Alleviating Effect Of Urticaria L On Intestinal In Flammatory Response Of Zebrafish And Chicks Induced By LPS

Since antibiotics have been banned from feed,the use of plant-derived active substances to replace antibiotics has gradually become the focus of research.Urtica cannabina L(UL),widely distributed in the Northern Hemisphere,has rich nutritional value and pharmacological effects,but its anti-inflammatory mechanism remains to be further studied.The aim of this experiment was to investigate the anti-inflammatory effect and mechanism of UL at different concentrations on zebrafish and chicks.Three hundred zebrafish(13 weeks old)and 180 chicks(3 days old)were used as the study targets to investigate the protective effect of UL on intestinal inflammatory response of zebrafish and chicks induced by E.coli Lipopolysaccharides(LPS).UL was crushed and added into zebrafish feed(1% and 3%)and chick feed(3% and 6%)to make diets.The inhibition effect of UL on LPS inflammatory response was detected by the changes of morphology,histology,gene and protein levels.The results showed as follows: 1)After caudal fin excision,caudal fin scar appeared in positive control group and UL30 mg/g group,and caudal fin healing area decreased,while caudal scar was light in UL10 mg/g group,and the caudal healing area was close to that in control group,which was significantly higher than that in positive control group and UL30 mg/g group(P<0.01).2)Through intestinal microflora analysis,it was found that bacteroides probiotics increased in UL10 mg/g group,while pathogenic bacteria Clostridium,Firmicutes and Proteus decreased.3)LPS treatment significantly inhibited intestinal goblet cells of zebrafish,which was reduced by 42%compared with the control group(P<0.001),and UL treatment significantly restored the inhibition caused by LPS.The addition of UL also effectively protected the intestinal goblet cells morphology,number and intestinal villi morphology of zebrafish.4)LPS significantly increased the m RNA expressions of inflammatory cytokines IL-6,IL-8 and TNF-α in zebrafish,which were 1.87 times(P<0.05),2.01 times(P<0.05)and 2.05 times(P<0.05),respectively,and UL supplementation inhibited the effects of LPS on the expression of the above three genes.5)LPS caused the decrease in daily daily gain of zebrafish,and UL mitigated the effect.LPS inhibited the daily gain of chicks,and UL also improved the weight of chicks to maintain the level of control group.6)Intestinal goblet cells of chicks were significantly reduced after LPS treatment,by 45 % compared with control group(P<0.05).The intestinal goblet cells in UL30 mg/g+LPS and UL60 mg/g+LPS groups were close to the level of control group,and increased by 71 %(P<0.05)and 35 % compared with LPS group,respectively.In addition,UL supplementation promoted the return of intestinal villus length and chorionic gland ratio to normal levels.7)The m RNA expressions of IL-6,IL-8 and TNF-α were increased 3.4 times(P<0.05),0.6 times(P > 0.05)and 3.4 times(P<0.05),respectively,by LPS.In UL30 mg/g+LPS and UL60 mg/g+LPS groups,IL-6 gene expression was decreased by 4.0 times(P<0.05)and 4.8 times(P<0.05),and TNF-α gene expression was decreased by 4.9 times(P<0.05)and 4.1 times(P<0.05),respectively.8)LPS significantly increased the abnormal high expression of TNF-α protein in the intestinal tract of chicks(P<0.05),and UL supplementation inhibited the effect of LPS on the expression of TNF-α protein(P<0.05).In addition,LPS induced zebrafish inflammatory factor associated protein CD40 L protein expression increased by 1.43 times(P < 0.01),but UL10 mg/g treatment restored to the control level.These results indicate that UL has a strong inhibitory effect on the intestinal inflammatory response of zebrafish and chicks induced by LPS,indicating that UL is a developable feed additive to improve disease resistance and health of livestock.