Impacts of the unsaturation degree of long-chain fatty acids on the volatile fatty acid profiles of rumen microbial fermentation in goats in vitro

This study investigated the impacts of the degree of unsaturation （unsaturity） of long-chain fatty acids on volatile fatty acid （VFA） profiles of rumen fermentation in vitro. Six types of long-chain fatty acids, including stearic acid （C18：0, control group）, oleic acid （C18：1, n-9）, linoleic acid （C18：2, n-6）, a-linolenic acid （C18：3, n-3）, arachidonic acid （C20：4, n-6） and eicosapentaenoic acid （C20：5, n-3）, were tested. Rumen fluid from three goats fitted with ruminal fistulae was used as inoculum and the inclusion rate of long-chain fatty acid was at 3% （w/w） of substrate. Samples were taken for VFA analysis at 0, 3, 6, 9, 12, 18 and 24 h of incubation, respectively. The analysis showed that there were significant differences in the total VFA among treatments, sampling time points, and treatment×time point interactions （P〈0.01）. a-Linolenic acid had the highest total VFA （P〈0.01） among different long-chain fatty acids tested. The molar proportion of acetate in total VFA significantly differed among treatments （P〈0.01） and sampling time points （P〈0.01）, but not treatment×time point interactions （P〉0.05）. In contrast, the molar proportion of propionate did not differ among treatments during the whole incubation （P〉0.05）. However, for butyrate molar proportions, significant differences were found not only among sampling time points but also among treatments and treatment×time point interactions （P〈0.01）, with eicosapentaenoic acid having the highest value （P〈0.01）. Additionally, no statistically significant differences were found in the acetate to propionate ratios among treatments groups （P〉0.05）, even the treatments stearic acid and a-linolenic acid were numerically higher than the others. The inclusion of 3% long-chain unsaturated fatty acids differing in the degree of unsaturation brought out a significant quadratic regression relation between the total VFA concentration and the double bond number of fatty acid. In conclusion, the a-linolenic acid with 3 double bonds appeared better for improving rumen microbial fermentation and the total VFA concentration.

The effects of the unsaturated degree of long-chain fatty acids on the rumen microbial protein content and the activities of transaminases and dehydrogenase in vitro

This study investigated the effects of the degree of unsaturation（unsaturity） of long-chain fatty acids on microbial protein content and the activities of transaminases and dehydrogenase in vitro using goat rumen fluid as the cultural medium.Six types of fatty acids,stearic acid（C18：0,group A,control group）,oleic acid（C18：1,n-9,group B）,linoleic acid（C18：2,n-6,group C）,α-linolenic acid（C18：3,n-3,group D）,arachidonic acid（C20：4,n-6,group E）,and eicosapentaenoic acid（C20：5,n-3,group F）,were tested,and the inclusion ratio of each fatty acid was 3%（w/w） in total of culture substrate.Samples were taken at 0,3,6,9,12,18 and 24 h,respectively,during culture for analyses.Compared with stearic acid,linoleic acid,a-linolenic acid,and arachidonic acid increased the bacterial protein content,while oleic acid and eicosapentaenoic acid had no significant effects;the protozoal protein content was reduced for all the unsaturated fatty acids,and the magnitude of the reduction appeared to be associated with the degree of unsaturity of fatty acids.The total microbial protein content was dominantly accounted by the protozoal protein content（about 4-9 folds of the bacterial protein）,and only increased by linoleic acid,but reduced by oleic acid,arachidonic acid and eicosapentaenoic acid.There were no significant effects in the activities of both glutamic oxaloacetic transaminase（GOT） and glutamic-pyruvic transaminase（GPT） for all the other fatty acids,except for arachidonic acid which enhanced GOT activity and oleic acid which enhanced GPT activity.The total dehydrogenase activity was positively correlated with the degree of unsaturation of fatty acids.In conclusion,the inclusion of 3%of long-chain unsaturated fatty acids increased bacterial protein content,whereas reduced protozoal protein content and enhanced dehydrogenase activity.The fatty acids with more than three double bonds had detrimental effects on the microbial protein content.This work demonstrates for the first time the effect rule of the unsaturation degree of long-chain fatty acids on the rumen microbial protein in vitro.

Effects of long-chain fatty acid supplementation on the growth performance of grower and finisher pigs: a meta-analysis

Background: Supplementation of feed with long-chain fatty acids(LCFAs) during the grower and finisher phases has long been discussed as a growth promotion strategy in pigs, but its effects are inconsistent. The purpose of our study was to comprehensively evaluate its effects on the growth performance based on the average daily gain(ADG), average daily feed intake(ADFI) and gain: feed(G:F) ratio and to unveil the roles of the basal diet, LCFA concentration and LCFA saturation.Results: We searched the Pub Med and Web of Science databases(articles published from Jan 1 st, 2000, to Sep 30 th,2018;restricted to English) and compared LCFA-supplemented diets with control diets. We retrieved 2346 studies, 18 of which(1314 pigs, 26 records) were eligible for our analysis. We used a random-effects model to calculate the weighted mean differences(WMDs) and 95% confidence intervals(CIs). LCFA supplementation in the grower-finisher phase improved the ADG(WMD = 41.74 g/d, 95% CI: 8.81 to 74.66, P = 0.013) and G:F ratio(WMD = 0.019, 95% CI: 0.006 to 0.032, P = 0.003). For supplementation solely in the finisher phase, we found a similar performance in the ADG(WMD = 39.93 g/d, 95% CI: 26.48 to 53.38, P < 0.001) and G:F ratio(WMD = 0.019, 95% CI: 0.006 to 0.032, P < 0.001) but a reduction in the ADFI(WMD =-83.863 g/d, 95% CI:-156.157 to-11.569, P = 0.023). Specifically, approximately 5%LCFA supplementation in the finisher phase had significant effects on the ADG(WMD = 51.385 g/d, 95% CI: 35.816 to66.954, P < 0.001), ADFI(WMD =-102.869 g/d, 95% CI:-189.236 to-16.502, P = 0.02) and G:F ratio(WMD = 0.028, 95%CI: 0.018 to 0.039, P < 0.001), whereas a concentration of approximately 1% exhibited no effects.Conclusions: Overall, regardless of the basal diet and saturation, LCFA supplementation greatly improves the growth performance of grower and finisher pigs, primarily by increasing the energy density.

Identification of a Long-Chain Fatty Acid Elongase from Nannochloropsis sp. Involved in the Biosynthesis of Fatty Acids by Heterologous Expression in Saccharomyces cerevisiae

The marine microalga Nannochloropsis sp.contains various elongases and desaturases that are critical for biosynthesis of polyunsaturated fatty acids.A full-length cDNA encoding a long-chain fatty acid elongase,named Ns FAE,was cloned from Nannochloropsis sp..The open reading frame of Ns FAE(GenBank accession no.MF680548)consisted of 1068 bp and encoded a predicted protein of 355 amino acids with molecular mass 38.8 k Da.The deduced polypeptide showed 43%–44%identity to fatty acyl elongases from other algae.RT-PCR experiments indicated that the Ns FAE gene exhibited the highest expression in Nannochloropsis sp.at 72 h(i.e.,during the third growth stage)and the expression was significantly lower in the other four growth stages.Plasmid p Ns FAE-CRISPR and a recombinant DNA fragment(ADH1p-Ns FAE-CYCt)were transformed into Saccharomyces cerevisiae strain BY4742 using the CRISPR-Cas system.Yeast transformants containing Ns FAE produced three fatty acids not normally present in wild-type BY4742-linoleic acid,linolenic acid and eicosadienoic acid-indicating that Ns FAE encodes a functional elongase enzyme.

Study on Extracting Rare Earth from Sulfate System by Long-Chain Fatty Acid

The extraction of rare earths by long-chain fatty acid in kerosene from sulphate system was described.It was demonstrated from the experimental results that the ratio of kerosene: fatty acid: isooctanol = 55 : 30: 15 ( V/V),By the saturation capability method and the slope method, the extracted reaction mechanism of the extraction of rare earth was studied.It is shown that the extraction reaction conform to the cation exchange reaction mechanism.The extracted sequence of rare earth was determined in this system and it is shown that there is no tetrad effect and the position of yttrium is between lanthanum and cerium.

Evaluation of Fourier Transform Infrared Spectroscopy for Diagnosis of Peroxisomal Diseases with Abnormal Very-Long-Chain Fatty Acid Metabolism

Very long chain fatty acids (VLCFAs) are accumulated in cells and blood in patients with peroxisomal diseases, such as adrenoleukodystrophy (ALD) and Zellwger Syndrome (ZS). The purpose of this study is to investigate usefulness of Fourier transform infrared spectroscopy (FTIR) with attenuated total reflection (ATR) analysis method for clinical diagnosis of those diseases, thereby we measured the infrared spectra of the sera of patients and healthy controls. Correlation coefficients between 2nd derivative FTIR spectra of the serum samples and the VLCFA content ratio which is used as a clinical parameter to date were comprehensively calculated to investigate which wavenumber showed high correlation with the VLCFA ratio. Multiple regression analysis using the serum FTIR spectra showed that high correlations were observed with VLCFA ratios (C26:0/C22:0 ratio), and we could construct a suitable regression model (R2 = 0.97, p ﹣19). In addition, the model system using various VLCFAs in newborn bovine serum also showed that several FTIR peaks in 800 ~ 900 cm﹣1 region were found to have good correlation with VLCFA ratios. Our results support that FTIR analysis is useful for diagnosis of peroxisomal diseases.

Protective effect of long-chain polyunsaturated fatty acids on hepatorenal syndrome in rats

BACKGROUND Hepatorenal syndrome(HRS)is the most prevalent form of acute kidney injury in cirrhotic patients.It is characterized by reduced renal blood flow and represents the most severe complication in cirrhotic patients with advanced disease.Previous research has indicated that antioxidants can delay the onset of a hyperdynamic circulatory state in cirrhosis and improve renal function in HRS patients.Regular omega-3 supplementation has significantly reduced the risk of liver disease.This supplementation could represent an additional therapy for individuals with HRS.AIM To evaluated the antioxidant effect of omega-3 polyunsaturated fatty acid supplementation on the kidneys of cirrhotic rats.METHODS Secondary biliary cirrhosis was induced in rats by biliary duct ligation(BDL)for 28 d.We used 24 male Wistar rats divided into the following groups:I(control);II(treated with omega-3,1 g/kg of body weight);III(BDL treated with omega-3,1 g/kg of body weight);and IV(BDL without treatment).The animals were killed by overdose of anesthetic;the kidneys were dissected,removed,frozen in liquid nitrogen,and stored in a freezer at-80℃for later analysis.We evaluated oxidative stress,nitric oxide(NO)metabolites,DNA damage by the comet assay,cell viability test,and apoptosis in the kidneys.Data were analyzed by one-way analysis of variance,and means were compared using the Tukey test,with P≤0.05.RESULTS Omega-3 significantly decreased the production of reactive oxygen species(P<0.001)and lipoperoxidation in the kidneys of cirrhotic rats treated with omega-3(P<0.001).The activity of the antioxidant enzymes superoxide dismutase and catalase increased in the BDL+omega-3 group compared to the BDL group(P<0.01).NO production,DNA damage,and caspase-9 cleavage decreased significantly in the omega-3-treated BDL group.There was an increase in mitochondrial electrochemical potential(P<0.001)in BDL treated with omega-3 compared to BDL.No changes in the cell survival index in HRS with omega-3 compared to the control group(P>0.05)were observed.CONCLUSION The study demonstrates that omega-3 can protect cellular integrity and function by increasing antioxidant enzymes,inhibiting the formation of free radicals,and reducing apoptosis.

Milk fat globule membrane supplementation protects againstβ-lactoglobul-ininduced food allergy in mice via upregulation of regulatory T cells and enhancement of intestinal barrier in a microbiota-derived short-chain fatty acids manner

Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice model.MFGM was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body weight.Results demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula occludens-1.Furthermore,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A expressions.The increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain extent.In summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of GPRs.These findings suggest that MFGM may be useful as a promising functional ingredient against CMA.

Maternal supplementation with n-3 fatty acids affects placental lipid metabolism, inflammation, oxidative stress, the endocannabinoid system, and the neonate cytokine concentrations in dairy cows

Background The placenta plays a crucial role in supporting and influencing fetal development.We compared the effects of prepartum supplementation with omega-3(n-3)fatty acid(FA)sources,flaxseed oil(FLX)and fish oil(FO),on the expression of genes and proteins related to lipid metabolism,inflammation,oxidative stress,and the endocannabinoid system(ECS)in the expelled placenta,as well as on FA profile and inflammatory response of neonates.Late-pregnant Holstein dairy cows were supplemented with saturated fat(CTL),FLX,or FO.Placental cotyledons(n=5)were collected immediately after expulsion,and extracted RNA and proteins were analyzed by RTPCR and proteomic analysis.Neonatal blood was assessed for FA composition and concentrations of inflammatory markers.Results FO increased the gene expression of fatty acid binding protein 4(FABP4),interleukin 10(IL-10),catalase(CAT),cannabinoid receptor 1(CNR1),and cannabinoid receptor 2(CNR2)compared with CTL placenta.Gene expression of ECS-enzyme FA-amide hydrolase(FAAH)was lower in FLX and FO than in CTL.Proteomic analysis identified 3,974 proteins;of these,51–59 were differentially abundant between treatments(P≤0.05,|fold change|≥1.5).Top canonical pathways enriched in FLX vs.CTL and in FO vs.CTL were triglyceride metabolism and inflammatory processes.Both n-3 FA increased the placental abundance of FA binding proteins(FABPs)3 and 7.The abundance of CNR1 cannabinoid-receptor-interacting-protein-1(CNRIP1)was reduced in FO vs.FLX.In silico modeling affirmed that bovine FABPs bind to endocannabinoids.The FLX increased the abundance of inflammatory CD44-antigen and secreted-phosphoprotein-1,whereas prostaglandin-endoperoxide synthase 2 was decreased in FO vs.CTL placenta.Maternal FO enriched neonatal plasma with n-3 FAs,and both FLX and FO reduced interleukin-6 concentrations compared with CTL.Conclusion Maternal n-3 FA from FLX and FO differentially affected the bovine placenta;both enhanced lipid metabolism and modulated oxidative stress,however,FO increased some transcriptional ECS components,possibly related to the increased FABPs.Maternal FO induced a unique balance of pro-and anti-inflammatory components in the placenta.Taken together,different sources of n-3 FA during late pregnancy enhanced placental immune and metabolic processes,which may affect the neonatal immune system.

Carboxyl Ester Lipase Protects Against Metabolic Dysfunction-Associated Steatohepatitis by Binding to Fatty Acid Synthase

Carboxyl ester lipase(CEL),a pivotal enzyme involved in lipid metabolism,is recurrently mutated in obese mice.Here,we aimed to elucidate the functional significance,molecular mechanism,and therapeutic potential of CEL in metabolic dysfunction-associated steatohepatitis(MASH).Hepatocyte-specific carboxyl ester lipase gene(Cel)knockout(Cel^(DHEP))and wildtype(WT)littermates were fed with cholinedeficient high-fat diet(CD-HFD)for 16 weeks,or methionine-and choline-deficient diet(MCD)for three weeks to induce MASH.Liquid chromatography–mass spectrometry and co-immunoprecipitation were employed to identify the downstream targets of CEL.CD-HFD/MCD-fed WT mice received intravenous injections of CEL-adeno-associated viral,serotype 8(AAV8)to induce specific overexpression of CEL in the liver.We observed a decrease in CEL protein levels in MASH induced by CD-HFD or MCD in mice.Cel^(DHEP) mice fed with CD-HFD or MCD exhibited pronounced hepatic steatosis,inflammation,lipid peroxidation,and liver injury compared to WT littermates,accompanied by increased hepatic nuclear factor kappa-light-chain-enhancer of activated B cell(NF-jB)activation.Consistently,Cel knockdown in mouse primary hepatocytes and AML12 cells aggravated lipid accumulation and inflammation,whereas CEL overexpression exerted the opposite effect.Mechanistically,CEL directly bound to fatty acid synthase(FASN),resulting in reduced FASN SUMOylation,which in turn promoted FASN degradation through the proteasome pathway.Furthermore,inhibition of FASN ameliorated hepatocyte lipid accumulation and inflammation induced by Cel knockdown in vivo and in vitro.Hepatocyte-specific CEL overexpression using AAV8-Cel significantly mitigated steatohepatitis in mice fed with CD-HFD or MCD.CEL protects against steatohepatitis development by directly interacting with FASN and suppressing its expression for de novo lipogenesis.CEL overexpression confers a therapeutic benefit in steatohepatitis.

Fatty Acid Composition of Hazelnut Kernel Oil from Coula edulis Collected in the Republic of Congo

Coula edulis is non-timber forest product (NTFP) used in Africa for its hazelnuts, which contain edible seeds with a demonstrated nutritional potential. However, there have been very few scientific studies of this species in the Republic of Congo. Thus, the aim of the current study was therefore to determine the fatty acid composition of the oil extracted from Coula edulis hazelnut seeds collected at random in the Republic of Congo. The oil was extracted using the Soxhlet method and its fatty acid composition was determined by gas chromatography. The extracted oil from Coula edulis hazelnut kernels is rich in monounsaturated fatty acids (95.28%), particularly oleic acid (94.5%), which classifies it as an oleic oil and gives it interesting nutritional and therapeutic properties. On the other hand, saturated fatty acids (4.15%) and polyunsaturated fatty acids (0.35%) are not well represented. Its low poly-unsaturated fatty acid content makes it more stable when stored at room temperature.

USP19 Stabilizes TAK1 to Regulate High Glucose/Free Fatty Acid-induced Dysfunction in HK-2 Cells

Objective Obesity-induced kidney injury contributes to the development of diabetic nephropathy(DN).Here,we identified the functions of ubiquitin-specific peptidase 19(USP19)in HK-2 cells exposed to a combination of high glucose(HG)and free fatty acid(FFA)and determined its association with TGF-beta-activated kinase 1(TAK1).Methods HK-2 cells were exposed to a combination of HG and FFA.USP19 mRNA expression was detected by quantitative RT-PCR(qRT-PCR),and protein analysis was performed by immunoblotting(IB).Cell growth was assessed by Cell Counting Kit-8(CCK-8)viability and 5-ethynyl-2′-deoxyuridine(EdU)proliferation assays.Cell cycle distribution and apoptosis were detected by flow cytometry.The USP19/TAK1 interaction and ubiquitinated TAK1 levels were assayed by coimmunoprecipitation(Co-IP)assays and IB.Results In HG+FFA-challenged HK-2 cells,USP19 was highly expressed.USP19 knockdown attenuated HG+FFA-triggered growth inhibition and apoptosis promotion in HK-2 cells.Moreover,USP19 knockdown alleviated HG+FFA-mediated PTEN-induced putative kinase 1(PINK1)/Parkin pathway inactivation and increased mitochondrial reactive oxygen species(ROS)generation in HK-2 cells.Mechanistically,USP19 stabilized the TAK1 protein through deubiquitination.Importantly,increased TAK1 expression reversed the USP19 knockdown-mediated phenotypic changes and PINK1/Parkin pathway activation in HG+FFA-challenged HK-2 cells.Conclusion The findings revealed that USP19 plays a crucial role in promoting HK-2 cell dysfunction induced by combined stimulation with HG and FFAs by stabilizing TAK1,providing a potential therapeutic strategy for combating DN.

Serum bile acid and unsaturated fatty acid profiles of non-alcoholic fatty liver disease in type 2 diabetic patients

BACKGROUND The understanding of bile acid(BA)and unsaturated fatty acid(UFA)profiles,as well as their dysregulation,remains elusive in individuals with type 2 diabetes mellitus(T2DM)coexisting with non-alcoholic fatty liver disease(NAFLD).Investigating these metabolites could offer valuable insights into the pathophy-siology of NAFLD in T2DM.AIM To identify potential metabolite biomarkers capable of distinguishing between NAFLD and T2DM.METHODS A training model was developed involving 399 participants,comprising 113 healthy controls(HCs),134 individuals with T2DM without NAFLD,and 152 individuals with T2DM and NAFLD.External validation encompassed 172 participants.NAFLD patients were divided based on liver fibrosis scores.The analytical approach employed univariate testing,orthogonal partial least squares-discriminant analysis,logistic regression,receiver operating characteristic curve analysis,and decision curve analysis to pinpoint and assess the diagnostic value of serum biomarkers.RESULTS Compared to HCs,both T2DM and NAFLD groups exhibited diminished levels of specific BAs.In UFAs,particular acids exhibited a positive correlation with NAFLD risk in T2DM,while theω-6:ω-3 UFA ratio demonstrated a negative correlation.Levels ofα-linolenic acid andγ-linolenic acid were linked to significant liver fibrosis in NAFLD.The validation cohort substantiated the predictive efficacy of these biomarkers for assessing NAFLD risk in T2DM patients.CONCLUSION This study underscores the connection between altered BA and UFA profiles and the presence of NAFLD in individuals with T2DM,proposing their potential as biomarkers in the pathogenesis of NAFLD.

Targeted metabolomics study of fatty-acid metabolism in lean metabolic-associated fatty liver disease patients

BACKGROUND The annual incidence of metabolic-associated fatty liver disease(MAFLD)in China has been increasing and is often overlooked owing to its insidious charac-teristics.Approximately 50%of the patients have a normal weight or are not obese.They are said to have lean-type MAFLD,and few studies of such patients are available.Because MAFLD is associated with abnormal lipid metabolism,lipid-targeted metabolomics was used in this study to provide experimental evidence for early diagnosis and pathogenesis.MAFLD and analyze metabolic pathways.UPLC-Q-Orbitrap/MS content determination was used to determine serum palmitic acid(PA),oleic acid(OA),linoleic acid(LA),and arachidonic acid(AA)levels in lean-type MAFLD patients.RESULTS Urea nitrogen and uric acid levels were higher in lean-type MAFLD patients than in healthy individuals(P<0.05).Alanine transaminase and cholinesterase levels were higher in lean-type MAFLD patients than in healthy indi-viduals(P<0.01).The expression of high-density lipoprotein and apolipoprotein A-1 were lower in lean-type MAFLD patients than in healthy individuals(P<0.05)and the expression of triglycerides and fasting blood glucose were increased(P<0.01).A total of 65 biomarkers that affected the synthesis and metabolism of fatty acids were found with P<0.05 and variable importance in projection>1.The levels of PA,OA,LA,and AA were significantly increased compared with healthy individuals.CONCLUSION The metabolic profiles of lean-type MAFLD patients and healthy participants differed significantly,yielding 65 identified biomarkers.PA,OA,LA,and AA exhibited the most significant changes,offering valuable clinical guidance for prevention and treatment of lean-type MAFLD.

Effects of forsythin extract in Forsythia leaves on intestinal microbiota and short-chain fatty acids in rats fed a high-fat diet

Forsythia suspensa,belonging to the deciduous shrubs of the Luteaceae family,a traditional Chinese medicine,has effects of alleviating swelling,clearing heat,detoxification and promoting blood circulation.The leaves of F.suspensa contain multiple chemical components and have a long history of use in folk medicines and health foods.The purpose of this study was to explore the effects of forsythin extract from F.suspensa leaves on intestinal microbiota and short-chain fatty acid(SCFA)content in rats with obesity induced by a high-fat diet.Forsythin extract in F.suspensa leaves increased the abundance of the intestinal microbiota,ameliorated intestinal microbiota disorders and inhibited the increase in total SCFA content in the intestinal tract in rats with obesity induced by a high-fat diet.These results suggested that forsythin extract in F.suspensa leaves may slow the development of obesity induced by a high-fat diet;thus,its active components and efficacy are worthy of further study.

Identification and validation of novel prognostic fatty acid metabolic gene signatures in colon adenocarcinoma through systematic approaches

Colorectal cancer(CRC)belongs to the class of significantly malignant tumors found in humans.Recently,dysregulated fatty acid metabolism(FAM)has been a topic of attention due to its modulation in cancer,specifically CRC.However,the regulatory FAM pathways in CRC require comprehensive elucidation.Methods:The clinical and gene expression data of 175 fatty acid metabolic genes(FAMGs)linked with colon adenocarcinoma(COAD)and normal cornerstone genes were gathered through The Cancer Genome Atlas(TCGA)-COAD corroborating with the Molecular Signature Database v7.2(MSigDB).Initially,crucial prognostic genes were selected by uni-and multi-variate Cox proportional regression analyses;then,depending upon these identified signature genes and clinical variables,a nomogram was generated.Lastly,to assess tumor immune characteristics,concomitant evaluation of tumor immune evasion/risk scoring were elucidated.Results:A 8-gene signature,including ACBD4,ACOX1,CD36,CPT2,ELOVL3,ELOVL6,ENO3,and SUCLG2,was generated,and depending upon this,CRC patients were categorized within high-risk(H-R)and low-risk(L-R)cohorts.Furthermore,risk and age-based nomograms indicated moderate discrimination and good calibration.The data confirmed that the 8-gene model efficiently predicted CRC patients’prognosis.Moreover,according to the conjoint analysis of tumor immune evasion and the risk scorings,the H-R cohort had an immunosuppressive tumor microenvironment,which caused a substandard prognosis.Conclusion:This investigation established a FAMGs-based prognostic model with substantially high predictive value,providing the possibility for improved individualized treatment for CRC individuals.

Electrolyte dependence for the electrochemical decarboxylation of medium-chain fatty acids (n-octanoic acid) into fuel on Pt electrode

The deoxygenation of organic acids, important biomass feedstocks and derivatives, to synthesize hydrocarbon products under mild electrochemical conditions, holds significant importance for the production of carbon-neutral biofuels. There is still limited research on the influential factors of the electrochemical decarboxylation reaction of medium-chain fatty acids. In this study, n-octanoic acid (OA) was chosen as the research subject to investigate the electrochemical decarboxylation behavior of OA on a platinum electrode, focusing on the influence of different alkali metal cations (Li^(+), Na^(+), K^(+)), common anions (SO^(4)^(2−), Cl^(−)), and electrolyte pH. It was found that KOH as an electrolyte exhibited the best performance for OA. Possibly, the larger size of K^(+) increased the alkalinity of the electrode surface, facilitating OA deprotonation. LiOH electrolyte reduced the solubility of OA, thereby inhibiting the decarboxylation reaction. SO^(4)^(2−) exhibited a weak promoting effect on the decarboxylation reaction of OA, while Cl^(−) showed no adverse effect although Cl^(−) may adsorb on the electrode surface. Furthermore, unlike short-chain fatty acids, medium-chain OA can only achieve efficient decarboxylation under alkaline conditions due to its solubility properties. This study provides references and foundations for future efforts to enhance the efficiency of electrochemical decarboxylation synthesis of hydrocarbon biofuels from medium-chain fatty acids.

Saikosaponin D improves nonalcoholic fatty liver disease via gut microbiota-bile acid metabolism pathway

Non-alcoholic fatty liver disease(NAFLD)is the main cause of chronic liver disease worldwide.Bupleurum is widely used in the treatment of non-alcoholic fatty liver,and saikosaponin D(SSD)is one of the main active components of Bupleurum.The purpose of this study was to investigate the efficacy of SSD in the treatment of NAFLD and to explore the mechanism of SSD in the improvement of NAFLD based on“gut-liver axis”.Our results showed that SSD dose-dependently alleviated high fat diet-induced weight gain in mice,improved insulin sensitivity,and also reduced liver lipid accumulation and injury-related biomarkers aspartate aminotransferase(AST)and alanine aminotransferase(ALT).Further exploration found that SSD inhibited the mRNA expression levels of farnesoid X receptor(Fxr),small heterodimer partner(Shp),recombinant fibroblast growth factor 15(Fgf15)and apical sodium dependent bile acid transporter(Asbt)in the intestine,suggesting that SSD improved liver lipid metabolism by inhibiting intestinal FXR signaling.SSD can significantly reduce the gut microbiota associated with bile salt hydrolase(BSH)expression,such as Clostridium.Decreased BSH expression reduced the ratio of unconjugated to conjugated bile acids,thereby inhibiting the intestinal FXR.These data demonstrated that SSD ameliorated NAFLD potentially through the gut microbiota-bile acidintestinal FXR pathway and suggested that SSD is a promising therapeutic agent for the treatment of NAFLD.

Expression and clinical significance of short-chain fatty acids in patients with intrahepatic cholestasis of pregnancy

BACKGROUND Intrahepatic cholestasis of pregnancy(ICP)is a pregnancy-specific liver condition that typically arises in the middle and late stages of pregnancy.Short-chain fatty acids(SCFAs),prominent metabolites of the gut microbiota,have significant connections with various pregnancy complications,and some SCFAs hold potential for treating such complications.However,the metabolic profile of SCFAs in patients with ICP remains unclear.AIM To investigate the metabolic profiles and differences in SCFAs present in the maternal and cord blood of patients with ICP and determine the clinical significance of these findings.METHODS Maternal serum and cord blood samples were collected from both patients with ICP(ICP group)and normal pregnant women(NP group).Targeted metabolomics was used to assess the SCFA levels in these samples.RESULTS Significant differences in maternal SCFAs were observed between the ICP and NP groups.Most SCFAs exhibited a consistent declining trend in cord blood samples from the ICP group,mirroring the pattern seen in maternal serum.Correlation analysis revealed a positive correlation between maternal serum SCFAs and cord blood SCFAs[r(Pearson)=0.88,P=7.93e-95].In both maternal serum and cord blood,acetic and caproic acids were identified as key metabolites contributing to the differences in SCFAs between the two groups(variable importance for the projection>1).Receiver operating characteristic analysis demonstrated that multiple SCFAs in maternal blood have excellent diagnostic capabilities for ICP,with caproic acid exhibiting the highest diagnostic efficacy(area under the curve=0.97).CONCLUSION Compared with the NP group,significant alterations were observed in the SCFAs of maternal serum and cord blood in the ICP group,although they displayed distinct patterns of change.Furthermore,the SCFA levels in maternal serum and cord blood were significantly positively correlated.Notably,certain maternal serum SCFAs,specifically caproic and acetic acids,demonstrated excellent diagnostic efficiency for ICP.

The biosynthesis of alarm pheromone in the wheat aphid Rhopalosiphum padi is regulated by hormones via fatty acid metabolism

Aphids are major insect pests in agriculture and forestry worldwide.Following attacks by natural enemies,many aphids release an alarm pheromone to protect their population.In most aphids,the main component of the aphid alarm pheromone(AAP)is the sesquiterpene hydrocarbon(E)-β-farnesene(EβF).However,the mechanisms behind its biosynthesis and regulation remain poorly understood.In this study,we used the bird cherry–oat aphid Rhopalosiphum padi,which is an important wheat aphid,to investigate the regulatory mechanisms of EβF biosynthesis.Our results showed that EβF biosynthesis occurs during the mature embryo period and the molting period of the 1st-and 2nd-instar nymphs.Triglycerides provide the prerequisite material for EβF production and release.Based on transcriptome sequencing,RNAi analysis,hormone treatments,and quantitative measurements,we found that the biosynthesis of EβF utilizes acetyl coenzyme A produced from fatty acid degradation,which can be suppressed by juvenile hormone but it is promoted by 20-hydroxyecdysone through the modulation of fatty acid metabolism.This is the first systemic study on the modulation of EβF production in aphids.The results of our study provide insights into the molecular regulatory mechanisms of AAP biosynthesis,as well as valuable information for designing potential aphid control strategies.