Effect of the polyphenol‐rich extract fromAllium cepaon hyperlipidemic sprague‐dawley rats

Abstract

Allium cepa is used for the prevention and treatment of hyperlipidemia-related diseases such as atherosclerosis in the folk. This study was mainly aimed at investigating the effects of A. cepa extract (ACE) enriched in polyphenols on hyperlipidemia Sprague-Dawley (SD) experiment rat models. The levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), malondialdehyde (MDA), and superoxide dismutase (SOD) activity in serum and liver were measured using ELISA kits. In addition, hematoxylin-eosin (HE) technique was used to observe the liver and the aortic arch pathology. Moreover, western blotting (WB) method was applied to analyze LDL receptor (LDLR) and 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase (HMGCR) in liver. As a result, quercetin (2.42 mg/g DW) and isoquercitrin (4.60 mg/g DW) were the main constituents of ACE using HPLC analysis. Furthermore, ACE reduced the levels of TC, TG, LDL-C, and MDA, and increased HDL levels and elevated SOD activity both in serum and liver in hyperlipidemic SD rats (p < .05). HE results showed that liver fat drops of the rats in ACE group were obviously decreased, and the lipid and foam cells of the aortic arch of the rats in ACE group were markedly ameliorated. WB results showed that ACE promoted the degradation of HMGCR and increased LDLR expression in liver (p < .05). In conclusion, ACE alleviated hyperlipidemia with downregulation of HMGCR and upregulation of LDLR. Practical applications Atherosclerosis, a major cardiovascular disease, is the leading cause of mortality and morbidity in the developed countries. Moreover, accumulating data indicate that, during atherosclerosis development, hyperlipidemia is an important risk factor. To date, hyperlipidemia is mainly treated with hyperlipidemic agents including statins, in spite of the side effects and poor tolerance in some patients. In addition, Allium cepa is a medicinal and edible plant. Furthermore, A. cepa is used for the prevention and treatment of hyperlipidemia-related diseases such as atherosclerosis in the folk. But the underlying mechanism is still unclear. In fact, this research showed that A. cepa extract (ACE) alleviated hyperlipidemia with downregulation of HMGCR and upregulation of LDLR, suggesting that ACE might be a potential option for hyperlipidemia as non-statin lipid-lowering agent. How to cite this article: Li W, Yang C, Mei X, et al. Effect of the polyphenol-rich extract from Allium cepa on hyperlipidemic sprague-dawley rats.

Onion and Apple Functional Ingredients Intake Improves Antioxidant and Inflammatory Status and Vascular Injury in Obese Zucker Rats

“…Supporting the present finding, sulphur compounds, such as cycloalliin, S -methyl-L-cysteine, S -propyl-L-cysteine sulphoxide, dimethyl trisulphide, and especially S -methyl-L-cysteine sulphoxide, were reported to be effective in inhibiting formation of oil drop in the cells, suggesting that these compounds may be involved in the antiobesity effect of the onion extract [ 45 ]. Therefore, the present results are in agreement with those reported in the literature showing lipid-lowering effects of different Allium cepa and apple products or extracts [ 15 , 46 , 47 ]. Regarding glycemia and insulinemia, a marked and significant reduction in plasma glucose and insulin in OO group (−35% and −49%, respectively) compared to OC group was found; meanwhile, plasma glucose and insulin levels in OA group were lower than in OC group, but less pronounced (−23%, −34%; respectively).…”

Allium cepa: A Treasure of Bioactive Phytochemicals with Prospective Health Benefits

“…These plaques causes narrowing and/or blocking of the blood vessels which disrupts blood flow in vital organs of the body such as heart and brain and thereby raising the risk of heart attack and stroke. A study performed by Wenyi Li et al to assess the antihypercholesterolemic activities of A. cepa on six groups of hyperlipidemic rats showed that there was a substantial decrease in total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-c) levels, and a raise in high density lipoprotein cholesterol (HDL-c) levels in both plasma and liver following 4 weeks of oral administration of A. cepa extract at different concentration for each group of rats [ 106 ]. Ming and his group of researchers performed a clinical trial on twenty-four mildly hypercholesterolemic adults to determine the effectiveness of onion juice against this condition, and the results showed that, after eight weeks of daily administration, the blood plasma TC, LDL-c, and LDL-c/HDL-c ratio levels were significantly lowered in onion juice treated subjects.…”

Bioactivity of Dietary Polyphenols: The Role in LDL-C Lowering

“…In an animal model study conducted by Li and colleagues revealed that the decrease of the plasma LDL-C content by 45% in the onion-fed group was associated with the inhibition of HMGR and the upregulation of LDLR expression, which was a plausible mechanism for its LDL-C lowering effect. Researchers concluded that this effect was due to the presence of quercetin and isoquercitrin in onion [79]. Polyphenols-rich grape extract capsules (300 mg/day) were orally given to obese individuals for a period of 12 weeks.…”