Astaxanthin-Rich Extract from the Green Alga Haematococcus pluvialis Lowers Plasma Lipid Concentrations and Enhances Antioxidant Defense in Apolipoprotein E Knockout Mice

Abstract

Dyslipidemia and oxidative stress contribute to atherogenesis. Astaxanthin (ASTX) is a red-colored carotenoid well known for its high antioxidant capacity. However, its effects on lipid metabolism and antioxidant defense mechanisms have received only limited investigation. We fed male apoE knockout (apoE)(-/-) mice, a mouse model for atherosclerosis, a high-fat (15%)/high-cholesterol (0.2%) diet alone (control) or supplemented with ASTX-rich Hematococcus pluvialis extract (0.03% ASTX by weight) for 4 wk. ASTX-fed apoE(-/-) mice had significantly lower plasma total cholesterol and TG concentrations than controls, but body weight and plasma alanine aminotransferase and aspartate aminotransferase did not differ between the groups. qRT-PCR analysis demonstrated significantly greater mRNA levels of LDL receptor (LDLR), 3-hydroxy-3-methylglutaryl CoA reductase, and sterol regulatory element binding protein 2 (SREBP-2) and greater mature SREBP-2 protein in the livers of ASTX-fed mice, indicating that increased LDLR expression may be responsible for the hypocholesterolemic effect of ASTX. Hepatic lipogenic gene expression was not altered, but carnitine palmitoyl transferase 1, acetyl-CoA carboxylase β, and acyl-CoA oxidase mRNA abundance were significantly increased by ASTX supplementation, suggesting the TG-lowering effect of ASTX may be due to increased fatty acid β-oxidation in the liver. Expression of the nuclear factor E2 related factor 2-responsive endogenous antioxidant gene also was induced with concomitantly lower glutathione disulfide levels in the livers of ASTX-fed apoE(-/-) mice compared to controls. In conclusion, these results suggest that supplementation of ASTX-rich H. pluvialis extract improves cholesterol and lipid metabolism as well as antioxidant defense mechanisms, all of which could help mitigate the progression of atherosclerosis.

Positive Effects of Astaxanthin on Lipid Profiles and Oxidative Stress in Overweight Subjects

“…In an SHR/NDmcrcp rat model treated with astaxanthin, adiponectin and HDLcholesterol were increased, but triglycerides and non-esterified fatty acids were decreased by improving insulin resistance [12]. Recently, Yang et al [15] have also reported that astaxanthin lowers plasma LPs and enhances antioxidant defence in apolipoprotein E knockout mice. One clinical trial evaluated the effect of astaxanthin on LPs [13].…”

Astaxanthin prevents TGFβ1-induced pro-fibrogenic gene expression by inhibiting Smad3 activation in hepatic stellate cells

“…Studies have demonstrated that ASTX exerts protective effects against oxidative stress [19,20], inflammation [21,22], type 2 diabetes [23], and cardiovascular diseases [24]. Our previous study demonstrated that ASTX lowered plasma lipid levels and enhanced hepatic antioxidant capacity in apolipoprotein E knockout mice [25]. However, whether ASTX can prevent the development of liver fibrosis has never been addressed.…”

Effects of Lutein Supplement on Serum Inflammatory Cytokines, ApoE and Lipid Profiles in Early Atherosclerosis Population

“…Serum LDL cholesterol-related parameters could effectively predict the risk of cardiovascular diseases 28) , and therapies aimed at lowering serum LDL-cholesterol had significant effects on the progression of atherosclerosis 29,30) . Although the mechanisms by which lutein exerts its biological functions in lipid regulation have not been well defined, evidence from an animal study suggested that xanthophyll carotenoids might lower serum LDL-cholesterol and triglyceride levels by increasing LDL uptake and fatty acid β-oxidation 31) . Yang et al observed that the livers of mice fed astaxanthin, another xanthophyll carotenoid, had significantly higher greater mRNA levels of LDL receptor, 3-hydroxy-3methylgutaryl CoA reductase, and sterol regulatory element bind protein 2.…”