Effects Of Tryptophan And Chlorogenic Acid On The Metabolism Of Tryptophan Kynurenine Pathway In Normal Physiological State And In Model Of Cadmium Exposure

Tryptophan is involved in protein synthesis,immune response,regulating lipid metabolism and son on.Kynurenine pathway can participate in the regulation of immune,compression,nerve and other aspects of the physiological process.In this study,the effects of tryptophan intake on kynurenine pathway in the liver of normal finishing pigs were investigated,the effects of polyphenols extracted from Eucommia ulmoides leaf on kynurenine pathway and the effects of chlorogenic acid uptake on kynurenine metabolic pathway in cadmium-exposed SD rats were also investigated.The results of this study could provide a new perspective for the study of tryptophan metabolic pathways and the protective effect of phenolic acids.Experiment 1:to investigate the effect of dietary supplementation of 0.2%tryptophan on kynurenine pathway in liver with finishing pigs model.The pigs were randomly divided into two groups:control group(control group):fed basal diet;tryptophan group(0.2%Trp group):fed basal diet+0.2%tryptophan(Trp).After feeding for 2 months,sampled.Compared with the control group,the activity of ALP in serum of 0.2%Trp group was significantly decreased.The content of amino acids(Thr,Glu,Tyr,His,Arg,Pro)in serum were significantly increased,and the content of amino acids(Met,Phe,His)in liver tissue was significantly decreased.In addition,the contents of Trp,Kyn and 3-HAA in 0.2%Trp group were significantly increased in the serum of finishing pigs.Conclusion:The addition of 0.2%tryptophan could improve liver functions and the addition of tryptophan increase the concentration of amino acids in the amino acid metabolic pool of serum.Metabolite(Trp,Kyn,3-HAA)of the tryptophan kynurenine pathway were increased,thereby promoting upstream metabolism.Experiment 2:To investigate the effects of 800 mg/kg polyphenols extracted from Eucommia ulmoides leaf on the kynurenine pathway in liver by using finishing pigs model.The pigs were randomly divided into two groups:control group(control group):fed basal diet;polyphenols extracted from Eucommia ulmoides leaf group(PEE group):fed basal diet+800 mg/kg PEE.After feeding for 60 days,sampled.Compared with the control group,ALT and ALP were significantly decreased in the PEE group.The amino acids(Asp,Thr,Ala,Arg)in the serum and the amino acids(Cys,Ile,Leu,Tyr)in the liver were significantly increased.In addition,the key enzyme-KYNU and metabolite-3-HAA,VB3 in PEE group significantly improved.Conclusion:Adding polyphenol extract from Eucommia ulmoides leaves can help improve liver function.And the addition of extract from Eucommia ulmoides leaves is helpful to improve the serum and liver amino acid metabolic pool amino acid content.Polyphenol extract from Eucommia ulmoides leaves will increase upstream key enzyme-KYNU activity and content of intermediate VB3 in the kynurenine pathway,therefore contributed to the kynurenine pathway metabolism.Experiment 3:To investigate the effecst of dietary supplementation of chlorogenic acid on kynurenine pathway in cadmium-exposed SD rats.The rats were randomly divided into three groups:the control group was treated as follows:control group(Control group):sterilized saline;cadmium chloride group(CdCl2 group):6mg/kg bw cadmium chloride Acid+CdCl2 group(CGA+CdCl2):50mg/kg bw chlorogenic acid+6mg/kg bw cadmium chloride.After adaptive feeding for 7 days,formal experiment 14 days,sampling.Compared with the Control group,the AST activity of the CdCl2 group was significantly increased,while the AST in the CGA+CdCl2 group only have the trend of increasement.The blood glucose of CdCl2 group was significantly decreased,while the Glu of CGA+CdCl2 group only have the trend of decreasement.Compared with CdCl2 group,the content of amino acid Phe and the amino acid(Ser,Glu,Cys,Tyr)in serum of CGA+CdCl2 group were significantly increased.Compared with the control group,the content of IDO in CdCl2 group and CGA+CdCl2 group was significantly increased,and the content of KYNU and QPRT were significantly decreased.Compared with CdCl2 group,the content of IDO and QPRT in CGA+CdCl2 group was significantly decreased.Conclusion:Chlorogenic acid has the effecst of protecting the liver in the case of cadmium exposure.In addition,chlorogenic acid can enrich the contents of amino acids in serum and liver amino acid metabolic pools.And chlorogenic acid can regulate the status of tryptophan kynurenine pathway in cadmium exposure through the regulation of kynurenine pathway upstream key enzyme activity.And then it improved the kynurenine metabolic disorders under the conditions of exposure of cadmium.