| Studies have shown that barley is rich in flavonoids,?-glucans,phenolic compounds,proteins and other active ingredients,with functions such as regulating glucose and lipid metabolism,lowering cholesterol,and improving obesity.With the biological activity of fermented barley significantly enhanced,the nutritional function and application range changed accordingly.Caenorhabditis elegans(hereinafter referred to as C.elegans)has the advantages of simple structure,rapid propagation,short growth cycle,and convenient observation.The fat metabolism pathway is highly similar to humans,and the enzymes of the key metabolic steps are basically the same,which is an important Model organisms.The fat metabolism pathways are similar to human,and the enzymes of each key metabolic step are almost the same.In recent years,this model organism is used to study the functional activity of food ingredients or extracts,especially in regulating lipid metabolism and anti-aging.However,study on the regulation of lipid metabolism of C.elegans by fermented barley extract has not been reported.In this dissertation,barley was fermented by Lactobacillus plantarum(L.p)dy-1,which was separated and identificated by our laboratory,and the C.elegans obesity model was established to study the effect of fermented barley extract(LFBE)on lipid metabolism and its possible mechanism.The main research contents and results are as follows:(1)Study the effect of fermentation time on composition and functional activity of fermentation broth.The samples of fermentation broth of L.p dy-1 fermented barley were collected at different periods.The contents of main components were analyzed by phenol-sulfuric acid method,BCA kit method,LC and GC-MS.The results showed that the content of protein in the sample remained unchanged after fermentation to 8 h,but the content of total phenol,organic acid and tannin kept rising in the subsequent fermentation process;when the fermentation time reached 20 h or more,LFBE showed significant lipid-lowering effect,fermentation of LFBE 24 h can reduce the fat deposition of C.elegans 36%.(2)Study the effect of LFBE and its total sugar,total protein and phenolic compounds on fat deposition of C.elegans.A wild-type C.elegans obesity model was established to analyze the main components of LFBE affecting fat deposition of C.elegans by oil red O staining.It was found that LFBE had the function of reducing fat deposition in the C.elegans obesity model,and that phenolic compounds were the most prominent,followed by total protein.When the concentration of LFBE reached 800?g/m L and above,fat deposition in the C.elegans obesity model was significantly inhibited,and when the total protein concentration was 120?g/m L and the phenolic compound concentration was 4?g/mL,it had a significant lipid-lowering activity.The total sugar concentration needs to reach 480 ?g/mL to show its effect of reducing fat deposition.(3)Study the mechanism of LFBE and its main active components in inhibiting fat deposition of C.elegans,and use two gene-deficient C.elegans for preliminary validation.Oil Red O staining was used to observe the effects of LFBE and its main active components on fat deposition in two deficient C.elegans models.Real-time fluorescence quantitative PCR was used to determine the expression levels of lipid metabolism related genes in the C.elegans model.It is found that LFBE and its major active components regulate the lipid metabolism process dependent on the daf-2 gene,but does not depend on the daf-16 gene.The pathway to reduce fat deposition also includes effect of fat-5 expression levels in fat synthesis pathway and cpt-2 expression level in the ?-oxidation pathway.Therefore,it is speculated that,on the one hand,LFBE regulates the expression of daf-2 gene and regulates the expression of fat-5,thereby inhibiting lipid anabolism.On the other hand,LFBE up-regulates the expression of cpt-2,promotes the entry of fatty acids into the mitochondria for ?-oxidation,and promotes lipid catabolism. |
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