International Journal of Biochemistry and Biotechnology

International Journal of Biochemistry and Biotechnology Vol. 1 (3), pp. 137-145, May, 2012. © International Scholars Journals

Full Length Research Paper 

Effects of lipid extracts from nigella sativa seeds on the reduction of ATP and the inhibition of alpha glucosidase activity

 Widad Sobhi^a, Bachra Khettal^b, Djebbar Atmani^a,B, Caroline Stevigny^c, Marie- Jeanne Mukazayire^c, Pedro Buc CALDERON ^D, Pierre Duez^c and Mustapha Benboubetra^a* 

^a Laboratory of Applied Biochemistry, Faculty of  Sciences, University of Setif, Algeria.

^b Department of Physical and Chemical Biology, Faculty of Life and Nature Sciences, University of Bejaia; Algeria.

^c Laboratory of  Pharmacognosy, Bromatology and Human Nutrition, Institute of Pharmacy, Université Libre de Bruxelles (ULB), Belgium.

^d Pharmacocinétic Unit, Metabolism, Nutrition and Toxicology, Faculty of Medicine, Catholic University of Louvain, Bruxelles, Belgium.

*Corresponding Author’s E-mail: [email protected]

Received March 12, 2012; Accepted May 18, 2012

Abstract

Extracts from the seeds of Nigella sativa have been traditionally used to treat inflammations, liver disorders and arthritis. Experimentally, it has been demonstrated they possess antioxidant and hepatoprotective properties. Beside the hypoglycaemic and hypolipidic effects, this study was carried out to evaluate, in vitro, toxicological effect of lipid extracts from the Nigella sativa seeds. The tested fractions were: (i) defatted methanolic extract, (ii) total lipid extract obtained by hexane extraction from methanolic extract and (iii) neutral and polar lipid fractions. Toxicological evaluation was carried out on precision-cut rat liver slices (PCLS). The fractions were assessed, in vitro, for their inhibitory potential on the activity of alpha-glucosidase as suppressing the enzyme activity it is one of the therapeutic approaches for decreasing postprandial hyperglycaemia.On PCLS, lipid extracts reduced ATP levels by 27-35 %. High inhibition of alpha-glucosidase by the two polar lipid fractions (F6 and F7) was reflected by their IC₅₀ (0.51 ± 0.04 mg/ml and 0.55 ± 0.09 mg/ml, respectively), compared to acarbose (0.53 ± 0.06 mg/ml) and thymoquinone (0.65 ± 0.05 mg/ml). The inhibitory effect on alpha-glucosidase activity could be a result of an inhibition of the early steps of carbohydrate metabolism and hence are good candidates for the anti-hyperglycaemic effect of this medicinal plant.

Keywords: Alpha-glucosidase, Hepatotoxicity, Induced-Diabetes, Nigella sativa, Polar lipids.