ORIGINAL ARTICLE
Inhibition of α-glucosidase and glucose intestinal
absorption by Thymelaea hirsuta fractions
Sanae ABID,
1
Abdenbi LEKCHIRI,
2
Hassane MEKHFI,
1
Abderrahim ZIYYAT,
1
Abdekhaleq LEGSSYER,
1
Mohamed AZIZ,
1
and Mohamed BNOUHAM
1
1
Laboratory of Physiology and Ethnopharmacology, and
2
Laboratory of Genetics and Biotechnology, Department of Biology, Faculty of
Sciences, University Mohamed Ist, Oujda, Morocco
Correspondence
Mohamed Bnouham, BP: 717,
Department of Biology, Faculty of
Sciences, University Mohamed Ist, Oujda
60 000, Morocco.
Tel: +21 2 6762 7496
Fax: +21 2 3650 0603
Email: mbnouham@yahoo.fr
Received 16 March 2013; revised 29
August 2013; accepted 8 November 2013.
doi: 10.1111/1753-0407.12106
Abstract
Background: Thymelaea hirsuta (L.) Endl. (Thymelaeaceae) is a medicinal
plant used in Morocco to treat diabetes. In previous studies T. hirsuta has
shown a potent antihyperglycemic effect. Our aim was to study the effect of
the plant on α-glucosidase inhibition and intestinal glucose absorption.
Methods: Five fractions of T. hirsuta were tested, in vitro, in vivo and, in
situ, to elucidate the inhibition of α-glucosidase and intestinal glucose uptake.
Results: The fractions induced, in vitro, a significant inhibition of
α-glucosidase. The ethyl acetate fraction (EATh) had high activity and its
inhibition mode was non-competitive. The EATh at 50 and 100 mg/kg doses,
decreased significantly, in vivo, the postprandial hyperglycemia after sucrose
loading in normal and diabetic mice. Moreover, 50 mg/kg of EATh signifi-
cantly decreased intestinal glucose uptake, in situ, in rats.
Conclusion: The antihyperglycemic effect of T. hirsuta can be explained, in
part, by the inhibition of intestinal α-glucosidase and intestinal glucose
absorption.
Keywords: diabetes, intestinal glucose absorption, streptozotocin, Thymelaea
hirsuta, α-glucosidase inhibitor.
Introduction
Diabetes mellitus is a metabolic disorder characterized
by a persistent hyperglycemia, caused by the impairment
of pancreatic insulin secretion and/or insulin cellular
resistance. Currently, it is estimated that 220 million
people worldwide have diabetes and that the number will
increase to 300 million by 2025.
1
Increased sugar uptake
and physical inactivity are considered causal factors.
This illness has become a global health problem, due
to increasing occurrence and concomitant micro and
macrovascular complications such as retinopathy, neu-
ropathy, cardiovascular diseases and concomitant dia-
betic mortality.
Several studies have suggested that a cause of chronic
complications is postprandial hyperglycemia.
2,3
Therefore, controlling blood glucose level is the treat-
ment aim of diabetes. One of the therapeutic approaches
to this disease is the inhibition of postprandial hypergly-
cemia. This approach targets inhibition of intestinal
α-glucosidase (delaying digestion of polysaccharides to
monosaccharide) and reduction of intestinal glucose
absorption.
Currently, the search for natural antihyperglycemic
products has received attention because they have fewer
side-effects than synthetic drugs and are more economic.
In Moroccan folk medicine, the aerial parts (flowers,
leaves, branches) of Thymelaea hirsuta (L.) Endl.
Significant findings of the study: The ethyl acetate fraction of T. hirsuta inhibits α- glucosidase and intestinal
glucose transporters.
What this study adds: For the first time, a mechanism for the antihyperglycemic action of T. hirsuta, has been
demonstrated.
Journal of Diabetes •• (2014) ••–••
1 © 2013 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd