Leaf Aqueous Extract of Argania spiniosa Exhibits Antihyperglycemic Effect in Diabetic Rats

Abstract

Introduction: Argania spiniosa L. (Sapotaceae) is an endemic species from south-western Morocco. This plant has many traditional uses including its use in the treatment of diabetes.

Objective: The objective of the study was to evaluate the antidiabetic activity of Argania spiniosa Leaf Aqueous Extract (A.S.L.A.E).

Methods: The antidiabetic effect of A.S.L.A.E was evaluated in both normal and streptozotocin (STZ)-induced diabetic rats treated at a dose of 20 mg/kg body weight for 15 days. The histopathological changes in the liver were evaluated. In addition, the antioxidant activity of this extract was also studied.

Results: Single oral administration of A.S.L.A.E (20 mg/kg) showed no significant change in blood glucose levels in both normal and STZ induced diabetic rats after 6 hours of administration. Furthermore, in normal rats, repeated oral administration of A.S.L.A.E reduced blood glucose levels. Moreover, blood glucose levels decreased in STZ diabetic rats after fifteen days of treatment. According to the oral glucose tolerance test, the A.S.L.A.E (20 mg/kg) was shown to prevent significantly the increase in blood glucose levels in normal treated rats. Moreover, A.S.L.A.E showed antioxidant activity.

Conclusion: The results show that Argania spiniosa leaf aqueous extract possesses significant antihyperglycemic activity.

Keywords: Antihyperglycemic effect; Argania spinosa; antioxidant activity; diabetes; oral glucose tolerance test; streptozotocin..

Fig. (1)

Plasma glucose levels over 6 h after a single oral administration of A.S.L.A.E (20 mg/kg) in normal (A) and diabetic rats (B). Data are expressed as means ± S.E.M. n=6 rats per group. *p<0.05; **p<0.01; ***p<0.001 and ****p<0.0001 when compared to baseline values.

Fig. (2)

Plasma glucose levels over once daily repeated oral administration of A.S.L.A.E (20 mg/kg) for 15 days in normal (A) and diabetic rats (B). Data are expressed as means ± S.E.M. n= 6 rats per group. *p<0.05; **p<0.01; ***p<0.001 and ****p<0.0001 when compared to baseline values.

Fig. (3)

Body weight change after once daily repeated oral administration of A.S.L.A.E (20 mg/kg) for 15 days in normal (A) and diabetic rats (B). Data are expressed as mean ± S.E.M. n= 6 rats per group. *p<0.05; **p<0.01; ***p<0.001 and ****p<0.0001 when compared to baseline values (the start of treatment).

Fig. (4)

Effect of A.S.L.A.E (20 mg/kg) on oral glucose tolerance diabetic rats. Values are means ± SEM; n=5. (*) p<0.05; (**) p<0.01; (***) p<0.001; (****) p<0.0001 vs. control.

Fig. (5)

Effect of orally administered A.S.L.A.E on liver histology. Representative images of the liver in normal rats (A), STZ-induced diabetic rats (B), diabetic rats treated with 20 mg/kg/day A.S.L.A.E (C) and diabetic rats treated with glibenclamide (5 mg/kg/day) (D) Images were taken under 40× magnification.

Fig. (6)

DPPH radical scavenging activity of A.S.L.A.E.