| BackgroundMetabolic syndrome(MS)takes central obesity as its core,and together with impaired glucose tolerance,hypertension,hyperuricemia,hypertriglyceridemia,low high-density lipoprotein hyperlipidemia and other multiple risk factors of metabolic diseases.For these years number of obese population in the world growing sharply.The newest research reported that relative factors of MS are related to gut microbiota.Gut microbiota regulate host mainly by their intermediary products,and has multiple mechanism in MS mediated that the neuro-endocrine-immune barrier of intestinal local is one of the key points.Oral bioavailability of many components of Chinese herb and natural plants is low,and these components need to be transformed by the intestinal flora in order to effectively be used by the host.Moveover,these components have been found impact on the structure of intestinal flora,therefore the intestinal flora may be a target and key point for Chinese medicine to play a curative effect.Coptis as a commonly used herb on MS contains alkaloids,non-alkaloids and other ingredients which have influences on heat-cleaning and damp-drying,purging fire and detoxicating.Berberine(BBR)have been reported to regulate the gut microbiota of MS,and our previous study indicated that compared with the BBR,the coptis decoction(containing the same dosage of BBR)moderated glucose and lipid metabolism better.It remains an open question as to whether the mediation of gut microbiota by coptis decoction(CD)and BBR is the same or not,and whether the regulation on colonic GPR43 pathway by metabolin of gut microbiota is the same or not.ObjectiveTo investigate the effects of Coptis decoction and BBR on the gut microbiota of the rats with(MS)induced by high-fat diet(HFD),and to investigate the effect of intestinal flora on colonic glp-1 and pyy through the GPR43 pathway.Methods1.Molding:Sixty Sprague Dawley rats were randomly divided into normal diet(ND)group(n = 15)and HFD group(n = 45).According to our previous modeling experience,three rats were excluded,weight and weight gain rate of which were lower than that of ND group rats after 8 weeks of feeding.The HFD group(n=42)was further divided into three groups:a group treated with a combination of CD and HFD for 4 weeks,a group treated with a combination of BBR and HFD for 4 weeks,and a group treated only with HFD for 4 weeks continually.2.Intragastric administration:8.31%BBR was determined in the CD by high-performance liquid chromatography.According to the formula of dose conversion between rat and human,the intragastric dose of BBR group was calculated as 150mg/kg.BBR group and CD group received the same amount of BBR hydrochloride,so the intragastric dose of CD group was calculated as 150/8.3%=1807mg/kg.The intragastric dose in each group was calculated according to the weight of rats every week,and CD fire heating decocting concentrated to about 200ml,BBR was dissolved in 200ml distilled water and made into suspension,while ND group and HFD group were treated with the same volume of Sterile water.3.Determination:(1)Throughout the experiment,the body weight of each rat was recorded once weekly,and the food intake of each rat was monitored every day.(2)Serum HDL-C,LDL-C,TC,TG,FBS were measured by biochemical method.Irisin levels were measured by enzyme immunoassay,and FINS were measured by radio-immuno-assay.(3)Left epididymal fat was excised and precisely weighed.(4)Total genomic DNA of the gut microbiota was extracted from cecal feces samples,then DNA library were bulid,the V3-V4 region of the cecum microbiota 16S rRNA gene amplicon was sequenced on the Illumina MiSeq platform.All the work was done by BGI Co.,Ltd(Shenzhen,China).Finally,bioinformatics analysis were done with the sequencing data.(5)Associations among the gut microbiota composition with serum index,weight,weight gain and epididymal fat wet weight were analysed by canonical correlation analysis and Kendall rank correlation coefficient.(6)Colonic glp-1 was measured by immunoblotting.(7)Colonic PYY was measured by enzyme immunoassay.Results(1)Food intake in all HFD groups was slightly lower than that in the ND group,and food intak have no significantly difference among with three HFD groups.The CD and BBR groups Inhibited the growth of body weight in rats,while the effect is more obvious in the CD group.(2)Compared to the ND group,the serum LDL-C and irisin levels were significantly increased in the HFD group,whereas the serum HDL-C levels were significantly reduced in the HFD group.LDL-C and HDL-C of the HFD group were not significantly different from those of the two drug treatment groups,but irisin of the HFD + BBR group was significantly higher than that of the HFD group.(3)Compared to the ND group,the epididymal fat weight was significantly increased in the HFD group.The epididymal fat weight was not significantly different from those of the two drug treatment groups.(4)The cecum microbiota of our MS rats have been changed obviously:diversity of the cecum microbiota decreased,and conditional pathogen increased,and intestinal barrier repair bacteria reduced.CD and BBR almost reversed these changes.However,the structure of cecum microbiota in this two groups were no the same.Compared with the CD group,A.Muciniphila which can repair Intestinal barrier,Bacteroides which produces propionic acid was observably higher in the BBR group,whereas,the abundance of bacteria which produce butyrate as Oscillospira was lower in the BBR group.Compared with the BBR group,diversity of the gut microbiota is higher in the CD group,and the structure of gut microbiota in the CD group was more close to the ND group.(5)To investigate the relationship between the variation in gut bacterial community and these MS indicators,an association analysis based on CCA regression model was conducted using the 1,149 OTUs obtained.HDL-C was the most relevant to the ND group,whereas left-epididymal-fat and 4-week-weight gain were the most relevant to the HFD group.LDL-C was the most relevant to the HFD + CD group,whereas blood glucose was the most relevant to the HFD + BBR group.Based on the 231 OTUs,nonparametric Kendall's rank correlation analysis was performed on evaluating the associations of the MS-related indicators with these OTUs.The results showed that HDL-C was most significantly correlated with these OTUs.(6)Colonic glp-1 was no obviously difference between all the groups.Compared with the ND group,glp-1 in the three HFD group have an increasing trend;Compared with the HFD group,glp-1 in the BBR and CD group have an increasing trend.(7)Compared with the ND group,PYY significantly increased only in the CD group,PYY in the BBR group have an increasing trend.There was no significant difference between four groups after protein calibration.Conclusion(1)CD could reverse the change on structure of gut microbiota of MS rats caused by HFD,and the mechanism underlying the treatments of BBR and CD on HFD-induced MS was partly different.(2)Berberine could significantly increase the level of serum irisin of MS rats,(3)Among the indicator of serum and basic index of MS rats,HDL-c was most significantly correlated with gut microbiota.(4)The modulation of colonic glp-1 and pyy by metabolin of gut microbiota was consistent with propionic acid-GPR43-glp-1/PYY bathway. |
PDF Full Text Request