Pecher Christiane, Kamtchouing Pierre, Dimo Théophile, Tack Ivan, Girolami Jean-Pierre;
Diabetes mellitus is a chronic disease and a major cause of morbidity and mortality. Its prevalence is increasing more rapidly in low- and middle-income countries. Pterocarpus soyauxii Taub used in Africa for its treatment was assessed for its antidiabetic effects, but not yet for its intracellular action mechanism.
We investigated the effects of the Pterocarpus soyauxii stem bark aqueous extract (75-300 mg/kg of BW) in type 1 diabetes. Type 1 diabetes was induced in C57 BL/6 normal mice by a daily i.p. injection of streptozotocine (STZ: 80 mg/kg for 3 days). The treatment was adjusted in drinking water for 42 days, according to the doses to be administered.
The 42 days treatment with the P. soyauxii aqueous extract significantly reduced (p<0.01) the glycemia and triglyceridemia, increased (p<0.05) serum total proteins and hepatic glycogen, while reducing (p<0.05–p<0.01) the IGF-1β receptor expression and Erk 1/2 phosphorylation, increasing (p<0.05) the IRS-1 expression, without having a major effect on Akt phosphorylation in the liver, skeletal muscle and the kidney of C57 BL/6-STZ diabetic treated mice, comparatively to the diabetic control mice.
P. soyauxii aqueous stem bark extract would have mediated its antidiabetic effects on metabolic alterations of STZ-induced type 1 diabetes by reducing the MAP-kinase pathway activation, probably by activating the insulin receptor, either: 1) directly by its bioactive metabolites; 2) or indirectly via the insulin released thanks to its pancreatostimulating effect, then justifying its traditional use to manage the diabetes.
Key words: C57 BL/6-STZ diabetic mice, metabolites dysregulation, P. soyauxii Taub, insulin signaling pathways
