The Effect And Potential Mechanism Of Lutein On Serum Uric Acid In High Fat Fed Rats

Objectives:The study aimed to investigate the effect of lutein on serum uric acid (SUA) inSD rats fed with high fat diet and to explore the possible mechanisms of lutein on uricacid metabolism by comparing the enzyme levels of xanthine oxidase (XOD),adenosine deaminase (ADA),.superoxide dismutase (SOD) and the level ofmalondialdehyde both in serum and liver.Methods:To evaluate the effect of high fat diet on lipid and uric acid in rats,20male SDrats were randomly divided into control group and high fat diet group, fed with labchow diet and high fat diet respectively for eight weeks. The level of serum uric acid,total cholesterol (TC), triglyceride (TG), and the activity of XOD and ADA weremeasured.To study the effects of lutein on lipid and uric acid in rats fed with high fat diet,40male SD rats were randomly divided into control group and high fat diet group,fed with lab chow diet and high fat diet respectively for four weeks. Then the rats inhigh fat diet group were divided into four groups (HF, HF+lutein L, HF+lutein M,HF+lutein H). The rats in lutein groups were given the doses of12.5,25.0, and50.0mg/kg·d-1lutein by gavage for four weeks. The rats were weighted weekly. After fourweeks of gavage, the levels of SUA, TC, TG, high density lipoprotein cholesterol(HDL-C), serum creatinine (SCr), blood urea nitrogen (BUN), and malondialdehyde(MDA) were measured. The activities of XOD, ADA, and superoxide dismutase(SOD) and MDA levels both in serum and liver were also measured. The histologicalchanges of kidney were checked under light microscope after hematoxylin-eosin (HE)staining. All the data were processed and analyzed by using SPSS12.0software.Independent-sample T-test and one-way analysis of variance (ANOVA) were used toanalyze the results. LSD test was used to analyze the difference between groups.Results:（1） By eight weeks of feeding, the levels of serum uric acid, TC, TG and the activity of XOD were significantly higher in the rats fed by high fat diet than thosefed with lab chow (P<0.05).（2） By four weeks of feeding, the body weight and the levels of serum uric acid,TC, TG and the activity of XOD were significantly higher, while the serim HDL-Cwas significantly lower in HF group rats than that in the ND group rats (P<0.05).There were no significant differences for the levels of BUN, Scr, and ADA activityamong the groups (P>0.05).After four weeks of gavage, the levels of SUA, TC, andMDA in HF+lutein M and HF+lutein H groups were significantly lower, while SODactivity was significantly higher than that of the HF group (P<0.05). The BUN levelswere significantly lower in the groups of rats fed with lutein than that in those in HFgroup (P<0.05). The ADA activities in blood and liver were significantly lower in therats of HF+lutein H group than that in the HF group rats..Conclusion:（1）High fat diet could induce hyperuricemia in rats.（2）Lutein has hypouricemic and renal protecting effects at appropriate dosagelevel in hyperuricemic rats on high fat diet.（3）The hypouricemic effect of lutein might due to improving lipid metabolismand reducing hepatic XOD activity, increasing antioxidant capacity, and reducinglipid peroxidation in rats fed with high fat diet.