Objective To explore the efficacy of a compound nutrition preparation on wound healing after acute trauma and investigate the underlying mechanism primarily.Methods After skin wound model was successfully constructed on totally 60 male SD rats surgically,they were randomly divided into control group(CON group),whey protein group(WP group)and low-and high-dose nutritional formula groups(LDF and HDF groups),with 15 animals in per group.From the next day after surgery,the rats in each group were given corresponding nutritional interventions for 2 weeks.During the intervention,the wound conditions were observed and recorded,and the wound area was measured.The samples were collected on the 3rd,7th and 14th days after surgery,respectively.Serum albumin(ALB),prealbumin(PA),total protein(TP),inflammatory factors(TNF-α,IL-1β,IL-6 and IL-10),immunoglobulins(IgA,IgG and IgM)and hydroxyproline(Hyp)were detected by the corresponding reagent kits.The histopathologic changes of wound were observed with HE staining.Masson staining was used to observe the collagen fiber deposition in wound tissue.The angiogenesis of wound tissue was evaluated by immunohistochemical staining.Results Compared with the CON group,the wound healing speed,collagen synthesis and angiogenesis speed were significantly accelerated in the WP group,LDF group and HDF group(P＜0.05),and the effects were the most obvious in the HDF group.On the 3rd day after surgery,in the WP,LDF and HDF groups,the serum ALB,PA and TP levels were significantly increased(P＜0.05),serum TNF-α and IL-1β levels were obviously decreased(P＜0.05),and serum IL-10 level was notably increased(except WP group)when compared with the CON group.The serum IgG and IgM levels were significantly increased in the LDF group and HDF group(P＜0.05)and significant increment of IgA was only observed in the HDF group(P＜0.05).On the 7th day after modeling,the levels of ALB,PA and TP were significantly increased(P＜0.05),the levels of TNF-α,IL-1β and IL-6 were obviously decreased(P＜0.05),and the levels of IL-10 were remarkably increased(P＜0.05)in the HDF group than the CON group;The LDF group and HDF group had significantly elevated serum IgG and IgM levels(P＜0.05),but only the former group had statistically increased serum IgA level(P＜0.05).On the 14th day after modeling,the HDF group had significantly increased levels of ALB and TP(P＜0.05),decreased levels of IL-1β(P＜0.05),and raised levels of IgG and IgM when compared with the CON group(P＜0.05).Conclusion Our compound nutrition preparation promotes wound healing in rat model of acute trauma,which might be related to its improving the nutritional status,promoting collagen synthesis,and thus alleviating inflammatory response and enhancing immune function.

Objective To develop a composite nutritional preparation that can effectively improve exercise performance under calorie restriction(CR)condition.Methods A total of 24 male C57BL/6J mice(weighing 23～26 g,8 weeks old)were randomly divided into control group(CON),CR,CR+basal nutrient group(CRN1),and CR+compound nutrient group(CRN2).All groups underwent moderate-intensity running training 5 d per week,for totally 3 weeks.The grip strength of the forelimbs were measured weekly,and in 3 weeks after training,exhaustion and post-exhaustion distance tests were conducted to evaluate exercise performance.Blood biochemical indicators,levels of skeletal muscle and liver redox biomarkers,and histopathological conditions were measured and observed.Results After 21 d of intervention,the CR group and CRN1 group had the post-exhaustion running distance prolonged by 278%and 289%,respectively,reduced blood glucose level,and decreased muscle mass,subcutaneous fat and epididymal fat mass when compared with the CON group(P<0.05).Compared with the CON group,the CRN1 and CRN2 groups demonstrated significantly higher gastrocnemius glycogen content.The CRN2 group obtained even longer post-exhaustion distance(increased by 52%and 36%respectively,compared with the CON group and CRN1 group,P<0.05),enhanced grip strength of the forelimbs(raised by 9%,17%and 15%,respectively than the CON,CR and CRN1 groups,P<0.05),elevated brown fat mass(compared to the CON group and CRN1 group,P<0.05),increased blood glucose level(compared to the CRN1 group,P<0.05),decreased blood low-density lipoprotein cholesterol level(compared to the CON and CR groups,P<0.05),and increased glutathione peroxidase content in the gastrocnemius muscle(compared to the CON group,P<0.05).Conclusion Supplementing with compound nutritional supplements in mice under CR can promote exercise performance,including improving fatigue recovery after exhaustive exercise and enhancing forelimb grip strength.

Objective To investigate the protective effects of Qiji Special Dietary Food on exercise-induced myocardial injury in mice.Methods An exercise-induced myocardial injury model was established using a treadmill running protocol,and at the same time,the modeled mice were administered Qiji Special Dietary Food via oral gavage,followed by a 4-week treadmill exhaustion test.Serum levels of cardiac troponin T(cTnT),creatine kinase(CK),and lactate dehydrogenase(LDH)were measured.Myocardial tissues were analyzed for superoxide dismutase(SOD)activity and malondialdehyde(MDA)content.Histopathological alterations and ultrastructural changes in myocardial tissue were evaluated using light microscopy and transmission electron microscopy(TEM).Results After 4 weeks of exhaustive training,compared to the control group,the model group exhibited significantly elevated serum cTnT,CK,and myocardial MDA levels(P<0.01),along with reduced myocardial SOD activity(P<0.01).Compared to the model group,high-,medium-,and low-dose treatment significantly attenuated the exhaustive exercise-induced increases in serum cTnT level and myocardial MDA content(P<0.01),restoring these indicators to the levels comparable to those of the normal control group(P<0.05).Additionally,all treatment groups had markedly increased myocardial SOD activity,with no significant difference from the normal group.Histopathological and ultrastructural analyses revealed markedly alleviated myocardial damage in the treatment groups,with the medium-dose group exhibiting the most pronounced protective effects.Conclusion Qiji Special Dietary Food demonstrates significant protective effects against exercise-induced myocardial injury in mice,which maybe associated with its antioxidant activity and mitigation of oxidative stress.

Objective To investigate the alterations in skeletal muscle function and mass in an experimental mouse model of high-intensity exercise in a hot and humid environment.Methods Twenty-four male C57BL/6J mice(7～8 weeks old,weighing 21.30±0.67 g)were randomly assigned to a control group(CON group),a normal temperature and humidity exercise group(NE group),and a high temperature and humidity exercise group(HE group),with 8 mice in each group.The HE group was subjected to a high-temperature simulation chamber,maintaining a temperature of 37～39℃and humidity of 70%～80%,for a 60-minute exercise intervention at a 10° incline and 80%of maximum velocity(12 min of exercise followed by 8 min of rest,for 3 cycles).The CON group did not exercise,while the NE group exercised in the same manner in a normal temperature and humidity environment.The overall condition of the mice was evaluated by monitoring their body weight and analyzing their body composition.Their serum creatinine and urea levels were detected using an automated biochemical analyzer.After exercise,skeletal muscle function in the mice of each group was assessed by measuring their grip strength and exhaustion time.The skeletal muscle contractility and resistance to fatigue were evaluated using an in situ/in vivo/ex vivo muscle testing system.HE staining was employed to observe the morphological and structural changes in the skeletal muscles,and the average cross-sectional area and diameter of the muscle fibers were analyzed.Genes related to protein synthesis(Eif4ebp1,p70S6k)and breakdown(Foxo3,Fbxo32,Trim63)and heat stress-related genes(Hsf-1,Hspa1a,Hsp90aa)were quantified using RT-qPCR.Results ① Compared with the CON and NE groups,the HE group exhibited significant decreases in body weight(P<0.01)and lean body mass(P<0.05),an upward trend of creatinine level(P<0.05),and increases in the urea content(P<0.01).② The mice in the HE group had notably reduced grip strength(P<0.001),diminished skeletal muscle contraction,and weakened resistance to fatigue(P<0.05)than the CON and NE groups.③ The HE group demonstrated a reduction in the average cross-sectional area of muscle fibers(P<0.05)and a decrease in average fiber diameter(P<0.05),with particular up-regulation of Fbxo32,Trim63 and Eif4ebp1(P<0.01)and down-regulation of p70S6k(P<0.05)in comparison to the NE and CON groups.④ The expression levels of heat stress-related genes were higher in the HE group than the CON and NE groups(P<0.05).Conclusion High-intensity exercise in a hot and humid environment can lead to a decline in skeletal muscle function and mass in mice,potentially due to the disturbance of skeletal muscle protein synthesis and degradation triggered by excessive heat stress.

Objective To explore the role of indole-3-propionic acid(IPA)in the pathogenesis of metabolic associated fatty liver disease(MAFLD)induced by high-fat diet(HFD)in order to reveal the role and related mechanism of adipose tissue metabolism in the process.Methods A mouse model of MAFLD was induced by HFD.Male C57BL/6J mice(6～7 weeks old)were randomly divided into control group(CON),HFD group,and HFD+IPA intervention group(HFD+IPA).The CON group was fed with control diet,and the HFD group and HFD+IPA group were fed with 60％of high-fat diet.The experiment period was 12 weeks,and IPA was administered at 20 mg/(kg·d)for 6 weeks starting from the 7th week.The body weight and food intake of each group were monitored weekly.After the intervention,the body composition of mice was detected by animal body composition analyzer.After the mice were euthanized,the morphological and structural changes in the liver and adipose tissues were observed by HE staining,the indicators relevant to lipid metabolism in the serum,l iver and adipose tissues were detected by automatic blood biochemical analyzer and biochemical kits,and the mRNA expression changes of lipid metabolism and inflammation related genes were detected by qRT-PCR.Results Compared with the CON group,the HFD group had significantly increased body weight and body fat percentage,obvious lipid deposition in the liver,obviously elevated serum alanine aminotransferase,aspartate aminotransferase,liver triglyceride and total cholesterol levels(P＜0.05),and raised mRNA levels of liver fatty acid transporter CD36(P＜0.05),while IPA intervention significantly reversed the above changes(P＜0.05).IPA intervention significantly inhibited the HFD-induced enlargement of visceral and brown fat cells,reduced the content of visceral adipose tissue(VAT)and serum level of free fatty acids(P＜0.05),and increased the mRNA expression levels of VAT lipolysis(HSL,CGI58),browning genes(Cidea,ND5,UCP1,Prdm16)(P＜0.05),as well as those of brown adipose tissue(BAT)lipolysis(HSL,ATGL)and fatty acid beta oxidation(Cpt1a,PPARα)genes(P＜0.05).Meanwhile,the mRNA levels of TNF-α,IL-1β,CXCL1 and CCL2 in VAT and BAT were decreased after IPA intervention(P＜0.05).Conclusion IPA can improve the occurrence of MAFLD induced by HFD,and its mechanism may be closely associated with its regulation of BAT and VAT morphology,and the mRNA expression of metabolic function and inflammation related genes.

Objective To construct a model of Fat-1/APPPS1 transgenic mice and a cellular model of microglia and explore the improvement effect and underlying mechanism of n-3 polyunsaturated fatty acids(n-3 PUFAs)on the learning and memory abilities of APPPS1 mice by regulating microglial activation and polarization.Methods After the male mice with heterozygous Fat-1 genotype were mated with the female ones with heterozygous APPPS1 genotype,genetic identification was used to screen the male offspring with Fat-1/APPPS1 genotype.Then after the male wild-type(WT)mice and those with Fat-1,Fat-1/APPPS1,and APPPS1 genotypes were bred until 9 months old,their learning and memory abilities were evaluated with Morris water maze(MWM)test.In addition,gas chromatography-mass spectrometry(GC-MS)was performed to detect the concentration of PUFAs in the brain,and immunohistochemistry(IHC)was applied to detect the deposition of β-amyloid protein(Aβ)in the hippocampal regions.Moreover,immunofluorescence assay,qRT-PCR,and enzyme-linked immunosorbent assays(ELISA)were conducted to measure inflammation,and transcription and expression of Iba-1(indicating the microglial activation)and CD86 and CD206(indicating microglial polarization)in central nervous system(CNS).After pretreated with DHA+EPA(25 pmol/mL∶25 μmol/mL),microglial model of inflammatory injury was established in immortalized mouse BV2 cells induced by LPS(1 μg/mL).Afterwards,immunofluorescence assay,qRT-PCR and Western blotting were used to detect inflammation and microglial activation and polarization.Results Compared with the APPPS1 mice,endogenous n-3 PUFAs effectively improved the learning and memory disorders in Fat-1/APPPS1 ones(P＜0.05),remarkably alleviated Aβ deposition in the hippocampal regions(P＜0.05),evidently reduced CNS inflammation and microglial activation(P＜0.05)and transformed the activated microglia from M1 to M2(P＜0.05).Furthermore,BV2 cells with DHA+EPA pretreatment obviously resisted LPS-induced cellular inflammation and induced activated ones from M1 to M2(P＜0.05).Conclusion n-3 PUFAs inhibit the microglial activation,regulate the microglial polarization from M1 to M2,reduce CNS inflammation,and thus alleviate learning and memory disorders in APPPS1 mice.

Objective To investigate the effects of a 45％high-fat diet(HFD)with isocaloric intake on energy metabolism and endurance exercise capacity in SD rats.Methods Twenty-four male SD rats were randomly divided into normal chow diet group(CON),HFD group,normal chow diet+exercise training group(CONT),and HFD+exercise training group(HFDT).The CON and CONT groups received normal chow diet,while the HFD and HFDT groups received a 45％high-fat diet with isocaloric intake.The HFDT and CONT groups underwent an endurance training of moderate-intensity running for 6 weeks.Body weight,fat mass,and lean mass were measured weekly.Energy expenditure and basal metabolic rate during rest and exercise states were measured using Pheno Master/Calo Treadmill system.Blood glucose,lipids,and creatine kinase levels were detected after the exhaustion test.Results In 6 weeks after intervention,the endurance exercise capacity was significantly enhanced in the HFDT group than the CONT group(P＜0.05).There were no obvious differences in body weight and body composition among the groups under isoenergetic feeding conditions.At rest,no statistical differences were observed in total energy expenditure and basal metabolic rate among the groups.However,prior to the 4th week,the CON group primarily metabolized carbohydrates while the HFD group primarily metabolized fats.But the carbohydrate metabolism was decreased and then increased,and the substrate metabolism rates eventually reached similar levels between the 2 groups on the 5th to 6th week.The HFDT group primarily metabolized fats while the CONT group primarily metabolized carbohydrates,with significant differences persisting after 6 weeks of training(P＜0.05).HFD led to elevated levels of serum cholesterol,triglycerides(TG),and high-density lipoprotein cholesterol(HDL-C),but,endurance training resulted in decreased lipid levels in the HFDT group,accompanied by an increase inβ-hydroxybutyrate(βHB)level(P＜0.05).Isoenergetic diets had no significant differences in their effects on liver and kidney function or muscle damage indicators.Conclusion An isoenergetic HFD can improve fat utilization ability and extend endurance exercise time in rats without altering body composition or affecting liver and kidney function.

Objective To explore the effect of chenodeoxycholic acid(CDCA)on the expression of glucagon-like peptide-1(GLP-1)in the intestine of mice induced by high-fat diet(HFD)through farnesoid X receptor(FXR),and investigate the related mechanism.Methods Forty C57BL/6 mice were divided into control group,HFD group,HFD+CDCA group,HFD+Z-Gug(FXR antagonist)group,and HFD+CDCA+Z-Gug group,with 8 animals in each group.During intervention for 8 weeks,body weight and 24-hour food intake were measured every week.At the 8th week,oral glucose tolerance test(OGTT)and intraperitoneal glucose tolerance test(IPGTT)were conducted.After the mice were sacrificed,the serum levels of GLu,TG,CHO,LDL-C and HDL-C were detected;the expression levels of GLP-1 and FXR in intestinal tissues were detected by immunofluorescence assay;and the mRNA levels of TNF-α,IL-6,IL-1β,Gcg and FXR were detected by RT-qPCR;the serum level of GLP-1 was detected by ELISA,and the proportion of intraepithelial lymphocytes(IELs)subsets and the expression of CD26/DPP4 were detected by flow cytometry.Results Compared with the control group,the HFD group had increased body weight,abnormal serum glucose and lipid metabolism,impaired oral glucose tolerance,and weakened secretion of gastrointestinal hormones(P＜0.05),enhanced FXR expression at mRNA and protein levels,declined Gcg mRNA level and GLP-1 secretion level(P＜0.05),increased mRNA levels of intestinal inflammatory factors TNF-α,IL-6 and IL-1β(P＜0.05),raised proportions of TCRαβ+IELs,TCRαβ+CD8αα+IELs,and TCRαβ+CD8αβ+IELs but reduced proportion of TCRγδ+IELs,and increased total CD26/DPP4 expression in IELs(P＜0.05).Compared with the HFD group,HFD+CDCA treatment resulted in significantly increased body weight,impaired oral glucose tolerance,decreased secretion of gastrointestinal hormones,increased FXR mRNA and protein expression,and decreased Gcg mRNA expression and GLP-1 secretion(P＜0.05);decreased proportions of TCRαβ+IELs,TCRαβ+CD8αα+IELs and TCRααβ+CD8αβ+IELs but increased proportion of TCRγδ+ cells in IELs,and increased expression of total CD26/DPP4 in IELs(P＜0.05),which were significantly improved after Z-Gug intervention(P＜0.05).Conclusion CDCA may inhibit the expression and secretion of GLP-1 in intestinal tissue by activating FXR,and reduce the secretion of GLP-1.At the same time,CDCA may inhibit the expression of related inflammatory factors,regulate the proportions of IELs subsets,up-regulate the expression level of CD26/DPP4,promote the degradation of GLP-1 and aggravate insulin resistance.

Objective To develop a nutritional formula on enhancing the endurance of heavy load exercise,and evaluate its efficacy comprehensively.Methods Sixty C57BL/6J male mice were randomly divided into control group(CON group)and low-,medium-and high-dose nutritional formula groups(LDF,MDF and HDF groups),with 15 mice in each group.Each group received intervention with nutritional formula at corresponding dose for 2 weeks,and underwent adaptive training and heavy load exercise in the 1 st and 2nd weeks,respectively.Exhaustion exercise time,skeletal muscle antioxidant indicators(SOD,MDA,PC and GSH),fatigue related indicators(serum URA,LDH and LA),muscle glycogen,and serum exercise injury related indicators(ALT,AST,CK and CK-MB)were measured and detected in the mice,and comprehensive evaluation was conducted according to relevant evaluation standards.Results The LDF group,MDF group and HDF group had significantly prolonged running exhaustion time than the CON group(P＜0.05),with the HDF group showing the greatest improvement(P＜0.05).Compared with the CON group,the activities of SOD and GSH in the skeletal muscles were significantly increased(P＜0.05),while the levels of MDA and PC in skeletal muscles were obviously decreased in the 3 doses of nutritional formula groups(P＜0.05).PAS staining of the skeletal muscles displayed that the glycogen content was significantly increased in the MDF group and the HDF group than the CON group(P＜0.05),and the highest increase was observed in the HDF group(P＜0.05).Biochemical test revealed that the levels of LDH,LA,ALT,AST,CK,and CK-MB were remarkably lower in the 3 doses of nutritional formula groups than the CON group(P＜0.05).Conclusion The nutritional formula can significantly improve the endurance and skeletal muscle antioxidant capacity in mice under heavy load exercise,and has anti-fatigue and-injury protection effects.This nutritional formula can be used to support physical fitness during heavy load endurance exercise.

Objective To investigate the effect and mechanism of quercetin (QUE)in improving lipid accumulation in hepatocytes by regulating lipolysis and lipophagy pathway.Methods The human hepatocyte cell line 5 (HHL-5)was induced by palmitic acid (PA)to establish a steatogenic hepatocyte model.Quercetin at different concentrations (5,10,20 and 40 μmol/L)has been utilized to interfere with HHL-5 cells for 24 h,and the experiment was divided into six groups:control group,PA group,PA+QUE5 group,PA+QUE10 group,PA+QUE20 groupand PA+QUE40 group.In order to determine the influence of lipophagy on QUE effect,3-methyladenine (3-MA)was used to block autophagy,and HHL-5 cells were divided into the control,PA,PA+QUE40,3-MA,PA+3-MA and PA+3-MA+QUE40 groups.The contents of triglyceride (TG),accumulations of lipid droplets,expression of lipolysis and lipophagy related molecules,and degree of co-localization,and expression level of substrate of autophagy P62 were detected in above 2 types of experimental groups.Results Compared with the control group,the TG content and the lipid accumulation were significantly increased,the protein levels,average fluorescence intensities and colocalization degree of lipolysis related molecules adipose triglycerides lipase(ATGL)and comparative gene identification-58(CGI58),and lipophagy related molecules Ras-related protein 7(RAB7)and microtubule-associated protein 1 light chain 3 beta (LC3β)were significantly decreased,while the expression of P62 was enhanced in HHL-5 cells in the PA group (all P<0.05 ).Compared with the PA group,the triglyceride content and the degree of lipid accumulation in the PA+QUE40 group were significantly decreased,and the protein expression level,average fluorescence intensity and co-localization degree of lipolysis and lipophagy related molecules were significantly increased,while P62 was significantly decreased (P<0.05).When 3-MA was added to the steatogenic hepatocytes to inhibit autophagy,the improvement effect of QUE on lipid accumulation and the regulation of lipolysis and liphagy related molecules in steatogenic hepatocytes were neutralized.Conclusion QUE alleviates lipid accumulation in HHL-5 cells by promoting the expression and interaction of molecules related to lipolysis and lipophagy pathways.However,these effects can be weakened by the autophagy inhibitor 3-MA.