Study On The Weight Loss Effect And Mechanism Of Trilobatin From Lithocarpus Polystachyus Rehd On Obese Rats Induced By High-fat Diet

The leaves of Lithocarpus Polystachyus Rehd(LPR)are known for their sweetness.It was once a sweet tea in the south of the Yangtze River in China,especially in Jiangxi,Guangxi,Hunan,Sichuan,Yunnan and other provinces,as well as India,Thailand,and Laos in Southeast Asia.Since 2017,LPR has been approved as a new food raw material due to its edible and medicinal functions.At the same time,LPR extract has physiological functions such as antioxidant,anti-inflammatory,anti-bacterial,anti-diabetic,anti-cancer,liver protection,heart protection,anti-obesity,nerve protection and anti-allergy.The main biological activity of LPR is the components of phlorizin and trilobatin,and the content of trilobatin is greater than that of phlorizin.Studies have shown that both the extracts of saccharum and phlorizin can significantly reduce the body weight,fasting blood sugar and insulin resistance of obese rats induced by high-fat diet.However,in animal models,there has been no research on the weight-reducing effect of trilobatin,the main flavonoid compound in LPR.LPR has a long drinking history.It not only has high sweetness,low calorie,safety and non-toxicity,but also has the same medicine,sugar,tea and other comprehensive functions.The basic theoretical research on the value of nutrition and health has great social and economic significance for the diversification of its product development and the enhancement of its industrial value.Therefore,in this study,trilobatin from LPR was taken as the research object,and SD obese rats are used as experimental animal models.Based on this,in this study,the study is based on the study of the trilobatin,and the SD obese rats are used as the experimental animal model.By setting high,medium,and low doses of trilobatin,the effect of trilobatin on the high-fat diet-induced weight loss in obese rats,and explore the possible weight loss mechanism of trilobatin from three aspects: fat metabolism genes,activation of brown adipose tissue activity and intestinal microbes.Finally,the effects of trilobatin on oxidative stress in obese rats during weight loss were studied,and the positive effects of trilobatin on the prevention and treatment of obesity were discussed.It is expected to provide a theoretical basis for its nutritional and health value for the development of LPR and trilobatin health products and clinical drugs.The main research conclusion reports are as follows:(1)Study on the weight loss effect and mechanism of trilobatin from LPR on obese rats by induced high-fat dietTaking SD rats as the experimental research object,the obese rat model was induced by high-fat diet,and then the weight loss effect of trilobatin was investigated by gavage intervention with positive drugs and high,medium and low doses of trilobatin.At the same time,blood lipid levels(TG,TC,HDL-C,LDL-C),liver function(AST and ALT),liver and white adipose tissue morphology changes are analyzed and checked.The mechanism of trilobatin's weight loss effect was discussed at the hormone and gene level.The results of weight loss experiments show that trilobatin can significantly reduce the weight gain of obese SD rats induced by high-fat diet without affecting food intake(p<0.05),indicating that trilobatin has an effect on obesity caused by high-fat diet.Rats have obvious weight loss effects.Among them,the middle and high doses of trilobatin significantly reduced the fat percentage of obese SD rats(p<0.05).The test results of blood lipid indexes and liver function indexes showed that trilobatin can significantly reduce the serum TG,TC,and LDL-C contents in rats(p<0.05)and the effect is better than the positive control drug orlistat.After the intervention of trilobatin and orlistat,the activities of ALT and AST were also significantly reduced(p<0.05),and the effect of the high-dose trilobatin group was better than that of orlistat.Histomorphological examination results show that trilobatin can significantly reduce the void area in liver tissue and heal inflammatory cells,reduce lipid deposition,and reverse liver tissue lesions caused by fat deposition;at the same time,the cell volume in white adipose tissue is significantly reduced.The mechanism research results show that(a)medium and high-dose trilobatin and orlistat can significantly reduce the serum insulin,lysin and neuropeptide Y content(p<0.05),and significantly improve lysin resistance and insulin resistance.Reducing the secretion of NPY,thereby reducing the desire for food intake,helps control the development of obesity.(B)Both trilobatin and orlistat can significantly down-regulate the expression of PPAR? and ACC genes,thereby inhibiting the differentiation and proliferation of preadipocytes and reducing the deposition of body lipids.High-dose trilobatin and orlistat can significantly down-regulate the expression of FAS gene in liver and white fat(p<0.05),and reduce the production of fatty acids.At the same time,TR-H and HFD-PD can significantly up-regulate the expression of PPAR? gene in liver and white fat(p<0.05),thereby accelerating fat oxidation,increasing fat decomposition in liver and white fat tissue,and improving liver cell steatosis and reducing The accumulation of lipid droplets in fat cells restores the normal state of fat cells.The trilobatin group can also significantly up-regulate the expression of HSL gene(p<0.05),which is 1.34 times(TR-L),1.47 times(TR-M)and 1.75 times(TR-H)respectively compared with the HFD group.The middle and high doses of trilobatin and orlistat can significantly up-regulate the expression of CPT1 gene(p<0.05).Therefore,we speculate that trilobatin may have the effects of PPAR?,HSL and CPT1 agonists,and stimulate the expression of three genes,thereby accelerating the body's lipolysis,reducing fat content and fat accumulation in visceral tissues.At the same time,high-dose trilobatin significantly up-regulated the expression of UCP1 gene in white adipose tissue(p<0.05),induced browning of white adipose tissue,and increased non-trembling heat production in the body,which indicates that more energy will be promoted as heat.It is released and cannot be used for the synthesis of fat,which has a positive meaning for weight loss.The above results indicate that trilobatin can significantly reduce weight gain in obese rats induced by high-fat diet,improve dyslipidemia,repair liver tissue lesions,and these may be through improvement of glycine,insulin sensitivity,diet control,and up-regulation of lipolysis genes The result of the expression and down-regulation of the expression of fat synthesis genes.(2)The effect of trilobatin from LPR on the functional activity of brown fat mediated by Tyk2/STAT3 signaling pathway.Western blotting was used to investigate the expression of Tyk2 and STAT3 proteins in the Tyk2/STAT3 signaling pathway in brown adipose tissue,as well as the downstream PPAR?,PRDM16,C/EBP?,PPAR? and UCP1 protein expression changes,from the perspective of activating the functional activity of brown fat The mechanism of trilobatin on weight loss in obese rats was discussed.The results showed that compared with the LFD group,the expression of Tyk2 protein and STAT3 protein in the brown fat of the HFD group obese rats decreased significantly(p<0.05),which means that the information transmission capacity of the Tyk2/STAT3 signaling pathway is reduced,leading to the functional activity of brown fat.Weak,that is,the efficiency of "fat burning" heat generation decreases.The intervention of trilobatin can significantly increase the expression of Tyk2 protein and STAT3 protein,can offset the inhibition of Tyk2/STAT3 signal pathway activity caused by high-fat diet to a certain extent,restore the normal development of brown adipose tissue and regulate lipid metabolism.At the same time,obesity induced by a high-fat diet reduces the expression of PPAR?,PRDM16 and C/EBP? in brown fat,resulting in the inhibition of brown fat cell differentiation and a corresponding decrease in the number.This will limit the normal function of brown adipose tissue,and increase the conversion of excess energy to fat.The most direct manifestation is that more and more multi-eye lipid droplets in the cells become monocular lipid droplets.Trilobatin can up-regulate the expression of PPAR?,PRDM16 and C/EBP? protein,restore the normal differentiation of brown adipocytes,improve the morphology of brown adipose tissue,and reduce the adverse effects of high-fat diet.Compared with the LFD group,the expression of PPAR? protein and UCP1 protein in the HFD group was significantly down-regulated(p<0.05),which to a certain extent indicates that obesity leads to the reduction of energy conversion into heat,and the functional activity of brown fat is inhibited.Trilobatin can significantly increase the expression of PPAR? and UCP1 protein,increase the metabolic activity of brown adipose tissue and increase thermogenesis.The above results indicate that trilobatin can maintain the proliferation and differentiation of brown adipocytes by activating the activity of the Tyk2/STAT3 signal transduction pathway,increase the mass of brown fat,and ultimately up-regulate the expression of the thermogenesis factor UCP1 protein,which consumes more energy and converts it into heat release.This may be another way to achieve weight loss with trilobatin.(3)The effect of trilobatin from LPR on gut microbiota and intestinal microecology of obese rats.Gas chromatography was used to detect the content of 6 short-chain fatty acids(SCFAs)in the cecum.At the same time,Mi Seq high-throughput sequencing technology was used to sequence the V3 region of the rat intestinal flora 16 Sr DNA,and the composition and abundance of the intestinal flora were determined based on the Illumina platform.The Chao index,Simpson index,Shannon index and Goods coverage were used to analyze the alpha diversity of the gut microbial,and the beta diversity was analyzed by principal coordinate analysis(PCo A).SCFAs test results show that trilobatin can significantly increase the content of short-chain fatty acids in the intestinal tract,especially the content of butyric acid.High-throughput sequencing results showed that compared with the high-fat control group,the intervention of trilobatin significantly increased the relative abundance of Lactobacillus and Oscillospira(p<0.05),and decreased Blautia and Allobaculum,The relative abundance of Phascolarctobacterium and Coprococcus(p<0.05),resulting in an increase in the ratio of Firmicutes and Bacteroidetes.This shows that at the level of phylum and genus,trilobatin regulates the structure and diversity of gut microbiota of obese rats,and this change of gut microbiota can promote the metabolism of blood lipids in obese rats and reduce inflammation and increase Positive regulation of leptin and body health.PICRUSt analysis predicted KEGG metabolic pathway results showed that between the trilobatin treatment group(TR-L,TR-M and TR-H)and HFD group,the KEGG pathway predicted by PICRUSt is significantly different,mainly involved in lipid metabolism(steroids Biosynthesis,steroid hormone biosynthesis),amino acid metabolism(D-arginine and D-ornithine metabolism),other secondary metabolites(flavonoid biosynthesis),terpenoids and polyketides(carotenoid biosynthesis)),as well as cofactors and vitamins(retinol metabolism),indicating that trilobatin may participate in the body's lipid synthesis and energy metabolism through the influence of intestinal flora,and then play a positive role in the body's obesity.The above results reveal the contribution of intestinal flora to the weight loss effect of trilobatin in LPR and predict the potential regulatory mechanism of obesity induced by high-fat diet.(4)The effect of trilobatin from LPR on oxidative stress in obese rats induced by high-fat diet.The experiment was conducted to detect malondialdehyde(PC),carbonylated protein(PC),superoxide dismutase(SOD),and catalase(CAT)in the serum and tissues(liver,white adipose tissue and brown adipose tissue)of obese rats.)And glutathione(GSH),investigated the effect of trilobatin on the level of oxidative stress in obese rats,and studied the mechanism of trilobatin against oxidative stress in obese rats at the gene level..The results of the study showed that compared with the LFD group,the levels of MDA and PC in the serum and tissues of the obese rats in the HFD group increased significantly(p<0.05),and severe oxidative stress occurred in the obese rats.The intervention of trilobatin and the positive drug orlistat can significantly reduce the content of MDA and PC in serum and tissues.Among them,the content of MDA and PC in the TR-H group decreased significantly(p<0.05);at the same time,the trilobatin group(TR-L?TR-M?TR-H)the SOD activity,CAT activity and GSH content were all increased and enhanced,and the effect of high dose trilobatin was the most significant(p<0.05).Nuclear factor E2-related factor 2(Nrf2)is considered to be a key regulator of the body's resistance to oxidative stress.Compared with the HFD group,trilobatin can up-regulate the expression of Nrf2 in liver,white fat and brown fat in a dose-dependent manner,especially the high-dose trilobatin group up-regulated 2.48 times,1.20 times and 1.23 times,respectively.Combining the changes of SOD,CAT and GSH in the tissues and serum of rats in the previous article,we speculate that trilobatin may increase the expression of Nrf2 to promote the expression of SOD,CAT and GSH and other antioxidant enzymes,and then reduce the body's oxidative stress.The above results indicate that trilobatin can significantly reduce the level of oxidative stress in obese rats,and its mechanism of action may be achieved by up-regulating the expression of the Nrf2 gene.Conclusion: This study systematically studied the weight loss effect of trilobatin from LPR on obese rats induced by high-fat diet,and confirmed that trilobatin has a strong weight loss effect,and it also lowers blood sugar and blood lipids.And protect the liver and protect the liver.It is revealed that trilobatin can up-regulate the expression of lipolysis genes in the liver and white adipose tissue of obese rats and down-regulate the expression of fat synthesis genes,accelerate lipolysis and fatty acid oxidation,and reduce body fat synthesis and deposition to play a weight loss effect;confirms three Foliar glycosides promote the browning of white adipose tissue and increase the energy consumption of the body without trembling heat production;further studies have confirmed that trilobatin activates and enhances the functional activity of brown fat mediated by Tyk2/STAT3 signaling pathway,making the body more Energy is released as heat energy through non-thrilling heat production,which increases the rate of lipolysis and fatty acid oxidation to exert weight loss;reveals the contribution of intestinal flora to the weight loss effect of trilobatin in LPR,and predicts the potential regulation of obesity induced by high-fat diet Mechanism: It is confirmed that trilobatin increases the activity or content of the body's antioxidant enzymes by up-regulating the expression of the Nrf2 gene,alleviating the body's oxidative stress level,reducing the inflammatory response in obese rats,and contributing to the treatment of obesity.