Screening Of Serum Metabolites From Two Breeds Of Pigs And Their Roles In Oxidative Damage Of Skeletal Muscle

Different pig breeds exhibit varying levels of fat content in their bodies and demonstrate diverse reactions to internal and external environmental stimuli.These variations arise from disparities in factors such as their growth environment,physical activity,and dietary composition.It has been shown that skeletal muscle oxidation state is closely related to meat quality.Improving the antioxidant capacity of meat is always one of the hot issues to be solved by researchers.Thus,to identify metabolites with protective effects against oxidative stress-induced damage and to explore their mechanisms of action,this study firstly screened serum differential metabolites and target metabolites of different pig breeds through metabonomics.technology combined with bioinformatics analysis.Secondly,development of a model of oxidative stress in skeletal muscle satellite cells.Finally,target metabolites were added to skeletal muscle satellite cells with oxidative stress to study the effect of target metabolites on oxidative stress.The details are as follows:1.Screening of serum differential metabolites:This experiment was divided into two groups:Anqing Liu Bai pigs and Du Chang Da pigs,with 10 pigs in each group,160 days old,and serum samples were collected.Based on liquid chromatography technology and combined with bioinformatics analysis,a total of 262 metabolites were screened with significant differences that were significantly enriched in pathways such asβ-alanine metabolism,tryptophan metabolism,and the citric acid cycle.The most significant differential metabolite in theβ-alanine metabolic pathway is carnosine（q-value=0.007,The difference factor is 44 times）.2.Building a model of oxidative stress of skeletal muscle satellite cells:This experiment is divided into 3 groups:a control group,a 0.5 mmol/L hydrogen peroxide（H₂O₂）treatment group,and a 1 mmol/L H₂O₂ treatment group.After 4 h of culture,cells and cell fluid were collected and parameters related to oxidative stress and cell viability were determined.The results showed that:in H₂O₂ environment,MDA,ROS and cell apoptosis rate were significantly increased（P<0.01）,cell viability,SOD（P<0.01）and GSH-Px enzyme activity units were significantly decreased（P<0.01）.Showing that a skeletal muscle satellite cell oxidative stress model was successfully constructed3.Protective effect of carnosine on oxidative damage of skeletal muscle:Experimental analysis for five groups,0.5 mmol/L H₂O₂ treatment group,0.5 mmol/L H₂O₂+20μmol/L carnosine group,0.5 mmol/L H₂O₂+200μmol/L carnosine group and 0.5 mmol/L H₂O₂+20mmol/L carnosine group.After culturing for 4 h,cells and cell fluid were collected to detect oxidative stress,cell viability,and lipid metabolism.The results showed that after treatment with carnosine,MDA,cell apoptosis rate and ROS content levels decreased extremely significantly（P<0.01）,and SOD,cell viability and GSH-Px enzyme activity units increased extremely significantly（P<0.01）.The rate decreased significantly（P<0.01）.The results showed that carnosine has a certain protective effect against oxidative damage to skeletal muscles.The above results indicated that carnosine inβ-alanine metabolic pathway was more significant among the serum metabolites of the two types of pigs.Carnosine has a protective effect on oxidative damage of skeletal muscle.This study provides new ideas for exploring the most effective concentration of carnosine in oxidative damage of skeletal muscle and improving pork quality of local pig breeds.