Protective effect of Urtica dioica leaf hydro alcoholic extract against experimentally-induced atherosclerosis in rats

Objective: Finding compounds that could be used for prevention of atherosclerosis (AS) is highly desired. The present study evaluated the protective effects of Urtica dioica (UD, commonly known as stinging nettle) leaf ethanolic extract against high-fat diet-induced AS in rats. Materials and Methods: In this study, 40 male adult Sprauge-Dawley rats were randomly allocated to 4 equal groups and treated as follows for 9 consecutive weeks: (1) Normal control (NC; normal rats that were fed with a basic diet); (2) Atherosclerotic rats (AT; which received no particular treatment); (3) Atherosclerotic rats that received 100 mg/kg/day ethanolic extract of UD orally and (4) Atherosclerotic rats that received simvastatin 4 mg/kg/day orally. Atherosclerosis was induced by a high-fat diet accompanied by propylthiouracil and vitamin D3. Results: Marked hypercholesterolemia and significant increase in LDL-C/HDL-C ratio were observed in rats of AT group. Administration of UD significantly reduced these parameters as compared to AT group (p<0.05 for all cases). In histopathological evaluations of the aortic arch, AT rats showed atherosclerotic lesions, which were markedly ameliorated in rats treated with UD or simvastatin. Simvastatin and UD significantly reduced medial (p<0.05) but not intimal thickness. Increased level of malondialdehyde (MDA) and reduced total antioxidant capacity (TAC) were observed in the aortic arch of AT rats (p<0.05 for all cases). In contrast with simvastatin, UD extract had no significant effect on these parameters. Conclusion: Ethanolic extract of UD prevents establishment of atherosclerotic lesions in rat aorta, which is associated with positive effects on serum lipid profile without significantly affecting antioxidant status.