关键词: 藜麦；不同色型；肥胖；脂代谢

Abstract: This work aimed to explore the effects of different colored quinoas from the same habitat on lipid metabolism in high-fat diet-fed mice. Totally, 50 specific pathogen-free (SPF) male mice were fed adaptively for seven days and then randomly divided into five groups: blank control, model, white quinoa, black quinoa and red quinoa according to their body mass. After eight weeks of dietary intervention, physiological and biochemical indicators including Lee’s index, waist circumference, abdominal fat mass, and total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) levels in serum and liver tissue were determined. The mRNA and protein expression levels of key genes related to cholesterol and lipid metabolism in liver were detected by quantitative real-time polymerase chain reaction (q-PCR) and Western blotting. The results indicated that compared with the model group, quinoa reduced the Lee’s index, waistline and abdominal fat mass, significantly lowered TC and TG levels in serum and liver (P < 0.05), increased HDL-C level in liver (P < 0.05), and down-regulated the mRNA and protein expression levels of 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoAr) and sterol regulatory element binding protein (SREBP)-1c (P < 0.05). The mRNA expression level of HMG-CoAr was decreased by 56.22%, 72.55% and 27.77% by white, black and red quinoas, respectively, and the protein expression level was decreased by 53.02%, 29.72% and 29.80%, respectively. The mRNA expression of SREBP-1c was decreased by 62.96%, 45.50% and 21.27%, respectively, and the protein expression was decreased by 20.79%, 23.97% and 20.26%, respectively. The mRNA expression levels of AMP-activated protein kinase (AMPK)-α, low density lipoprotein receptor (LDL-R), liver X receptor (LXR), peroxisome proliferators-activated receptor-α (PPARα) and cytochrome P450 family 7 subfamily A member 1 (CYP7A1) and the protein expression levels of LDL-R and PPARα were significantly increased by dietary supplementation of quinoa. LDL-R mRNA expression was increased by 243.86%, 273.04% and 121.93% by white, black and red quinoas, respectively, and protein expression was up-regulated by 18.02%, 17.16% and 22.45%, respectively. The mRNA expression of PPARα was increased by 62.45%, 87.54% and 126.91%, and protein expression was up-regulated by 54.26%, 51.10% and 33.82%, respectively. Collectively, the different colored quinoas can improve lipid metabolism disorders in high-fat diet-fed mice, white quinoa and black quinoa being more effective than the red one. The underlying mechanism may be related to the reduction of cholesterol synthesis and de novo synthesis of fatty acids.

Key words: Chenopodium quinoa; different colored quinoas; obesity; lipid metabolism