Dietary D-Allulose Reduces Body Fat Accumulation in Rats with and without Medium-Chain Triacylglycerol Supplementation.

d-Allulose (d-psicose) is a rare sugar, that contains no calories and exhibits 70% relative sweetness when compared with sucrose. Recently, several studies have demonstrated the anti-obesity effect of d-allulose, mediated by suppressing lipogenesis and increasing energy expenditure. Medium-chain triacylglycerols (MCTs) are lipids formed by 3 medium-chain fatty acids (MCFAs) with 6-12 carbon atoms attached to glycerol. MCTs have been expensively studied to reduce body fat accumulation in rats and humans. The anti-obesity effect of MCTs was not confirmed depending on the nutritional conditions because MCT might promote lipogenesis. In the present study, we examined the effects of simultaneous intake of diets containing low (5%) or high (13%) MCTs, with or without 5% d-allulose, on body fat accumulation in rats (Experiment 1). Furthermore, we assessed the interaction between 5% MCT and 5% d-allulose in the diet (Experiment 2). In Experiment 1, intra-abdominal adipose tissue weight was significantly greater in the high MCT diet groups than in the commercial diet (control) group. d-Allulose significantly decreased weights of intra-abdominal adipose tissue, carcass fat, and total body fat, however, these weights increased as the amount of MCT added increased. In Experiment 2, d-allulose significantly decreased almost all body fat indicators, and these values were not influenced by the presence or absence of MCT addition. The anti-obesity effect of d-allulose was observed with or without dietary MCT, and no synergistic effect was detected between d-allulose and MCT. These results suggest that d-allulose is a beneficial food ingredient in diets aimed at reducing body fat accumulation. However, further research is required on the synergistic effects between d-allulose and MCTs.

Kaempferia parviflora Ethanol Extract, a Peroxisome Proliferator-Activated Receptor γ Ligand-binding Agonist, Improves Glucose Tolerance and Suppresses Fat Accumulation in Diabetic NSY Mice.

This study assessed the effect of Kaempferia parviflora, also known as black ginger (BG), and its ethanol extract (BGE) on peroxisome proliferator-activated receptor (PPAR) γ agonistic activity, glucose tolerance, fat accumulation, and lipids-induced hypertriglyceridemia in mice. PPARγ ligand-binding capacity in vitro and polymethoxy flavone contents were highly observed in organic solvent extracts. In an animal experiment A, male diabetic Nagoya-Shibata-Yasuda mice were divided into five dietary groups and fed each diet for 8 weeks: AIN-93G diet (low-fat [LF] diet), high-fat (HF) diet, HF diet supplemented with 1% BG, HF diet supplemented with 0.19% BGE, and HF diet supplemented with pioglitazone (PPARγ agonist, 3 mg/kg/day) as a PPARγ agonistic positive control. As determined from glucose and insulin tolerance tests, plasma glucose levels were improved in the BG and BGE groups. The BGE extract suppressed fat accumulation in adipose tissues, liver, and muscles without changing the plasma adiponectin level. In an animal experiment B, in order to investigate the effect of BG and BGE on lipid-induced hypertriglyceridemia, male ddY mice were divided into three test groups: control, BG-administered group (500 mg/kg), and BGE-administered group (100 mg/kg). The plasma triacylglycerol level was not different among the groups during the lipids administration test. These results conclude that the BGE extract containing several kinds of polymethoxy flavones showed PPARγ ligand-binding capacity in vitro and prevented obesity and insulin resistance independent of adiponectin secretion in mice. PRACTICAL APPLICATION: Kaempferia parviflora, also known as black ginger (BG), is often used as a folk medicine and a functional food material to prevent metabolic syndrome mainly in Asian regions. Here, we have clarified that ethanol extract from BG (BGE) contains several kinds of polymethoxy flavones to show PPARγ ligand-binding capacity and is an active extract for the improvement of obesity and insulin resistance. The BGE is expected to be applied for functional food materials in health food markets. Also, polymethoxy flavones to show PPARγ ligand-binding capacity can be generally applied as a physiological active compound of functional food supplements.

Dietary D-sorbose decreases serum insulin levels in growing Sprague-Dawley rats.

D-Sorbose is naturally occurring rare sugar. In this study, we examined the effects of dietary D-sorbose in rats. Four-week-old male Sprague-Dawley rats were fed either an AIN-93G-based control diet or a 3% D-sorbose diet for 28 d. Body weight and body fat accumulation were not different between the two diet groups. Dietary supplementation of D-sorbose lowered the serum insulin level (*p<0.05) significantly compared to the control, although the glucose was not changed. In addition, the relative weight of the cecum increased significantly in the D-sorbose group (**p<0.01). These findings suggest that intake of D-sorbose may improve the glucose metabolism by reducing insulin secretion, and D-sorbose can be used as a food ingredient.

Dietary soybean phospholipids increase the oxidative stability of lipids extracted from fish fillets.

We previously reported that the feeding of soybean phospholipids to fish increased the storage stability of n-3 polyunsaturated fatty acids (PUFA)-rich fish fillets. In this study, we examined the storage stability of lipids extracted from fish fed a diet containing soybean phospholipids and fish oil. Rainbow trout were divided into two groups, and were fed an either 2.5% soybean phospholipids (test) or no phospholipids (control) containing diet for 4 weeks. Lipids were extracted from fish fillets after the feeding period, and were subjected to an oxidation test. Lipids extracted from the fillets of fish in the test group exhibited lower values of oxygen absorption than those in the control group, and the degradation of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) was inhibited. Higher percentages of DHA and EPA were bound to phosphatidylcholine and phosphatidylethanolamine in the extracted lipids in the test group than in the control group. These results indicate that the oxidative stability of lipids extracted from fish fed soybean phospholipids is high, and that the higher percentages of DHA and EPA in PC and PE may have resulted in the higher stability of the lipids extracted from fish fillet.

Effects of 4 weeks iron supplementation on haematological and immunological status in elite female soccer players.

The effects of 4 weeks iron supplementation on haematological and immunological status were studied in 25 elite female soccer players aged 20-28 years. The subjects were randomized and assigned to one of the following two groups; subjects given 40 mg/day iron supplementation (S group) or those given placebo (C group). The oral iron supplementation (40 mg elemental iron) was taken in 15 ml solution once a day by the S group, and the C group took a placebo for 4 weeks. Daily energy and protein intakes met the Korean Recommended Dietary Allowances. Blood haemoglobin concentration did not change in the S group, but decreased significantly (P<0.05) in the C group over the 4-week experimental period. Haematocrit, mean cell volume, mean cell haemoglobin and total iron binding capacity decreased significantly, and mean cell haemoglobin concentration increased significantly (P<0.05) in both the S and C groups. Plasma ferritin concentration increased significantly (P<0.05) in the S group, but did not change in the C group. The change of plasma immunological parameters and erythrocyte anti-oxidative enzyme activities were almost the same between the S and C groups. These results suggest that 4 weeks of iron supplementation by elite female soccer players significantly increased body iron stores and inhibited decrease of haemoglobin concentration induced by soccer training.

Effects of voluntary resistance exercise and high-protein snack on bone mass, composition, and strength in rats given glucocorticoid injections.

We examined the effects of a voluntary resistance exercise (climbing) together with high-protein snacks (60% protein) on bone mass and strength in rats given glucocorticoid-injections (2 mg/kg/day) as a model of age-related osteopenia. Fifty-two male Sprague-Dawley rats, 8 weeks age, were assigned to exercise or sedentary groups. These groups were further divided into groups that received no snack, snack during activity or a snack during rest. All groups were meal-fed 7:30-8:30 h and 19:30-20:30 h and the snack was fed 23:30-0:30 h (active) or 11:30-12:30 h (resting). Energy and protein intake were approximately equal in all groups. The exercise groups were allowed to climb a wire-mesh tower cage (phi 20 cm x 200 cm) to drink water from a bottle set at the top. Weight gain during the 8-week experimental period was inhibited by a glucocorticoid-injection. Bone mass and strength were increased by climbing exercise with a high-protein snack, while no effect of snack nor any effect of snack timing was observed. Bone weight, calcium content and protein content were positively correlated to maximum load or structural stiffness. These results suggest that resistance exercise and high-protein supplementation may be a preventive therapy for osteoporosis associated with aging.

Body fat accumulation is greater in rats fed a beef tallow diet than in rats fed a safflower or soybean oil diet.

The effects of dietary fats , consisting of different fatty acids, on body fat accumulation and uncoupling protein (UCP) in interscapular brown adipose tissue were studied in rats. Metabolisable energy in experimental diets based on safflower oil, soybean oil or beef tallow was measured strictly (experiment 1). Male Wistar rats were then meal-fed an isoenergetic diet for 8 weeks (experiment 2). Each group of rats showed the same weight gain during the 8-week experimental period. Carcass fat content was greater in rats fed the beef tallow diet than in those fed the with the safflower or soybean oil diets, whereas the weight of abdominal adipose tissue was the same for all three dietary groups. Gene expression of UCP1 and the UCP content of the interscapular brown adipose tissue was lower in the beef tallow diet group than in the other dietary groups. A negative correlation was observed between carcass fat content and n-6 unsaturated fatty acid content in dietary fats. These results suggest that the greater body fat accumulation in rats fed the beef tallow diet results from lower expression of UCP1 mRNA and lower UCP content in brown adipose tissue. n-6 Polyunsaturated fatty acids may be the most effective fatty acids in limiting body fat.

D-psicose is a rare sugar that provides no energy to growing rats.

D-Psicose (D-ribo-2-hexulose), a C-3 epimer of D-fructose, is present in small quantities in commercial carbohydrate complexes and agricultural products. We have previously reported that D-psicose supplements in diets suppressed hepatic lipogenic enzyme activity The lower fat accumulation in rats fed D-psicose may be due to lower lipogenesis in the liver. The present study examined the energy available in D-psicose for rat growth. Male Wistar rats received 7 g daily of a basal diet to which fixed amounts of sucrose, D-fructose, or D-psicose (0.5-2.0 g) were added for 20 d. Body weight gain and body energy gain increased with increases in sucrose and D-fructose, but not with D-psicose. One gram of sucrose, D-fructose, and D-psicose produced a net energy gain of 2.29, 1.76, and 0.007 kcal, respectively. The efficiency of energy deposition from D-psicose was 0.3% that of sucrose. The energy value of D-psicose was effectively zero. These results suggest that D-psicose is a rare sugar providing zero energy that may be useful in sweeteners for obese people as an aid for weight reduction.