Study On Functional Activity Of Soybean Diacylglycerol In Vitro And In Vivo

At present,the functional research on soybean diacylglycerol focuses on its weight loss effect,and the research on whether it has antioxidant effect and its regulatory effect on adipocytes remains at a relatively shallow level.The influence of soybean diacylglycerol on bacterial flora and lipid metabolism has not been deeply studied.Therefore,in this study,we explored the inhibitory effect of soybean diacylglycerol on fat through in vitro cell experiments and it’s antioxidant effect through in vitro antioxidant experiments.A D-galactose-induced aging rat model was established and fed a diet containing soybean diglyceride.By measuring the lipid content and the activities of antioxidant enzymes in the rat serum,observing the liver slices and colon slices,and analyzing the changes of intestinal bacteria and changes in gene expression in colonic epithelial cells to study the effects of soybean diglycerides on aging rats..The research results are as follows:（1）In vitro antioxidant experiments showed that soybean diacylglycerol had a certain scavenging ability of DPPH·,·OH,O^2-·and Fe²⁺chelation ability.It had certain reducing ability and could inhibit lipid peroxidation to a certain extent.Compared with Model group,the activity of total superoxide dismutase,glutathione peroxidase,and total antioxidant capacity in the serum of rats were significantly increased after soybean diacylglycerol intervention,which may be the result of comprehensive regulation.3T3-L1 cell experiment showed that 3T3-L1 cells treated with soybean diacylglycerol accumulated fewer lipid droplets during differentiation.qPCR analysis showed that soybean diacylglycerol significantly down-regulated mRNA expression of PPARγ,C/EBPα,and C/EBPβduring3T3-L1 cell differentiation,thereby reducing fat accumulation.（2）The results of serum biochemical indexes showed that the intervention of soybean diacylglycerol increased the levels of high-density lipoprotein and decreased the levels of low-density lipoprotein,triglyceride,and total cholesterol,alleviating the lipid metabolism disorder of D-galactose induced aging rats.The serum levels of aspartate aminotransferase and alanine aminotransferase in rats were decreased compared with the model group under the intervention of soybean diacylglycerol,and there was no significant difference between the control group,indicating that soybean diacylglycerol alleviated liver damage in aging rats.The morphology of liver cells in aging rats fed soybean diacylglycerol was normal,and the colonic state was closer to that of healthy rats.（3）Soybean diacylglycerol alters gut bacteria and gene expression in colonic epithelial cells:16S rDNA analysis showed that soybean diacylglycerol restored two genera that were missing in the intestines of aging rats,namely Eisenbergiella and Veillonella.Further analysis showed that the relative abundances of Romboutsia and Ruminococcus＿2 in the intestinal microbiota of rats decreased significantly（P<0.05）,and the relative abundance of Lachnospiraceae＿NK4A136＿group increased significantly（P<0.05）with the influence of soybean diacylglycerol.Gene expression profiles of colonic epithelial cells showed that soybean diacylglycerol may regulate the health of the body by participating in the regulation of inflammation and immune-related genes.Further analysis showed that soybean diacylglycerol down-regulated two genes named Lipe and Fabp4 which were related to lipolysis of adipocytes in colonic epithelial cells to regulate lipid metabolism.Therefore,soybean diacylglycerol has a certain antioxidant capacity in vitro,and has the effect of inhibiting the aggregation of lipid droplets.It can improve lipid metabolism disorder and relieve liver cell damage and oxidative stress in aging rats,and it also helps the healthy state of colon in aging rats.Under the action of soybean diacylglycerol,the gut microbiota of aging rats induced by D-galactose was changed.Soybean diacylglycerol changed the genes related to lipid metabolism in colon epithelial cells to regulate lipid metabolism.