as determined by terminal restriction fragment length polymorphism (T-RFLP) patterns for fecal 16S ribosomal RNA, showed a significant response in the reduced occupation of Clostridium spp. and an increased trend of Bacteroides by dietary supplementation with EGCG. The 0.6% EGCG diet also influenced the status of Bifidobacterium and Prevotella to a lesser extent. Interestingly, the cecum of rats fed the 0.6% EGCG diet contained lower levels of acetic and butyric acids, whereas EGCG had little influence on the cecal level of propionic acid. EGCG also reduced the cecal p-cresol concentration in a dose-dependent fashion. In conclusion, dietary EGCG affects the growth of certain species of gut microbiota in rats and is associated with the cecal pattern of short chain fatty acids which could be responsible for regulating energy metabolism in the body.

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