ギムネマ・シルベスタ葉のギムネマ酸成分の糖吸収抑制作用 Suppression of Glucose Absorption by Some Fractions Extracted from Gymnema sylvestre Leaves

Author(s)

Abstract

ギムネマ・シルベスタ(Gymnema sylvestre)葉から抽出・精製したギムネマ酸類の各成分のモルモット回腸縦走筋の高濃度K^+収縮, モルモットおよびラット反転腸管を用いて糖輸送電位変化による糖輸送系およびラットの血糖に対する効果を相互に比較した. 高速液体クロマトグラフィーによる9分画(f1〜f9) (0.1 mg/ml)のうち, f2およびf4は平滑筋の高濃度K^+収縮を強く抑制し, f3, f5は中等度に, f8, f9は弱く抑制したが, その他の成分は影響がなかった. f2成分の高濃度K^+収縮抑制の大きさは74%であり, f4成分のそれの67%とほとんど同じであった. f2およびf4(0.1 mg/ml)により低下した収縮はピルビン酸(5.5 mM)の添加によりともに回復を示した, モルモットあるいはラット反転腸管のブドウ糖添加による糖輸送電位の増加に対して, f2およびf4 (0.1 mg/ml)はともに抑制し, その抑制の程度はともに40%であり, 両者に効力の差はほとんどなかった. また, ラットを用いたショ糖負荷試験においてf2およびf4はともに血糖上昇抑制作用を示した. これらのことから, f2およびf4はともにモルモット回腸縦走筋の収縮, モルモットおよびラット反転腸管の糖輸送電位の増加および血糖上昇を抑制する効果がある結果が得られた. 従ってこれらの成績によりギムネマ酸の各成分の一部は腸管におけるブドウ糖吸収を抑制することにより血糖上昇を抑制することが示唆される.

Extracts containing gymnemic acids, which were extracted from the leaves of Gymnema sylvestre (GS) as nine fractions, were evaluated for their effects on a high K^+-induced contraction of guinea-pig ileal longitudinal muscles, on glucose transport mediated by the difference of glucose-evoked transmural potential difference (△PD) in the inverted intestine of guinea-pig and rat, and on blood glucose in rat. Among nine fractions obtained by high performance liquid chromatography from the extract, f-2 and f-4 strongly suppressed the high K^+-induced contraction of the ileal muscle, f-3 and f-5 did so moderately, and f-8 and f-9 did so weakly, whereas the other fractions did not affect it. The degree of suppression of high K^+-induced contraction by f-2 at 74% was almost the same as that of f-4 at 67%, at concentrations of 0.1 mg/ml. The suppressed contraction by f-2 or f-4 was recovered by adding 5.5 mM pyruvate. The △PD increased by 5.5 mM glucose in the inverted intestines of guinea-pig and rat were equally suppressed by 0.1 mg/ml of f-2 or f-4 to 40%. In a rat sucrose tolerance test, f-2 and f-4 suppressed the elevation of blood glucose level. Both f-2 and f-4 suppressed the contraction of guinea-pig ileal longitudinal muscle, interfered with the increase in △PD induced by glucose in the inverted intestines of guinea-pig and rat, and inhibited the elevation of blood glucose level. In conclusion, it is suggested that some of the extracts containing gymnemic acids from GS leaves suppress the elevation of blood glucose level by inhibiting glucose uptake in the intestine.

Journal

  • The Journal of veterinary medical science

    The Journal of veterinary medical science 59(4), 245-251, 1997-04-25

    Japanese Society of Veterinary Science

References:  21

Cited by:  4

Codes

  • NII Article ID (NAID)
    110003915136
  • NII NACSIS-CAT ID (NCID)
    AA10796138
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    09167250
  • NDL Article ID
    4206405
  • NDL Source Classification
    ZR22(科学技術--農林水産--畜産)
  • NDL Call No.
    Z18-350
  • Data Source
    CJP  CJPref  NDL  NII-ELS 
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