Objective This study aims to clarify the characteristics and temporal patterns of colonic barrier damage in mice following a single simulated high-intensity exercise in hot and humid environment,and further investigate the protective effects of baicalein(BAI)intervention on colonic injury,thereby providing experimental evidence for the development of medical protection time windows and pharmaceutical intervention protocols for personnel engaged in high-intensity exercise and operations in hot and humid environments.Methods ①Thirty SPF-grade 8-week-old male C57BL/6J mice were randomly divided into 5 groups(n=6):control group,30 min post-exercise group,4 h post-exercise group,12 h post-exercise group,and 24 h post-exercise group.The mice in the exercise groups were subjected on a treadmill in a heat chamber(temperature:38℃,humidity:RH 75%)at 80%maximal exercise velocity(Vmax)(exercise 12 min,rest 8 min,3 cycles;slope 10°).Subsequently,the colon tissues were harvested for morphological observation by HE staining in each group;ELISA was used to detect the serum levels of inflammatory factors(TNF-α,IL-6,IL-10,and IL-1β)to observe the inflammatory response of each group.Intestinal fatty acid binding protein(I-FABP)and lipopolysaccharide(LPS)were detected to observe intestinal permeability;Microassay was performed to determine the concentrations of reduced glutathione(GSH)and malondialdehyde(MDA),as well as the activity of catalase(CAT)and superoxide dismutase(SOD)in the colon tissues;RT-qPCR was applied to detect the expression levels of intestinal tight junction protein related genes Occludin,ZO-1,Claudin-1,inflammation and oxidative stress related genes Tlr4,TNF-α,IL-1β,IL-6,IL-10,heme oxygenase-1(HO-1),and superoxide dismutase1(SOD1),as well as key transcription factors HSF1,NF-κB,PARP-1,and NRF2 in heat stress regulation;Western blotting was utilized to detect the protein of colonic tight junction protein Occludin.② For BAI intervention study,24 SPF-grade 8-week-old male C57BL/6J mice were randomly divided into 4 groups(n=6)control group,exercise group(high temperature and high humidity exercise,gavage with deionized water 200 μL),exercise+low-and high-dose intervention groups(BAI gavage 200 μL at 10 and 40 mg/kg per day).At 4 h after the end of exercise,colonic and blood samples were collected for serum levels of urea nitrogen(BUN)content,alanine aminotransferase(ALT),and aspartate aminotransferase(AST)to evaluate the safety of BAI.Other detection sites,indicators,and methods were the same as aforementioned.Results ① The core body temperature was significantly elevated in the exercise group(P<0.05);the structural damage,along with inflammatory cell infiltration was observed in colonic mucosa;the expression of colon Occludin,ZO-1,and Claudin-1 was downregulated(P<0.05),and the protein level of Occludin was decreased(P<0.05),and the serum levels of I-FABP and LPS were increased(P<0.05);The serum levels of TNF-α,IL-1β,IL-6,and IL-10 were increased(P<0.05),and the expression of IL-1β and IL-10 in the colon was upregulated(P<0.05);The concentration of MDA was increased(P<0.05),while the concentration of GSH and the activities of CAT and SOD were decreased(P<0.05);The expression of HSF1,PARP-1,NF-κB,Tlr4,TNF-α,IL-6,and SOD1 in the colon was upregulated(P<0.05),while the expression of NRF2 and HO-1 was downregulated(P<0.05).These changes were present at 30 min post-exercise,most prominent at 4 h post-exercise,and markedly recovered by 24 h.② After BAI intervention,the core body temperature was significantly decreased(P<0.05),and the serum levels of ALT and AST were decreased(P<0.05);colonic mucosal injury was alleviated;the expression of Occludin at mRNA and protein levels in the colonic tissues were increased(P<0.05);the expression of ZO-1 and Claudin-1 were upregulated(P<0.05),and serum levels of I-FABP and LPS were decreased(P<0.05);the serum level of IL-1β was decreased(P<0.05),and the expression of IL-1 β in the colon was downregulated(P<0.05);The concentration of MDA was decreased(P<0.05),while the concentration of GSH and activities of CAT and SOD in the colon were increased(P<0.05);The expression of HSF1,PARP-1,NF-κB,Tlr4,TNF-α,and IL-6 in the colon was downregulated(P<0.05),while the expression of NRF2 and HO-1 was upregulated(P<0.05).These results indicated that BAI possesses anti-inflammatory and antioxidant effects,with better efficacy in the low-dose group.Conclusion Peak colonic barrier injury occurs at 4 h after simulated high-intensity exercise in a hot and humid environment,and prophylactic use of BAI(10 mg/kg per day)can significantly inhibit inflammation and oxidative stress and alleviate injury,providing evidence for time windows and intervention basis for colonic injury induced by heat stress.

Exposure to acute hypoxia severely impairs skeletal muscle function, but the temporal dynamics and underlying mechanisms remain unclear. Male C57BL/6 mice were exposed to normobaric hypoxia (FiO2 = 11.8

Excessive exercise can induce metabolic disturbances that precede overt clinical disease. As the central metabolic organ, the liver plays a pivotal role in systemic metabolic adaptations to exercise, although its dynamic metabolic response remains poorly characterized. Characterizing hepatic metabolic shifts could advance early diagnostic and preventive strategies. Single exhaustive exercise (SEE) is an acute, short-duration, high exercise load, often used to model a single bout of supra-physiological exertion, whereas repeated exhaustive exercise (REE) models the cumulative physiological stress induced by consecutive exhaustive exercise sessions. This study systematically delineates temporal metabolic alterations in murine liver following SEE and REE. C57BL/6J mice were subjected to a single bout of exhaustive exercise or daily REE regimens for 7 consecutive days. Liver tissues and serum samples were collected at predetermined intervals (0, 1, 6, 12, 24, 48 h post-exercise) for comprehensive analysis, including untargeted metabolomics, histopathological evaluation, and quantification of liver injury biomarkers. SEE provoked transient metabolic perturbations that resolved within 24 h, whereas REE induced progressive metabolic remodeling, particularly involving amino acid metabolism. Both exercise modalities caused histologically confirmed hepatic injury, and the biomarkers for liver injury were elevated at an early stage but recovered within 24 h. Multivariate analysis identified "steroid hormone biosynthesis" and "taurine/hypotaurine metabolism" as key modules correlating with injury severity. Time-series analysis showed that most injury-related metabolites in the SEE group returned to baseline, whereas those in the REE group remained elevated through 48 h, suggesting sustained metabolic alterations within the observation window, which may reflect delayed recovery and/or adaptive metabolic remodeling in response to repeated exhaustive exercise. Our findings reveal distinct patterns of hepatic metabolic alteration: acute exhaustive exercise triggers self-limited metabolic adjustments, whereas repeated exhaustive exercise induces more sustained metabolic remodeling. These results underscore the importance of personalized exercise regimens and suggest that modulation of specific metabolic pathways may represent a potential strategy for mitigating exercise-induced hepatic stress.

BackgroundThe prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) has increased worldwide. In recent years, fecal microbiota transplantation (FMT) has become an important promising method for the treatment of MASLD. However, the mechanism remains unclear.MethodsThe animal model with C57BL/6 male mice induced by high-fat diet (HFD) for 12 weeks has been introduced. Fecal microbiota and indole-3-carbinol (I3C) was given by oral gavage.ResultsOur study demonstrated that a 6-week healthy gut microbiota transplantation tended to ameliorate hepatic steatosis and reverse the decreased liver ILC1 induced by HFD. Interestingly, there was also a negative correlation between liver ILC1 and liver TG, TC level. Furthermore, the protective effect was associated with the elevated levels of serum indole-3-carbinol (I3C). Also, a I3C administration for 6 weeks improved liver steatosis and increased the frequency of liver ILC1 induced by HFD through aryl hydrocarbon receptor (AhR) activation. Moreover, I3C binds to the residues of ALA349, PHE348, LEU309, TYR316, PHE318 on AhR through hydrogen bonds, Π bonds, hydrophobic bonds which was proved by molecular docking.ConclusionTo conclude, our data demonstrated that FMT improved liver steatosis induced by HFD associated with liver ILC1 regulation and indole-3-carbinol level. The study highlighted the potential treatment value of FMT and microbiota-derived I3C in the MASLD treatment and regulation of liver ILC1 function.

Despite the known benefits of exercise, an in-depth comparison of the effects of regular versus irregular exercise on brain-body interactions and molecular mechanisms remains lacking. This study demonstrates that regular exercise robustly enhances fear memory extinction in mice, whereas irregular exercise has only mild effects. This divergence arises from regular rather than irregular exercise strongly inhibiting axonal mRNA transport and local translation of choline acetyltransferase (ChAT) in septal cholinergic neurons projecting to the hippocampus, thereby reducing hippocampal acetylcholine (ACh) levels and inhibiting α7 nicotinic acetylcholine receptor (α7-nAChR) activation on astrocytes. Critically, this hippocampal ACh-α7-nAChR signaling modulates hepatic ACh via the amygdala-dorsal motor nucleus of the vagus (DMV)-hepatic vagus circuit. Irregular exercise inhibits this pathway inadequately, so that increasing hepatic ACh flux and recruiting a novel neutrophil subset characterized by high expression of F-box and leucine-rich repeat protein 6 (FBXL6high). Subsequent abnormal iron transport from these neutrophils to hepatocytes promotes the metabolism of arachidonic acid into the proinflammatory mediators prostaglandin H2 (PGH2) and leukotriene B4 (LTB4), exacerbating nonalcoholic fatty liver disease. The findings elucidate the essential mechanisms underlying the neurometabolic benefits of regular exercise and the pathological risks of irregular exercise, offering transformative insights for preventive strategies.

High-intensity exercise (HIE) induces liver dysfunction and is detrimental to exercise performance. The underlying mechanism and preventive strategy urgently need to be explored. We increased the amount of tryptophan appropriately in the diet and explored the effect of an L-tryptophan-rich diet on the alleviation of HIE-induced liver dysfunction and the underlying mechanism. In this work, by establishing a C57BL/6 mouse model of high-intensity swimming exercise, the results demonstrated an L-tryptophan-rich diet significantly attenuated HIE-induced liver dysfunction, which was associated with increased levels of the tryptophan metabolite indole-3-acetic acid (IAA). Furthermore, IAA indeed exerted a protective effect against HIE-induced liver dysfunction in vivo and LPS-induced hepatocyte dysfunction in vitro. In conclusion, an L-tryptophan-rich diet may be a promising strategy to prevent HIE-induced liver dysfunction and metabolic disturbance via the metabolite indole-3-acetic acid and AhR activation.

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.

Insulin resistance is a common metabolic disease, and its pathogenesis is still unclear. The decrease of glucagon-like peptide-1 (GLP-1) level mediated by the alteration of gut microbiota may be the pathogenesis. The study was to investigate the regulatory effect of dihydromyricetin (DHM) on GLP-1 level and insulin resistance induced by high-fat diet (HFD), and to further explore its possible molecular mechanism. Mice were fed an HFD to establish the model of insulin resistance to determine whether DHM had a protective effect. DHM could improve insulin resistance. DHM increased serum GLP-1 by improving intestinal GLP-1 secretion and inhibiting GLP-1 decomposition, associated with the alteration of intestinal intraepithelial lymphocytes (IELs) proportions and decreased expression of CD26 in IELs and TCRαβ + CD8αβ + IELs in HFD-induced mice. DHM could ameliorate GLP-1 level and insulin resistance by modulation of gut microbiota and the metabolites, particularly the regulation of chenodeoxycholic acid (CDCA) content, followed by the inhibition of farnesoid X receptor (FXR) expression in intestinal L cells and increased glucagon gene (Gcg) mRNA expression and GLP-1 secretion. This research demonstrates the role of “gut microbiota-CDCA” pathway in the improvement of intestinal GLP-1 levels in HFD-induced mice by DHM administration, providing a new target for the prevention of 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 1st 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 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 identify the effect of acute stress induced by composite factors on intestinal barrier dysfunction and explore the relevant mechanism. Methods Twenty male C57BL/6 mice (7-8 weeks old, body mass 20-22 g) were randomly divided into control group (CON group, n=10) and model group (MOD group, n=10). To establish an acute stress model of complex factors, the mice of the MOD group were given rest of 4 h, sleep deprivation of 15 h, and then followed by 3 h of noise (120 dB)/flash (2 000±500 lx) and 2 h of forced swimming (water temperature 26±1 ℃, water depth 45 cm) within 24 h. While the mice in the CON group were placed in a noiseless environment with constant temperature and humidity and normal circadian rhythm but been given no any treatment. At the end of forced swimming, the mice from the MOD group were anesthetized for blood samples and then euthanized. Serum markers of intestinal injury were detected by immunoenzyme-linked adsorption assay kit, morphological changes in colonic tissues were observed by HE staining, protein and mRNA levels of colonic tissue barrier function related molecules and inflammatory factors were detected by immunofluorescence, immunohistochemistry and RT-qPCR, and intestinal flora changes were analyzed by 16S rRNA technique. Results Compared with the CON group, the serum markers of intestinal damage, lipopolysaccharide (LPS), intestinal fatty acid binding protein (I-FABP) and Zonulin were significantly increased in the MOD group (P < 0.05). HE staining showed that intestinal tissue damage was obvious in the MOD group. The results of immunofluorescence staining and RT-qPCR showed that the levels of mechanical barrier related molecules Zona occludens 1 (ZO-1) and Occludin were obviously decreased (P < 0.05). Immunohistochemistry and PAS staining indicated the number of chemical barriers associated goblet cells, and expression of mucin2 (Muc-2), antimicrobial peptide regenerating islet derived-3γ (Reg3γ) and regenerating islet derived-3β (Reg3β) were notably reduced (P < 0.05). Intestinal flora β diversity significantly changed, with harmful bacteria Bacteroidetes and Desulfovibrio significantly increased, while beneficial bacteria Rumenococcus family, norank_f_Erysipelotrichaceae, Gemella genus and Erysipelotrichaceae genus declined (P < 0.05). The levels of TNF-α, IL-6 and ROS were significantly enhanced (P < 0.05). Conclusion Acute stress of complex factors significantly induces intestinal injury and barrier dysfunction.

Exhaustive exercise is known to induce muscle damage characterized by inflammation and oxidative stress. Although “regular” and “weekend warrior” exercise regimens have been shown to confer comparable health benefits in human studies, such as reduced risks of all-cause, cardiovascular disease (CVD), and cancer mortality, their differential impacts on muscle damage post-exhaustive exercise remain unclear. This study aimed to compare the effects of long-term, moderate-intensity (LTMI) and short-term, high-intensity (STHI) training modalities, matched for total exercise volume, on gut microbiota, short-chain fatty acids (SCFAs), and exhaustive exercise-induced muscle damage in mice, as well as to evaluate the correlation between these factors. LTMI is considered a regular exercise regimen, while STHI shares some similarities with the “weekend warrior” pattern, such as promoting exercise intensity and condensing training sessions into a short period. Our findings indicate that LTMI training significantly enhanced the abundance of SCFA-producing bacteria, including Akkermansia, Prevotellaceae_NK3B31_group, Odoribacter, Alistipes, and Lactobacillus, thereby increasing SCFA levels and attenuating muscle damage following exhaustive swimming. In contrast, STHI training increased the abundance of opportunistic pathogens such as Staphylococcus and Bilophila, without altering SCFA levels, and was associated with exacerbated muscle damage. Moreover, we observed a significant negative correlation between the abundance of SCFA-producing bacteria and SCFA levels with the expression of inflammatory cytokines in the muscle of mice post-exhaustive exercise. Conversely, the abundance of Staphylococcus and Bilophila showed a notable positive correlation with these cytokines. Additionally, the effects of LTMI and STHI on exhaustive exercise-induced muscle damage were transmissible to untrained mice via fecal microbiota transplantation, suggesting that gut microbiota changes induced by these training modalities may contribute to their contrasting impacts on muscle damage. These results underscore the significance of selecting an appropriate training modality prior to engaging in exhaustive exercise, with implications for athletic training and injury prevention.

Background: Considerable researches have directed toward metabolic disorders caused by sleep restriction (SR). SR-induced disruption of circadian metabolic rhythmicity is identified as an important pathophysiological mechanism. The flavonoid pterostilbene (PTE) is abundant in the traditional Chinese medicine dragon's blood with protective efficacy against obesity-related metabolic dysfunctions. Our previous study found that PTE ameliorates exercise intolerance and clock gene oscillation in the skeletal muscles subjected to SR. Purpose: This study aimed to explore whether PTE improves SR-induced metabolic disorders and delineate the relationship between PTE and the circadian clock. Study design and methods: Two hundred male C57/B6J mice were kept awake for 20 h/d over five consecutive days and concurrently gavaged with 50, 100, or 200 mg/kg & sdot;bw/d PTE. Food consumption and body weight were monitored, and the metabolic status of the mice was evaluated by performing OGTT and ITT, measuring the serum lipid profiles and liver histopathology in response to SR. Daily behavior was analyzed by Clocklab (TM). The circadian rhythms of the liver clock genes and metabolic output genes were evaluated by cosine analysis. Binding between PTE and ROR alpha/gamma or NR1D1/2 was investigated by molecular docking. A luciferase reporter assay was used to determine the impact of PTE on Bmal1 transcription in SR-exposed mice co-transfected with Ad-BMAL1LUC plus Ad-ROR gamma-mCherry or Ad-NR1D1-EGFP. Results: PTE significantly ameliorated abnormal glucose and lipid metabolism (p < 0.05) in SR-exposed mice. PTE improved circadian behavior (p < 0.05) and rescued the circadian rhythm oscillation of the liver clock (p < 0.05) and metabolic output genes (p < 0.05) under SR condition. Molecular docking disclosed that PTE might interact with RORs, and PTE was found to increase Bmal1 promoter luciferase activity with RORE elements in the presence of Ad-ROR gamma-mCherry (p < 0.05). Conclusions: PTE may protect against SR-induced metabolic disorders by directly modulating ROR gamma to maintain circadian metabolic rhythm. The findings provide valuable insights into the potential use of PTE in the treatment of metabolic disorders associated with disruptions in the circadian rhythm.

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, liver 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.

Lipopolysaccharide (LPS) is an important neurotoxin that can cause inflammatory activation of microglia. ZC3H12D is a novel immunomodulator, which plays a remarkable role in neurological pathologies. It has not been characterized whether ZC3H12D is involved in the regulation of microglial activation. The aim of this study was to investigate the role of ZC3H12D in LPS-induced pro-inflammatory microglial activation and its potential mechanism. To elucidate this, we established animal models of inflammatory injury by intraperitoneal injection of LPS (10 mg/kg). The results of the open-field test showed that LPS caused impaired motor function in mice. Meanwhile, LPS caused pro-inflammatory activation of microglia in the mice cerebral cortex and inhibited the expression of ZC3H12D. We also constructed in vitro inflammatory injury models by treating BV-2 microglia with LPS (0.5 μg/mL). The results showed that down-regulated ZC3H12D expression was associated with LPS-induced pro-inflammatory microglial activation, and further intervention of ZC3H12D expression could inhibited LPS-induced pro-inflammatory activation of microglia. In addition, LPS activated the TLR4-NF-κB signaling pathway, and this process can also be reversed by promoting ZC3H12D expression. At the same time, the addition of resveratrol, a nutrient previously proven to inhibit pro-inflammatory microglial activation, can also reverse this process by increasing the expression of ZC3H12D. Summarized, our data elucidated that ZC3H12D in LPS-induced pro-inflammatory activation of brain microglia via restraining the TLR4-NF-κB pathway. This study may provide a valuable clue for potential therapeutic targets for neuroinflammation-related injuries.

Dihydromyricetin (DHM) is a polyphenolic phytochemical found mainly in plants such as Ampelopsis grossedentata, which has beneficial effects on insulin resistance. However, the specific mechanism has not been clarified. In this study, C57BL/6 mice were exposed to a high-fat diet (HFD) for eight weeks. DHM could improve insulin resistance via enhancing the incretin effect. DHM increased serum GLP-1 by improving intestinal GLP-1 secretion and inhibiting GLP-1 decomposition, associated with the alteration of intestinal intraepithelial lymphocytes (IELs) proportions and decreased expression of CD26 in IELs and TCRαβ+ CD8αβ+ IELs in HFD-induced mice. Meanwhile, DHM could ameliorate GLP-1 level and insulin resistance by modulation of gut microbiota and the metabolites, particularly the regulation of intestinal bile acid CDCA content, followed by the inhibition of FXR expression in intestinal L cells as well as increased Gcg mRNA expression and the secretion of GLP-1. These findings clarify the role of the “gut microbiota-CDCA” pathway in the improvement of intestinal GLP-1 levels in HFD-induced mice by DHM administration, providing a new pharmacological target for the prevention of insulin resistance. ### Competing Interest Statement The authors have declared no competing interest. * Abx : antibiotic AUC : area under curve ATCC : American type culture collection BSH : bile salt hydrolase CA : cholic acid CDCA : chenodeoxycholic acid CHO : cholesterol CCK-8 : cell counting kit-8 DHM : dihydromyricetin DPP-IV : ipeptidyl peptidase-4 ELISA : enzyme linked immunosorbent assay FXR : farnesoid X receptor GLP-1 : glucagon-like peptide-1 Glu : glucose Gcg : glucagon gene HFD : high-fat diet HDL-C : high-density lipoproteins IELs : intestinal intraepithelial lymphocytes IECs : intestinal epithelial cells IPGTT : intraperitoneal glucose tolerance test ITT : insulin tolerance test LDL-C : low-density lipoproteins OGTT : oral glucose tolerance test OTU : operational taxonomic units PCA : Principal Component Analysis PBS : phosphate buffered saline QC : quality control qPCR : quantitative polymerase chain reaction SPF : secific pathogen free T-β-MCA : tauro-β-muricholic acid TCA : taurochenodeoxycholic acid TG : triacylglycerol TUDCA : tauroursodeoxycholic acid T2DM : diabetes mellitus type 2 Z-Gug : Z-Guggulsterone

BACKGROUND:Previous studies indicate that dihydromyricetin (DHM) could alleviate intestinal inflammation and improve intestinal barrier integrity, yet the underlying mechanism remains obscure.METHODS:C57BL/6 male mice were fed with a control diet, high-fat diet (HFD), or HFD + DHM diet for 12 weeks. The intestinal permeability and expression of intestinal tight junction (TJ) protein were detected to evaluate the effects of DHM on intestinal barrier integrity. The interleukin 22 (IL-22) production of group 3 innate lymphoid cells (ILC3s) in small intestine lamina propria was tested to clarify the effects of DHM on ILC3s. In addition, an MNK3 cell line, which expresses the same transcription factors and cytokines as ILC3, was used to investigate the molecular mechanism under DHM-induced IL-22 expression.RESULTS:DHM effectively protected HFD-fed mice against intestinal barrier destruction by promoting ILC3 activation and IL-22 secretion, and IL-22 expression increased the expression levels of TJ molecules to protect intestinal barrier integrity. Moreover, DHM increased activation of the AMPK/SIRT3/STAT3 pathway, which in turn promoted IL-22 expression in MNK3 cells.CONCLUSIONS:DHM improved IL-22 production in ILC3 cells to alleviate HFD-induced intestinal barrier destruction via the AMPK/SIRT3/STAT3 pathway.

The study investigated the effect of pterostilbene (PTE) on intestinal glucose absorption and its underlying mechanisms in high-intensity swimming exercise (HISE)-treated mice. Male C57BL/6 mice were treated with PTE for 4 weeks and performed high-intensity swimming training in the last week. Intestinal epithelial cells (IECs) were pretreated with 0.5 and 1.0 μM PTE for 24 h before being incubated in hypoxia/reoxygenation condition. Intestinal glucose absorption was detected by using an oral glucose tolerance test and d-xylose absorption assay, and the levels of factors related to mitochondrial function and pyroptosis were measured via western blot analyses, cell mito stress test, and quantitative real-time polymerase chain reaction. In vivo and in vitro, the results showed that PTE attenuated HISE-induced intestinal glucose absorption dysfunction and pyroptosis in mice intestine. Moreover, PTE inhibited NLRP3 inflammasome and the mitochondrial homeostasis as well as the ROS accumulation in IEC in vitro. Additionally, knockdown of SIRT3, a major regulator of mitochondria function, by siRNA or inhibiting its activity by 3-TYP abolished the effects of PTE on pyroptosis, mitochondrial homeostasis, and ROS generation of IEC in vitro. Our results revealed that PTE could alleviate HISE-induced intestinal glucose absorption dysfunction associated with the inhibition of NLRP3 inflammasome-induced IECs pyroptosis.

Background: Exercise-induced gastrointestinal syndrome (GIS) has symptoms commonly induced by strenuous sports. The study aimed to determine the effect of dihydromyricetin (DHM) administration on high-intensity exercise (HIE)-induced intestinal barrier dysfunction and the underlying mechanism involved with intestinal intraepithelial lymphocytes (IELs). Methods: The HIE model was established with male C57BL/6 mice using a motorized treadmill for 2 weeks, and DHM was given once a day by oral gavage. After being sacrificed, the small intestines of the mice were removed immediately. Results: We found that DHM administration significantly suppressed HIE-induced intestinal inflammation, improved intestinal barrier integrity, and inhibited a HIE-induced increase in the number of IELs and the frequency of CD8αα+ IELs. Meanwhile, several markers associated with the activation, gut homing and immune functions of CD8αα+ IELs were regulated by DHM. Mechanistically, luciferase reporter assay and molecular docking assay showed DHM could activate the aryl hydrocarbon receptor (AhR). Conclusions: These data indicate that DHM exerts a preventive effect against HIE-induced intestinal barrier dysfunction, which is associated with the modulation of the quantity and phenotype of IELs in the small intestine. The findings provide a foundation to identify novel preventive strategies based on DHM supplementation for HIE-induced GIS.