| Red yeast rice is fermented rice from the fungus Monascus,which produce a series of Monascus pigments.Monascus pigments are a group of fungal metabolites called azaphilones;it has been widely used in food industry in the world,especially in China and Japan.Monascus pigments such as monascin and ankaflavin also have a series of biological activity.In recent years,researchers have found that red yeast rice has the lower blood pressure,hypolipidemia,anti-inflammatory and other biological activities.In the past two centuries,people have paid more and more attention on Monascus pigments;more than 50 kinds of Monascus pigments have been reported.This paper is aim to compare the effects of red yeast rice and yellow pigments(monascin and ankaflavin separated from red yeast rice)in lipid metabolism of hamsters.Drying sample of red yeast rice was ground into powder,then it was extracted by water and 75%ethanol assisted with ultrasonic,respectively.After enrichment,red yeast rice extract is resolubilized with 75%ethanol to remove sugar,and two yellow pigments in crude extraction were separated with preparative high performance liquid chromatography(HPLC).The two separated yellow fractions were collected respectively.The solvent was removed under reduced pressure and lyophilization,the resultant fractions were further analyzed by analytical HPLC.The purity of two yellow pigments was confirmed more than 95%.According to the results of liquid chromatography mass spectrometry detection,the molecular weight and molecular formula of two yellow pigmints was confirmed as monascin and ankaflavin.Red yeast rice and purified yellow pigments(monascin and ankaflavin:the same dosage of that in Red yeast rice)was administered to hamsters,respectively.The serum total cholesterol(TC),triglycerides(TG),low density lipoprotein cholesterol(LDLC),high density lipoprotein cholesterol(HDLC)were measured,the results showed that red yeast rice gavage administration group reduced serum TC(p>0.05),lower the level of HDLC,but was not obvious,while the LDLC level decreased significantly(p<0.05).Pigments gavage administration group had no obvious effect on TC and TG,increased the level of HDLC and decreased LDLC with no significant difference(p>0.05).The lovastatin gavage administration positive control group increased cholesterol and triglyceride content in liver,while in red yeast rice and pigments gavage administration group,cholesterol level in liver decreased by 18.1%and 27.0%,respectively.The content of triglyceride in liver was also increased significantly(p<0.01)in pigments gavage administration group.The transcriptional expression level of cholesterol metabolism related genes were determined by the method of real-time quantitative PCR.The expression of SREBP-2 at transcriptional level in lovastatin and red yeast rice group increased,but significantly decreased(p<0.01)in pigments group.The expression of HMGCR in all administration groups was decreased,especially in red yeast rice and pigment group(p<0.01).The expression of LDLR in all administration groups was significantly lower than that in the high cholesterol fed group.The expression of LXR-α in lovastatin and red yeast rice group increased and increased significantly(p<0.01)in red yeast rice group.The expression of CYP7A1 in high cholesterol fed group was higher than that in normal diet control group.The expression of CYP7A1 in all Administration groups were lower than that in high cholesterol fed group,among them,pigments group reduced significantly(p<0.05).According to the above experimental results,it can be seen that both red yeast rice and two purified pigments have lipid-lowering effect,and the hypolipidemia effect of red yeast rice is better than that of pigments. |
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