Anti-atherosclerotic effect of Cynodon dactylon extract on experimentally induced hypercholesterolemia in rats

Abstract

Cynodon dactylon (Bermuda grass) is a perennial plant traditionally used as an herbal medicine in many countries. In the present study, anti-atherosclerotic property of ethanolic extract of C. dactylon was investigated in the experimentally induced hypercholesterolemia in rats. In this study, 36 male Wistar rats were selected and allocated into six groups (n = 6). The control group received a normal diet, sham group received a high cholesterol diet (HCD; 1.50% cholesterol and 24.00% fat) and other groups received a HCD and ethanolic extract of C. dactylon at low (100 mg kg^-1), moderate (200 mg kg^-1) and maximum (400 mg kg^-1) doses via gavages. The last group received atorvastatin (10 mg kg^-1) through gavage with a HCD. The study period for all groups was six months. At the end of this period, parameters including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were assessed in the blood samples. Additionally, histopathological and immunohistochemical examinations on coronary and aorta arteries sections were performed. The results showed an increase in vessels wall thickness and proliferation of smooth muscle cells in the HCD group, while these pathological changes were not seen in C. dactylon-treated groups. Treatment of HCD animals with C. dactylon positively changed lipid profile by lowering of TC, TG and LDL-C. The results indicate that C. dactylon prevents from early atherosclerotic changes in the vessels wall.

Keywords: Atherosclerosis; Cynodon dactylon; Hypercholesterolemia; Lipid profile.

Fig. 1

Measurements of intima and media layers thickness of thoracic aortas from rats treated with or without C. dactylon (n = 6).  *^,# indicate significant differences compared to control and non-treated HCD groups at p < 0.05, respectively. HCD: high cholesterol diet; HCD+L: low dose of C. dactylon; HCD+M: medium dose of C. dactylon; HCD+H: high dose of C. dactylon and HCD+STN: HCD+atorvastatin

Fig. 2

Photomicrographs of H & E (left) and Azan trichrome (right) cross sections of the thoracic aortas of control, high cholesterol diet (HCD), low dose (100 mg kg^-1) of C. dactylon (HCD+L ), medium dose (200 mg kg^-1) of C. dactylon (HCD+M ), high dose (400 mg kg^-1) of C. dactylon (HCD+H) and atorvastatin (10 mg kg^-1) group (HCD+STN

Fig. 3

Photomicrographs of Azan trichrome cross sections of the coronary artery. Density of blue colored fibers indicates vascular wall fibrosis. HCD: high cholesterol diet; HCD+L: low dose of C. dactylon; HCD+M: medium dose of C. dactylon; HCD+H: high dose of C. dactylon and HCD+STN: HCD+atorvastatin

Fig. 4

Analysis of cellular proliferation. A) Nuclear positivity for proliferating cell nuclear antigen (PCNA) immunostaining (arrows) increases within coronary artery regions indicate the association of observed vascular remodeling with smooth muscle cells proliferation, PCNA immunostaining,. B) Analysis of the density of PCNA-positive cells. C) Software analyses for distribution of PCNA positive cells (pixel-based histogram). Each value represents the average positive-cell density and the mean ± SD of six animals. *^,# indicate significant differences compared to control and non-treated HCD groups at p < 0.05, respectively. HCD: high cholesterol diet; HCD+L: low dose of C. dactylon; HCD+M: medium dose of C. dactylon; HCD+H: high dose of C. dactylon and HCD+STN: HCD+atorvastatin

Fig. 5

Proliferating cell nuclear antigen (PCNA) staining of aortic cross sections. A) Nuclear positivity for PCNA immunostaining (arrows) increases with in aorta wall indicate that observed vascular remodelling is associated with smooth muscle cells proliferation, PCNA immunostaining,. B) Analysis of the density of PCNA-positive cells. C) Software analyses for distribution of PCNA positive cells (pixel-based histogram). Each value represents the average positive-cell density and the mean ± SD of six animals. *^,# indicate significant differences compared to control and non-treated HCD groups at p < 0.05, respectively. HCD: high cholesterol diet; HCD+L: low dose of C. dactylon; HCD+M: medium dose of C. dactylon; HCD+H: high dose of C. dactylon and HCD+STN: HCD+atorvastatin