Assessment of Antihyperglycemic Effect and Acute Toxicity of the Aqueous Scorzonera undulata Extract in Rats

Aims: The current study was carried out in order to assess the antihyperglycemic effect of Scorzonera undulata (S. undulata). Backgroud: Scorzonera undulata subsp. deliciosa (DC.) Maire is used in the Moroccan pharmacopeia for managing diabetes.

Objective: The objective of the study was to evaluate the anithyperglycemic activity in normal and streptozotocin (STZ)- induced diabetic rats as well as the acute toxicity of the aqueous extract of the roots of Scorzonera undulata (S. undulata).

Methods: This study investigated the effects of the root aqueous extract of Scorzonera undulata (AERSU) at a dose of 20 mg/kg on blood glucose levels in normal and streptozotocin(STZ)-induced diabetic rats and the acute toxicity of AERSU was examined. Histopathological examination, preliminary phytochemical investigation, determination of glycogen content and evaluation of α-amylase were also performed.

Results: Both single and repeated oral doses of AERSU (20 mg/kg) produced a significant reduction of blood glucose levels in normal and diabetic rats. Furthermore, repeated oral administration of AERSU during 15 days increased the glycogen content in the liver in both normal and diabetic rats, inhibited α-amylase activity and improved the histological architecture of the liver and pancreas in treated diabetic rats and ameliorated some biochemical parameters such as ALT and AST. In addition, the preliminary phytochemical investigation showed the richness of the roots of S. undulata in certain phytochemicals particularly in polyphenols.

Conclusion: AERSU exhibits an evident antihyperglycemic activity. This pharmacological effect may be due at least to protection of surviving pancreatic β cells, to the protection of hepatocytes, to α-amylase inhibitory effect and to the improvement of glycogen storage in the liver. The dose used in this study seems to be free of any toxicity.

Keywords: Scorzonera undulata; diabetes; glycogen; hypoglycemic; medicinal plant.; streptozotocin; toxicity; α-amylase.