We previously reported that persimmon leaf extract inhibits the release of histamine by a basophilic cell line. In this study we examined the effects of persimmon leaf extract on atopic dermatitis in a model mouse strain, NC/Nga. After skin lesions had developed, NC/Nga mice were orally administered a control diet or the control diet plus persimmon leaf extract for four weeks. The severity of skin lesions, serum IgE levels and scratching behavior were then measured. Persimmon leaf extract significantly decreased the severity of these three parameters compared to the control diet. In addition, oral administration of persimmon leaf extract suppressed the passive cutaneous anaphylaxis (PCA) reaction more markedly than tien-cha or perilla extract. These results suggest that persimmon leaf extract exerts an anti-allergic action.

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Compressed bakers' yeast was treated with defatted rice bran extract to enrich it with thiamine. We then prepared bread containing 0.9-2.5mg thiamine per 100g using this thiamine-rich yeast, and fed it at 50g/day for 3 or 4 days to 19 healthy adults to assess the bioavailability of the thiamine. Urinary thiamine excretion and blood thiamine concentration on the final day of the test period were increased significantly in comparison with those on the first day, indicating that thiamine in the test bread was absorbed and had bioavailability. Multiple regression analysis showed that the blood thiamine concentration on the final day of the test period was positively correlated with the blood thiamine concentration on the first day, and the dietary animal protein ratio and mg thiamine intake per 1, 000kcal (4, 200kJ) on the final day of the test period. The urinary thiamine excretion level and blood thiamine concentration on the first day were lower than the reference values in 68% and 21% of the subjects, respectively, indicating that latent vitamin B₁ deficiency might not be rare in Japan.

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Exogenous oxidized cholesterol (OxChol) has deleterious effects on lipid metabolism. We therefore examined the effect of simultaneous consumption of wine polyphenol (WPP) and fish oil containing a high level of docosahexaenoic acid (DHA) in rats fed OxChol. The inhibition of hepatic cholesterol biosynthesis by exogenous OxChol was slightly alleviated by the consumption of both WPP and DHA. The activity of hepatic cholesterol 7α-hydroxylase tended to be higher in rats fed both WPP and DHA than in those fed the control diet without polyphenol containing safflower oil as dietary fat. On the other hand, dietary WPP and DHA lowered hepatic Δ46 desaturase activity compared with that in the control group. Moreover, the level of OxChol excreted in feces was significantly higher in rats fed both WPP and DHA than in those fed the control diet. Thus, the simultaneous consumption of both WPP and DHA seems to alleviate the modulation of lipid metabolism by dietary OxChol, possibly through a combination of both the inhibition of OxChol absorption from the small intestine by WPP and the modulation of lipid metabolism by DHA.

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In the present study, we investigated the effects of intake of lemon juice or citric acid with glucose just after a 1-h exercise bout on concentrations of blood components influenced by exercise. Six healthy male subjects (25-30 years old) participated. After 1h of exercise on a bicycle ergometer, the subjects drank lemon juice (0.4g as citric acid/kg body weight)+glucose (1.5g/kg body weight), citric acid (0.4g/kg body weight) +glucose, or glucose solution alone (control). Blood was taken from the subjects just before exercise, and at 0, 20, 40 and 60min (recovery period) after exercise, for measurement of the concentrations of blood components. Alterations in the concentrations of blood glucose, insulin, ammonia and urea during the recovery period after exercise were not affected by the lemon juice drink or the citric acid drink. The increased blood lactate concentration following exercise decreased gradually during the recovery period, and the rate of the decrease was promoted by the lemon+glucose and the citric acid+glucose drinks compared with the glucose drink. These results demonstrate that lemon juice and citric acid drinks promote removal of blood lactate after exercise.

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Obesity is defined as abnormal deposition of triglyceride in fat cells, due to acceleration of lipogenesis in fat cells relative to the rate of lipolysis. Although both glucose and lipoproteins in blood are used as materials for lipogenesis in fat cells, lipoproteins (chylomicron and VLDL) are more suitable materials than glucose because fat cells are able to incorporate lipoprotein-derived fatty acids without hormonal control. Thus it seems possible that reduction of serum chylomicron might help to protect against obesity caused by a high-fat diet. It was found that chondroitin sulfate, chitin chitosan and/or lactosucrose was decreased in serum chylomicron. Intestinal absorption of dietary fat was reduced by a decrease in hydrolysis of dietary fat due to the inhibitory actions of chondroitin sulfate and chitin chitosan on pancreatic lipase activity, by inhibition of fatty acid absorption due to chondroitin sulfate, and by inhibition of 2-monoglyceride absorption due to lactosucrose. All these functional substances were found to prevent the increases in adipose tissue weight and liver triglyceride level in mice with obesity caused by a high-fat diet.

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Standard reference ranges for all laboratory test values are mandatory. This study was designed to establish a reference standard for vitamin C (ascorbic acid) levels in human plasma, since the normal range has not been determined in the Japanese population. We standardized plasma ascorbic acid levels and compared three different reference methods: HPLC/EC, HPLC/UV, and the ascorbate oxidase procedure. The reference range was obtained in 54 healthy volunteers (female university students) given a diet containing 200mg of vitamin C per day for three days. Total ascorbic acid levels (ascorbic acid plus dehydroascorbic acid) in plasma were determined before and after administration of the test meal for three days by three laboratories using the above procedures. Although no significant differences were observed in mean ascorbic acid levels among the three laboratories, the standard deviations converged after diet control for three days. In subjects who had lower plasma ascorbic acid levels before the test, the levels increased to more than 0.62mg/dL after intake of 200mg ascorbic acid per day for three days. Since plasma ascorbic acid levels exhibit a Gaussian distribution, the mean±2SD ranges for plasma ascorbic acid levels were standardized from 0.70 to 1.38mg/dL by the HPLC/ECD procedure. There were high correlations in the values obtained by the three different methods. The lower reference levels coincided with the value (i.e., more than 0.7mg/dL) cited in the Recommended Dietary Allowances (DRIs) for vitamin C in the Japanese population.

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