Dandelion Polysaccharides Ameliorate High-Fat-Diet-Induced Atherosclerosis in Mice through Antioxidant and Anti-Inflammatory Capabilities

Abstract

Dandelion (Taraxacum officinale), a member of the Asteraceae (Compositae) family, is well known as the traditional medical plant. Dandelion polysaccharides, a natural active ingredient extracted from the dandelion, possess immune regulation, anti-inflammatory, antioxidant, and anti-aggregation properties. These properties suggest that dandelion polysaccharides might alleviate atherosclerosis. Using an ApoE^-/- atherosclerotic mice model fed a high-fat diet, we investigated the impact and potential mechanism of dandelion polysaccharides on atherosclerosis. We observed that dandelion polysaccharides significantly reduced the levels of triglyceride, total cholesterol, and low-density lipoprotein-cholesterol in serum, while elevated the high-density lipoprotein-cholesterol level. Concomitantly, dandelion polysaccharides reduced the area of atherosclerotic lesions and necrotic core of the aortic sinus, and increased the collagen content. Mechanistic studies showed that dandelion polysaccharides were effective in reducing serum malondialdehyde levels while elevating the enzymatic activities of superoxide dismutase and glutathione peroxidase. Furthermore, dandelion polysaccharides reduced the expression of chemotactic factor Mcp-1 and pro-inflammatory cytokines (Tnf-α, Il-1β, and Il-6) in atherosclerotic lesions. Overall, these results indicated that dandelion polysaccharides may take an important part in the attenuation of atherosclerosis via its antioxidant and anti-inflammatory properties.

Keywords: anti-inflammatory; antioxidant; atherosclerosis; blood lipid profiles; dandelion polysaccharides.

Figure 1

FT−IR spectrum of dandelion polysaccharides.

Figure 2

Scheme of dandelion polysaccharides intervention in HFD-induced atherosclerosis in ApoE^−/− mice.

Figure 3

Effects of dandelion polysaccharides on body weight and food intake in HFD-induced ApoE^−/− mice. The body weight (A) and feed consumption (B,C) in dandelion polysaccharides and saline group. Results were presented as means ± SD, and n = 10 in each group. t-test, ns, p > 0.05.

Figure 4

Effect of dandelion polysaccharides on serum lipids in HFD-induced ApoE^−/− mice. TG (A), TC (B), LDL-C (C), and HDL-C (D) levels of serum in dandelion polysaccharides and saline group. Results were presented as means ± SD, and n = 10 in each group. t-test, * p < 0.05, ** p < 0.01, *** p < 0.001.

Figure 5

Effect of dandelion polysaccharides on atherosclerotic lesion in HFD-induced ApoE^−/− mice. Representative images for Oil red O staining (A), HE staining (B), quantitative chart (C), and curve chart (D) of atherosclerotic lesion area by HE staining. The proportion of early, moderate, and advanced atherosclerotic plaques based on histological staging (E). The sale bar is 250 μm. Results were presented as means ± SD and n = 10 in each group. t-test, * p < 0.05, ** p < 0.01, *** p < 0.001.

Figure 6

Effect of dandelion polysaccharides on plaques’ necrotic core and collagen in HFD-induced ApoE^−/− mice. Curve chart (A) and quantitative chart (B) of atherosclerotic necrotic core area. Representative images (C) and quantitative chart (D) of atherosclerotic collage area. Quantitative chart of macrophage number (E) and vascular smooth muscle cell area (F) in atherosclerotic plaque. The sale bar represents 150 μm. Results were presented as means ± SD, and n = 10 in each group. t-test, ** p < 0.01, *** p < 0.001.

Figure 7

Effect of dandelion polysaccharides on antioxidant markers in HFD-induced ApoE^−/− mice. MDA concentration in serum (A). Activities of SOD (B) and GSH-PX (C) in serum. Results were presented as means ± SD, and n = 10 in each group. t-test, * p < 0.05, ** p < 0.01.

Figure 8

Effect of dandelion polysaccharides on chemotactic factors and inflammatory cytokines in HFD-induced ApoE^−/− mice. Relative mRNA expression of Tnf-α (A), Il-1β (B), Il-6 (C), and Mcp-1 (D) of mice aortas. (E) Immunoblotting of the expression of Tnf-α, Il-1β, Il-6, and Mcp-1 in mice aortas from both saline and dandelion polysaccharides-treated groups. (F) Quantification of protein expression in E. Results were presented as means ± SD, and n = 10 in each group. t-test, * p < 0.05, ** p < 0.01.

Figure 9

Schematic illustration of dandelion polysaccharides in ameliorating atherosclerosis. Compared with the saline group, the dandelion polysaccharide treatment improved the serum lipids and antioxidant markers, while lowering the expression of chemotactic factors and inflammatory cytokines in atherosclerotic mice.