α-D-glucosidase inhibition property of malian antidiabetic plants
Introduction: A survey among diabetic patients at the National Diabetic Centre of Bamako (Mali) showed that patients use medicinal plants in combination with conventional treatment. Anacardium occidentale, Moringa oleifera, Sclerocarya birrea and Ziziphus mauritiana were the most used plants in the management of diabetes according to patients. Literature reports scientific hypoglycaemic activity for all these plants [1 – 4] but no scientific information exists on the mechanism of their activity.
Objective: This study aims at determining the α-D-glucosidase inhibition properties of Sclerocarya birrea, Anacardium occidentale, Moringa oleifera and Ziziphus mauritiana extracts
Methodology: Water, ethanol and methanol extracts of the leaves and stem bark of Sclerocarya birrea and Anacardium occidentale and the leaves of Moringa oleifera and Ziziphus mauritiana were prepared. A thin layer chromatography bio autography technique was used. The enzyme α-D-glucosidase was dissolved in sodium acetate buffer. TLC plate was sprayed with enzyme solution and incubated at room temperature for 60 min. Enzyme inhibitors were visualised as white spots on the TLC plates after spraying with solutions of 2-naphthyl-α-D- glucopyranoside and Fast Blue Salt. Acarbose was used as positive control.
Results and Discussion: The results showed a dose-dependent α-D-glucosidase inhibition property of Moringa oleifera water, ethanol and methanol extracts. Water and alcohol-soluble compound(s) are then responsible of the activity. The result explains the mechanism of the hypoglycaemic property of Moringa oleifera although the compounds responsible of the activity are not known. The finding also helps doctors to adjust the treatment or advice patients who combine conventional α-D glucosidase inhibitors drugs with Moringa oleifera on the risk of drug-herbs interactions.
Keywords: plants, diabetes, mechanism of action, α-D glucosidase inhibition
 Lawrence A. Olatunji, John I. Okwusidi, and Ayodele O. Soladoye 2005 Antidiabetic Effect of Anacardium occidentale Stem-Bark in Fructose-Diabetic Rats Pharmaceutical Biology, Vol. 43, No. 7, pp. 589 – 593
 Luangpiom Ampa Kourjampa Watchara Junaimaung Tanaree 2013, Anti-hyperglycemic Properties of Moringa oleiferaLam. Aqueous Leaf Extract in Normal and Mildly Diabetic Mice: British Journal of Pharmacology and Toxicology, 4; 3; 106
 Gondwe M; Kamadyaapa DR, Tufts M, Chuturgoon AA and Musabayane CT 2008 Slerocarya birrea [(A. Rich.) Hochts.] [Anacardiaceae] stem bark ethanolic extract modulates blood glucose, glomerular filtration rate and mean arterial blood pressure of STZ-induced diabetic rats. Phytomedicine 15 699 – 709
 Cisse A, Ndiaye A, Lope z-Sall P, Seck F, Faye B. Etude de l'activite antidiabetic de Zizyphus mauritiana Lam (Rhamnaceae). Antidiabetic activity of Zizyphus mauritiana Lam (Rhamnaceae). Dakar- Med. 2000; 45(2): 105 – 7.