Cabbage Core Powder as a New Food Material for Paste Preparation with "Nata Puree".

Cabbage core (CC) is regarded as a waste part of the vegetable, despite being edible and containing various nutritional and functional compounds. We investigated the properties of CC powder with particle sizes < 1 mm as a new food material. CC powder was more resistant to structural deformation than leaf-derived powder, particularly CC powder with particles ≥ 0.3 mm in size. To examine the application of CC powder in 3D printed foods, we investigated the effects of "nata puree," a disintegrated nata de coco made with tamarind seed gum (NPTG), on paste made with CC powder. NPTG promoted stable binding of paste made using CC powder, which was successfully extruded using a syringe to form a bar with a granular structure. Thus, CC powder possesses unique textural/structural properties for its application in next-generation foods.

Organic Acid Analysis in Green Tea Leaves Using High-performance Liquid Chromatography.

Green tea is a popular refreshing drink with several functional properties attributed to its bioactive compounds. The bioactive content and composition vary with several factors. Several advances in chromatographic studies have facilitated the study of chemical composition of green tea leaves; however, the content of organic acids, particularly quinic acid, has not been explored fully. Therefore, changes in the content of organic acids, including quinic acid, in green tea leaves, were investigated in this study. All the studied varieties contained large amounts of quinic and oxalic acids. Kukicha and Matcha contained the highest and lowest amounts of quinic acid, respectively. Furthermore, high-grade Matcha had a significantly lower quinic acid content than low-grade Matcha. The Asatsuyu sample had the lowest quinic acid content in 2018 and 2019 compared with the other green tea varieties. The content of quinic acid increased with maturity, but that of oxalic, malic, succinic, and citric acids decreased after a slight increase. Shading cultivation in Saeakari significantly lowered the quinic acid content and slightly increased the content of malic, citric, and oxalic acids. Malic acid and citric acid content in Yabukita changed with sunrise and sunset, but that of other organic acids did not show any considerable change. These results show that using an appropriate plucking time could lead to further improvement in the quality of green tea leaves. Overall, green tea is a good source of quinic acid, which will attract attention in future functional research on this drink.

Gas chromatographic Analysis of Organic Acids in Japanese Green Tea Leaves.

Herein, gas chromatography is used to determine and quantify organic acids in Japanese green tea leaves, and the established method is employed to profile the acid components of Matcha, Gyokuro, Sencha green teas, and green tea varieties and thus acquire data needed to ensure the high quality and safety of green tea. The tea leaves were esterified with 10 vol% sulfuric acid in 1-butanol at 100℃ for 2 h. Oxalic acid contents were high in Asatsuyu and Okuyutaka samples and were low in Sofu, increasing in the order of Sencha < Gyokuro < Matcha, while citric acid content increased in the order of Sencha < Matcha < Gyokuro. Moreover, the oxalic acid content of Gyokuro only slightly increased with increasing tea grade. The relative contents of the different fatty acids did not strongly vary between the different green tea varieties. However, the n-3 to n-6 ratio was found to be low in Sofu. The progressing maturity increased the n-3 to n-6 ratio of Yabukita. The n-3 to n-6 ratio was low in high-grade Matcha, Gyokuro, Sencha green teas, and was related to the green tea quality. The developed method was concluded to be suitable for the evaluation of green tea quality.

The Inhibitory Effects of Anthocyanin-Rich Sunrouge Tea on Pancreatic Lipase Activity.

This study investigated the in vitro and in vivo effects of Sunrouge (SR), which is an anthocyaninrich green tea. Hot and cold water extracts (CWEX) of Yabukita (YK; regular green tea), SR second crop (SR2), and SR third crop (SR3) were prepared. The 50% inhibitory concentrations for YK, SR2, and SR3 CWEXs against pancreatic lipase in vitro were 12.3±2.8, 6.2±0.3, and 4.0±1.1 mg/mL, respectively. Epigallocatechin gallate (EGCG) accounted for 4.3%, 6.0%, and 6.3% of YK, SR2, and SR3 CWEXs, respectively. SR2 had the highest anthocyanin content of these three samples. In vivo, the increase in the plasma triacylglycerol (TG) concentration following oral administration of oil to mice was significantly suppressed at 60 and 120 min in animals treated with SR2. No significant differences were observed between the plasma TG concentration in the YK and control groups. These results suggested that concomitant administration of SR with oil may suppress lipid absorption and that EGCG may exert this effect.

Relationship between the effect of dietary fat on swimming endurance and energy metabolism in aged mice.

AIM: The aim of this study was to investigate the effect of different dietary fats on alterations in endurance, energy metabolism, and plasma levels of interleukin-6 (IL-6) and minerals in mice. METHOD: Male mice (aged 58 weeks) were fed diets containing 6% safflower oil, fish oil, or lard for 12 weeks. Swimming time to exhaustion, energy metabolism, and plasma IL-6 levels were subsequently determined. RESULTS: Mice fed safflower oil exhibited a marked increase in swimming time compared to the baseline level. Mice fed lard exhibited a significant decrease in swimming time, while mice on a fish oil diet exhibited a small decrease in swimming time. The final swimming time of mice fed safflower oil was significantly longer than that of animals fed lard. This improvement in endurance with dietary safflower oil was accompanied by decreased accumulation of lactate and less glycogen depletion during swimming. In the safflower oil group, muscle carnitine palmitoyltransferase activity increased significantly after swimming, while the plasma non-esterified fatty acid concentration decreased significantly. A trend to increased plasma IL-6 levels was observed in sedentary animals on a safflower oil diet compared to those on a lard diet. CONCLUSIONS: These results suggest that dietary safflower oil improves the swimming endurance of aged mice to a greater extent than lard, and that this effect appears to involve glycogen sparing through increased fatty acid utilization.

The effect of methanol extracts of tsao-ko (Amomum tsao-ko Crevost et Lemaire) on digestive enzyme and antioxidant activity in vitro, and plasma lipids and glucose and liver lipids in mice.

Our previous study showed that tsao-ko intake can lower plasma and liver triacylglycerol (TG) concentrations and has hypoglycemic and antioxidant activity in mice. This study involved separating two major fractions (A and B) from the methanol extracts (MeX) of tsao-ko using silica gel column chromatography, and then determining the effect of the fractions in vivo and in vitro to clarify the most effective components of tsao-ko. An intake of MeX and A fraction statistically significantly reduced body lipids and plasma thiobarbitutic acid reactive substances (TBARS) concentrations compared with the control and inhibited lipase and alpha-glucosidase activities. These reductions were not observed in mice fed the B fraction and these inhibitions of B fraction were mild compared with MeX and A fraction. The plasma and liver TG concentrations of each fraction group did not show significant differences compared with the control. The [M-H](+) and maximum UV absorption of the A fraction were 291 m/z and 279 nm, respectively. The peak of A fraction appeared at a similar time to the epicatechin standard in the LC/MS/MS analysis and the MS/MS spectrum of the A fraction was similar to that of the epicatechin standard. It was concluded that the most effective component of tsao-ko for body lipid reduction and hypoglycemic and antioxidant activity was contained in the polar fraction and the evidence suggested that this component could be epicatechin. However, the strongest TG lowering components of tsao-ko may be methanol insoluble.

A comparative study of the effects of erabu sea snake (Laticauda semifasciata) lipids, green tea extract and conjugated linoleic acid on the swimming endurance of mice.

The aim of this study was to assess the interaction between physical and biochemical parameters in mice fed 1 % sea snake lipids (SSL) and compare these with animals fed diets containing 0.2 % green tea extract (GTE) or 0.5 % conjugated linoleic acid (CLA). The swimming times of the SSL group were significantly increased at Weeks 12 and 16 (p<0.001), and those of the GTE group, at Week 12 (p<0.005), but not those of the control or CLA group, compared with those at Week 0. The increase tended to be significant in the SSL group compared with the control group at Week 12 (p=0.09). Both the SSL and GTE groups had significantly longer swimming times than the CLA group at Weeks 12 and 16 (p<0.001). After 5 minutes of swimming exercise, the SSL group exhibited significantly lower levels of plasma and muscle lactates (p<0.01), and plasma non-esterified fatty acid (NEFA) (p<0.001) than the control group. There were no significant differences in any of plasma glucose, muscle and liver glycogens, muscle lactate dehydrogenase (LDH), carnitine palmitoyltransferase (CPT), or monocarboxylate transporter 1 (MCT1) between SSL and control groups. The results suggest that the intake of 1 % SSL improved endurance more than the intake of 0.2 % GTE or 0.5 % CLA in mice. This action may involve the promotion of lactate oxidation for utilization.

L-lactic acid's improvement of swimming endurance in mice.

The aim of this study was to investigate the effect of L-lactic acid on swimming endurance of mice. Mice (n = 50) were injected intraperitoneally with saline, then with L-lactic acid (either 25 mg/kg or 50 mg/kg body weight), then after 2 days with the same doses of glucose, and after another 2 days again with L-lactic acid at the same doses. Swimming times to exhaustion were determined at 30 min after each injection, in a tank filled with 25 cm of water maintained at 23 degrees C. After another week, mice were given either saline, L-lactic acid, or glucose (25 or 50 mg/kg) dissolved in saline and sacrificed after 30 min for biochemical analyses. The ratios of swimming times of L-lactic acid or glucose injections to saline injection were calculated as an index for endurance changes. Swimming-time ratios for mice injected with L-lactic acid were significantly higher at either dose than for those injected with the corresponding doses of glucose (p < .05). The ratio of swimming time was greater in those given a dose of 50 mg/kg than in those given 25 mg/kg for mice in the L-lactic acid groups (p < .05) but not in the groups given glucose. There were no marked differences in biochemical parameters of plasma and muscle lactate, muscle and liver glycogen, or plasma glucose and nonesterified fatty acid between the L-lactic acid, glucose, and saline injection groups. These results suggest that L-lactic acid can enhance swimming endurance of mice and that this action is dose dependent.

Effect of lipid extracted from tsao-ko (Amomum tsao-ko Crevost et Lemaire) on digestive enzyme activity, antioxidant activity, plasma and liver lipids, and blood glucose levels of mice.

Lipids extracted from tsao-ko were separated into three fractions with silica gel column chromatography and fed to mice (3 mo old) for 90 d to clarify their inhibitory activity on digestive enzyme activity. The diets contained the following: control--no tsao-ko, 0.05% total lipid of tsao-ko (TL), 0.0109% chloroform fraction (CF), 0.0245% acetone fraction (AF), or 0.00365% methanol fraction (MeF). Although CF and AF slightly inhibited the activities of alpha-glucosidase, alpha-amylase, and lipase, intakes of these fractions had little influence on plasma and liver lipid concentrations when compared with the control diet. MeF did not inhibit alpha-glucosidase but had DPPH radical scavenging activity and the mice fed this fraction had the most marked reduction in plasma glucose and TBARS concentrations compared with the other diet groups. These results suggest that the fat-soluble polar components of tsao-ko contain an active component that might be associated with decreased plasma glucose and TBARS concentrations in mice.

Effects of yogurt supplemented with fish oil on plasma lipid and glucose concentrations, and liver lipid contents in mice.

The aim of this study is to clarify the effects of yogurt supplemented with fish oil on plasma lipid and glucose concentrations, and hepatic lipid contents in mice. Male Crlj:CD-1 (ICR) mice were fed five experimental diets for 12 weeks. The experimental diets were as follows: without yogurt and fish oil (control diet); 10% (w/w) yogurt without fish oil [10% FO(-)]; 10% yogurt with fish oil [10% FO(+)]; 30% yogurt without fish oil [30% FO(-)]; 30% yogurt with fish oil [30% FO(+)]. Plasma triacylglycerol concentrations in the 10% FO(+) and 30% FO(-) groups were significantly lower than that in the control diet group (p < 0.05 and p < 0.05, respectively). Plasma total cholesterol and phospholipid concentrations were significantly lower in the 30% FO(+) group than in the control diet group (p < 0.005). Concentrations tended to be lower with supplementation with fish oil. Plasma glucose concentrations in the 10% FO(+) and 30% FO(+) groups were significantly lower than those in the control diet group (p < 0.005 and p < 0.01, respectively). Hepatic triacylglycerol and total cholesterol contents in the 30% FO(+) group were significantly lower than those in the control diet group (p < 0.05 and p < 0.005, respectively). These results suggest that plasma triacylglycerol and glucose concentrations are effectively decreased by supplementation of yogurt with fish oil.

Effects of herring roe on plasma lipid, glucose, insulin and adiponectin levels, and hepatic lipid contents in mice.

We previously reported that lipids extracted from salted herring roe product (Kazunoko), which contains large amounts of cholesterol, phosphatidylcholine and n-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), decreased plasma lipid and glucose concentrations in mice. The aim of this study was to evaluate the effects of Kazunoko containing large amounts of protein on lipid and glucose metabolism in mice. Male Crlj:CD-1 (ICR) mice were fed three experimental diets containing lyophilized Kazunoko for 12 wk. The experimental diets were as follows: without Kazunoko (control diet); 1% Kazunoko (1% Kazunoko diet); and 4% Kazunoko (4% Kazunoko diet). Plasma total cholesterol, phospholipid and glucose concentrations tended to be lower in the 1% and 4% Kazunoko diet groups than in the control diet group. There were significant differences in plasma glucose concentration between the control and 4% Kazunoko diet groups (p<0.05). Plasma adiponectin concentrations in mice fed the 4% Kazunoko diet were also significantly higher than in those fed the control diet (p<0.05), but there were no marked differences in plasma insulin concentration among the three dietary groups. Hepatic total cholesterol and phospholipid contents tended to be lower in the 4% Kazunoko diet group than in control diet group. Plasma and hepatic n-3/n-6 ratios in the 1% Kazunoko diet and 4% Kazunoko diet groups were significantly higher when compared with those of the control diet group (p<0.005 and p<0.0005, respectively). These results suggest that ingestion of Kazunoko influences lipid and glucose metabolism in mice fed the Kazunoko diets, as compared with animals fed the control diet.

Effects of simultaneous intakes of fish oil and green tea extracts on plasma, glucose, insulin, C-peptide, and adiponectin and on liver lipid concentrations in mice fed low- and high-fat diets.

AIMS: The purpose of this study was to clarify the effects of a simultaneous intake of fish oil and green tea extracts (GTE) on plasma lipids, glucose (Glu), insulin, C-peptide, and adiponectin concentrations and on liver lipids in mice fed low- and high-fat diets. METHODS: Male mice (5 months old) were fed low-fat (5%) or high-fat (20%) diets containing 0% (5 or 20% lard), 1% (4 or 19% lard) or 5% (0 or 15% lard) fish oil with or without 1% GTE for 3 months. RESULTS: Single or combined intakes of fish oil and GTE intakes significantly lowered plasma and liver total cholesterol (T-chol) and triacylglycerol (TG) concentrations in mice on high-fat diets. However, a positive effect of GTE alone was not observed in the plasma T-chol and TG concentrations of mice on low-fat diets. Plasma Glu concentrations were significantly lowered by dietary fish oil in mice on the low- and high-fat diets. A tendency of GTE intake to decrease plasma Glu in mice on both the low- and high-fat diets was not significant. An intake of GTE only minimally influenced plasma insulin, C-peptide, and adiponectin concentrations, but fish oil supplementation increased the adiponectin concentration in mice on the low- and high-fat diets. GTE addition to the diets had no adverse effects on reductions by fish oil. CONCLUSION: These results suggest that a simultaneous intake of fish oil and GTE can improve plasma and liver lipid and plasma Glu profiles in mice fed a high-fat diet without any negative interactions of fish oil and GTE.

Levels of plasma insulin, leptin and adiponectin, and activities of key enzymes in carbohydrate metabolism in skeletal muscle and liver in fasted ICR mice fed dietary n-3 polyunsaturated fatty acids.

The aim of this study was to clarify the mechanisms related to plasma glucose concentration in mice fed a diet rich in n-3 polyunsaturated fatty acids (n-3 PUFAs). Male Crlj:CD-1 (ICR) mice were fed experimental diets containing 6% lard (LD), 6% fish oil (FO) or 4.1% lard plus 1.5% docosahexaenoic acid ethyl ester and 0.4% eicosapentaenoic acid ethyl ester (DE) for 12 weeks. There were no marked differences in plasma glucose and insulin concentration changes on glucose tolerance test between the three dietary groups. At the end of the feeding trial, plasma glucose concentration was significantly lower in fasted mice in the FO group than in those in the LD group (P<.005). Plasma adiponectin concentration was significantly higher in the FO group than in the LD group (P<.05). Hexokinase, phosphofructokinase, glucose-6-phosphate dehydrogenase and glycerophosphate dehydrogenase activities in skeletal muscle tended to be lower in the FO group than in the LD group, while there were no differences in glucokinase and phosphofructokinase activities in liver between the three dietary groups. However, hepatic glycerophosphate dehydrogenase activity was 53-fold and 4.2-fold higher in the FO group than in the LD and DE groups, respectively (P<.0005 and P<.05, respectively). These results suggest that the reduction in plasma glucose concentration in mice fed n-3 PUFAs is mainly caused by acceleration of glucose uptake and glycerol synthesis in the liver rather than in the skeletal muscle.

Effect of Erabu sea snake (Laticauda semifasciata) lipids on the swimming endurance of mice.

BACKGROUND/AIM: This study was designed to investigate the effect of Erabu sea snake (Laticauda semifasciata) lipids on the swimming endurance of mice. METHOD: Twelve-week-old male Crlj: CD-1 (ICR) mice were fed one of three experimental diets containing 6% lard, fish oil or sea snake lipids for 16 weeks. Swimming exercise was conducted in an acrylic plastic tank filled with 25 cm of water maintained at 23 degrees C. Every 4 weeks, the mice were made to perform swimming exercises with loads attached to their tails, corresponding to approximately 1 or 2% of their body weights. RESULTS: The group fed the sea snake lipid diet exhibited significantly improved swimming endurance compared with the lard diet group (p < 0.05); however, this result was not observed in the fish oil diet group. In the sea snake lipid diet group, plasma and muscle lactates were significantly lower, and plasma glucose and muscle glycogen were significantly higher than in the lard diet group (p < 0.05). CONCLUSION: These results suggest that the intake of sea snake lipids enhanced the swimming endurance of the mice by delaying the accumulation of lactate during swimming exercise.

Effect of docosahexaenoic acid on brain 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity in male ICR mice.

We investigated the influence of docosahexaenoic acid ethyl ester (DHA-EE) on 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity in the brains of adult and aged mice. Male mice (Crlj:CD-1) were fed diets containing 3% lard plus 2% linoleic acid ethyl ester (LA-EE), or 2% DHA-EE, for 3 months. The brain HMG-CoA reductase activity of 8-month-old (adult) mice was not significantly influenced by dietary intake of DHA-EE. However, in 18-month-old (aged) mice, its activity was enhanced with dietary intake of DHA-EE. Brain HMG-CoA reductase activity and brain cholesterol content significantly increased with age. Hepatic HMG-CoA reductase activity and the cholesterol content of both adult and aged mice were reduced in DHA-EE diet groups, compared with LA-EE diet groups. The DHA percentages of brain and liver microsomal fractions increased with the intake of DHA-EE in adult and aged mice. These results suggest that DHA may enhance brain HMG-CoA reductase activity in aged mice.

Effect of Erabu sea snake (Laticauda semifasciata) lipids on the swimming endurance of aged mice.

The effect of Erabu sea snake (Laticauda semifasciata) lipids on the swimming endurance was investigated in aged mice. Fifty three-week-old male Crlj:CD-1 (ICR) mice were fed one of three experimental diets containing either 6% lard, 6% fish oil, or 6% sea snake lipids for 16 wk. The swimming exercise was carried out in an acrylic plastic tank filled with 25 cm of water maintained at 23(o)C. Swimming times to exhaustion were measured with a load of 2% of their body weights attached to the tails of the mice. The swimming times to exhaustion of the group that were fed the sea snake lipid diet tended to be longer than those of the lard diet group, and were significantly improved compared with the fish oil diet group (p<0.05). The plasma and muscle lactate levels were significantly lower in the sea snake lipid diet group than in the lard and fish oil diet groups (p<0.05). The liver glycogen and plasma glucose levels of the sea snake lipid diet group did not differ markedly from those of the lard diet group (p>0.05), and were significantly higher than those of the fish oil diet group (p<0.05). These results suggest that an intake of sea snake lipids but not the fish oil, which is also rich in n-3 polyunsaturated fatty acids (n-3 PUFAs), is useful for improving the swimming endurance of aged mice by attenuating lactate production and/or enhancing lactate clearance during swimming exercise, and the n-3 PUFAs contained in the sea snake lipids did little or nothing for this improved endurance.

Effect of lipids from Erabu sea snake, Laticauda semifasciata, on plasma glucose, insulin, and adipocytokine concentrations of normal and streptozotocin-diabetic mice.

AIMS: To clarify the influence of Erabu sea snake lipid on levels of plasma insulin and adipocyte-derived hormones. METHODS: Normal male mice (6 months) and streptozotocin-diabetic mice (a single administration, 150 mg/kg i.p.) were fed diets containing 10% fat as either lard or a mixture of 5% lard and 5% sea snake lipid for 4 months. RESULTS: The normal mice on the sea snake lipid diet had a significantly lower plasma glucose concentration (198 +/- 16 mg/dl; 148 +/- 11 mg/dl) than those mice on the lard diet. Although plasma insulin concentrations were not influenced by the dietary fat type, leptin (10 +/- 1 ng/ml; 16 +/- 2 ng/ml) and adiponectin (18 +/- 1 mug/ml; 21 +/- 1 mug/ml) concentrations were significantly higher in the sea snake lipid group than in the lard group. However, these effects of a sea snake lipid intake were not evident in the streptozotocin-diabetic mice. CONCLUSION: The results suggest that the decrease in plasma glucose following the intake of sea snake lipids could be related to a corresponding increase in leptin and adiponectin level.

Reduction in plasma glucose after lipid changes in mice fed fish oil, docosahexaenoic acid, and eicosapentaenoic acid diets.

BACKGROUND/AIM: Effects of the dietary docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and fish oil on weekly changes in plasma glucose, total cholesterol, triacylglycerol, and phospholipid concentrations of male Crlj:CD-1 mice were investigated. METHOD: Animals were fed five different experimental diets which contained 6.0% lard (lard diet), 6.0% fish oil (fish oil diet), 1.5% DHA-ethyl ester+4.5% lard (DHA diet), 0.4% EPA-ethyl ester+5.6% lard (EPA diet), and 1.5% DHA-ethyl ester+0.4% EPA ethyl ester+4.1% lard (DHA+EPA diet) for 17 weeks. Glucose and lipid concentrations in plasma collected at weeks 0, 1, 2, 4, 6, 8, 12, and 16 were measured. RESULTS: Plasma phospholipid concentrations were significantly lower in mice fed the fish oil and DHA+EPA diets than in those fed the lard diet at week 2. Plasma total cholesterol and glucose concentrations were significantly lower in the fish oil diet group than in the lard diet group at weeks 6 and 8, respectively. CONCLUSION: These results indicate that the decreases in plasma glucose concentrations in response to intakes of DHA and EPA in mice take place over a longer period of time than similar decreases in the plasma lipid concentrations.

Effects of dietary herring roe lipids on plasma lipid, glucose, insulin, and adiponectin concentrations in mice.

The aim of this study was to evaluate the effects of dietary Kazunoko (salted herring roe) lipids, which contain large amounts of cholesterol, phosphatidylcholine, and n-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), on lipid and glucose metabolism in mice. Male Crlj:CD-1 (ICR) mice were fed one of four experimental diets which contained 6% lard, 1% Kazunoko lipids + 5% lard, 3% Kazunoko lipids + 3% lard, and 6% Kazunoko lipids for 12 weeks. Plasma total cholesterol, triacylglycerol, phospholipid, and glucose concentrations were significantly lower in the 3% and 6% Kazunoko lipid diet groups than in lard and 1% Kazunoko lipid diet groups (p < 0.05). Plasma adiponectin concentrations of mice fed the 6% Kazunoko lipid diet were higher than those of animals fed the lard diet group. These results suggest that EPA and DHA rather than cholesterol in the Kazunoko lipids influence the plasma total cholesterol level. The constituent Kazunoko lipids may not only decrease the levels of plasma lipids but also decrease glucose concentrations by enhancing plasma adiponectin levels in mice.

Effect of lipids extracted from a salted herring roe food product on maze-behavior in mice.

Male mice (11 mo old) were fed 5% lard, fish oil, or Kazunoko (salted fish roe product) lipids for 4 mo to investigate their effects on maze behavior. The time required and distance traveled to reach the maze exit, and number of times that a mouse strayed into blind alleys in the maze, and the fatty acid compositions of brain lipids after the maze-behavior experiment were measured. The Kazunoko lipid group showed a significant improvement in all three parameters compared with the lard diet group, but the fish oil group showed only a significant decrease in the number of times that a mouse strayed into blind alleys compared with the lard diet group. The mice in the fish oil and Kazunoko lipid groups had significantly lower levels of arachidonic acid and higher percentages of docosahexaenoic acid in brain lipids compared with animals in the lard group. The mice in the Kazunoko lipid group had significantly lower levels of arachidonic acid in brain lipids than those in the fish oil group but the percentages of docosahexaenoic acid were not significantly different between these two diet groups. Our results suggest that an intake of Kazunoko lipids may suppress the percentage of n-6 fatty acids in brain lipids and this diet can be even more effective than fish oil as a supplement to improve learning capacity in mice.