Strong antihyperglycemic effects of water-soluble fraction of Brazilian propolis and its bioactive constituent, 3,4,5-tri-O-caffeoylquinic acid.
To clarify the suppression of postprandial blood glucose rise via alpha-glucosidase (AGH) inhibitory action by natural compounds, propolis was examined in this study. A single oral administration of propolis extract (50% methanol fraction on XAD-2 column chromatography) in Sprague-Dawley rats demonstrated a potent antihyperglycemic effect with the significant AUC(0-120 min) reduction of 38% at a dose of 20 mg/kg compared to that of controls. Among the active compounds isolated from the fraction, 3,4,5-tri-caffeoylquinic acid was found to be a prominent candidate that exerts the effect and shows a strong maltase-specific inhibition with an IC(50) value of 24 microM. In addition, the noncompetitive inhibition power apparently increased with the number of caffeoyl groups bound to quinic acid.
Matsui
Toshiro
T
Department of Bioscience and Biotechnology, Division of Bioresource and Bioenvironmental Sciences, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka, Japan. tmatsui@agr.kyushu-u.ac.jp
Ebuchi
Sumi
S
Fujise
Tomoko
T
Abesundara
Kanthi J M
KJ
Doi
Shima
S
Yamada
Hideo
H
Matsumoto
Kiyoshi
K
D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001786:Blood Glucose / Q000187:drug effects; D001938:Brazil; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000494:pharmacology*; D008297:Male; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D011429:Propolis / Q000737:chemistry; D011801:Quinic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D013997:Time Factors; D014867:Water
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D010936:Plant Extracts; C472707:caffeoylquinic acid; D011801:Quinic Acid; D014867:Water; D011429:Propolis