title: Effects of Teucrium polium spp. capitatum flavonoids on the lipid and carbohydrate metabolism in rats.
abstract: BACKGROUND
  The main objective of the study was to investigate the biochemical mechanism of the antidiabetic activities of the dry extracts of Teucrium polium L. ssp. capitatum (L.) Arcangeli (Lamiaceae), from Republic of Macedonia, traditionally used to treat diabetes.
  
  
  METHODS
  Aerial parts of the plant were extracted in alcohol and freeze- or spray-dried, analyzed by high performance liquid chromatography (HPLC) and examined for insulinotropic effect in INS-1E cells in vitro. Their effect on blood glucose, lipids and carbohydrate-related enzymes was tested in normo- and streptozotocin hyperglycemic rats.
  
  
  CONCLUSIONS
  HPLC analyses revealed several flavonoids: luteolin, apigenin, cirsiliol, diosmetin, cirsimaritin and cirsilineol as both free aglycons and glycosides. The extract and mixture of commercial flavonoids showed a distinct insulinotropic effect on INS-1E cells at 500 µg/ml. Intragastric (i.g.) administration of identical doses of the extract (125 mg/kg) in both normo- and hyperglycemic rats was more efficient in lowering the blood glucose than intraperitoneal injection (35% vs. 24% reduction) with highest effect (50% reduction) 8 h after administration. After 10 days of treatment, the magnitude of the effect was comparable to i.g. administration of 2.5 mg/kg of glibenclamide (38% reduction). No effect was seen on blood lipid profiles. In OGTT (oral glucose tolerance test), the extract lowered blood glucose levels by ~35%. The treatment reduced hepatic glycogen and tended to normalize the activity of gluconeogenic enzymes.
  
  
  CONCLUSIONS
  The results demonstrate that examined plant extracts contain flavonoids with insulinotropic and antihyperglycemic effects.
authors: Faculty of Pharmacy, Vodnjanska, Skopje, Macedonia. gstefkov@yahoo.com
authors: Gjoshe
authors: G
authors: Stefkov
authors: Svetlana
authors: S
authors: Kulevanova
authors: Biljana
authors: B
authors: Miova
authors: Suzana
authors: S
authors: Dinevska-Kjovkarovska
authors: Per
authors: P
authors: Mølgaard
authors: Anna K
authors: AK
authors: Jäger
authors: Knud
authors: K
authors: Josefsen