BENEFICIAL EFFECTS IN THE LIVER OF ANTIDIABETIC PLANTS USED IN TRADITIONAL MEDICINE BY THE CREE OF BAY JAMES IN CANADA

ABIR NACHAR(1,3), AMMAR SALEEM(2), LINA MUSALLAM(1,3), DIANE VALLERAND(1,3), LOUIS LAVOIE (1,3),JOHN.T ARNASON(2), PIERRE.S HADDAD(1,3)

1 Natural Health Products and Metabolic Diseases Laboratory, Dept. of Pharmacology, Université de Montréal, Montréal, Québec, Canada.
2 Phytochemistry, Medicinal Plant and Ethnopharmacology Laboratory, Dept. of Biology, University of Ottawa, Ottawa, Ontario, Canada.
3 Canadian Institutes of Health Research Team in Aboriginal Antidiabetic Medicines and Montreal Diabetes Research Center

Pierre S. Haddad, PhD.
Department of Pharmacology, Université de Montréal. P.O. Box 6128, Station Centre-Ville. Montréal, Québec, H3C 3J7 Canada
Email:pierre.haddad@umontreal.ca Phone: 514-343-6590; Fax: 514-343-2291

The liver plays an essential role in the regulation of glucose homeostasis and in the pathogenesis of type 2 diabetes mellitus. This study sought to determine the potential beneficial effect of putative antidiabetic medicinal plants used by the Eastern James Bay Cree of Northern Quebec (Canada) on the activity of key enzymes of gluconeogenesis and glycogen synthesis.
Glucose-6-phosphatase (G6Pase) activity was measured by glucose oxidase enzymatic assay and glycogen synthase (GS) activity was assessed by the amount of radioactive UDP-glucose incorporated into glycogen in hepatic cell lines. The phosphorylation of AMP-dependent protein kinase (AMPK) and Glycogen synthase kinase-3 (GSK-3), the two key kinases which control the two pathways for glucose homeostasis, were probed by Western blot.
Eight of the tested seventeen plant extracts significantly inhibited G6Pase, the key enzyme for gluconeogenesis, and activated glycogen synthase, the enzyme responsible for storage of glucose as glycogen. Phosphorylation of AMPK and GSK-3 were increased