Polyphenolic compounds from Artemisia dracunculus L. inhibit PEPCK gene expression and gluconeogenesis in an H4IIE hepatoma cell line

Autor: Sithes Logendra, Debora Esposito, William T. Cefalu, Yanxin Wang, Dmitry Govorko, David M. Ribnicky, Alexander Poulev, Slavko Komarnytsky, Ilya Raskin, Zhong Q. Wang
Rok vydání: 2007
Předmět:
Zdroj: American journal of physiology. Endocrinology and metabolism. 293(6)
ISSN: 0193-1849
Popis: An ethanolic extract of Russian tarragon, Artemisia dracunculus L., with antihyperglycemic activity in animal models was reported to decrease phospho enolpyruvate carboxykinase (PEPCK) mRNA expression in STZ-induced diabetic rats. A quantitative polymerase chain reaction (qPCR) assay was developed for the bioactivity-guided purification of the compounds within the extract that decrease PEPCK expression. The assay was based on the inhibition of dexamethasone-stimulated PEPCK upregulation in an H4IIE hepatoma cell line. Two polyphenolic compounds that inhibited PEPCK mRNA levels were isolated and identified as 6-demethoxycapillarisin and 2′,4′-dihydroxy-4-methoxydihydrochalcone with IC50values of 43 and 61 μM, respectively. The phosphoinositide-3 kinase (PI3K) inhibitor LY-294002 showed that 6-demethoxycapillarisin exerts its effect through the activation of the PI3K pathway, similarly to insulin. The effect of 2′,4′-dihydroxy-4-methoxydihydrochalcone is not regulated by PI3K and dependent on activation of AMPK pathway. These results indicate that the isolated compounds may be responsible for much of the glucose-lowering activity of the Artemisia dracunculus extract.
Databáze: OpenAIRE