Takashi Kometani

Dr. Takashi Kometani


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 April 2023 in Nutrients
Verified
Journal Article
Open access
PDF file
XLXuan Li
Xuan Li
HYHiroaki Yamada
Hiroaki Yamada
SMSayo Morita
Sayo Morita
YYYusuke Yamashita
Yusuke Yamashita
YKYOUNGIL KIM
YOUNGIL KIM
MKMujo Kim
Mujo Kim
A great number of chemically diverse pancreatic lipase (PL) inhibitors have been identified to tackle obesity; however, very few of them have entered clinical studies. The ethanolic extract of sesame meal is a potent PL inhibitor, and its activity hinges exclusively on two free fatty acids: linoleic acid and oleic acid, which were proven to reduce postprandial triglyceride excursion in rats. Herein, to investigate the clinical efficacy of the sesame meal extract, in a crossover trial, 30 healthy volunteers were randomized to receive the sesame meal extract containing experimental food or placebo along with a high-fat meal. Treatment with the sesame meal extract significantly lowered the incremental postprandial serum triglyceride concentration and reduced the incremental area under the curve (iAUC) by 16.8% (p-value = 0.03) compared to placebo. Significant decreases in postprandial remnant-like lipoprotein particle cholesterol and low-density lipoprotein particles were also observed, whereas high-density lipoprotein cholesterol was increased. These results suggest that treatment with the sesame meal extract significantly reduced the postprandial excursion of triglycerides and improved the lipidemic profile after high dietary fat intake in healthy individuals, indicating the substantial potential of free linoleic acid and oleic acid and natural products rich in these compounds for the management of obesity and related conditions.

5 December 2024 in Nutraceuticals
Verified
Journal Article
Open access
PDF file
KTKumiko Takemori
Kumiko Takemori
EYEi Yamamoto
Ei Yamamoto
TCTakaaki Chikugo
Takaaki Chikugo
ESEri Shiratsuchi
Eri Shiratsuchi
TKTakashi Kometani
Takashi Kometani
Skin aging is intrinsic and extrinsic. Intrinsic, or chronological, skin aging is an inevitable process of chronological and physiological alterations. The factors contributing to extrinsic skin aging involve sunlight, nutrients, and stress. Thus, extrinsic aging is thought to be superimposed over intrinsic aging and depends on the intensity and duration of environmental exposure and skin type (e.g., dry skin, oily skin, or eczema). The most significant extrinsic aging factor is UV radiation, which causes cellular senescence in a process known as photoaging. This study aimed to illuminate the mechanism whereby solubilized elastin peptide lotion (EL) from the bulbus arteriosus of yellowtail (Seriola quinqueradiata) prevents skin photoaging in hairless mice. EL reduced wrinkle formation, epidermal skin thickness, and Ki67 (cell growth marker) mRNA expression in skin tissues from ultraviolet B (UVB)-irradiated mice. EL treatment also reduced glyoxalase-1 (key enzyme of glucose metabolism) levels in skin tissue. Although no significant differences in collagen and elastin contents were found in dermal areas, matrix metalloproteinase-12 (wrinkle-related marker) expression was reduced following EL application. Furthermore, skin DPP-IV/CD26 (new senescence marker) levels decreased following EL treatment in photoaging model mice. These results suggest that EL moderates skin damage caused by UVB irradiation by regulating senescence-related molecule expression.

3 July 2024 in Nutraceuticals
Verified
Journal Article
Open access
PDF file
ARArif Yanuar Ridwan
Arif Yanuar Ridwan
YSYuki Shimozu
Yuki Shimozu
NNNikesh Narang
Nikesh Narang
TKTakashi Kometani
Takashi Kometani
YYYusuke Yamashita
Yusuke Yamashita
YKYOUNGIL KIM
YOUNGIL KIM
Jabuticaba fruit (Plinia cauliflora) is widely consumed in various forms such as juice, jam, wine, and liquors; however, its potential therapeutic effects on diabetic complications remain inadequately explored. We aimed to investigate the potential antiglycation activity of Jabuticaba, identify the active compounds through bioassay-guided fractionation, and assess its effects on cataract formation in a Streptozotocin-induced diabetic type 1 rat model. Through bioassay-guided fractionation, we identified gallic acid (IC50: 24.7 µg/mL), protocatechuic acid (IC50: 1.22 µg/mL), and an ellagitannin, Repandinin B (IC50: 0.55 µg/mL), as active compounds contributing to antiglycation effects. In the animal study, the addition of Jabuticaba juice extract to the drinking water at a concentration of 0.5% (w/v) for 12 weeks demonstrated an amelioration in cataract progression. These results suggest that Jabuticaba has high antiglycation effects leading to the delaying of cataract formation in type 1 diabetes.

1 July 2024 in Nutrients
Verified
Journal Article
Open access
PDF file
ASAngga Sanjaya
Angga Sanjaya
AIAkiko Ishida
Akiko Ishida
XLXuan Li
Xuan Li
YKYugweng Kim
Yugweng Kim
HYHiroaki Yamada
Hiroaki Yamada
YKYOUNGIL KIM
YOUNGIL KIM
Background: Our search for plant-derived ceramides from sustainable sources led to the discovery of ceramides and glucosylceramides in wine lees. Objective: This study evaluated the efficacy and safety of wine lees extract (WLE)-derived ceramides and glucosylceramides in enhancing skin barrier function. Methods: A randomized, double-blind, placebo-controlled study was conducted with 30 healthy Japanese subjects aged 20–64. Subjects were allocated to receive either the WLE-derived ceramides and glucosylceramides (test group) or placebo for 12 weeks. The primary outcome was transepidermal water loss (TEWL), and secondary outcomes included skin hydration, visual analog scale (VAS) of itching sensation, and the Japanese Skindex-29. Results: One participant withdrew for personal reasons, resulting in 29 subjects for data analysis (placebo n = 15; test n = 14). The test group showed a tendency of lower TEWL compared to the placebo after 8 weeks (p = 0.07). Furthermore, after 12 weeks of administration, the test group had significantly lower TEWL than the placebo (p = 0.04). On the other hand, no significant differences were observed in the secondary outcome parameters. No adverse events related to the supplements were reported. Conclusions: Oral supplementation of WLE-derived ceramides and glucosylceramides is a prominent and safe approach to enhancing skin barrier function and health. Trial registration: (UMIN000050422).

1 January 2022 in Food Science and Technology Research
Verified
Journal Article
Closed access
PDF file
KTKumiko Takemori
Kumiko Takemori
MOMinami Okano
Minami Okano
ASAoi Shimeno
Aoi Shimeno
TKTakashi Kometani
Takashi Kometani
Polyphenol composition in persimmon fruits were analyzed for 30 cultivars using thiolysis-liquid chromatography mass spectrometry. Regarding the amount of proanthocyanidins, persimmon polyphenols were classified into three groups: pollination constant and non-astringent (PCNA) from Japan, non-PCNA (pollination variant and non-astringent (PVNA), pollination variant and astringent (PVA), pollination constant and astringent (PCA)) from Japan and PCA from China, and PCA from Korea. Similar to the genetic-based classification and the molecular structures including the degree of polymerization and galloyl group ratio, as well as the bioactivities, such as the anti-oxidative activities and the inhibitory effects on amylolytic enzymes, were consistent with the amount of proanthocyanidins. In all cultivars investigated, the inhibitory activity of α-amylase was the strongest, followed by that of α-glucosidase, maltase, and sucrase. Since persimmon polyphenols have been reported to suppress the increase in postprandial blood glucose levels, they can be used for glycemic control regardless of the cultivars.

15 May 2022 in Nippon Shokuhin Kagaku Kogaku Kaishi
Verified
Journal Article
Closed access
PDF file
TKTakashi Kometani
Takashi Kometani
「食を通じて人々の健康の維持・向上に貢献する」ことを目的に, 機能性食品素材・食品の研究開発を行った. リン酸化オリゴ糖カルシウム (POsCa) , 高度分岐環状デキストリン (HBCD) およびα-グルコシルヘスペリジン (Hsp-G) を酵素を用いて合成した. POsCaは齲蝕予防に利用され, HBCDは持久力を高め, Hsp-Gは血液循環を改善し, それぞれ実用化できた. その後, これらの研究から得られた知識と経験に基づいて, 研究を拡大した. 口腔衛生分野では, 咀嚼, 嚥下しやすい高齢者向けのビスケットおよびたんぱく分解酵素により舌苔を除去し口臭を抑制するタブレットを開発した. 持久力研究は, 血糖コントロールによる糖尿病患者向けのせんべいの開発と食後の血糖上昇を抑制する柿ポリフェノールの研究に繋がった. 血液改善の研究で得られた自律神経の知識を用いて, GABAによりストレスを低減できるチョコレートの開発と睡眠を促進するornithineの探索ができた. さらに, DOHaD説に基づく, 栄養不良の母親から生まれた子の成長後の健康に関する研究では, 世代を超えた栄養摂取の状態が非常に重要であることが明らかとなった.