Arctium lappa root extract containing L-arginine prevents TNF-α-induced early atherosclerosis in vitro and in vivo

Atherosclerosis is a chronic inflammatory disease affecting the aorta and is a major cause of cardiovascular disease. Arctium lappa root is a plant widely used in traditional Chinese medicine (TCM), and Arctium lappa root extract (ALE) has been reported to exhibit anti-inflammatory capacity and to ameliorate endothelial dysfunction. Thus, we hypothesized that ALE would inhibit the early atherosclerotic stage. In this study, we evaluated the inhibitory effect of ALE on early arteriosclerosis and its mechanisms of action. ALE suppressed TNF-α-induced monocyte adhesion to the vascular endothelium by suppressing NF-κB signaling in HUVECs. In an acute mouse model of atherosclerosis, ALE suppressed TNF-α-induced monocyte infiltration of the vascular endothelium and the expression of genes encoding inflammatory cytokines including IL-1β, IL-6, TNF-α, and MCP-1 in the mouse aorta. Moreover, inulin-type fructan and amino acids, especially L-aspartate and L-arginine (60.27 and 42.17 mg/g, respectively) were detected by NMR, MALDI-TOF MS, and HPLC analysis as the main components of ALE. Notably, L-arginine suppressed TNF-α-induced monocyte adhesion to HUVECs. Therefore, these results suggest that ALE may be a functional food for the suppression or prevention of early stages of atherosclerosis.

Antidiabetic, hypolipidemic and hepatoprotective effects of Arctium lappa root's hydro-alcoholic extract on nicotinamide-streptozotocin induced type 2 model of diabetes in male mice

OBJECTIVE

Arctium lappa (burdock), (A. lappa) root has hypoglycemic and antioxidative effects, and has been used for treatment of diabetes in tradition medicine. This study was conducted to evaluate the antidiabetic and hypolipidemic properties of A. lappa root extract on nicotinamide-streptozotocin (NA-STZ)-induced type2 diabetes in mice.

MATERIALS AND METHODS

In this investigation, 70 adult male NMRI mice (30-35g) randomly divided into 7 groups (n=10) as follow: 1-control, 2-type 2 diabetic mice, 3-diabetic mice that received glibenclamide (0.25 mg/kg) as an anti-diabetic drug, 4, 5, 6 and 7- diabetic and normal animals that were pre-treated with 200 and 300 mg/kg A. lappa root extract, respectively, for 28 days. Diabetes has been induced by intraperitoneal injection of NA and STZ. Finally, the blood sample was taken and insulin, glucose, SGOT, SGPT, alkaline phosphatase, leptin and lipid levels was evaluated.

RESULTS

Induction of diabetes decreased the level of insulin, leptin and high density lipoprotein (HDL) and increased the level of other lipids, glucose, and hepatic enzymes significantly (p<0.05). Administration of both doses of the extract significantly decreased the level of triglyceride, very low density lipoprotein, glucose and alkaline phosphatase in diabetic mice (p<0.05). Insulin levels increased in animals treated with 200 mg/kg (p<0.05) and HDL and leptin levels increased in animals treated with 300 mg/kg of the extract (p<0.01).

CONCLUSION

The results showed that A. lappa root extract, at specific doses, has an anti-diabetic effect through its hypolipidemic and insulinotropic properties. Hence, this plant extract may be beneficial in the treatment of diabetes.