- Made available online as an Accepted Preprint 8 January 2010
- Accepted Preprint first posted online on 8 January 2010
Sclerocarya birrea (Anacardiaceae) stem-bark extract corrects glycaemia in diabetic rats and acts on β-cells by enhancing glucose-stimulated insulin secretion
- Ivonne Gisèle Makom Ndifossap1,2,
- Francesca Frigerio1,
- Marina Casimir1,
- Florence Ngueguim Tsofack2,
- Etienne Dongo3,
- Pierre Kamtchouing2,
- Théophile Dimo2 and
- Pierre Maechler1
- 1Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland Departments of
2Animal Biology and Physiology
3Organic Chemistry, Faculty of Science, University of Yaoundé 1, PO Box 812, Yaoundé, Cameroon
- (Correspondence should be addressed to P Maechler; Email: pierre.maechler{at}unige.ch)
Abstract
Sclerocarya birrea is a plant widely used as traditional medication for the treatment of diabetes in sub-Saharan regions. However, the mechanism of action is unknown and only hypoglycaemic effects of S. birrea extract (SBE) in diabetic rats have been reported to date. Here, we tested aqueous extracts of S. birrea on insulin-secreting INS-1E cells and isolated rat islets. Following 24 h of treatment at 5 μg/ml, the extract markedly potentiated glucose-stimulated insulin secretion. Neither basal insulin release nor non-nutrient stimulation was affected. The potentiation of the secretory response at stimulatory glucose appeared after 12 h of treatment. No acute effects were observed and, at the effective concentration, SBE was safe regarding cell integrity and differentiation. The mechanism of action of the SBE was related to glucose metabolism as both ATP generation and glucose oxidation were enhanced following the 24-h treatment. In streptozotocin-induced diabetic rats, SBE administration corrected glycaemia and restored plasma insulin levels after 2 weeks of treatment. These data show direct action of S. birrea on insulin-secreting cells and favour further delineation for use of the plant in the management of diabetes.
- Received in final form 7 December 2009
- Accepted 8 January 2010
- © 2010 Society for Endocrinology
