The present study investigated the quantitative effect of dietary fats and ingestion of alcohol on serum and liver lipids, fatty acid bound to phospholipids and their class distribution of male Wistar rats. The rats in C (control) and A (alcohol) groups were fed a standard laboratory diet, HFC (high fat-control) and HFA (high fat-alcohol) groups were fed a high fat diet (standard diet supplemented with 20g%w/w, sunflower oil: lard mixture 1:1) for 6 wk. Alcohol-treated rats consumed alcohol at the rate of 9g/kgbw/d (15-20% energy). Liver phospholipid (PL) content was decreased, and phospholipid/cholesterol liver molar ratio increased in the alcohol treated rats. The proportion of serum sphingophospholipid (Sph) was significantly lower and proportion of phosphatidylcholin (PC) significantly higher in serum PL in alcohol-treated rats. Phospholipid class distribution was unaffected by alcohol feeding in liver. Significantly lower levels of 16:1n-7 and higher levels of 20:5n-3 and 22:4n-6 in the serum PL were observed in the alcohol-treated rats. The groups on the HF diet increased levels of 20:4n-6, 22:4n-6 and total n-6, polyunsaturated fatty acid (PUFA)and decreased levels of 18:1n-9 and total monounsaturated fatty acids (MUFA)in both liver and serum PL, but n-3 fatty acid increased in serum PL and decreased in liver PL compared to groups on the standard diet. Alcohol fat interaction was evident in MUFA and PUFA/SFA in serum PL and n-6, MUFA, PUPA and polyunsaturated/saturated fatty acid ratios (PUFA/SFA) in liver PL. This study showed that the high fat intake in alcohol-treated rats increased levels of 20:4n-6, 22:4n-6 and 20:4/18:2 ratio, and decreased level of 18:1n-9 in liver and serum phospholipids.
Taurine is reported to increase contractility of skeletal muscle and cardiac myocyte, which can increase exercise performance. The present study aimed to clarify taurine's effect on chronic endurance exercise, especially accumulation of lactic acid (LA), a marker of fatigue and ability of aerobic exercise, and urinary secretion of 3-methylhistidine (3-MH), a marker of muscle breakdown in rats. After exercise blood levels of LA and urinary excretion of 3-MH were significantly increased and this increase was significantly less in those with chronic treatment of taurine. Taurine treatment also significantly decreased fat accumulation and blood levels of cholesterol and triglyceride, which might improve insulin resistance and utilization of fat and glucose. These results indicate taurine treatment is useful for reducing physical fatigue and muscle damage during exercise training in rats, presumably due to antioxidant property and improvement of muscle and cardiac functions by taurine.
Barley, which is high in soluble dietary fiber (particularly β-glucan), is thought to have hypocholesterolemic effects. The present study was performed to further elucidate the hypocholesterolemic actions of waxy barley, and the extent to which they can be attributed to β-glucan. Male Sprague-Dawley rats (n=21) were fed control (fiber-free) diets, diets with the addition of 2.5% refined β-glucan or 30% waxy barley that provides approximately 2.5% β-glucan in the diet for 2 wk. Body weight gain and food efficiency of rats were unaffected by diet. β-glucan or waxy barley decreased serum levels of total cholesterol (p<0.05) by 13.5% or 18.9%, and also decreased LDL-cholesterol 19.4% or 24.3%, respectively. Addition of refined β-glucan or waxy barley to the diet resulted in greater bile acid excretions (p<0.05) compared to the control group. The waxy barley diet up-regulated by 2.3 times and the β-glucan diet by 1.5 times the activity of cholesterol 7α-hydroxylase (CYP7A1). Hepatic CYP7A1 mRNA level paralleled the increases in enzyme activity. The results of this study suggest that the hypocholesterolemic effects of both β-glucan and a waxy barley diet may be due to the enhancement of CYP7A1 expression resulting from increased fecal excretion of bile acids.
The purpose of this experiment was to clarify the effects of nutrients on the gonadal development of male rats kept under constant darkness as a model of disturbed daily rhythm. Protein, methionine, vitamins, minerals and fat were selected as experimental factors, and eight kinds of diets were prepared based on the L8(27) type orthogonal array. Dietary contents of the nutrients were normal (AIN-76 diet) or 1/3 to 1/2 of the normal content. Four-week-old rats (Fischer 344 strain) were kept under constant darkness for 4 wk. Control groups were kept under 12-h light/dark cycle. After 4 wk, the gonadal weights and serum testosterone content were evaluated. The effects of nutrients on gonadal development in rats differed between constant darkness groups (D-groups) and normal lighting groups (N-groups). Among the D-groups, the highest value for testes weight was observed under the normal protein, methionine added, low vitamin, low mineral and normal fat diet. The lowest value for testes weight was observed under the low protein, methionine added, normal vitamin, normal mineral and low fat diet. Among the N-groups, the highest value for testes weight was observed under the normal protein and no methionine diet, and the lowest value was observed under the low protein and no methionine diet. Among the D-groups, the highest value for serum testosterone was observed under the normal protein and low mineral diet. In the N-groups, serum testosterone was not affected by nutritional factors. It became clear that the amounts of protein, methionine, vitamins, minerals, and oil which are necessary for the gonadal development of growing male rats change when kept in constant darkness.
Low selenium status draws much attention because of the possible involvement in the etiology of cardiovascular disease (CVD). Hyperlipidmia or dyslipidemia, a very important risk factor for CVD, occurs frequently in middle-aged Koreans. While selenium deficiency is supposed to aggravate blood lipid profiles, it has been shown that selenium status diminishes with advanced age. However, little is known about the selenium status of Koreans, its age-related change, and its relationship to blood lipid levels. In this study the serum selenium level of females according to age and its association with blood lipid profiles were examined. Serum selenium concentration was determined by the instrumental neutron activation analysis method (INAA) using the HANARO research reactor. The overall proportion of women having selenium deficiency, with less than 80.0μg/L of the selenium concentrations in the serum, was 18.3%. The serum selenium levels in the young-adult, middle-aged and elderly groups were 120.6μg/L, 97.2μgL, and 90.8μg/L, respectively. Biochemical indices derived from serum selenium levels showed that subjects with the lowest tertile of selenium concentration had significantly higher atherogenic index and lower HDL-cholesterol levels compared to those with the highest tertile. However, only the serum HDL-cholesterol level showed the dependency on the selenium status as determined by stepwise analysis in the subjects below the age of 40. It was noted that in the subjects over the age of 40 (pooled middle-aged and elderly), any dependency of serum lipid profiles on the selenium status was not observed. The results of this study indicated that there is a decreasing tendency of selenium levels with age and that selenium status is associated with blood lipid levels only in young-adult females.
To obtain information on the luminal absorption of oyster zinc, the zinc action during an in vitro protease digestion of oysters was examined. More than 90% of the zinc rendered solute at pH 1.3 or 3.0 irrespective of the pepsin digestion. The solute zinc was partially re-precipitated by neutralization, and trypsin digestion did not render the re-precipitated zinc solute. When the pepsin digestion was performed at pH 5.0, the ratio of soluble zinc in trypsin digest decreased. When the trypsin digest was fractionated by Sephadex G-25, the zinc was eluted later than the peptide fragments. These results indicate that the pH of the stomach juice rather than peptides released by the digestion of oyster protein highly contributes to the oyster zinc in the small intestine becoming solute.
In order to inspect the significance of the adsorbing property in the adjuvant activity to enhance IgE production, we immunized BALB/c mice against Kunitz-type soybean trypsin inhibitor (KSTI), the most potent experimental allergen among soybean proteins, associated with Aluminum hydroxide (alum) or DEAE-Sephadex particles. The production of immunoglobulin isotypes was analyzed at the various amounts, 3-3, 000μg per mouse, of the antigen dosages. In our experiments, although alum did not adsorb KSTI significantly, it augmented the total and the antigen-specific IgE without affecting the optimal range of the antigen dosage. On the other hand, alum did not effectively enhance the production of the other immunoglobulin isotypes. The production of immunoglobulin isotypes other than IgE increased dose-dependently on the antigen. These results ensured our previous finding that another protein, ovalbumin, was used as the antigen. We also demonstrated that the adsorption of KSTI by DEAE-Sephadex in the immunizing vehicle resulted in the requirement of more KSTI for accomplishing the equal immunity in BALB/c mice compared to the control. Moreover, we demonstrated that, regardless of the inability to adsorb KSTI, alum exerted its adjuvant activity only when it was co-injected with the antigen. These results showed that some biochemical effect, other than adsorptive activity, to enhance the production of the antigen-specific IgE resides in alum.
Fructooligosaccharides (FOS) reach the large intestine and are fermented into short-chain fatty acids (SCFA), lactate, and carbon dioxide. As the major energy source for the epithelial cells of the large intestine, n-butyrate stimulates the proliferation of cells as well as mineral and water absorption from the lumen. We examined the effect of dietary FOS supplementation on luminal SCFA production and its influence on the morphometrical variables of mucosa of the large intestine in commercially available pigs. Six weaning piglets were used. After 7 d of adaptation, three pigs were given a test diet containing FOS (10%) ad libitum for 10 d. The other three remained on the basal diet and were used as controls. At the end of the experiment, their large intestines were removed, and the cecum, gyri centripetales, gyri centrifugales, and rectum were separated. The contents of each portion were collected and measured for SCFA concentration, pH, and moisture. A micrometer was used to measure the crypt depth. The numbers of epithelial and mitotic cells in the crypt columns were also counted. The concentration of SCFA was significantly higher in piglets fed FOS than in the controls. The concentration of n-butyrate was markedly stimulated by FOS. The number of epithelial, mitotic, and mucin-containing cells was higher in piglets fed FOS than in the controls. Accordingly, the crypt depth was larger in the FOS-fed piglets. The luminal n-butyrate concentration showed a significantly positive correlation with the crypt depth and the number of epithelial, mitotic, and mucin-containing cells.
We investigated the influences of difructose anhydride III (DFAIII), a novel commercially available disaccharide, on sugar metabolism, breath hydrogen and serum acetate in the early stages after ingestion to determine whether DFAIII is an indigestible sugar and to what degree it is fermentable in humans. This study was designed as a randomized controlled single-blind crossover test with 9 healthy subjects, who drink a 200mL water solution containing 10g of DFAIII, lactulose or sucrose following overnight fasting. Blood samples (for analysis of glucose, fructose, insulin, triacylglycerol, free fatty acids, and acetate) were collected at 0, 0.5, 1, 2, 4, 8h after the ingestion and breath samples (for analysis of hydrogen and methane gases) were collected at 1h intervals until 8h after the ingestion. We also interviewed each subject hourly about the incidence and severity of specific abdominal complaints and other symptoms. The results revealed that ingestion of 10g of DFAIII did not change the serum levels of glucose, fructose, and insulin, similarly to the case with lactulose, and no increase in breath hydrogen excretion was comparable to the case with sucrose. The incidence of specific abdominal symptoms tended to be lower after DFAIII ingestion than after lactulose ingestion. It thus turned out that DFAIII was indigestible and low fermentable in the early stages after ingestion.
Vinegar is generally believed to be good for health. A mash consisting of 35% ethanolic extract from bitter melon malt vinegar-water (8 : 50 : 42) was subjected to further acetate fermentation and the resulting vinegar was converted to dried vinegar powder by spray drying after adsorption on dextrin, which was mixed with a commercial rat chow (CRF-1) in the ratio of 1:19 so as to prepare an experimental diet. Male 12-wk old rats of LETO and OLETF strains were fed this experimental diet in parallel with CRF-1(control) and examined for respiratory quotient (RQ) and blood or plasma parameters associated with diabetes mellitus. Administration of the experimental diet increased daily food intake as well as daily energy expenditure in both strains. RQ significantly lessened in the vinegar diet-fed group of LETO strain, which was reflected not only in the increased energy consumption from fat but also in the decreased energy consumption from carbohydrate, while no significant difference was observed between both dietary groups of OLETF strain in this respect. The profiles of diurnal energy expenditure in both dietary groups of LETO strain exerted two peaks before lights-on and lights-off. Nevertheless, there was a clear difference between both dietary groups of OLETF strain; interestingly the reproduction of the two peaks became conspicuous in the vinegar diet-fed group despite the lack of such peaks in the control. As a consequence of blood or plasma inspection, it turned out that there was no change in HbAlc but a significant increase in plasma cholesterol in the vinegar diet-fed OLETF rats. From these results, a long-term administration of bitter melon malt vinegar can be expected to suppress a lowering of energy turnover inherent with aging and thereby improve anorexia rather than to bring about a preventive effect against the manifestation of NIDDM.
An attempt to synthesize 6-hydroxypyridoxine (OPN), hydroxylation on C-6 of pyridoxine (PN) by hydroxyl radical (OH⋅), was conducted. Application of two well-known OH generating reactions, i.e. the Fenton reaction and the Fe2+-EDTA/ascorbate reaction, were unsuccessful, as large amounts of by-products were formed. Although generation of OH by autoxidation of ascorbic acid in the absence of metal ions was slow, by-products were formed in small quantities, and OPN was easily obtained in colorless crystals. Its structure was confirmed by spectral analyses. OPN was comparable to polyphenols such as (+)-cat-echin, rutin and gallic acid in the antioxidative activity against linoleic acid peroxidation, and was an effective DPPH radical scavenger, though the DPPH radical-scavenging activity of OPN was somewhat lower than that of the polyphenols. PN was relatively inactive under the conditions used here, indicating that the introduction of a hydroxyl group on C-6 of PN greatly enhanced both activities.
This study was conducted to assess the body fat content of free-living healthy human subjects taking a health supplement containing 0.4mg capsaicin, 625mg green tea extract (125mg catechins and 50mg caffeine) and 800mg essence of chicken (CGTE). Subjects were advised to maintain their regular dietary habits and routine physical activity throughout study duration. Their body fat content was measured before and throughout the trial duration using a hand-grip body fat monitor. After 2 wk of supplementation with CGTE, the mean body fat percentage of males and female subjects was significantly less than the initial value (p<0.05; t-test). 70.6% of volunteers showed a trend for decreasing body fat content with 4 subjects showing a significant decrease in body fat content over time. The findings suggested that the effects were more prominent in subjects with higher initial body fat content. It was also demonstrated that the resting energy expenditure (REE) of the subjects taking the test samples were significantly increased in groups supplemented with CGTE, compared to placebo group. Thus, the combined thermogenic effect of capsaicin, green tea extract and essence of chicken could translate to a positive clinical effect by reducing approximately 460g of body fat, following 2 wk of supplementation and the application of this natural health supplement for excess fat regulation, should be considered.
Sesamin, a lignan in sesame seeds and sesame seed oil, and capsaicin, the pungent principle of hot red pepper, affect lipid metabolism. Sesamin specifically inhibits 15 desaturase activity in the Mortierella alpina fungus and rat liver microsomes, however, the effects of sesamin and capsaicin on mRNA expressions of Δ6 and Δ5 desaturases are not still clear. In this study, we investigated the effects of sesamin and capsaicin on the desaturation indexes of Δ6 [(γ-linolenic acid+dihomo-γ-linolenic acid)/linolenic acid, (GLA+DGLA)/LA] and Δ5 (arachidonic acid/DGLA, AA/DGLA) and mRNA expressions of Δ6 and Δ5 desaturases in rat primary cultured hepatocytes. To measure the mRNA expressions of Δ6 and Δ5 desaturase, hepatocytes were cultured in the presence of sesamin or capsaicin for 24 h. To investigate the Δ6 or Δ5 desaturation index, hepatocytes were cultured in the presence of LA or DGLA, respectively, with sesamin or capsaicin for 24 h. The fatty acid composition of the cells was measured by GLC. The mRNA expressions of Δ6 and Δ5 desaturases were detected by real time quantitative RT-PCR. Sesamin and capsaicin had no effect on the mRNA expressions of Δ6 and Δ5 desaturases in rat hepatocytes. Capsaicin had no effect on both Δ6 and Δ5 desaturation indexes, either. On the other hand, sesamin significantly reduced the index of Δ5 desaturation but not Δ6 desaturation. These results suggested that sesamin reduced the Δ5 desaturation index without the changing of the Δ5 desaturase mRNA level.
Long-term administration of hesperidin (HES) or glucosyl hesperidin (GHES), a water-soluble analogue of HES, brings about an antihypertensive effect on spontaneously hypertensive rats (SHR). In the present study, we investigated the effects of long-term administration of HES and GHES (corresponding to 30mg/d/kg body weight) on serum lipid concentration and morphology of vasculature. Serum HDL cholesterol increased in both SHR and Wistar-Kyoto rats (WKY) fed a LIES- or GHES-containing diet for 25 wk. Simultaneously, GHES administration reduced the vascular diameter and media-intimal cross-sectional area of the abdominal aorta in SHR. These results suggest that HES as well as GHES improves serum cholesterol composition and that GHES inhibits hypertrophy in vasculature as well.
Antioxidative activity and protective effect against ethanol-induced gastric mucosal damage of potato protein hydrolysate (potato peptides, Po-P) were studied in vitro and in vivo. The Po-P obtained by proteolysis with Amano P and pancreatin inhibited linoleic acid oxidation either by 83% at its coexistent 0.005% in a ferric thiocyanate assay system or by 32% at its coexistent 0.0002% in a β-carotene decolorization assay system. Meanwhile Po-P were orally administered to male Wistar rats at doses of 12.5-100mg/kg of body weight (BW) 30min prior to ethanol injection. Consequently the ethanol-induced gastric damage was significantly reduced in a dose-dependent manner in the Po-P administered rat. The highest effect was observed in the group dosed with 100mg Po-P/kg BW; the inhibition ratio was 69.6%. The extent of antioxidation or protection against ethanolinduced gastritis was quite similar to those of the respective peptides from casein, corn protein and ovalbumin, suggesting that the potato protein hydrolysate could serve as a useful food ingredient in practical eating habits.