| Chitooligosaccharide is an oligosaccharide with various biological activities such as antibacterial,lipid-lowering,immune regulation,anti-sugar,etc.obtained from the degradation of chitosan.Hyperuricemia is a disease caused by the disorder of purine metabolism,mainly manifested as excessive uric acid production or insufficient uric acid excretion,and at the same time,it will cause intestinal microecological disorders.Although the treatment of hyperuricemia is effective,it will cause certain damage to the liver and kidney.Therefore,it is very necessary to find a suitable drug for lowering uric acid,and it also has a broad market prospect.Therefore,the following studies were carried out at the levels of molecular,cells,and animals,focusing on the regulatory effects of chitooligosaccharide and its composite solid beverage "ke suan ping" on hyperuricemia and its intestinal microecology.The inhibitory effect of chitooligosaccharide on xanthine oxidase(XOD),the key enzyme of uric acid production,was detected by enzymatic reaction in vitro.The results showed that chitooligosaccharide could not directly inhibit XOD enzyme activity in vitro.At the same time,the adsorption effect of chitooligosaccharide on uric acid precursor was detected by the liquid chromatography.The results showed that the chitooligosaccharide at1200,2400,and 4800 μg/m L could adsorb the free bases of hypoxanthine,guanine,inosine,and adenosine,which reduced the peak height and area of the maximum absorption peak.An unknown impurity peak appeared at 2.4 minutes,and the peak area increased with the increase of chitooligosaccharide concentration.The cell experiment determined the optimal dose range of chitooligosaccharide by cell activity test(MTT),established a high uric acid cell model,and tested the effect of chitooligosaccharide on uric acid lowering.In addition,the overexpression plasmid was transfected into cells to overexpress XOD,and the inhibitory effect of chitooligosaccharide on the transcription level of XOD was verified.The results showed that: 5,25,125 and 250μg/m L chitooligosaccharide did not have a great impact on cell activity,and could significantly reduce the supernatant uric acid in the cell model,and 250 μg/m L chitooligosaccharide can also down-regulate the transcript level of XOD.The hyperuricemia mouse model was established by gavage of 10 g/kg yeast extract and intraperitoneal injection of 300 mg/kg potassium oxonate.The experiment set up 9groups,negative control group(NC),hyperuricemia model group(M),low/medium/high-dose COS group(LCOS/MCOS/HCOS),low/medium/high-dose KSP group(LKSP/MKSP/HKSP),allopurinol group(AP).Collect mouse serum to detect blood clarification indicators,collect mouse liver,kidney,and intestine for HE staining and q-PCR,collect cecal contents for 16 S r DNA sequencing and metabolite detection and collect colon contents for short-chain fatty acids detection.The results showed that chitooligosaccharide and KSP can reduce serum uric acid/XOD/urea nitrogen/creatinine levels in hyperuricemic mice,alleviate liver and kidney damage,down-regulate the expression of XOD/URAT1/GLUT9/SMYD3/EZH2 transcript levels,and up-regulate the transcriptional level expression of ABCG2.In addition,chitooligosaccharide can reduce the relative abundance of Lachnospiraceae＿NK4A136＿group and Alistipes in hyperuricemic mice,while increasing the relative abundance of Lachnospiraceae＿UCG-006,and KSP reduces the relative abundance of Bacteroides,Alloprevotella,Prevotellaceae＿UCG-001,increasing the relative abundance of Lactobacillus.And chitooligosaccharide and KSP also can modulate the production of metabolites and short-chain fatty acids in hyperuricemic mice. |
