Protective Effect Of Main Metabolites Of Cyanidin-3-glucoside On Intestinal Mucosal Injury Of Weaned Piglets

The cyanidin-3-glucoside has strong anti-inflammatory and anti-oxidant capabilities,but it will be metabolized to variety of metabolites after intake.Moreover the chemical structure of cyanidin-3-glucoside is too complicated,hard to synthesize and unstable compare with its metabolites.In our previous research,three metabolites of cyanidin-3-glucoside with strong biological function have been chosen: protocatechuic acid,ferulic acid,vanillic acid.To explore the application in animal husbandry industry,3metabolites of cyanidin-3-glucoside was use in this study to find out the effect on intestinal inflammation in weaned piglets,examined the the influence of them on gut microbiota by 16 s RNA,and the relationship between inflammation,oxidation and expression of intestinal tight junction proteins in piglets.A total number of 60 28-day-old PIC weaned piglets with similar body weight and genetic foundation were randomly assigned into 5 groups: basal diet group(basal diet),antibiotic group(basal diet + 50 mg/kg chlortetracycline),protocatechuic acid group(basal diet containing 0.4% protocatechuic acid),ferulic acid group(basal diet containing 0.4% ferulic acid),vanillic acid group(basal diet containing 0.4% vanillic acid).There were 6 replicates per group and 2 piglets per replicate.The experiment lasted for 21 d after 3 days for accommodation.The results demonstrated that: 1)Dietary vanillic acid supplementation supplementation significantly increased f average daily gain of weaned piglets(P < 0.05),but show no significant difference in ADG and F/G.2)dietary supplementation with protocatechuic acid and ferulic acid significantly decreased the serum glucose,ferulic acid significantly decreased the serum ALT(P<0.05).3)dietary vanillic acid supplementation significantly increased the scrum IgG of weaned piglets(P<0.05).4)Dietary main metabolites of cyanidin-3-glucoside supplementation can significantly improve the antioxidant capacity of weaned piglets(P<0.05).Compared with the basal diet group and antibiotic group,dietary vanillic acid supplementation significantly increased the scrum T-AOC and decreased the scrum GSH-Px of weaned piglets(P<0.05),compared with the basal diet group,protocatechuic acid and ferulic acid group can significantly decreased the scrum MDA and GSH-Px of weaned piglets(P<0.05).5)Dietary main metabolites of cyanidin-3-glucoside supplementation can significantly decreased the inflammatory factors of weaned piglets(P<0.05).Compared with the basal diet group and antibiotic group,vanillic acid group can significantly decreased the scrum IL-1β(P<0.05),vanillic acid and ferulic acid group can significantly decreased the scrum IL-2(P<0.05),ferulic acid group can significantly decreased the scrum IL-6(P<0.05),protocatechuic acid,ferulic acid and vanillic acid group can significantly decreased the scrum TNF-α(P<0.05).6)Dietary main metabolites of cyanidin-3-glucoside supplementation can significantly improve the mRNA expression of tight junction proteins of weaned piglets(P<0.05).Compared with the basal diet group,protocatechuic acid group can significantly increase the expression of Claudin-1mRNA(P<0.05),vanillic acid and ferulic acid group can significantly increase the expression of Occludin mRNA of weaned piglets(P<0.05).High-throughput sequencing results shows that: Protocatechuic acid,ferulic acid and vanillin acid can significantly affect the composition of intestinal microorganisms in weaned piglets.At phylum level,Protocatechuic acid,ferulic acid and vanillin acid can significantly decreased the relative abundance of Bacteroidetes(P<0.05),increased the relative abundance of Firmicutes(P<0.05),ferulic acid significantly increased the ratio of Firmicutes/ Bacteroidetes(P<0.05).At family level,Protocatechuic acid,ferulic acid and vanillin acid can significantly decreased the relative abundance of Prevotellaceae(P<0.05),vanillin acid can significantly increase the relative abundance of Lactobacillaceae(P<0.05),Protocatechuic acid can significantly increase the relative abundance of Veillonellacea(P<0.05).According to correlation analysis Prevotella 1,Prevotella 2,Prevotella 9,Prevotellaceae NK3B31 group,Prevotella7,Syntrophococcus,Ruminococcus torques group was positively correlated with the expression of inflammatory factors,Roseburia,Lachnospira,Eubacterium ruminantium group,Eubacterium xylanophilum group,Desulfovibrio was negative correlated with the expression of inflammatory factors.Procatechuic acid,ferulic acid and vanilic acid can significantly decrease the relative abundance of Prevotella 2,Prevotella 9 and Syntrophococcus.Ferulic acid and vanilic acid can significantly decrease the relative abundance of Prevotellaceae NK3B31 group and Prevotella 7.Procatechuic acid and vanilic acid can significantly decrease the relative abundance of Ruminococcus torques group.Procatechuic acid can significantly decrease the relative abundance of Holdemanella.Vanilic acid can significantly increase the relative abundance of Roseburia,Lachnospira,Eubacterium ruminantium group,Eubacterium xylanophilum group,and procatechic acid and ferulic acid can increase the relative abundance of Desulfovibrio.In conclusion,vanillin acid can improve production performance,all the three metabolites all show a strong anti-inflammatory effect,which can alleviate the oxidative damage of weaned piglets and improve the expression of intestinal tightly junction mRNA,which may be through by regulating the intestinal flora of weaned pigs.