Antidiabetogenic activity of oleanolic acid glycosides from medicinal foodstuffs.
Oleanolic acid glycosides from several medicinal foodstuffs were found to show potent inhibitory activity on the increase of serum glucose levels in oral glucose-loaded rats. By examination of the structure-activity relationships, the 3-O-glucuronide moiety and the 28-carboxyl group in oleanolic acid glycosides were required to exert the hypoglycemic activity. Oleanolic acid glycosides were found to have neither insulin-like nor insulin-releasing activity, but they inhibited gastric emptying and glucose-uptake in the small intestine. Investigation of the mode of action revealed that the inhibition of gastric emptying was mediated by capsaicin-sensitive sensory nerves and the central nervous system. Furthermore, oleanolic acid glycosides were suggested to suppress the gastric emptying by stimulating the release and/or production of dopamine to act through dopamine2 receptors, which in turn causes the release of prostaglandins.
Kyoto Pharmacetutical University, Japan. shoyaku@mb.kyoto-phu.ac.jp
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M
Yoshikawa
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Matsuda
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D005746:Gastric Emptying / Q000187:drug effects; D005769:Gastrointestinal Motility / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007408:Intestinal Absorption / Q000187:drug effects; D051379:Mice; D009828:Oleanolic Acid / Q000494:pharmacology*; D010945:Plants, Edible; D010946:Plants, Medicinal; D051381:Rats; D011954:Receptors, Dopamine / Q000187:drug effects / Q000502:physiology; D012503:Saponins / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D011954:Receptors, Dopamine; D012503:Saponins; D009828:Oleanolic Acid; D005947:Glucose