Hepatic Triglyceride Content Research Articles

A high-trans fat, high-carbohydrate, high-cholesterol, high-cholate diet-induced nonalcoholic steatohepatitis mouse model and its hepatic immune response

Non-alcoholic fatty liver disease (NAFLD) is a chronic progressive disease that can progress to non-alcoholic steatohepatitis (NASH). Animal models are important tools for basic NASH research. Immune activation plays a key role in liver inflammation in patients with NASH. We established a high-trans fat, high-carbohydrate, and high-cholesterol, high-cholate diet-induced (HFHCCC) mouse model. C57BL/6 mice were fed a normal or HFHCCC diet for 24 weeks, and the immune response characteristics of this model were evaluated. The proportion of immune cells in mouse liver tissues was detected by immunohistochemistry and flow cytometry, Multiplex bead immunoassay and Luminex technology was used to detecte the expression of cytokines in mouse liver tissues. The results showed that mice treated with HFHCCC diet exhibited remarkably increased hepatic triglycerides (TG) content, and the increase in plasma transaminases resulted in hepatocyte injury. Biochemical results showed that HFHCCC induced elevated hepatic lipids, blood glucose, insulin; marked hepatocyte steatosis, ballooning, inflammation, and fibrosis. The proportion of innate immunity-related cells, including Kupffer cells (KCs), neutrophils, dendritic cells (DCs), natural killer T cells (NKT), and adaptive immunity-related CD3+ T cells increased; interleukin-1α (IL-1α), IL-1β, IL-2, IL-6, IL-9, and chemokines, including CCL2, CCL3, and macrophage colony stimulating factor (G-CSF) increased. The constructed model closely approximated the characteristics of human NASH and evaluation of its immune response signature, showed that the innate immune response was more pronounced than adaptive immunity. Its use as an experimental tool for understanding innate immune responses in NASH is recommended.

Oleanolic Acid Inhibits SCD1 Gene Expression to Ameliorate Fructose-Induced Hepatosteatosis through SREBP1c-Dependent and -Independent Mechanisms.

The mechanisms of oleanolic acid (OA) regulating hepatic sterol regulatory element-binding protein (SREBP) 1c/stearoyl-CoA desaturase (SCD) 1 pathway to ameliorate fructose-induced hepatosteatosis are investigated. Rats treated with 10% w/v fructose solution are co-administered by OA for 5 weeks, and then sacrifice after fasting for 14 h. OA reverses the fructose-induced increase in hepatic triglyceride (TG) content and downregulates Scd1 mRNA expression. However, two upstream transcription factors, ChREBP and SREBP1c, remain at normal levels with or without fructose and/or OA. In vivo and in vitro studies using SREBP1c-/- mice and HepG2 cell models show that OA also inhibits SCD1 gene overexpression and high hepatic TG levels induced by fructose. On the other hand, in SCD1-/- mice, when the fructose diet is supplemented with high levels of oleic acid (OLA) to compensate for the deficiency of SCD1, OA inhibits hepatic SREBP1c and lipogenic gene expression and reduces hepatic OLA (C18:1) production to improve fructose and/or OLA induced liver lipid deposition. Furthermore, OA promotes PPARα and AMPK to enhance fatty acid oxidation in fructose + OLA-fed SCD1-/- mice. OA may inhibit SCD1 gene expression to ameliorate fructose-induced hepatosteatosis through SREBP1c-dependent and -independent mechanisms.

Progesterone Has No Impact on the Beneficial Effects of Estradiol Treatment in High-Fat-Fed Ovariectomized Mice

In recent decades, clinical and experimental studies have revealed that estradiol contributes enormously to glycemic homeostasis. However, the same consensus does not exist in women during menopause who undergo replacement with progesterone or conjugated estradiol and progesterone. Since most hormone replacement treatments in menopausal women are performed with estradiol (E2) and progesterone (P4) combined, this work aimed to investigate the effects of progesterone on energy metabolism and insulin resistance in an experimental model of menopause (ovariectomized female mice-OVX mice) fed a high-fat diet (HFD). OVX mice were treated with E2 or P4 (or both combined). OVX mice treated with E2 alone or combined with P4 displayed reduced body weight after six weeks of HFD feeding compared to OVX mice and OVX mice treated with P4 alone. These data were associated with improved glucose tolerance and insulin sensitivity in OVX mice treated with E2 (alone or combined with P4) compared to OVX and P4-treated mice. Additionally, E2 treatment (alone or combined with P4) reduced both hepatic and muscle triglyceride content compared with OVX control mice and OVX + P4 mice. There were no differences between groups regarding hepatic enzymes in plasma and inflammatory markers. Therefore, our results revealed that progesterone replacement alone does not seem to influence glucose homeostasis and ectopic lipid accumulation in OVX mice. These results will help expand knowledge about hormone replacement in postmenopausal women associated with metabolic syndrome and non-alcoholic fatty liver disease.

Abstract 674: Transgelin Deficiency Is Associated With Elevated Low-density Lipoprotein Cholesterol And Atherogenesis In Mice.

Genetic hyperlipidemias are a major risk factor for atherosclerotic cardiovascular disease due to life-long exposure to elevated plasma lipids. However, the causality of hyperlipidemia is not known in a large proportion of patients, suggesting that unknown genes remain to be discovered. Applying a CRISPR/Cas9 screen, we recently identified transgelin (TAGLN), an actin binding protein, as a new gene involved in LDL metabolism. TAGLN supports LDL endocytosis presumably by interacting with actin filaments during LDL endocytosis; however, if TAGLN impacts on plasma lipid levels and atherogenesis in vivo is unknown. Aim: To investigate TAGLN’s impact on lipid profile and atherosclerosis development in a Tagln -knockout (KO) mouse model. Methods: Tagln -KO (n=18) and wild-type (WT) (n=18) mice were fed a high-fat diet (42% Cal from fat) for 12 weeks. We collected plasma for lipoprotein analysis, liver specimens for histopathology and lipid extraction/quantification, and aortas for quantifying atherosclerotic plaque area. Results: Tagln -KO mice showed higher total cholesterol than WT mice (20% increase, mean±SD: 299±51 vs. 251±59 mg/dL, p=0.014), without changes in triglyceride levels (p=0.36). Lipoprotein subfraction analysis by FPLC revealed an increase in the lipids associated with the LDL fraction of Tagln -KO mice. Although no differences were observed in hepatic histology or triglyceride content, Tagln -KO animals showed an increase in the hepatic content of total cholesterol (mean±SD: 376±65 vs. 317±70 μg/100 mg, p=0.012). Finally, Tagln -KO mice developed about twice more atherosclerotic lesion area than WT mice (Median(IQR): 0.997(0.347-1.451) vs 0.428(0.336-0.859), p=0.015). Conclusions: In line with a reduction in LDL uptake in hepatocytes, shown by our previous in vitro data, TAGLN deficiency was associated with hypercholesterolemia and high LDL cholesterol in mice, likely due to decreased hepatic LDL clearance. Despite the modest hypercholesterolemia, Tagln -KO mice showed disproportionally increased atherosclerosis, suggesting that TAGLN may regulate other atherogenic mechanisms, beyond LDL cholesterol.

Resveratrol supplementation or diet intervention effects on heart-liver axis in prediabetic female rats submitted to high-fat-high-sucrose diet

NAFLD and type 2 diabetes (T2D) share a bidirectional relationship and cardiovascular diseases (CVD) as leading death cause, but this relationship in prediabetes is still poorly known, especially for women which exhibit an exacerbated CVD risk. Here, we evaluated the effects of resveratrol supplementation (RSV) or diet intervention on the heart-liver axis of prediabetic female rats submitted to high-fat-high-sucrose diet (HFS). Forty Female Wistar rats were divided into 4 groups fed for 5 months with: a standard diet (CTRL), HFS diet (HFS), HFS diet supplemented for the last 2 months with RSV (1 mg/kg/day in water) (RSV) or HFS diet for 3 months followed by 2 months of standard diet (RSD). In vivo Magnetic Resonance Imaging was performed to study cardiac morphology/function. Then, tolerance to ischemia-reperfusion injury was investigated ex vivo by simultaneous measurement of cardiac function (RPP, EDP) and energy metabolism by 31P Magnetic Resonance Spectroscopy. Hepatic total lipid and triglycerides (TG) contents along expression of genes involved in lipid metabolism/inflammation were studied. HFS induced glucose intolerance (P < 0.01), increased diastolic left ventricular volume and thickness (P < 0.05) and heart weight to tibia length ratio (HTLR) (P < 0.01). HFS diet also altered myocardial tolerance to IR, with impaired RPP and EDP (P < 0.001) and PCr during reperfusion (P < 0.05). Both treatments improved glucose tolerance (P < 0.05). Importantly, despite maintained HFS diet, RSV restored the elevated diastolic volume and thickness in vivo (P < 0.01 CTRL, RSV vs. HFS, RSD) and HTLR level (P < 0.001 CTRL, RSV vs. HFS, RSD), conversely to RSD. Both treatments improved the tolerance to IR, with increased RPP (P < 0.05 vs. HFS) along with PCr during reperfusion (P < 0.001, P < 0.01 vs. HFS respectively). Only RSV decreased EDP during IR injury (P < 0.05). In the liver HFS diet induced total lipid and TG accumulation (P < 0.01) as well as elevated expression of lipid oxidation/peroxidation genes without effect on lipogenesis and inflammation cytokines genes. Both treatments normalized hepatic total lipid levels. RSD restored TG levels along elevated lipid metabolism gene expressions (P < 0.01) whereas RSV partially reduced the increase (P < 0.05). Despite maintained HFS and moderate hepatic lipid metabolism effects, RSV exhibited better cardioprotection than RSD, suggesting its potential to protect against early cardiac alterations associated with prediabetes and NAFLD, especially for women.

Sex-specific effect of AQP9 deficiency on hepatic triglyceride metabolism in mice with diet-induced obesity.

Studies in obese rats and human cell models of non-alcoholic fatty liver disease have indicated that knockdown of the hepatic glycerol channel aquaporin 9 (AQP9) leads to decreased hepatic steatosis. However, a study in leptin receptor-deficient mice did not find that knockout (KO) of AQP9 alleviated hepatic steatosis. The aim of this study was to investigate the effect of high-fat diet (HFD) on hepatic glycerol and triglyceride metabolism in male and female AQP9 KO mice. Male and female AQP9 KO mice and wild-type (WT) littermates were fed a HFD for 12weeks. Weight, food intake and blood glucose were monitored throughout the study and tissue analysis included determination of hepatic triglyceride content and triglyceride secretion. The expression of key molecules for hepatic glycerol and triglyceride metabolism was evaluated using qPCR and western blotting. AQP9 KO and WT mice demonstrated a similar weight gain throughout the study period, and we found no evidence for AQP9 deficiency being associated with a reduced hepatic accumulation of triglyceride or a reduced blood glucose level. Instead, we show that the effect of AQP9 deficiency on hepatic lipid metabolism is sex-specific, with only male AQP9 KO mice having a reduced hepatic secretion of triglycerides and an elevated expression of peroxisome proliferator-activated receptor α. Male AQP9 KO mice had an elevated blood glucose level after 12weeks of HFD when compared to baseline levels. Thus, we found no evidence for AQP9 inhibition being a target for alleviating the development of hepatic steatosis in mice with diet-induced obesity. KEY POINTS: This study investigates the effect of AQP9 deficiency on hepatic triglyceride metabolism in both male and female mice fed a high-fat diet (HFD) for 12weeks. No evidence was found for AQP9 deficiency being associated with a reduced hepatic accumulation of triglyceride or a reduced blood glucose level. The effect of AQP9 deficiency on hepatic triglyceride metabolism is sex-specific. Male AQP9 KO mice had a reduced hepatic secretion of triglycerides and an elevated expression of peroxisome proliferator-activated receptor α, which likely promotes an increased hepatic fatty acid oxidation. Male AQP9 KO had an elevated blood glucose level after 12weeks of HFD when compared to baseline levels.

Hepatic triglyceride content is intricately associated with numerous metabolites and biochemical pathways.

Non-alcoholic fatty liver disease (NAFLD) is characterized by the pathological accumulation of triglycerides in hepatocytes and is associated with insulin resistance, atherogenic dyslipidaemia and cardiometabolic diseases. Thus far, the extent of metabolic dysregulation associated with hepatic triglyceride accumulation has not been fully addressed. In this study, we aimed to identify metabolites associated with hepatic triglyceride content (HTGC) and map these associations using network analysis. To gain insight in the spectrum of metabolites associated with hepatic triglyceride accumulation, we performed a comprehensive plasma metabolomics screening of 1363 metabolites in apparently healthy middle aged (age 45-65) individuals (N = 496) in whom HTGC was measured by proton magnetic resonance spectroscopy. An atlas of metabolite-HTGC associations, based on univariate results, was created using correlation-based Gaussian graphical model (GGM) and genome scale metabolic model network analyses. Pathways associated with the clinical prognosis marker fibrosis 4 (FIB-4) index were tested using a closed global test. Our analyses revealed that 118 metabolites were univariately associated with HTGC (p-value <6.59 × 10-5 ), including 106 endogenous, 1 xenobiotic and 11 partially characterized/uncharacterized metabolites. These associations were mapped to several biological pathways including branched amino acids (BCAA), diglycerols, sphingomyelin, glucosyl-ceramide and lactosyl-ceramide. We also identified a novel possible HTGC-related pathway connecting glutamate, metabolonic lactone sulphate and X-15245 using the GGM network. These pathways were confirmed to be associated with the FIB-4 index as well. The full interactive metabolite-HTGC atlas is provided online: https://tofaquih.github.io/AtlasLiver/. The combined network and pathway analyses indicated extensive associations between BCAA and the lipids pathways with HTGC and the FIB-4 index. Moreover, we report a novel pathway glutamate-metabolonic lactone sulphate-X-15245 with a potential strong association with HTGC. These findings can aid elucidating HTGC metabolomic profiles and provide insight into novel drug targets for fibrosis-related outcomes.

Effects of supplemental octanoate on hepatic lipid metabolism, serum biochemical indexes, antioxidant capacity and inflammation-related genes expression of large yellow croaker (Larimichthys crocea) fed with high soybean oil diet.

Dietary high soybean oil (SO) levels might cause hepatic lipid deposition, induce oxidative stress and inflammatory response in aquatic animals, while octanoate (OCT) is beneficial to metabolism and health in mammals. However, the effect of OCT has been studied rarely in aquatic animals. In this study, a 10-week feeding trial was conducted to investigate the effect of supplemental OCT on hepatic lipid metabolism, serum biochemical indexes, antioxidant capacity and inflammatory response of large yellow croaker (Larimichthys crocea) fed with high SO levels diet. The negative control diet contained 7% fish oil (FO), while the positive control diet contained 7% SO. The other four experimental diets were supplemented with 0.7, 2.1, 6.3 and 18.9 g/kg sodium octanoate (OCT) based on the positive control diet. Results showed that OCT supplementation effectively reduced the hepatic crude lipid, triglyceride (TG), total cholesterol (TC) and non-esterified free fatty acids contents, and alleviated lipid accumulation caused by the SO diet. Meanwhile, OCT supplementation decreased the serum TG, TC, alanine transaminase, aspartate transaminase and low-density lipoprotein cholesterol levels, increased the serum high-density lipoprotein cholesterol level, improved the serum lipid profiles and alleviated hepatic injury. Furthermore, with the supplementation of OCT, the mRNA expression of genes related to lipogenesis (acc1, scd1, fas, srebp1, dgat1 and cebpα) and fatty acid (FA) transport (fabp3, fatp and cd36) were down-regulated, while the mRNA expression of genes related to lipolysis (atgl, hsl and lpl) and FA β-oxidation (cpt1 and mcad) were up-regulated. Besides that, dietary OCT increased the total antioxidant capacity, activities of peroxidase, catalase and superoxide dismutase and the content of reduced glutathione, decreased the content of 8-hydroxy-deoxyguanosine and malondialdehyde and relieved hepatic oxidative stress. Supplementation of 0.7 and 2.1 g/kg OCT down-regulated the mRNA expression of genes related to pro-inflammatory cytokines (tnfα, il1β and ifnγ), and suppressed hepatic inflammatory response. In conclusion, supplementation with 0.7-2.1 g/kg OCT could reduce hepatic lipid accumulation, relieve oxidative stress and regulate inflammatory response in large yellow croaker fed the diet with high SO levels, providing a new way to alleviate the hepatic fat deposition in aquatic animals.

Lycopene prevents non-alcoholic fatty liver disease through regulating hepatic NF-κB/NLRP3 inflammasome pathway and intestinal microbiota in mice fed with high-fat and high-fructose diet.

Lycopene (LY) belongs to carotenoids and is abundant in red fruits and vegetables. Several previous studies suggested that LY is beneficial for ameliorating non-alcoholic fatty liver disease (NAFLD), while the potential mechanisms are unclear. The present study aimed to clarify the potential mechanisms of LY in preventing NAFLD via exploring the hepatic NF-κB/NLRP3 inflammasome pathway and intestinal microbiota composition in high-fat and high-fructose diet (HFFD)-fed mice. Fifty eight-week-old male C57BL/6J mice were randomly assigned into 5 groups: Normal control group (NC); HFFD group; HFFD with low dose of lycopene group (LLY, 20 mg/kg/d); HFFD with high dose of lycopene group (HLY, 60 mg/kg/d) and HFFD with resveratrol group (RSV, 50 mg/kg/d, positive control). After 8 weeks, feces were collected and the 12 h fasted mice were sacrificed to acquire tissues and blood for parameters measurement. The results showed that the mice in LLY, HLY and RSV groups had significantly lower body weight gain, weight of white adipose tissue, serum levels of high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), lipopolysaccharide (LPS), alanine aminotransferase (ALT), and hepatic concentrations of triglyceride (TG) and interleukin-6 (IL-6) than that in the HFFD group (p < 0.05). HLY and RSV groups also displayed lower serum levels of TG, total cholesterol (TC) and hepatic levels of tumor necrosis factor-α (TNF-α) than the HFFD group (p < 0.05). Liver protein expressions of NLRP3, Pro-Caspase-1, Caspase-1 and NF-κB were lower in the LLY, HLY and RSV groups than those in the HFFD group (p < 0.05). The feces of LY -treated mice had higher relative levels of SCFAs producing bacteria Allobaculum and lower destructive bacteria, including Firmicutes, Lachnospiraceae_NK4A136_group, Desulfovibrio, and Alistipes over the HFFD group (p < 0.05). RSV group also displayed lower fecal levels of Lachnospiraceae_NK4A136_group, Desulfovibrio, and Alistipes than the HFFD group (p < 0.05). In conclusion, LY might prevent NAFLD by suppressing hepatic NF-κB/NLRP3 inflammasome pathway and attenuating gut microbiota dysbiosis.

PNPLA3 rs738409 risk genotype decouples TyG index from HOMA2-IR and intrahepatic lipid content

BackgroundRecent reports suggested a different predictive value for TyG index compared to HOMA-IR in coronary artery calcification (CAC) and other atherosclerotic outcomes, despite that both indices are proposed as surrogate markers of insulin resistance. We hypothesized a key role for liver pathology as an explanation and therefore assessed the relationship among the two indices and the intrahepatic lipid content stratified by PNPLA3 rs738409 genotypes as a known non-alcoholic fatty liver disease (NAFLD) genetic risk.MethodsThirty-nine women from a prior GDM-genetic study were recalled with PNPLA3 rs738409 CC and GG genotypes for metabolic phenotyping and to assess hepatic triglyceride content (HTGC). 75 g OGTT was performed, fasting lipid, glucose, insulin levels and calculated insulin resistance indices (TyG and HOMA2-IR) were used. HTGC was measured by MR based methods. Mann–Whitney-U, χ2 and for the correlation analysis Spearman rank order tests were applied.ResultsThe PNPLA3 rs738409 genotype had a significant effect on the direct correlation between the HOMA2-IR and TyG index: the correlation (R = 0.52, p = 0.0054) found in the CC group was completely abolished in those with the GG (NAFLD) risk genotype. In addition, the HOMA2-IR correlated with HTGC in the entire study population (R = 0.69, p < 0.0001) and also separately in both genotypes (CC R = 0.62, p = 0.0006, GG: R = 0.74, p = 0.0058). In contrast, the correlation between TyG index and HTGC was only significant in rs738409 CC genotype group (R = 0.42, p = 0.0284) but not in GG group. A similar pattern was observed in the correlation between TG and HTGC (CC: R = 0.41, p = 0.0335), when the components of the TyG index were separately assessed.ConclusionsPNPLA3 rs738409 risk genotype completely decoupled the direct correlation between two surrogate markers of insulin resistance: TyG and HOMA2-IR confirming our hypothesis. The liver lipid content increased in parallel with the HOMA2-IR independent of genotype, in contrast to the TyG index where the risk genotype abolished the correlation. This phenomenon seems to be related to the nature of hepatic fat accumulation and to the different concepts establishing the two insulin resistance markers.

Coronary artery calcium, hepatic steatosis, and atherosclerotic cardiovascular disease risk in patients with type 2 diabetes mellitus: Results from the Dallas heart study

IntroductionCardiovascular disease (CVD) risk amongst those with type 2 diabetes (T2D) is heterogenous. The role of imaging-based cardiometabolic biomarkers (e.g., coronary artery calcium [CAC] score, and hepatic triglyceride content [HTC]) in CVD risk stratification in T2D is unclear. To better understand this, we sought to evaluate the individual and joint associations between CAC and hepatic steatosis (HS) with clinical atherosclerotic CVD (ASCVD) in Dallas Heart Study (DHS) participants with and without T2D. MethodsWe examined participants in the DHS, a multi-ethnic cohort study, without self-reported ASCVD. CAC scoring was performed via computed tomography with the mean of two consecutive scores used. HTC was measured using magnetic resonance spectroscopy, and HS was defined as HTC >5.5% The primary outcome was incident ASCVD, defined as coronary heart disease (CHD; myocardial infarction, percutaneous coronary intervention, or coronary artery bypass graft surgery), ischemic stroke, transient ischemic attack, or CVD death. Cox regression analyses, and interaction testing was performed to evaluate the individual and joint associations between CAC and HS with ASCVD. The association between HS and coronary heart disease was validated in the UK Biobank (UKB). ResultsA total of 1252 DHS participants were included with mean age 44.8 ± 9.3 years, mean body mass index 28.7 ± 5.9 kg/m2, 55% female, and 59% black with an overall prevalence of T2D of 9.7%. CAC scores were significantly higher (p < 0.01) and HS was significantly more prevalent in those with T2D (p < 0.01). Over a median of 12.3 years, 8.3% of participants experienced ASCVD events. The ASCVD event rate was significantly higher in participants with T2D (20.5% vs 7.0%, p < 0.01). Continuous CAC was associated with ASCVD events in the overall cohort regardless of T2D status with a significant interaction present between CAC and T2D status on ASCVD, Pinteraction = 0.02. HTC was not associated with ASCVD risk in participants without T2D but was inversely associated with risk in participants with T2D (HR 0.91, 95% CI 0.83–0.99 per 1% increase in HTC, p = 0.02), Pinteraction = 0.02. Amongst 37,266 UKB participants, 4.5% had T2D. CHD events occurred in 2.2% of participants, with 10.2% of events occurring amongst those with T2D. An inverse relationship between HTC and CHD was also found amongst those with T2D in UKB with a significant interaction between T2D status and HTC on CHD (HR per 1% increase in HTC 0.95, 95% CI 0.91–0.99, p = 0.01, Pinteraction = 0.02). ConclusionsIn the DHS, we found that CAC was associated with ASCVD risk independent of T2D status. We did not observe an association between HTC and ASCVD in participants without T2D, but there was an inverse association between HTC and ASCVD in those with T2D that was replicated in the UKB cohort. Further investigation is warranted to understand the possible protective association of HS in participants with T2D.

Beneficial Effects of Viable and Heat-Inactivated Lactobacillus rhamnosus GG Administration on Oxidative Stress and Inflammation in Diet-Induced NAFLD in Rats

Oxidative stress and inflammation are well-known triggers of NAFLD onset and progression. The aim of this study is to compare the potential benefits of a viable probiotic (Lactobacillus rhamnosus GG) and its parabiotic (heat-inactivated) on oxidative stress, inflammation, DNA damage and cell death pathways in the liver of rats featuring diet-induced NAFLD. The consumption of the steatotic diet led to increased final body and liver weights, higher hepatic triacylglycerol content, altered serum transaminase levels and enhanced oxidative and inflammatory status. Administration of the probiotic and the parabiotic partially prevented the body weight increase induced by the steatotic diet, whereas the probiotic caused more effective decreasing hepatic triglyceride content. Sharp but nonstatistically significant decreases in serum transaminase levels were also observed for both treatments. The reduction in antioxidant enzyme activities found in the nontreated animals fed the steatotic diet was partially prevented by both treatments (GPx activity). Similarly, the reductions in nonenzymatic antioxidant protection (GSH content) and total antioxidant capacity (ORAC) found in the nontreated rats were restored by the administration of both treatments. These results show that both viable and heat-inactivated Lactobacillus rhamnosus GG administration partially prevent steatotic diet-induced liver oxidative stress and inflammation induced in rats.

Improvement of Estrogen Deficiency Symptoms by the Intake of Long-Term Fermented Soybeans (Doenjang) Rich in Bacillus Species through Modulating Gut Microbiota in Estrogen-Deficient Rats

Traditionally made doenjang (TMD) produced by the long-term fermentation of soybeans with salt may improve symptoms of estrogen deficiency. We aimed to evaluate the effects of four TMD types, containing low and high amounts of Bacillus species and biogenic amines (HBHA, HBLA, LBHA, and LBLA), on energy, glucose, and lipid metabolism, by altering the gut microbiota in estrogen-deficient ovariectomized (OVX) rats. Their mechanisms were also examined. The OVX rats were divided into the control, cooked soybean (CSB), HBHA, LBHA, HBLA, and LBLA groups. Sham-operated rats were the normal control group. Serum 17β-estradiol concentrations were similar among all OVX groups. Tail skin temperatures, which are indicative of hot flashes, were higher in the control than the HBHA and HBLA groups and were similar to the normal control group. Weight gain and visceral fat mass were lower in the TMD and CSB intake groups but not as low as in the normal control group. Lean body mass showed a trend opposite to that of visceral fat in the respective groups. The hepatic triglyceride content decreased with the TMD intake compared to the control and CSB groups. mRNA expressions of the peroxisome proliferator-activated receptor-γ (PPAR-γ) and carnitine palmitoyltransferase-1 in the TMD and CSB groups were as high as in the normal control group, and the PPAR-γ mRNA expression was more elevated in the HBLA group than in the normal control group. The morphology of the intestines improved in the TMD groups compared to the control, and the HBHA and HBLA groups showed an enhanced improvement compared to the CSB group. The HBHA, HBLA, and LBHA groups increased the α-diversity of the cecal microbiota compared to the control. Akkermenia and Lactobacillus were higher in the HBLA and LBLA groups compared to the control. The expression of the estrogen, forkhead box proteins of the class-O subgroup, and insulin-signaling pathways were lower in the control group, and HBHA and HBLA prevented their decrement. In conclusion, long-term treatment with TMD containing high amounts of Bacillus potentially improves estrogen deficiency symptoms more than unfermented soybeans.

A High Cholesterol, (n-3) Polyunsaturated Fatty Acid Diet Induces Hypercholesterolemia More than a High Cholesterol, (n-6) Polyunsaturated Fatty Acid Diet in Hamsters

This study was designed to study the effects of (n-3) polyunsaturated fatty acids (PUFA) on plasma and liver lipids, particularly lipoprotein cholesterol concentrations, in hamsters. Diets rich in (n-3) PUFA (21 g/100 g fatty acid) or (n-6) PUFA (37.4 g/100 g fatty acid) with or without 5 g/kg cholesterol (C) supplements were given for 4 wk to male hamsters weighing 70–90 g. The VLDL- and (IDL + LDL)-cholesterol concentrations were 114 and 128% higher in hamsters fed the (n-3) PUFA + C diet than in those fed the (n-6) PUFA + C diet. However, these differences were not observed when cholesterol was not supplemented. Hamsters fed the (n-3) PUFA diet had significantly lower plasma and hepatic triglyceride concentrations were comparable in hamsters fed (n-6) PUFA + C and (n-3) PUFA + C. Hepatic cholesteryl esters were significantly lower, while hepatic microsomal acyl-CoA:cholesterol acyltransferase activity and VLDL cholesteryl esters were significantly higher in hamsters fed the (n-3) PUFA + C diet than in those fed the (n-6) PUFA + C diet. Our results demonstrate that elevation of VLDL- and (IDL + LDL)-cholesterol in hamsters by (n-3) PUFA, compared with (n-6) PUFA, is dependent on dietary cholesterol supplementation and may be due to decreased catabolism of these lipoproteins.

Maternal Pea Protein Intake Provides Sex-Specific Protection against Dyslipidemia in Offspring from Obese Pregnancies.

Increased consumption of dietary pulse protein has been shown to assist in body weight regulation and improve a range of metabolic health outcomes. We investigated if the exchange of casein for yellow pea protein (YPPN) in an obese-inducing maternal diet throughout pregnancy and lactation offered protection against obesity and dyslipidemia in offspring. Sixty female Sprague Dawley rats were fed a low-calorie control diet (CON), a high-caloric obesity-inducing diet (with casein protein (CP), HC-CP), or an isocaloric/macronutrient-matched HC diet supplemented with YPPN isolate (HC-PPN) in pre-pregnancy, gestation, and lactation. Body weight (BW) and metabolic outcomes were assessed in male and female offspring at weaning and in adulthood after consuming the CON diet in the postnatal period. Consumption of the HC-PPN diet did not protect against maternal obesity but did improve reproductive success compared with the HC-CP group (72.7% versus 43.7%) and reduced total energy, fat, and protein in maternal milk. Male, but not female, offspring from mothers fed the HC-CP diet demonstrated hyperphagia, obesity, dyslipidemia, and hepatic triglyceride (TG) accumulation as adults compared with CON offspring. Isocaloric exchange of CP for YPPN in a high-calorie obese-inducing diet did not protect against obesity but did improve several aspects of lipid metabolism in adult male offspring including serum total cholesterol, LDL/VLDL cholesterol, triglycerides (TGs), and hepatic TG concentration. Our results suggest that the exchange of CP for YPPN in a maternal obese-inducing diet selectively protects male offspring from the malprogramming of lipid metabolism in adulthood.

The Mechanisms of Neochlorogenic Acid (3-Caffeoylquinic Acid) in Improving glucose and Lipid Metabolism in Rats with Insulin Resistance Induced by A High Fat-High Fructose Diet

This study investigated the effects and the mechanism of actions of neochlorogenic acid (3-caffeoylquinic acid; 3-CQA) on glucose and lipid metabolism in rats fed a high fat-high fructose diet (HFFD). Male rats were fed HFFD (40 % lard and 20 % fructose) for 16 weeks. At the 10th week, the HFFD rats were split into 3 groups: HFFD receiving distilled water (HFFD control group), HFFD receiving 3-CQA 50 mg/kg and HFFD receiving metformin 200 mg/kg once daily for a further 6 weeks. At the end of treatment, fasting blood glucose (FBG), oral glucose-tolerance test (OGTT), lipid profile, insulin, leptin, adiponectin, markers of oxidative stress, and hepatic triglyceride content were measured. Liver, adipose tissue, and skeletal muscle were collected for histological, gene and protein examinations. Compared to the HFFD control group, the 3-CQA group exhibited significantly reduced FBG, insulin and leptin levels, and improved OGTT. Serum adiponectin increased and lipid profiles were normalized. Hepatic triglyceride was reduced with a decrease in lipid droplets in liver histological sections. Levels of serum SOD and CAT activity, and MDA were reversed by 3-CQA treatment. Moreover, 3-CQA significantly reduced the expression of adipocyte pro-inflammatory cytokine genes (MCP-1, TNF-α, and IL-6), hepatic lipogenic genes (SREBP1c, FAS, and GPAT), and hepatic gluconeogenic genes (PEPCK and G6Pase). Additionally, 3-CQA increased expression of muscle GLUT4 gene, and of GLUT4 protein with increased p-AKT and p-AMPK in skeletal muscle. In conclusion, 3-CQA improves glucose and lipid metabolism plausibly by decreasing oxidative stress and inflammation-induced insulin resistance, downregulating the expression of lipogenic and gluconeogenic genes, and enhancing insulin signaling in HFFD-induced insulin-resistant rats. HIGHLIGHTS Neochlorogenic acid (3-CQA) improves glucose and lipid metabolism by decreasing insulin resistance Neochlorogenic acid (3-CQA) deceases insulin resistance due to its activities in ameliorating obesity, oxidative stress, and adipose tissue inflammation The beneficial effects of Neochlorogenic acid (3-CQA) to improve glucose and lipid homeostasis may be mediated via suppression of hepatic glucose production and lipogenesis, and activation of muscle glucose uptake and AKT and AMPK pathways GRAPHICAL ABSTRACT

Dose-Related Regulatory Effect of Raspberry Polyphenolic Extract on Cecal Microbiota Activity, Lipid Metabolism and Inflammation in Rats Fed a Diet Rich in Saturated Fats.

The amount of berry polyphenols required to exert health-promoting effects seems to be difficult to achieve by fresh fruit ingestion, so polyphenol-rich extracts could be considered a dietary alternative. In the present study, laboratory rats were fed high-fat diets supplemented with 0.1 or 0.3% raspberry polyphenols from pomace, with the former dose reflecting the amount of polyphenols consumed with a glass of fresh raspberries. It was hypothesized that beneficial changes in blood and hepatic tissue related to lipid metabolism would accompany both treatments, but the health-promoting effect would be more noticeable with the higher dose of extract. This hypothesis was confirmed, and the high dose of raspberry polyphenols was better than the low dose extract in terms of decreased epididymal white adipose tissue weight, hepatic triglyceride content, PPARγ and SREBP-1c expression in the liver, and plasma IL-6 concentration, as well as increased acetic acid concentration in the cecal digesta. These effects might be partially associated with the enhanced content of ellagitannin and anthocyanin metabolites found in the blood plasma of rats administered the high dose of the extract. The results showed that this extract could be considered a dietary vehicle to provide an amount of raspberry polyphenols that could promote health.

Feeding of Hermetia illucens Larvae Meal Attenuates Hepatic Lipid Synthesis and Fatty Liver Development in Obese Zucker Rats.

The present study tested the hypothesis that dietary insect meal from Hermetia illucens (HI) larvae attenuates the development of liver steatosis and hyperlipidemia in the obese Zucker rat. To test the hypothesis, a 4-week trial with male, obese Zucker rats (n = 30) and male, lean Zucker rats (n = 10) was performed. The obese rats were assigned to three obese groups (group O-C, group O-HI25, group O-HI50) of 10 rats each. The lean rats served as a lean control group (L-C). Group L-C and group O-C were fed a control diet with 20% casein as protein source, whereas 25% and 50% of the protein from casein was replaced with protein from HI larvae meal in the diets of group O-HI25 and O-HI50, respectively. The staining of liver sections with Oil red O revealed an excessive lipid accumulation in the liver of group O-C compared to group L-C, whereas liver lipid accumulation in group O-HI25 and O-HI50 was markedly reduced compared to group O-C. Hepatic concentrations of triglycerides, cholesterol, C14:0, C16:0, C16:1, C18:0, C18:1, the sum of total fatty acids and hepatic mRNA levels of several genes associated with lipid synthesis and plasma concentration of cholesterol were markedly higher in group O-C than in group L-C, but lower in group O-HI50 than in group O-C (p < 0.05). In conclusion, partial replacement of casein by HI larvae meal attenuates liver steatosis and dyslipidemia in obese Zucker rats. This suggests that HI larvae meal serves as a functional food protecting from obesity-induced metabolic disorders.

Maternal Betaine Supplementation Mitigates Maternal High Fat Diet-Induced NAFLD in Offspring Mice through Gut Microbiota

Maternal betaine supplementation has been proven to alleviate non-alcoholic fatty liver disease (NAFLD) in offspring caused by maternal high-fat diet (MHFD). The gut-liver axis plays an important role in NAFLD pathogenesis. However, whether maternal betaine supplementation can alleviate NAFLD in offspring by the gut-liver axis is unknown. C57BL/6J mice were fed with high-fat diet for 4 weeks before mating, and supplemented with 1% betaine during pregnancy and lactation. After weaning, offspring mice were fed with standard diet to 10 weeks. Maternal betaine supplementation reduced hepatic triglyceride content and alleviated hepatic steatosis in offspring mice exposed to MHFD. Furthermore, the mRNA expression of PPARα, CPT1α and FATP2 was increased and TNFα was reduced by maternal betaine supplementation. Maternal betaine intake decreased the relative abundances of Proteobateria, Desulfovibrio and Ruminococcus, but increased the relative abundances of Bacteroides and Parabacteroides. Moreover, maternal betaine intake increased the concentrations of short-chain fatty acids (SCFAs), including acetic acid, butyric acid and valeric acid, in the feces. Gut microbiota and SCFAs were significantly correlated with hepatic triglyceride content and expression of the above genes. Maternal betaine intake had no effect on other gut microbiota-related metabolites (bile acid and trimethylamine-n-oxide). Altogether, maternal betaine supplementation ameliorated MHFD-induced NAFLD possibly through regulating gut microbiota and SCFAs in offspring mice.

Hepatoprotective effect of gallic acid against type 2-induced diabetic liver injury in male rats through modulation of fetuin-A and GLP-1 with involvement of ERK1/2/NF-κB and Wnt1/β-catenin signaling pathways.

Gallic acid is a phenolic compound with biological and pharmacological activities. Therefore, our study aimed to examine whether gallic acid has a beneficial effect against type 2-induced diabetic hepatic injury in rats and attempt to discover its possible intracellular pathways. Adult male rats were subdivided into six groups: Control, DM (diabetes mellitus), GA (gallic acid)+DM, DM+GA, DM+MET (metformin) and DM+GA+MET. Type 2 diabetes mellitus (T2DM) induced a significant increase in the blood glucose, HOMA-IR, liver enzymes, fetuin-A, hepatic triglycerides content with diminished serum insulin and hepatic glycogen content associated with impairment of cellular redox balance. Administration of gallic acid successfully restored all these alterations which was confirmed by marked improvement of the histopathological changes of the liver. Significantly, gallic acid increased the expression of glucagon-like peptide-1 (GLP-1) immunoreactive cells in the terminal ileum with negative correlation observed between fetuin-A and GLP-1 cells. Furthermore, our results discovered that gallic acid could diminish the DM-induced hepatic damage via upregulated hepatic mRNA expression of GLUT-4, Wnt1 and β-catenin with inhibitory effects on the elevated expression of ERK1/2/NF-κB. In conclusion, this study suggests that gallic acid provides a significant protection against T2DM-mediated liver injury. The use of gallic acid with traditional anti-diabetic drug enhanced its efficiency compared with traditional drug alone.