Nigella sativa inhibits intestinal glucose absorption and improves glucose tolerance in rats.
OBJECTIVE
Nigella sativa L. (Ranunculaceae) seeds have been used traditionally for centuries, notably for treating diabetes.


METHODS
We studied the effects of the crude aqueous extract of Nigella sativa seeds on intestinal glucose absorption in vitro using a short-circuit current technique and in vivo using an oral glucose tolerance test.


RESULTS
The aqueous extract of Nigella sativa (0.1 pg/ml to 100 ng/ml) exerted dose-dependent inhibition of sodium-dependent glucose transport across isolated rat jejunum. Maximal inhibition exceeded 80% and IC50 was close to 10 pg/ml. An oral glucose tolerance test was carried out in rats after the initial dose and after a 6-week treatment of Nigella sativa (2 g/(kg day)), and compared to metformin (300 mg/(kg day)). Chronic Nigella sativa treatment improved glucose tolerance as efficiently as metformin. Nigella sativa and metformin also reduced body weight without any toxic effect.


CONCLUSIONS
To our knowledge, this is the first demonstration that Nigella sativa directly inhibits the electrogenic intestinal absorption of glucose in vitro. Together with the observed improvement of glucose tolerance and body weight in rats after chronic oral administration in vivo, these effects further validate the traditional use of Nigella sativa seeds against diabetes.
Meddah
Bouchra
B
Laboratory of Pharmacology and Toxicology, Faculty of Medicine and Pharmacy, Université Mohammed V-Souissi, Rabat, Morocco.
Ducroc
Robert
R
El Abbes Faouzi
Moulay
M
Eto
Bruno
B
Mahraoui
Lahcen
L
Benhaddou-Andaloussi
Ali
A
Martineau
Louis Charles
LC
Cherrah
Yahia
Y
Haddad
Pierre Selim
PS
D000818:Animals; D001835:Body Weight / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007408:Intestinal Absorption / Q000187:drug effects*; D008297:Male; D008687:Metformin / Q000494:pharmacology; D031881:Nigella sativa; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012639:Seeds
D007004:Hypoglycemic Agents; D010936:Plant Extracts; D008687:Metformin; D005947:Glucose