Antiatherogenic Effect of Camellia japonica Fruit Extract in High Fat Diet-Fed Rats

Abstract

Hypercholesterolemia is a well-known etiological factor for cardiovascular disease and a common symptom of most types of metabolic disorders. Camellia japonica is a traditional garden plant, and its flower and seed have been used as a base oil of traditional cosmetics in East Asia. The present study was carried out to evaluate the effect of C. japonica fruit extracts (CJF) in a high fat diet- (HFD-) induced hypercholesterolemic rat model. CJF was administered orally at three different doses: 100, 400, and 800 mg·kg(-1)·day(-1) (CJF 100, 400, and 800, resp.). Our results showed that CJF possessed strong cholesterol-lowering potency as indicated by the decrease in serum total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL), accompanied by an increase in serum high-density lipoprotein (HDL). Furthermore, CJF reduced serum lipid peroxidation by suppressing the formation of thiobarbituric acid reactive substance. In addition, oil red O (ORO) staining of rat arteries showed decreased lipid-positive staining in the CJF-treated groups compared to the control HFD group. Taken together, these results suggest that CJF could be a potent herbal therapeutic option and source of a functional food for the prevention and treatment of atherosclerosis and other diseases associated with hypercholesterolemia.

Figure 1

Effect of Camellia japonica fruits extract (CJF) on serum lipid peroxidation. (a) Measurement of thiobarbituric acid reactive substance (TBARS) level was done by comparison with the standard curve obtained using various dilutions of malondialdehyde (MDA). Values are expressed as mean ± SE (standard error), n = 8. ^† P < 0.05 (versus normal diet); ^∗ P < 0.05 (versus high fat diet). HFD: high fat diet. (b) Difference in transparency of serum in each group. After centrifuge of rat blood, compared to normal diet group with transparent serum, rats fed with HFD show turbid serum due to the presence of high amount of lipid. In case of CJF-treated group, serum of rats treated with CJF 400 and CJF 800 shows clearly low turbidity with respect to HFD and their transparency is almost similar to normal diet group.

Figure 2

Histological analysis of oil red O staining of the rat's artery. The figure shows the photograph of ORO stained artery of Wistar rats. Scale bar beneath the artery represents the actual length of each artery. Arrow head indicates the red positive stain of ORO dye of the lipid accumulated on the vessel wall.