YOKOYAMA Daigo

写真a

Affiliation

Faculty of Agriculture Department of Biochemistry and Applied Biosciences

Title

Assistant Professor

External Link

Degree 【 display / non-display

  • 博士(農学) ( 2019.3   宮崎大学 )

Research Areas 【 display / non-display

  • Life Science / Food sciences

 

Papers 【 display / non-display

  • Active-phase Plasma Alkaline Phosphatase Isozyme Activity Is a Sensitive Biomarker for Excessive Fructose Intake Reviewed

    Suzuki Y., Yokoyama D., Matsuura C., Kondo K., Shimazaki T., Ryoke K., Kobayashi A., Sakakibara H.

    In Vivo   37 ( 5 )   1967 - 1974   2023.9

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)   Publisher: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.

    DOI: 10.21873/invivo.13293

    Scopus

    PubMed

  • Suppressive effects of sugarcane molasses concentrate on starch-induced hyperglycemia in mice Reviewed

    Kubota H., Shinohara S., Yokoyama D., Tanaka W., Matsuyama H., Arimura T., Kimura S., Sakakibara H.

    Journal of Functional Foods   107   2023.8

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    Authorship:Lead author   Publishing type:Research paper (scientific journal)   Publisher:Journal of Functional Foods  

    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.

    DOI: 10.1016/j.jff.2023.105652

    Scopus

  • Social confrontation stress decreases hepatic fibroblast growth factor-21 expression in aged mice Reviewed

    Tanaka W., Matsuyama H., Shimoi K., Yokoyama D., Sakakibara H.

    Biochemistry and Biophysics Reports   34   101454   2023.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Biochemistry and Biophysics Reports  

    We previously showed that social stress exposure in mature adult mice increased blood corticosterone concentrations at 2 days, disrupted hepatic lipid metabolism-related pathway at 30 days, and increased the risk of overweight with hepatic hypertrophy at 90 days. To further investigate the effects of aging on the physiological responses to social stress, we conducted a study using male BALB/c mice at the ages of 2 months (mature age), 14 months (middle age) and 26 months (old age), and exposed them to confrontation stress for 2 or 7 days. Blood corticosterone concentrations were increased at 2 days of stress, and then returned to baseline concentrations. This change was observed only at 2 months of age. We further examined the effect of aging on hepatic gene expression of fibroblast growth factor-21 (Fgf21) and found that its expression was significantly decreased after 7 days of stress at 14 months of age and after 2 days of stress at 26 months of age, indicating these decreasing effects became more pronounced with age. In conclusion, our study suggests that hepatic Fgf21 expression decrease under exposure to confrontation stress at middle or more age, indicating that stress response on Fgf21 related pathway might be more pronounced with age when exposed to stress.

    DOI: 10.1016/j.bbrep.2023.101454

    Scopus

    PubMed

  • Novel Biomarker Establishment for Evaluation of Excessive Fructose Consumption Using a Rat Model Reviewed

    Suzuki Y., Kondo K., Toyoda K., Tanaka Y., Kobayashi A., Yokoyama D., Sakakibara H.

    In Vivo   37 ( 1 )   173 - 181   2023.1

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:In Vivo  

    Background/Aim: The habitual consumption of excessive fructose is associated with the onset and progression of lifestyle-related diseases, such as nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the physiological changes observed when consuming a diet containing excessive fructose on the viewpoints of hepatotoxicity biological markers using a rat model and explored the biomarker candidates that could detect the effects of excessive fructose intake at an early stage. Materials and Methods: Male rats were fed 63% high fructose diet (HFrD) ad libitum and their blood samples were collected before and at 1, 2, 3, and 4 weeks after allocation. The plasma biochemical parameters, hepatotoxic enzyme activities including alkaline phosphatase (ALP) isozymes were analyzed. Results: HFrD consumption for 4-weeks created NAFLD-like symptoms, including elevated plasma lipid parameters and hepatotoxicity markers, as well as fat accumulation in the liver compared with rats consuming a control diet. Alanine aminotransferase (ALT) and glutamate dehydrogenase (GLDH) were increased from the 3rd and 2nd weeks, respectively, but no changes were observed on ALP activity. However, the daily consumption of the HFrD increased the plasma activities of liver-type ALP isozyme, and decreased plasma small intestinal-type ALP isozyme soon after the start of feeding. Conclusion: ALP isozyme analysis in combination with GLDH and ALT activities in the plasma samples could be a useful tool to detect the physiological changes induced by excessive fructose intake at an early stage of the development of NAFLD.

    DOI: 10.21873/invivo.13066

    Scopus

    PubMed

  • Maltose consumption exacerbates high-fat diet-induced overweight and related parameters in mice Reviewed

    Shibazaki N., Tanaka W., Suzuki Y., Matsuyama H., Kubota H., Ogawa K., Yokoyama D., Sakakibara H.

    Functional Foods in Health and Disease   12 ( 11 )   680 - 691   2022.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Functional Foods in Health and Disease  

    Background: Maltose is a disaccharide formed from two units of glucose. The amount of maltose in raw sweet potatoes reportedly increased by more than 40-fold after baking. We aimed to investigate the effects of maltose consumption on diet-induced obesity using a mouse model. Methods: Male C57BL/6J mice were divided into three dietary groups: a control diet of American Institute of Nutrition (AIN)-93 (CD), an AIN-93-based 30% high-fat diet (HFD), or an HFD diet containing 7.0% maltose (HFD+Mal). After 13 weeks, body mass index, blood glucose, lipid parameters, including total cholesterol and triglyceride, and hepatic fatty acid content were evaluated. Results: After 6 weeks on the special diet, weight gain was significantly higher in the HFD+Mal group than in the HFD group. The body mass index rose steadily and was significantly higher in the HFD+Mal group (5.03 ± 0.22), compared to the CD (3.32 ± 0.30) and HFD (4.57 ± 0.40) groups at 12 weeks. The relative liver weight per weight was also significantly higher in the HFD+Mal group than in the other two groups. The increases in blood glucose levels were more significant in the HFD+Mal group compared to the HFD group, as were the plasma levels of total cholesterol, high-density lipoprotein (HDL)-cholesterol and non-HDL-cholesterol. In the liver, levels of the following fatty acids increased in both the HFD and HFD+Mal groups relative to those in the CD group: C14:0 (myristic acid), C16:0 (palmitic acid), C18:0 (stearic acid), C18:1 (oleic acid), C18:2 (linoleic acid) and C18:3 (α-linolenic acid). Additionally, the C16:0 content in the HFD+Mal group was significantly higher than that in the HFD group. Conclusion: The results of this study suggest that daily consumption of maltose exacerbated the development of obesity and related parameters, including body mass index and plasma cholesterol levels, under the high-fat diet consumption. It is possible that the consumption of maltose-rich cooked sweet potatoes, as part of an overall HFD, might exacerbate HFD-induced overweight.

    DOI: 10.31989/ffhd.v12i11.997

    Scopus

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