Journal of Nutritional Science and Vitaminology
Online ISSN : 1881-7742
Print ISSN : 0301-4800
ISSN-L : 0301-4800
Volume 53 , Issue 3
Showing 1-16 articles out of 16 articles from the selected issue
Regular Paper
  • Jun IWAMOTO, Azusa SEKI, Tsuyoshi TAKEDA, Harumoto YAMADA, Yoshihiro S ...
    2007 Volume 53 Issue 3 Pages 191-197
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    The beneficial effects of alfacalcidol (ALF) on bone mass, bone formation, and bone resorption have been established in ovariectomized rats. Our previous studies showed that high-dose glucocorticoid (GC) administration (methylprednisolone sodium succinate, 5.0 mg/kg, s.c., 3 times a week) for 4 wk induced cancellous osteopenia without significantly affecting cortical bone mass in Sprague-Dawley rats, and that high-dose GC administration for 8 wk also resulted in cortical osteopenia. The purpose of the present study was to examine the effects of ALF on cancellous and cortical bone mass in GC-treated rats. Forty female Sprague-Dawley rats, 3 mo of age, were randomized by the stratified weight method into four groups of 10 rats each, as follows: age-matched control group (CON); 8-wk GC administration with administration of vehicle during the latter 4 wk of treatment (GC group); 8-wk GC administration with administration of a low dose of ALF (0.08 μg/kg) during the latter 4 wk of treatment (low-dose ALF group); 8-wk administration of GC with administration of a high dose of ALF (0.16 μg/kg) during the latter 4 wk of treatment (high-dose ALF group). The GC (methylprednisolone sodium succinate, 5.0 mg/kg) was administered subcutaneously 3 times a week, and ALF was administered orally 5 times a week. At the end of the experiment, static and dynamic bone histomorphometric analyses were performed on cancellous bone of the proximal tibial metaphysis and cortical bone of the tibial diaphysis. Eight-week GC administration resulted in loss of the cancellous bone volume/total tissue volume (BV/TV) and percent cortical area (Ct Ar) as a result of decreased trabecular bone formation, increased trabecular and endocortical bone resorption, and decreased periosteal bone formation. Low-dose ALF restored the cancellous BV/TV by mildly suppressing bone resorption and restoring bone formation, whereas high-dose ALF increased it beyond the value observed in the age-matched controls by strongly suppressing bone resorption and markedly increasing bone formation. Both low- and high-dose ALF prevented the GC-induced reduction of the percent Ct Ar by increasing periosteal bone formation and suppressing endocortical bone resorption. The effects of ALF on cancellous bone mass, bone formation, and bone resorption were all dose-dependent. The present study showed the beneficial effects of ALF on cancellous and cortical bone mass in GC-treated rats.
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  • Kazuki NUKUI, Yuki MATSUOKA, Toshihiko YAMAGISHI, Hiromi MIYAWAKI, Kiy ...
    2007 Volume 53 Issue 3 Pages 198-206
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    PureSorb-QTM40 (water-soluble type CoQ10 powder, CoQ10 content is 40 w/w%; hereinafter referred to as P40) is reported in the single-dose human and rat studies to have a greater absorption rate and absorbed volume of CoQ10 even taken postprandially, than those of regular CoQ10, which is lipid-soluble and generally taken in the form of soft-gel capsules. Thus, it was anticipated that the serum CoQ10 level might be higher with P40 tablets than with soft-gel capsules, even for the same dose of CoQ10. In the present study, in order to confirm the safety and measure the serum CoQ10 level for the case of an excessive dose of P40, a double-blinded Placebo controlled comparative study was conducted on 46 healthy volunteers and they were randomly divided into two groups. The P40 tablets or placebo were repeatedly taken by the volunteers. As the result of the study, for the group of taking 2,250 mg/d of P40 (that is, 900 mg/d of CoQ10) for 4 consecutive wk, the serum CoQ10 level peaked at 2 wk after the start of intake at 8.79±3.34 μg/mL, and at 4 wk, it was at the level of 8.33±4.04 μg/mL. At 2 wk from withdrawal of intake, the serum CoQ10 level decreased to 1.30±0.49 μg/mL. The serum CoQ10 levels at these three points were significantly higher than those of the first day of intake and the Placebo group, which had no significant change throughout the study. Furthermore, P40 intake did not cause any significant changes in symptoms or clinical laboratory results as assessed by physical, hematological, blood biochemical or urinalysis tests. Physician examinations also did not reveal any abnormalities. These results confirm that P40 is an extremely safe material and it can produce better absorption of CoQ10.
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  • Keisuke HOSOTANI, Masahiro KITAGAWA
    2007 Volume 53 Issue 3 Pages 207-212
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    In this study, a dietary survey for 3 weekdays of young unmarried subjects [workers and students, 159 males and 160 females, ages 18-19 y (17.2%), 20-24 y (56.2%), 25-29 y (18.6%), 30-34 y (6.7%) and 35 y- (1.3%)] was performed. We evaluated the intake of green and yellow vegetables in this survey and determined the carotenoids (β-carotene, α-carotene, lycopene, β-cryptoxanthin, and lutein+zeaxanthin) in 15 kinds of green and yellow vegetables frequently consumed. The carotenoid intake of each subject was calculated from the intake of these vegetables and the amount of carotenoid. Moreover, we studied the intake of protein, fat, and dietary fiber, and investigated its relationship to the intake of vegetables. The mean green and yellow vegetable intake/d in all subjects was 60.5±58.7 g, much lower than the recommended level [120 g/d, (Health Japan 21 by Japanese Ministry of Health, Labour and Welfare)]. The intake of green and yellow vegetables was greater in females than males, and in workers than students. In all subjects, the mean total carotenoid intake/d was 2,852.8±2,354.3 μg. In the total intake of carotenoids, there was no difference between males and females; however, the intake was greater in workers than in students. The intake of β-carotene and α-carotene was greater in males than females. However, the intake of β-cryptoxanthin, lycopene, and lutein+zeaxanthin was greater in females than males. The group with the low green and yellow vegetable intake had not only a low carotenoid intake, but also a low intake of protein, fat, and dietary fiber. Therefore, it was suggested that carotenoid absorption may be affected by a low intake of protein, fat, and dietary fiber.
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  • Yasuko MURAKAMI, Tomoko KOYABU, Aiko KAWASHIMA, Naoko KAKIBUCHI, Takay ...
    2007 Volume 53 Issue 3 Pages 213-218
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    We investigated the effects of zinc supplementation on clinical observations in chronic hepatitis C patients receiving pegylated interferon (PEG-IFN) α-2b plus ribavirin combination therapy. Patients were randomly allocated to receive 150 mg polaprezinc (zinc group, n=11) or no supplement (control group, n=12) daily in addition to PEG-IFN α-2b plus ribavirin therapy and 300 mg vitamin E and 600 mg vitamin C supplementation daily for 48 wk. Among the patients who continued treatment, the serum alanine aminotransferase (ALT) level at 12 wk in the zinc group was significantly lower than that in the control group. All patients in the zinc group (9/9) and 67% (8/12) of the control patients at 24 wk, and all patients in the zinc group (7/7) and 60% (6/10) of the control patients at 48 wk showed a decrease in serum ALT levels to within the normal range (7-44 U/L). HCV RNA disappeared in all patients (7/7) in the zinc group and in 8 of 10 control patients at 48 wk. Polaprezinc supplementation decreased plasma thiobarbituric acid reactive substances and prevented the decrease of polyunsaturated fatty acids of erythrocyte membrane phospholipids. No significant differences were observed in the dosage of medicines or other clinical data during the treatment. These observations indicate that polaprezinc supplementation may have induced some antioxidative functions in the liver which resulted in reduced hepatocyte injury during PEG-IFN α-2b plus ribavirin therapy.
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  • Natsuko SOGABE, Rieko MARUYAMA, Takayuki HOSOI, Masae GOSEKI-SONE
    2007 Volume 53 Issue 3 Pages 219-224
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    Alkaline phosphatase (ALP) hydrolyzes a variety of monophosphate esters into inorganic phosphoric acid and alcohol at a high optimal pH, and is thought to play an important role in phosphate metabolism. Intestinal ALP, located at the brush border of intestinal epithelial cells, is known to be affected by several kinds of nutrients, but little is known about the physiological function of intestinal ALP. Vitamin K is an essential cofactor for the post-translational carboxylation of glutamate residues into gamma-carboxy glutamate (Gla). Recently, novel functions of vitamin K have been clarified, but no data exist on the relation between vitamin K and intestinal ALP. The aim of this study was to examine the effects of both vitamin Ks (K1: phylloquinone, and K2: menaquinone) on ALP activity. Sprague-Dawley rats (6-wk-old) were divided into three groups: a control, phylloquinone (PK: 600 mg/kg diet), or menaquinone-4 (MK-4: 600 mg/kg diet) diet group. After 3 mo of feeding, we measured intestinal ALP activity by dividing it into five segments. In each segment, both PK and MK-4 increased intestinal ALP activity. The levels of intestinal ALP activity in the duodenum and proximal jejunum from the PK group were significantly higher than in the control group (p<0.05). Moreover, the levels of intestinal ALP activity from the proximal jejunum and distal ileum of the intestine in the MK group were significantly higher than in the control group (p<0.05). In this study, we clarified for the first time that both vitamin K1 and K2 as nutritional factors enhance intestinal ALP activity.
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  • Junichi MATSUMOTO, Kazuo ENAMI, Mikiharu DOI, Taro KISHIDA, Kiyoshi EB ...
    2007 Volume 53 Issue 3 Pages 225-231
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    The purpose of this study was to examine whether katsuobushi, smoked-dried bonito (KB), which is a traditional Japanese food, prevents ovarian hormone deficiency-induced hypercholesterolemia. In experiment 1, ovariectomized rats (OVX-rats) were fed a purified diet containing casein or KB. Compared with the casein diet, the KB diet reduced the plasma cholesterol concentration and apparent protein digestibility, and increased the fecal dry weight and fecal bile acid excretion. In experiment 2, OVX-rats were fed one of the following four diets: casein diet containing corn oil or fish oil (CA/CO or CA/FO), or a diet containing the digested or undigested fraction of KB after treatment with microbial protease (KBE or KBR). KBR contains mainly two components: oil and protease-undigested protein of KB origin. In comparison with the CA/CO diet, the KBE diet did not affect the plasma and liver lipids concentrations, apparent protein digestibility nor fecal bile acid excretion. However, the KBR and CA/FO diets reduced the plasma cholesterol and triacylglycerol (TAG) concentrations and the liver total lipid and TAG concentrations, but increased the liver total and esterified cholesterol concentrations. The KBR diet increased fecal bile acid excretion and fecal dry weight, whereas the CA/FO diet did not. Thus, the preventive effect of KB on the ovarian hormone deficiency-associated increase in plasma cholesterol concentration appears to be mediated by an increase in bile acid excretion through a promoted secretion of bile acids by the binding of bile acids to resistant proteins.
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  • Hitomi OKUBO, Satoshi SASAKI, Kentaro MURAKAMI, Mi Kyung KIM, Yoshiko ...
    2007 Volume 53 Issue 3 Pages 232-238
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    Although several nutrients and foods have been suggested to be preventive for constipation, all previous studies have examined a single nutrient or food in each analysis. In contrast, analysis of dietary patterns may provide new insights into the influence of diet on functional constipation. We conducted a cross-sectional examination of the association between dietary pattern and functional constipation in 3,770 Japanese female dietetic course students aged 18-20 y from 53 institutions in Japan. Diet was assessed with a validated self-administered diet history questionnaire with 148 food items, from which 30 food groups were created and entered into a factor analysis. Functional constipation was defined using the Rome I criteria, which has previously been used in several epidemiologic studies on constipation. The prevalence of functional constipation was 26.0% (n=979). Four dietary patterns were identified: 1) “Healthy,” 2) “Japanese traditional,” 3) “Western,” and 4) “Coffee and dairy products.” After adjustment for several confounding factors, the “Japanese traditional” pattern, characterized by a high intake of rice, miso soup, and soy products and a low intake of bread and confectionaries, was associated with a significantly lower prevalence of functional constipation. In comparison with the lowest quintile, the multivariate adjusted odds ratio (95% confidence interval) was 0.52 (0.41-0.66) in the highest quintile (p for trend <0.0001). Other dietary patterns were not associated with functional constipation. The Japanese traditional dietary pattern, characterized by a high intake of rice and a low intake of bread and confectionaries, may be beneficial in preventing functional constipation in young Japanese women.
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  • Kijin KIM, Seongno LEE, Rudy J. VALENTINE
    2007 Volume 53 Issue 3 Pages 239-246
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    This study examined whether the Pro12Ala polymorphism of the PPARγ2 gene is associated with obesity, hypertension and cardiovascular risk profiles in Korean adult women. We studied 129 Korean women (aged 42.71±8.56 y) who were divided into 2 groups as a Pro12Pro homozygous group and a Pro12Ala heterozygous or Ala12Ala homozygous group based upon PPARγ2 genotype. Anthropometric parameters, blood pressure, abdominal fat area and blood lipid profiles were compared between the 2 groups, and the association of Ala allele frequency in PPARγ2 gene with obesity or hypertension was evaluated. Most anthropometric parameters and blood lipid profiles did not differ significantly between the genotypes. However, all variables of skinfold thickness, body circumference and abdominal fat area of Pro12Ala heterozygous were consistently higher compared to the Pro12Pro homozygous subjects without a significance differences. The hypertensive group had significantly higher (p=0.004) Ala12 allele frequency than the normotensive group whereas allele frequencies did not differ significantly between the obese group and non-obese group. Ala allele carriers had a significantly higher risk of hypertension than non-carriers in logistic regression analysis. There was no evidence that the Ala allele can be regarded as an independent risk factor for obesity. In conclusion, all variables related to obesity showed a consistently higher trend in Pro12Ala heterozygous subjects compared to Pro12Pro homozygous subjects. Pro12Ala heterozygous subjects showed an increasing trend of elevated blood pressure compared to Pro12Pro homozygous subjects. Ala12 variant as well as BMI and TG were regarded as independent risk factors for hypertension in our subjects.
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  • Pei-Ying LIN, Bui Thi NHUNG, Nguyen Cong KHAN, Nobuko S ...
    2007 Volume 53 Issue 3 Pages 247-252
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    To elucidate the effect of a typical Vietnamese diet including a high content of white rice on postprandial blood glucose levels, the present study was designed. Thirty healthy female subjects with a similar body mass index, 10 each in their twenties, forties and sixties, were recruited. Four meals with a similar protein energy percentage (13-15%) but different energy ratios of fat and carbohydrate (FC ratio) and vegetable contents were provided by cross-over design. Meal A was designed according to the commonly consumed diet in Vietnam. The FC ratio was 14 : 71 and 84 g of carbohydrate was from rice. Meal B contained carbohydrate in a lower ratio than meal A by fat replacement and its FC ratio was 30 : 57. Meal C was similar to meal A except lacking vegetables. The energy of meal A, B and C was about 2.1 MJ. Meal D was designed to match the amount of carbohydrate and fat within A and B, respectively. The FC ratio of meal D was 26 : 61 and the energy was about 2.4 MJ. Fasting blood glucose was measured before consumption of a test meal. Postprandial blood glucose was measured every 30 min for 2 h. Areas under the curve (AUC) were calculated to compare the glycemic response among the four test meals. There was no significant difference in AUC among the four test meals in the subjects in their twenties. In the subjects in their forties, the AUC of meal A tended to be lower than that of meal C (p=0.07). In the subjects in their sixties, the AUC of meal A was significantly higher than that of meal B (p<0.001). Glycemic responses showed a significant relationship with age (r=0.26, p<0.01); however, there was no association between glycemic responses and BMI (p=0.20). Dietary fat ratios were inversely associated with glycemic responses (r=−0.28, p<0.01). In conclusion, the diet with about 70% energy from carbohydrate which is commonly consumed by Vietnamese may increase glycemic response, especially in elderly people and dietary vegetables may be beneficial to prevent such an increase in glycemic response.
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  • Hsin-Ping OU, Ming-Fu WANG, Sheng-Chin YANG, Shigeru YAMAMOTO, Chiun-C ...
    2007 Volume 53 Issue 3 Pages 253-260
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    The purpose of this study was to evaluate the impact of Monascus-fermented products (MP) as regards certain changes in behavior for SAMP8 mice. Both male and female SAMP8 mice were fed a 0.03% MP diet from 3 mo of age to 11 mo of age. The results indicated that the grading score of passive avoidance behavior was significantly lower in the MP diet groups than in the control diet groups in both male and female SAMP8 mice (p<0.05). The MP diet-augmented test-animal body weight, feed intake and feed efficiency did not differ significantly from the corresponding values for control mice. The MP diet-fed mouse group revealed significantly improved learning and memory as revealed by average escape-response testing score when comparing with control mice (p<0.05). Further, the level of serum triglyceride and total cholesterol for the MP-fed group were shown to be significantly lower than for the control group of SAMP8 mice at 11 mo of age. The test mice fed an MP diet appeared to be significantly lower in aging score than the control group (p<0.05). The MP diet-fed mouse group revealed significantly improved total antioxidation of liver. Subsequent to supplementation of SAMP8 mice diets with MP for a period of 8 mo, these MP-fed mice revealed significantly lower lipofuscin-cell numbers within the hippocampus (p<0.05). The results suggest that dietary supplementation with MP might improve both learning and memory behaviour, and retard the aging process for SAMP8 mice.
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  • Hironobu TANIGUCHI, Rieko MUROI, Kazuo KOBAYASHI-HATTORI, Yasushi UDA, ...
    2007 Volume 53 Issue 3 Pages 261-266
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    We have shown previously that Japanese radish (Raphanus sativus) sprouts (JRS) improve blood glucose levels in diabetic rats. In this study, we investigated the components in JRS that caused this hypoglycemic effect, by examining the effects of water-soluble (WSE) and fat-soluble (FSE) extracts of JRS on diabetes markers in normal (NM) and streptozotocin (STZ)-induced diabetic (DM) rats. The NM and DM rats were divided into a control group and 2 test groups (WSE (2.2%) or FSE (0.2%)), with the rats (n=6/group) then being maintained for 3 wk on either a control diet or one of the test diets; this was followed by the measurement of serum concentrations of glucose, insulin, glycoalbumin, fructosamine, ketone bodies, and lipids (cholesterol and triglyceride) and liver concentrations of lipids (total lipid, total cholesterol, and triglyceride). The FSE suppressed insulin secretion and improved lipid metabolism in the NM rats. The effect of WSE was different from that of the FSE as it decreased blood glucose levels without increasing insulin secretion and also lowered glycoalbumin and fructosamine levels in the DM rats. Therefore, the WSE have potential as functional food components with the hypoglycemic effect.
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  • Truong Tuyet MAI, Nghiem Nguyet THU, Pham Gia TIEN, Nguyen Van CHUYEN
    2007 Volume 53 Issue 3 Pages 267-276
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    The prevention and treatment of non-communicable diseases by using the beneficial biological effects of polyphenolic plants have attracted increasing interest from nutritional scientists. The α-glucosidase inhibitory and antioxidant activities of aqueous and methanolic extracts from 28 common Vietnamese edible plants, comprising 4 groups (plants used for making drinks, edible wild vegetables, herbs, and dark green vegetables), were investigated in vitro. The polyphenol contents of these extracts were determined by the Folin-Ciocalteu method and calculated as catechin equivalents. The extracts from plants used for making drinks showed the highest activities for both α-glucosidase inhibition and as antioxidants, followed by edible wild vegetables, herbs, and dark green vegetables. Positive relationships among α-glucosidase inhibitory activities, antioxidant activities and polyphenol contents of these 28 edible plants were found in both aqueous and methanolic extracts. Four new promising materials that are similar to or better than guava leaf extract, including Syzygium zeylanicum, Cleistocalyx operculatus, Horsfieldia amygdalina and Careya arborea demonstrated high α-glucosidase inhibitory activity (93, 76, 68 and 67%, respectively) at the final concentration of 0.8 mg lyophilized material/mL solution and antioxidant activity (85, 87, 78 and 80%, respectively) at the final concentration of 30 μg lyophilized material/mL solution. These four edible plants contained significantly high polyphenol contents (equivalent to 251.7, 146.6, 136.6 and 168.6 mg of catechin/g dry weight, respectively). Thus, these four materials might be possible new sources of α-glucosidase inhibition and antioxidants suitable for use as functional foods in the future.
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  • Kazuhiko TAMAKI, Takeshi TAMAKI, Takashi YAMAZAKI
    2007 Volume 53 Issue 3 Pages 277-286
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    The deodorizing effect of the mushroom (Agaricus bisporus) extract on the malodor produced after garlic consumption was investigated using an electronic sensor and sensory evaluation measurements. Comparative gas chromatography analysis revealed that the quantity of methane- and allylthiols that were usually found after garlic solution rinse, significantly fell after mushroom extract rinsing. Furthermore, in-vitro analysis (mixing the garlic solution and mushroom extract) showed that the methanethiol reaction with the mushroom extract proceeded faster than that of the allylthiol. Ab initio calculations implicated an addition reaction as the possible mechanism between the thiol compounds and the polyphenols. In comparison to the methanethiol, the higher activation energy required by allylthiol for a feasible reaction path way with the model acceptor, o-quinone, is expected to contribute to the difference in the rate of the reaction.
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Note
  • Young A LEE, Eun Ju CHO, Takashi TANAKA, Takako YOKOZAWA
    2007 Volume 53 Issue 3 Pages 287-292
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    The present study was carried out to evaluate the promising potential of polymers and oligomers from proanthocyanidins of persimmon peel as antioxidants and therapeutic agents for diabetes. Both polymers and oligomers showed the scavenging effect of 2,2-diphenyl-1-picrylhydrazyl, with IC50 values of 4.35 and 2.41 μg/mL, respectively, and they also showed a protective activity against protein oxidation induced by 2,2'-azobis (2-amidinopropane) dihydrochloride. In particular, oligomers exerted a stronger activity against free radicals than polymers. In addition, to investigate their protective potential against diabetes-related pathological conditions, their inhibitory activities on digestive enzymes and advanced glycation endproduct (AGE) formation were evaluated. Polymers showed a strong inhibitory activity against α-amylase, while oligomers had a relatively weak effect. This suggests that the inhibition of α-amylase activity would probably depend on the degree of polymerization. On the other hand, against α-glucosidase activity and AGE formation, oligomers exerted a stronger protective effect than polymers. The present study suggests that polymers and oligomers from proanthocyanidins of persimmon peel could play a role as antidiabetic agents with antioxidative effects. Moreover, oligomers rather than polymers from proanthocyanidins of persimmon peel may be expected to be a more promising antioxidative and antidiabetic agent in relation to utilization in biological systems.
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  • Yuuichi UKAWA, Yoshiya IZUMI, Takayuki OHBUCHI, Tetsunari TAKAHASHI, S ...
    2007 Volume 53 Issue 3 Pages 293-296
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    We examined whether the extract from Hatakeshimeji (Lyophyllum decastes, LD) mushrooms suppresses the development of atopic dermatitis (AD)-like skin lesions induced by repeated application of picryl chloride (PiCl) in NC/Nga mice. Oral administration of LD extract to NC/Nga mice inhibited the development of AD-like skin lesions based on lower total skin severity scores and serum immunoglobulin E (IgE) levels. Splenic lymphocytes were stimulated with the T cell mitogen concanavalin A, and secretion of a Th1 cytokine (IFN-γ) and a Th2 cytokine (IL-4) was determined by ELISA. IFN-γ production was not inhibited by treatment with LD extract. On the other hand, IL-4 production was significantly decreased by treatment with LD extract. These results suggest that LD extract exerts anti-allergic actions by suppressing the serum IgE and Th2-type immune responses.
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  • Siquin ZHAORIGETU, Masahiro SASAKI, Norihisa KATO
    2007 Volume 53 Issue 3 Pages 297-300
    Published: 2007
    Released: November 27, 2007
    JOURNALS FREE ACCESS
    This study was conducted to examine the mechanisms of the anti-colon tumor effect of dietary sericin. Dietary supplementation of 3% sericin reduced colon mucosal lipid peroxide and aberrant crypt foci in 1,2-dimethylhydrazine-treated rats. The colon content from sericin-fed rats had much stronger antioxidant activity compared to that from control rats not receiving sericin. The amino acid composition of undigested proteins in the colon contents from sericin-fed rats was similar to that of sericin ingested. The results suggest that the strong antioxidant activity of undigested sericin in the colon content causes lower oxidative stress and tumorigenesis in the colon.
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