Hypoglycemic effects of clove (Syzygium aromaticum flower buds) on genetically diabetic KK-Ay mice and identification of the active ingredients

• Published in: Journal of natural medicines Vol. 66; no. 2; pp. 394 - 399
• Main Authors: Kuroda, Minpei, Mimaki, Yoshihiro, Ohtomo, Takayuki, Yamada, Junji, Nishiyama, Tozo, Mae, Tatsumasa, Kishida, Hideyuki, Kawada, Teruo
• Format: Journal Article
• Language: English
• Published: Japan Springer-Verlag 01-04-2012; Springer Japan
• Subjects: 3T3-L1 Cells; active ingredients; Adipocytes - cytology; Adipocytes - drug effects; Animals; Biomedical and Life Sciences; Biomedicine; blood glucose; buds; Cell Differentiation - drug effects; cloves; Complementary & Alternative Medicine; Diabetes Mellitus - drug therapy; ethanol; Female; fractionation; functional foods; glycemic effect; humans; Hypoglycemic Agents - chemistry; Hypoglycemic Agents - pharmacology; Hypoglycemic Agents - therapeutic use; Lignans - chemistry; Medicinal Chemistry; Mice; noninsulin-dependent diabetes mellitus; oleanolic acid; Peroxisome Proliferator-Activated Receptors - metabolism; Pharmacology/Toxicology; Pharmacy; Plant Extracts - chemistry; Plant Extracts - pharmacokinetics; Plant Extracts - therapeutic use; Plant Sciences; Syzygium - chemistry; Syzygium aromaticum; Triterpenes - chemistry; PPAR-γ ligand-binding activity; Triterpenoid; Neolignan; Clove
• ISSN: 1340-3443; 1861-0293
• DOI: 10.1007/s11418-011-0593-z

Clove (Syzygium aromaticum flower buds) EtOH extract significantly suppressed an increase in blood glucose level in type 2 diabetic KK-Ay mice. In-vitro evaluation showed the extract had human peroxisome proliferator-activated receptor (PPAR)-γ ligand-binding activity in a GAL4-PPAR-γ chimera assay. Bioassay-guided fractionation of the EtOH extract resulted in the isolation of eight compounds, of which dehydrodieugenol (2) and dehydrodieugenol B (3) had potent PPAR-γ ligand-binding activities, whereas oleanolic acid (4), a major constituent in the EtOH extract, had moderate activity. Furthermore, 2 and 3 were shown to stimulate 3T3-L1 preadipocyte differentiation through PPAR-γ activation. These results indicate that clove has potential as a functional food ingredient for the prevention of type 2 diabetes and that 2–4 mainly contribute to its hypoglycemic effects via PPAR-γ activation.