Dietary oleic acid intake increases the proportion of type 1 and 2X muscle fibers in mice.

Skeletal muscle is one of the largest metabolic tissues in mammals and is composed of four different types of muscle fibers (types 1, 2A, 2X, and 2B); however, type 2B is absent in humans. Given that slow-twitch fibers are superior to fast-twitch fibers in terms of oxidative metabolism and are rich in mitochondria, shift of muscle fiber types in direction towards slower fiber types improves metabolic disorders and endurance capacity. We previously had reported that oleic acid supplementation increases type 1 fiber formation in C2C12 myotubes; however, its function still remains unclear. This study aimed to determine the effect of oleic acid on the muscle fiber types and endurance capacity. An in vivo mouse model was used, and mice were fed a 10% oleic acid diet for 4 weeks. Two different skeletal muscles, slow soleus muscle with the predominance of slow-twitch fibers and fast extensor digitorum longus (EDL) muscle with the predominance of fast-twitch fibers, were used. We found that dietary oleic acid intake improved running endurance and altered fiber type composition of muscles, the proportion of type 1 and 2X fibers increased in the soleus muscle and type 2X increased in the EDL muscle. The fiber type shift in the EDL muscle was accompanied by an increased muscle TAG content. In addition, blood triacylglycerol (TAG) and non-esterified fatty acid levels decreased during exercise. These changes suggested that lipid utilization as an energy substrate was enhanced by oleic acid. Increased proliferator-activated receptor γ coactivator-1ß protein levels were observed in the EDL muscle, which potentially enhanced the fiber type transitions towards type 2X and muscle TAG content. In conclusion, dietary oleic acid intake improved running endurance with the changes of muscle fiber type shares in mice. This study elucidated a novel functionality of oleic acid in skeletal muscle fiber types. Further studies are required to elucidate the underlying mechanisms. Our findings have the potential to contribute to the field of health and sports science through nutritional approaches, such as the development of supplements aimed at improving muscle function.

Dietary olive oil intake induces female-specific hepatic lipid accumulation without metabolic impairment in mice.

Olive oil is one of the most widely researched Mediterranean diet components in both experimental models and clinical studies. However, the relationship between dietary olive oil intake and liver function in a healthy state of the body remains unclear. Because men are at a greater risk of developing hepatic diseases than women, and because hepatic metabolism is regulated by sex hormones, we hypothesized that olive oil-induced changes in hepatic metabolism would differ by sex. To test our hypothesis, 12-week-old C57BL/6JJcl male and female mice were fed an olive oil diet for 4 weeks. Blood was collected and serum biochemical components were analyzed. Hepatic lipid accumulation was determined via histological analysis using Sudan III staining. Finally, transcript expression levels of hepatic metabolism-related genes were analyzed using quantitative polymerase chain reaction. We observed significant increased hepatic lipid droplet accumulation in olive oil-fed female mice. Serum biochemical and liver messenger RNA expression analyses revealed that the hepatic lipid accumulation was nonpathological and did not involve inflammation. Moreover, the expression of genes related to triacylglycerol and fatty acid synthesis (Dgat1, Dgat2, Agpat3, and Fasn) was significantly upregulated in the liver of olive oil-fed female mice compared with control female mice. Our study demonstrates female-specific hepatic lipid accumulation without liver impairment in a dietary olive oil-fed mouse model. These findings provide a deeper mechanistic understanding of sex-dependent hepatic lipid metabolism of dietary oils.

Edible insect Locusta migratoria shows intestinal protein digestibility and improves plasma and hepatic lipid metabolism in male rats.

Although edible insect migratory locusts are considered sustainable food resources with proteins and n-3 lipids, their physiological effects on lipid metabolism are not clarified. Here, we clarified the amino acid (AA) value of the edible migratory locust powder (MLP), protein digestibility, and dietary effects of MLP on growth and lipid metabolism in rats. The AA score was 63, which was low score due to the limiting AA (Trp). MLP protein digestibility was resistant to gut pepsin but digestible to intestinal trypsin and chymotrypsin. Dietary MLP represented favorable growth and enhanced intestinal condition and lipid metabolism in rats, particularly, low-density lipoprotein metabolism and arteriosclerosis-related fatty acid profiles. Liver triglyceride accumulation and fatty acid desaturation indices were increased by activating lipids uptake into the liver, while lipogenic protein expression and enzyme activities and liver function indices were reduced by MLP. Conclusively, intestinal digestible MLP is a nutraceutical for the prevention of dyslipidemia.

Effect of total hip arthroplasty on improving locomotive syndrome in hip disease patients: A prospective cohort study focused on total clinical decision limits stage 3.

BACKGROUND: In 2020, the Japanese Orthopaedic Association established a new stage 3 in clinical decision limits (CDL) to evaluate the stage of locomotive syndrome (LS). This study focused on total CDL stage 3 with the aim of investigating indicators related to improvements in total CDL by evaluating the improvement of LS in patients who underwent total hip arthroplasty (THA). METHODS: Of the 125 patients who underwent THA at our hospital, the subjects of the analysis were 105 patients determined to be total CDL stage 3 in an evaluation performed before THA. LS was evaluated using the stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale (GLFS-25). Indicators related to improvements in total CDL were also investigated. All evaluation items were measured before THA and three months after THA. RESULTS: Before THA, all subjects (n = 105) were classified as total CDL stage 3. Three months after THA, improvements in total CDL were seen in 49 subjects (46.7%). The results of stepwise multiple logistic regression analysis showed that the before THA stand-up test and GLFS-25 were significantly related to improvements in total CDL. CONCLUSIONS: Three months after THA, improvements in LS were seen in approximately half of the subjects. The stand-up test and GLFS-25 can be used as indicators of improvement in total CDL. DESIGN: Prospective cohort study design.

Dietary Olive Oil Intake Improves Running Endurance with Intramuscular Triacylglycerol Accumulation in Mice.

Olive oil is a functional food shown to have a variety of bioactive effects. Therefore, we expect it to be a novel functional food with an exercise-mimetic effect on skeletal muscles. This study aimed to investigate the effect of olive oil on the endurance capacity and muscle metabolism in mice. Mice fed a 7% (w/w) olive oil diet for eight weeks showed improved treadmill running endurance and increased intramuscular triacylglycerol (IMTG) accumulation in the gastrocnemius muscle compared to soybean oil diet-fed controls. The increase in running endurance with olive oil intake was independent of the muscle fiber type. To elucidate underlying the mechanism of elevated IMTG levels, we examined the expression levels of the genes related to lipid metabolism. We found that the expression of diacylglycerol O-acyltransferase1 (DGAT1) was significantly upregulated in the muscle of olive oil diet-fed mice. In addition, the olive oil diet-fed mice showed no metabolic impairment or differences in growth profiles compared to the controls. These results suggest that dietary olive oil intake affects muscle metabolism and muscle endurance by increasing energy accumulation.

Evaluating the appropriate oral lipid tolerance test model for investigating plasma triglyceride elevation in mice.

The oral lipid tolerance test (OLTT) has been known to assess intestinal fat metabolism and whole-body lipid metabolism, but rodent models for OLTT are not yet established. Differences in OLTT methodology preclude the generation of definitive results, which may cause some confusion about the anti-hypertriglyceridemia effects of the test materials. To standardize and generate more appropriate methodology for the OLTT, we examined the effects of mice strain, dietary lipid sources, fasting period, and gender on lipid-induced hypertriglyceridemia in mice. First, lipid-induced hypertriglyceridemia was more strongly observed in male ddY mice than in C57BL/6N or ICR mice. Second, the administration of olive and soybean oils remarkably represented lipid-induced hypertriglyceridemia. Third, fasting period before the OLTT largely affected the plasma triglyceride elevation. Fasting for 12 h, but less than 48 h, provoked lipid-induced hypertriglyceridemia. Fourth, we explored the suppressive effects of epigallocatechin gallate (EGCG), a green tea polyphenol, on lipid-induced hypertriglyceridemia. The administration of 100 mg/kg of EGCG suppressed lipid-induced hypertriglyceridemia and intestinal lipase activity. Fifth, EGCG-induced suppressive effects were observed after lipid-induced hypertriglyceridemia was observed in male mice, but not in female mice. Lastly, lipid-induced hypertriglyceridemia could be more effectively induced in mice fed a high-fat diet for 1 week before the OLTT. These findings indicate that male ddY mice after 12 h fasting displayed marked lipid-induced hypertriglyceridemia in response to soybean oil. Hence, the defined experiment condition may be a more appropriate OLTT model for evaluating lipid-induced hypertriglyceridemia.

Nutritional and safety evaluation of locust (Caelifera) powder as a novel food material.

Insects are considered edible food resources with sufficient nutrients, but their nutrient composition and safety evaluation have not been fully investigated yet. In this study, we investigated the nutrient composition and the acute and sub-chronic toxicity of locust powder in male rats. In the acute oral toxicological experiment, rats were administered locust powder at a dose of 10 or 20 g/kg/dose, followed by monitoring general signs of toxicity for 14 days. In the sub-chronic toxicological experiments, rats were fed with a diet containing 1% and 3% locust powder for 28 and 90 days. General signs of toxicity, body weight, plasma and blood components, weight and fat accumulation in tissues, and fecal fat excretion were investigated. The locust powder was rich in proteins, essential amino acids, minerals, and polyunsaturated fatty acids. In the acute toxicological experiment, no general signs of acute toxicity were observed at a dose of 20 g/kg. In the sub-chronic toxicological experiments, parameters related to red blood cell were lowered by the 3% locust powder for 28 days, but not for 90 days. Liver lipid accumulation and fecal fat excretion were increased by the 3% locust powder for 90 days, but the liver lipids contents were considered to be within a nontoxic level. Cecum contents and cecum short-chain fatty acids were lowered by the locust powder, which can be caused by its fiber and fiber-like components. In conclusion, acute and sub-chronic intake of locust powder had little effect on general, biochemical, and hematological signs of toxicity in rats. PRACTICAL APPLICATION: Edible insects are increasingly viewed as new sustainable protein sources for human foods and livestock feeds worldwide because of their high nutritional balance, high food conversion rate, and environmental merits. Here, we have clarified that a locust powder contains high levels of protein, polyunsaturated functional fatty acids, and minerals (iron, zinc, and magnesium), and intake of locust powder (3% in diet) had little effects on general, biochemical, and hematological signs of toxicity in male rats. Locust as an edible insect, in powder form, can contribute to human dietary needs.

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.

Camellia japonica Seeds Extract SuppressesLipid-induced Hypertriglyceridemia and Fat Accumulation in Mice.

As the seed extract from Camellia japonica (CJ) contains saponins, inhibitory effects of pancreatic lipase activity and body fat accumulation are expected. To investigate the anti-obesity effect of CJ seed extract, ICR mice were fed with a high-fat diet that was either supplemented or not with 1% CJ seed extract for 53 days. Including CJ seed extract in the high-fat diets of mice increased fecal fat excretion and decreased the body weight gain and lipid parameters in plasma and in the liver. In addition, lipid-induced hypertriglyceridemia was delayed by a single administration of CJ in ddY mice. Small intestinal transit was increased in ddY mice that received the CJ seed extract, but gastric emptying remained unchanged. These data demonstrate that CJ seed extract can suppress excess fat absorption, which can lead to the prevention of diet-induced obesity.

Comparison of Anti-Obesity Effect between Two Types of Syrup Containing Rare Sugars in Wistar Rats.

D-Allulose-containing rare sugar sweeteners have been categorized into two types, rare sugar syrup (RSS), consisting of 4 rare monosaccharides, and modified glucose syrup (MGS), rich in D-allulose, which was previously referred to D-psicose. The anti-obesity effect of RSS and D-allulose has been already clarified, but that of rare monosaccharides other than D-allulose in RSS has not yet been well understood. Here, we investigated and compared the anti-obesity effect of RSS and MGS in rats. Male Wistar rats were divided into 4 dietary groups: a high-sucrose control diet group (S), a high-fructose corn syrup diet group (HFCS), an RSS diet group (RSS), and an MGS diet group (MGS). RSS significantly suppressed abdominal adipose tissue weight and total body fat accumulation in comparison to sucrose. On the other hand, MGS reduced body weight gain, but not abdominal fat accumulation, relative to sucrose. The weight of the liver and kidneys was significantly higher in the RSS and MGS groups than in the S and HFCS groups, but serum biochemical parameters and hepatic lipids contents were not significantly different among the groups. The present study shows that two types of D-allulose-containing rare sugar sweeteners can suppress body fat accumulation or weight gain in a different manner and that RSS could be used as more effective sweeteners in place of sucrose and HFCS to maintain healthy body weight.

Egg White Hydrolysate Can Be a Low-Allergenic Food Material to Suppress Ectopic Fat Accumulation in Rats Fed an Equicaloric Diet.

Egg white (EW) is known as a nutritional protein but can induce allergic reactions in humans. We investigated the dietary effects of EW and its hydrolysate (EWH), which contains less allergen, on body fat accumulation in Wistar rats fed an equicaloric high-fat and high-sucrose diet for 8 wk (Exp A). The pair-feeding of EW and equicaloric-feeding of EWH increased fecal fat excretion and suppressed lipid accumulation in the liver and muscles but not in the abdominal adipose tissues, carcass, or total body. Dietary EWH also suppressed the serum glucose level and alkaline phosphatase activity. Further, we showed a higher dispersibility of EW and EWH in physicochemical assay (Exp B). Next, we investigated the suppressive effects of a single administration of EW and EWH on lipid-induced hypertriglyceridemia and small intestinal meal transit in ddY mice (Exp C). However, a single administration of EW or EWH did not suppress the lipid-induced hypertriglyceridemia nor did it delay the rate of small intestinal transit. These findings indicated that dietary EW and EWH reduce hepatic and muscular (ectopic) fat accumulation mainly by suppressing fat absorption and supplying fat to the liver and muscles. Therefore, the low-allergenic EWH can be effective for the prevention of high-fat-diet-induced obesity.

Egg White Hydrolysate Improves Glucose Tolerance in Type-2 Diabetic NSY Mice.

We have previously reported that chicken egg white (EW) and low-allergenic EW hydrolysate (EWH) suppressed ectopic fat accumulation and improved serum glucose and insulin levels. In this study, the dietary effects of EW and EWH on glucose tolerance were investigated in different ways to clarify the effect of EW and EWH on intestinal glucose absorption. Type 2 diabetic Nagoya-Shibata-Yasuda mice were divided into four groups: a low-fat and low-sucrose casein-based diet group (NL); high-fat and high-sucrose (HFS) casein-based diet group (NH); HFS EW-based diet group (NE); and HFS EWH-based diet group (NEH). Mice were fed their respective diets for 8 wk. At the end of the 6th and 7th week, an oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were respectively conducted in experiment A. At the end of the 7th week, an intraperitoneal glucose tolerance test (ipGTT) was conducted in experiment B. In experiment A, the plasma glucose level was suppressed in the NE group during both OGTT and ITT, and suppressed in the NEH group during OGTT, but not during ITT. In experiment B, the plasma glucose level was similarly suppressed in the NEH group during ipGTT, but the suppressive effect was weakened compared to OGTT. Plasma insulin level was lower in the NE and NEH groups in both experiments. Fecal triacylglycerol excretion was increased in the NE and NEH groups in experiment A and liver triacylglycerol content was suppressed in the NE group in experiment B. These findings suggested that in addition to improving fat metabolism, EWH improves glucose tolerance via mechanisms related and unrelated to small intestinal function.

Dietary protein derived from dried bonito fish improves type-2 diabetes mellitus-induced bone frailty in Goto-Kakizaki rats.

Type-2 diabetes mellitus (T2DM) induces bone frailty. Protein and polyunsaturated fatty acids (PUFA) contained in fish can be effective in enhancing bone quality, but the bone developing effect of fish protein containing less PUFA has not been evaluated in young animals with T2DM. We prepared a bonito fish (BF) and defatted BF (DBF) and hypothesized that protein contained in BF and DBF would be effective for mitigating the effects of T2DM-induced bone frailty. We mainly evaluated the effect of dietary BF and DBF on bone and apparent calcium absorption in young Goto-Kakizaki (GK) rats with T2DM. GK rats were divided into 3 groups based on diets (casein, BF, and DBF) and fed with each diet for 6 wk. Wistar rats were fed with the casein diet as a non-T2DM control. Bone mass, bone strength, apparent calcium absorption, and serum biochemical parameters were determined. The dry weight and strength of the femurs were lower in the GK rats than in the Wistar rats fed with the casein diet. Dietary intake of the BF and DBF diets enhanced the maximum load and dry weight of the femurs and suppressed the serum alkaline phosphatase activity although the apparent calcium absorption was lower in the GK rats fed with the BF and DBF diets than in those fed with the casein diet. These parameters were not different between the rats fed with the BF and DBF diets. Our data suggest that protein contained in the BF and DBF diets improved T2DM-induced bone frailty.

Effect of egg white and its hydrolysate on stearoyl-CoA desaturase index and fat accumulation in rat tissues.

We investigated the dietary effects of egg white (EW) and its hydrolysate (EWH) on fat metabolism in rats. Wistar rats were divided into casein, EW and EWH dietary groups, and fed their respective diet for 8 weeks. Dietary EW and EWH decreased food intake, body weight gain and fat accumulation in the carcass, liver, muscles and adipose tissues, but muscle weight was increased. In addition, dietary EW and EWH decreased stearoyl-CoA desaturase (SCD) indices and glucose-6-phosphate dehydrogenase activity of the liver and gastrocnemius muscle. Dietary EW also increased the fecal excretion of triacylglycerol, cholesterol and total bile acids, and decreased the serum levels of triacylglycerol and leptin. The suppressive effects of dietary EW on food intake and body fat accumulation were weakened by dietary EWH. These findings indicate that EW and EWH, especially EW, are effective in reducing body fat accumulation by regulating hepatic and muscular SCD indices.

Increased muscular triglyceride content and hyperglycemia in Goto-Kakizaki rat are decreased by egg white hydrolysate.

We investigated the fat metabolic characteristics in non-obese and diabetic Goto-Kakizaki (GK) rat and the effects of dietary egg white hydrolysate (EWH) on glucose and fat metabolism. Wistar (W) and GK (G) rats were placed into dietary casein (WC and GC) or EWH (WE and GE) group, and fed their respective diet for six weeks. Triglyceride (TG) content and stearoyl-CoA desaturase (SCD) indices in the soleus muscle were higher in the GC group than WC group in parallel with worsening serum glucose metabolic parameters. The glucose metabolic parameters were significantly improved in the GE group. The TG accumulation and SCD indices in the soleus muscle were also significantly lower in the GE group than in the GC group. In conclusion, dietary EWH not only improved glucose metabolism but also reduced both TG accumulation and SCD indices in the soleus muscle of GK rat.

D-psicose increases energy expenditure and decreases body fat accumulation in rats fed a high-sucrose diet.

We investigated the anti-obesity effects of D-psicose by increasing energy expenditure in rats pair-fed the high-sucrose diet (HSD). Wistar rats were divided into two dietary groups: HSD containing 5% cellulose (C) and 5% d-psicose (P). The C dietary group was further subdivided into two groups: rats fed the C diet ad libitum (C-AD) and pair-fed the C diet along with those in the P group (C-PF). Resting energy expenditure during darkness and lipoprotein lipase activity in the soleus muscle were significantly higher in the P group than in the C-PF group. Serum levels of glucose, leptin and adiponectin; glucose-6-phosphate dehydrogenase activities in the liver and perirenal adipose tissue; and body fat accumulation were all significantly lower in the P group than in the C-PF group. The anti-obesity effects of D-psicose could be induced not only by suppressing lipogenic enzyme activity but also by increasing EE in rats.

Pioglitazone-induced increase in the stearoyl-CoA desaturation index and fat accumulation in rat muscles are not related to lipoprotein lipase activity.

Muscular insulin resistance is a characteristic of obesity and type 2 diabetes, but little is known about fatty acid (FA) metabolism in insulin-resistant skeletal muscle. In this study, we investigated the effects of the repeated administration of the PPAR-γ agonist pioglitazone on fat accumulation, FA composition, and stearoyl-CoA desaturase (SCD) index in rat tissues. Seventeen 4-week-old male Wistar rats were divided into control (C, n = 9) and pioglitazone treatment (P, n = 8) groups, and all the rats were fed a high-fat and high-sucrose diet for 8 weeks. Vehicle or pioglitazone (3 mg/kg) was orally administered daily to rats in the C group and P group, respectively. In the eighth week of the test period, an oral glucose tolerance test (OGTT) was performed after 12 h fasting. At the end of the test period, serum, liver, perirenal adipose tissue, and skeletal muscles were removed after 12 h fasting. The fasting serum and plasma glucose concentrations and OGTT glucose and insulin levels were significantly lower, while the serum adiponectin concentration was significantly higher in the P group than in the C group. Pioglitazone administration increased fat accumulation in the various muscle types examined, perirenal adipose tissue, and brown adipose tissue (BAT), but decreased fat accumulation in the liver. Pioglitazone administration increased the SCD indices for the muscles, perirenal adipose tissue, and liver, but not those of BAT. The lipoprotein lipase (LPL) activity of the BAT and perirenal adipose tissue, but not the muscles, was higher in the P group than in the C group. These results indicate that pioglitazone administration improved glucose tolerance and increased fat accumulation and SCD indices in the muscles and adipose tissues of rats. The increased fat accumulation was closely correlated with LPL activity in both adipose tissues, but not in the muscles.

Inhibition by dietary D-psicose of body fat accumulation in adult rats fed a high-sucrose diet.

We investigated the anti-obesity effects of dietary D-psicose on adult rats fed a high-sucrose diet. Wistar rats (16 weeks old) that had previously been fed a high-sucrose diet (HSD) were fed HSD or a high-starch diet (HTD) with or without 5% D-psicose for 8 weeks. The food efficiency, carcass fat percentage, abdominal fat accumulation, and body weight gain were all significantly suppressed by dietary D-psicose.

Effects of dietary trans fatty acids on fat accumulation and metabolic rate in rat.

Dietary intake of high trans-fatty acids (TFAs) is well known to increase the risk of cardiovascular diseases. However, few reports demonstrated definitive relationships between dietary TFAs and obesity. In addition, the difference in the gastrointestinal absorption rate of TFAs containing oil from that of cis-FAs containing oil was not taken into consideration in many rat studies. In experiment A, we investigated the difference in the apparent absorption rate of TFAs containing oil from control oil. Hydrogenated rapeseed oil and a mixture of camellia oil and tristearin (90:10 [w/w]) were used as TFA-containing test oil and control oil, respectively. Ten Wistar rats were divided into the control group or TFA group, and fed the respective diet containing the control oil or the test oil for 1 week. The apparent absorption rates of these oils were measured by fecal fat excretion rate and dietary fat intake. The results showed a significantly lower gastrointestinal apparent absorption rate of the test oil (93.1%) than that of the control oil (96.2%). In consideration of the apparent absorption rate of these dietary oils, the effects of dietary TFAs on body fat accumulation and energy metabolism were investigated in rats. Twenty-eight Wistar rats were divided into the control group or the TFA group. Each group received an isoenergetic diet containing the control oil or the test oil for 8 weeks. Pre- and postprandial metabolic rates were measured between weeks 7 and 8. The test oil-based diet did not significantly influence body weight gain, fat accumulation, and metabolic rate. In contrast, liver weight, hepatic triglyceride content, and serum non-high density lipoprotein (HDL)-cholesterol (CHO)/HDL-CHO ratio were significantly higher in the TFA group than in the control group. In conclusion, these findings suggest that dietary TFAs did not influence body fat accumulation but increased the levels of risk markers of cardiovascular diseases.

Effect of a fermented brown rice extract on the gastrointestinal function in methotrexate-treated rats.

We investigated the protective effect of a hydrous ethanol extract of brown rice fermented with Aspergillus oryzae (ERF) which contained nucleobases and low fiber on the methotrexate (MTX)-induced gastrointestinal damage in rats. The rats were assigned to three groups: control (CON), MTX, and MTX-ERF. The rats in the CON and MTX groups were fed for 4 weeks on a basal diet, and those in the MTX-ERF group were fed on a 9.16% ERF-containing basal diet. The rats in the MTX and MTX-ERF groups were administered with MTX after 3 weeks. The survival rate and incidence rate of diarrhea were monitored over 1 week. On day 4 after the administration, half of the rats in each group were killed, and gastrointestinal samples were collected. Feeding with ERF improved the incidence rate of diarrhea, increased the protein content in small intestinal mucosa, and also apparently improved the survival rate. These results indicate that dietary ERF could protect against MTX-induced gastrointestinal damage.