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農学部 農学部門応用生命化学領域 |
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Effect of harvest time of day on the isoflavone synthesis pathway in immature soybeans 査読あり
Ismayawati A.D., Yokoyama D., Nishiguchi Y., Saeki Y., Sakakibara H.
Food Research 8 ( 6 ) 411 - 417 2024年12月
担当区分：責任著者 掲載種別：研究論文（学術雑誌） 出版者・発行元：Food Research
Isoflavones, such as daidzein and genistein, are abundant in soybeans. As isoflavones have many beneficial health effects, the development of methods to increase the amounts of these compounds is important. In this study, the effect of harvest timing on expression patterns of isoflavone synthase (IFS) and cinnamate 4-hydroxylase (C4H), two major genes in the isoflavone synthesis pathway, in the pulp of immature soybeans from an open-air field were evaluated. The immature soybeans were collected at five different time points over a 24-hour period, and the gene expressions and isoflavone amounts were analyzed using reverse transcription-PCR and HPLC-diode array detector, respectively. The results showed that C4H expression increased during the day and decreased at night, although IFS expression tended to decrease during the middle of the night, but not significantly. Whereas isoflavone content was decreased during the day. These results suggested the possibility that the harvest of immature soybeans immediately after sunset is desirable for increasing isoflavone amounts.
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Mineral composition and antioxidant activity of partially digested coffee “Kopi Luwak” 査読あり
Ismayawati A.D., Yokoyama D., Goto R., Oya Y., Watanabe I., Horai S., Sakakibara H.
Functional Foods in Health and Disease 14 ( 11 ) 801 - 813 2024年11月
担当区分：筆頭著者 掲載種別：研究論文（学術雑誌） 出版者・発行元：Functional Foods in Health and Disease
Background: Kopi Luwak is a rare type of coffee, that is partially digested in the Asian palm civet’s digestive tract before roasting. It therefore possesses a distinctive flavor and unique properties, shaped by the digestive enzymes in the civet's intestine. Objective: In this study, the differences of mineral composition, antioxidant potency and total polyphenol amount between commercially available Kopi Luwak and regular coffees (without digestive fermentation) were evaluated. Methods: Twenty-one regular type of coffee bean and 17 of Kopi Luwak bean were purchased from local markets or Kopi Luwak production company in Indonesia. The samples were then analyzed for the levels of 23 minerals (Al, As, Ba, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Li, Mg, Mn, Mo, Ni, Pb, Rb, Se, Sn, Sr, V and Zn) using ICP-MS system. The total polyphenol amount and antioxidant activity were evaluated using Folin-Ciocalteu assay and DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical scavenging assay, respectively.Results: Of these 23 minerals, the concentrations of Mn and Ba were significantly lower in Kopi Luwak than in regular coffee. Otherwise, the concentrations of Cu and Rb in Kopi Luwak were significantly higher than those in regular coffee. The IC50 value on DPPH radical scavenging assay of Kopi Luwak (61.4±2.8 mg/dL) was significantly lower than that of regular coffee (93.6±1.9 mg/dL). Total polyphenol amount for Kopi Luwak was significantly higher than regular coffee. The correlation factor between these factors was r = -0.5910 and p < 0.001. Conclusion: Kopi Luwak had lower concentrations of Mn and Ba, but higher levels of Cu and Rb compared to regular coffee. Additionally, Kopi Luwak exerted strong antioxidant activity and contained higher polyphenol amounts than regular coffee. Thus, our findings imply that Kopi Luwak is an important candidate for functional foods.
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Watabe S, Tanaka W, Sakakibara H, Yokoyama D
Nutrients 16 ( 10 ) 2024年5月
担当区分：最終著者, 責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Nutrients
To maintain a beneficial concentration of eicosapentaenoic acid (EPA), the efficient conversion of its precursor, α-linolenic acid (α-LA), is important. Here, we studied the conversion of α-LA to EPA using ICR and C57BL/6 mice. A single dose of perilla oil rich-in α-LA or free α-LA had not been converted to EPA 18 h following administration. The α-LA was absorbed into the circulation, and its concentration peaked 6 h after administration, after which it rapidly decreased. In contrast, EPA administration was followed by an increase in circulating EPA concentration, but this did not decrease between 6 and 18 h, indicating that the clearance of EPA is slower than that of α-LA. After ≥1 week perilla oil intake, the circulating EPA concentration was >20 times higher than that of the control group which consumed olive oil, indicating that daily consumption, but not a single dose, of α-LA-rich oil might help preserve the physiologic EPA concentration. The consumption of high concentrations of perilla oil for 4 weeks also increased the hepatic expression of Elovl5, which is involved in fatty acid elongation; however, further studies are needed to characterize the relationship between the expression of this gene and the conversion of α-LA to EPA.
DOI： 10.3390/nu16101407
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Suzuki Y., Yokoyama D., Matsuura C., Kondo K., Shimazaki T., Ryoke K., Kobayashi A., Sakakibara H.
In Vivo 37 ( 5 ) 1967 - 1974 2023年9月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：In Vivo
Background/Aim: Excessive fructose intake reportedly leads to the development of nonalcoholic fatty liver disease (NAFLD). In our previous study, we reported that plasma activities of alkaline phosphatase (ALP) isozymes were markedly changed in rats with excessive fructose intake-induced hepatomegaly. In this study, we examined ALP isozyme activity prior to the occurrence of hepatomegaly, and investigated the effect of the timing of sample collection, to explore its potential as a biomarker. Materials and Methods: After 1-week intake of a 63% high-fructose diet (HFrD), blood samples were collected from male rats during sleep or active phases to analyze biochemical parameters. Results: Body and liver weights were similar between the HFrD and control diet groups, indicating that hepatomegaly due to excessive fructose intake had not occurred. The triglyceride levels and glutamate dehydrogenase (GLDH) activity were significantly elevated to similar degrees at both time points. HFrD intake significantly increased liver-type ALP (L-ALP) activity, stimulating it by 12.7% at the sleep phase and by 124.3% at the active phase. HFrD consumption also significantly decreased intestinal-type ALP (I-ALP) at the active phase, but only showed a decreasing trend during the sleep phase. Conclusion: Measurements of plasma ALP isozyme and GLDH activity, and triglyceride levels are effective early biomarkers of impending NAFLD caused by excessive fructose intake. L-ALP and I-ALP activities during the active phase are particularly sensitive for detection of excessive fructose intake before the occurrence of NAFLD.
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Suppressive effects of sugarcane molasses concentrate on starch-induced hyperglycemia in mice 査読あり
Hibiki Kubota, Suzuno Shinohara, Daigo Yokoyama, Wataru Tanaka, Hiroki Matsuyama, Tsutomu Arimura, Shigekatsu Kimura, Hiroyuki Sakakibara
Journal of Functional Foods 107 105652 2023年8月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Elsevier
Molasses is a by-product from refining sugarcane beets into sugar. In this study, we assessed the inhibitory effect of sugarcane molasses concentrate (SMC) on postprandial hyperglycemia using a mouse model. Starch administration into male ICR mice increased blood glucose levels, reaching a peak 60 min after administration. The simultaneous administration of SMC markedly suppressed this increase, and the area under the curve was reduced until 240 min after administration. Simultaneous administration of an ethanol-precipitated fraction (Et-Fr) of SMC with starch also exerted significant inhibitory effects. Ad libitum consumption of Et-Fr for 6 weeks did not exert any changes on fasting blood glucose levels. In vitro experiments showed that SMC and Et-Fr significantly inhibited α-glucosidase but not α-amylase activity. These results suggest that SMC has the potential to suppress postprandial hyperglycemia via inhibition of α-glucosidase.
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摘果マンゴー熱水抽出物が腸内細菌叢に与える影響
川野紗也香，石橋健太郎，榊原啓之，横山大悟
第29回日本フードファクター学会学術集会 2024年12月16日
開催年月日： 2024年12月16日 - 2024年12月17日
会議種別：ポスター発表
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シイタケ中GABA含量に対する乾燥工程の影響
水野奈津，榊原啓之，後藤龍生，坂本愛羽，横山大悟
第29回日本フードファクター学会学術集会 2024年12月16日
開催年月日： 2024年12月16日 - 2024年12月17日
会議種別：ポスター発表
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栽培方法の異なるシイタケが高脂肪・高ショ糖食摂取マウスに及ぼす影響
後藤龍生，坂本愛羽，榊原啓之，横山大悟
第29回日本フードファクター学会学術集会 2024年12月16日
開催年月日： 2024年12月16日 - 2024年12月17日
会議種別：ポスター発表
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ICP-MSを用いた原木及び菌床栽培シイタケのミネラル組成の比較
後藤 龍生、榊原 啓之、大矢 悠幾、渡邉 泉、 横山 大悟
第78回日本栄養･食糧学会大会 2024年5月25日
開催年月日： 2024年5月24日 - 2024年5月26日
会議種別：口頭発表（一般）
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青パパイア搾汁液が高脂肪・高ショ糖食摂 取マウスの腸内細菌叢に及ぼす影響
木原 倫太郎、後藤 龍生、榊原 啓之、 横山 大悟
第78回日本栄養･食糧学会大会 2024年5月25日
開催年月日： 2024年5月24日 - 2024年5月26日
会議種別：口頭発表（一般）
科研費（文科省・学振・厚労省）獲得実績 【 表示 ／ 非表示 】
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健康長寿延伸を企図した乳幼児の腸内フローラ制御を介した次世代機能性食品研究
研究課題/領域番号：24K17850 2024年04月 - 2027年03月
独立行政法人日本学術振興会 科学研究費基金 若手研究
担当区分：研究代表者