Study On The Regulating Effect Of Tomato Seed Oil On Lipid Metabolism And Gut Microbiota In Mice

Tomato seed oil(TSO)is a new food material rich in numerous active ingredients such as polyunsaturated fatty acids,lycopene and phytosterols,which has the potential to improve lipid metabolism disorder and regulate gut microbiota.In view of this,this study firstly analyzed the composition and content of fatty acids and beneficial concomitant substances of TSO,studied the preventive effect of TSO on the lipid metabolism disorder in high-fat diet mice,and further explored its mechanism of action.At the same time,the effect of TSO on the gut microbiota of mice with high-fat diet was investigated.It will lay a solid theoretical basis for the comprehensive utilization of tomato processing by-products.The main results were as follows:1.Characteristic analysis of fatty acid in TSO and content determination of beneficial concomitant.The results showed that TSO contained 9 main fatty acids,of which the total saturated fatty acid accounted for 19.3%,the total monounsaturated fatty acid accounted for 24.3%,and the total polyunsaturated fatty acids for 50.7%.The total unsaturated fatty acid accounted for 75.0%,and linoleic acid accounted for the highest proportion.The TSO contained 34.8 mg/kg lycopene,37.2 mg/kg ?-carotene,243.0 mg/kg stigmasterol content,and 396.5 mg/kg ?-sitosterol.2.TSO prevented the disorder of lipid metabolism in mice.The effects of low and high dose TSO on plasma lipids,liver lipids,fecal lipids,and oxidative stress were investigated in C57BL/6J mice fed high fat diet.The results showed that TSO can effectively prevent lipid metabolism disorders and oxidative stress in the high-fat diet induced mice by significantly reducing the body weight,plasma total cholesterol(-34.1%),triglyceride(-23.8%)and low density lipoprotein cholesterol(-34.8%),and significantly increasing plasma high density lipoprotein cholesterol(+79.5%).TSO could also prevente the formation of fatty accumulation in the liver by significantly reducing liver cholesterol(-28.2%)and total fatty acids(-47.2%),and promoting fecal cholesterol excretion.Furthermore,TSO significantly increased catalase activity(+81.2%),and reduced malondialdehyde content(-19.1%)in plasma,significantly increased total antioxidant capacity(+15.6%),superoxide dismutase activity(+18.2%)and glutathion peroxidase activity(+22.2%)in the liver.3.The possible mechanism of TSO regulating lipid metabolism were also explored at the mRNA levels.The results showed that TSO significantly upregulated the gene expression of liver hepatic lipase(HL),peroxisome proliferator activated receptor ?(PPAR?),acyl-CoA dehydrogenase(ACADL),cholesterol-7?-hydroxylase(CYP7A1),liver X receptor ?(LXR?),ATP binding cassette transporter(ABCA1)and scavenger receptor B class 1(SR-B1).TSO can significantly attenuate the dyslipidemia by(1)increasing HL,PPAR?,and ACADL to accelerate fatty acid ?-oxidation;(2)accelerating cholesterol metabolism through the “LXR?-CYP7A1-Bile acid” pathway;(3)activating ABCA1 and SR-B1 to promote cholesterol reverse transport.4.The regulating effects of TSO on gut microbiota were investigated using a 16 S rRNA high-throughput sequencing analysis by exploring the effect of TSO on the diversity and community composition of gut microbiota in high-fat diet mice.The results showed that TSO can improve ?-diversity and ?-diversity of the gut microbiota of mice with high-fat diet,reduced the ratio of Firmicutes/Bacteroidetes,significantly increased the relative abundance of Lactobacillus,and reduced the relative abundance of Rikenella and Enterorhabdus.Spearman's correlation analysis showed that plasma lipid levels were positively correlated with the relative abundance of Rikenella,but negatively related with that of Lactobacillus.