Housing mice near vs. below thermoneutrality affects drug-induced weight loss but does not improve prediction of efficacy in humans.

Evaluation of weight loss drugs is usually performed in diet-induced obese mice housed at ∼22°C. This is a cold stress that increases energy expenditure by ∼35% compared to thermoneutrality (∼30°C), which may overestimate drug-induced weight loss. We investigated five anti-obesity mechanisms that have been in clinical development, comparing weight loss in mice housed at 22°C vs. 30°C. Glucagon-like peptide-1 (GLP-1), human fibroblast growth factor 21 (hFGF21), and melanocortin-4 receptor (MC4R) agonist induced similar weight losses. Peptide YY elicited greater vehicle-subtracted weight loss at 30°C (7.2% vs. 1.4%), whereas growth differentiation factor 15 (GDF15) was more effective at 22°C (13% vs. 6%). Independent of ambient temperature, GLP-1 and hFGF21 prevented the reduction in metabolic rate caused by weight loss. There was no simple rule for a better prediction of human drug efficacy based on ambient temperature, but since humans live at thermoneutrality, drug testing using mice should include experiments near thermoneutrality.

Narirutin-Rich Celluclast Extract from Mandarin (Citrus unshiu) Peel Alleviates High-Fat Diet-Induced Obesity and Promotes Energy Metabolism in C57BL/6 Mice.

Mandarin peel, a main by-product from the processing of citrus juice, has been highlighted for its various bioactivities and functional ingredients. Our previous study proved the inhibitory effects of Celluclast extract from mandarin peel (MPCE) on lipid accumulation and differentiation in 3T3-L1 adipocytes. Therefore, the current study aimed to evaluate the anti-obesity effect of MPCE in high-fat diet (HFD)-induced obese mice. The high-performance liquid chromatography (HPLC) analysis exhibited that narirutin and hesperidin are the main active components of MPCE. Our current results showed that MPCE supplementation decreased adiposity by reducing body and organ weights in HFD-induced obese mice. MPCE also reduced triglyceride (TG), alanine transaminase (ALT), aspartate transaminase (AST), and leptin contents in the serum of HFD-fed mice. Moreover, MPCE significantly inhibited hepatic lipid accumulation by regulating the expression levels of proteins associated with lipid metabolism, including sterol regulatory element-binding protein (SREBP1c), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC). Furthermore, MPCE administration significantly inhibited both adipogenesis and lipogenesis, with modulation of energy metabolism by activating 5' adenosine monophosphate-activated protein kinase (AMPK) and lipolytic enzymes such as hormone-sensitive lipase (HSL) in the white adipose tissue (WAT). Altogether, our findings indicate that MPCE improves HFD-induced obesity and can be used as a curative agent in pharmaceuticals and nutraceuticals to alleviate obesity and related disorders.

Interleukin-4 inhibits the hypothalamic appetite control by modulating the insulin-AKT and JAK-STAT signaling in leptin mutant mice.

Our previous research identified interleukin-4 (IL-4) as a key regulator of glucose/lipid metabolism, circulatory leptin levels, and insulin action, suggesting its potential as a therapeutic target for obesity and related complications. This study aimed to further elucidate the role of IL-4 in regulating hypothalamic appetite-controlling neuropeptides using leptin dysfunctional Leptin145E/145E mice as the experimental model. IL-4 significantly reduces body weight, food intake, and serum glucose levels. Our data demonstrated that IL-4 exhibits multiple functions in regulating hypothalamic appetite control, including downregulating orexigenic agouti-related peptide and neuropeptide Y levels, promoting expression of anorexigenic proopiomelanocortin, alleviating microenvironmental hypothalamic inflammation, enhancing leptin and insulin pathway, and attenuating insulin resistance. Furthermore, IL-4 promotes uncoupling protein 1 expression of white adipose tissue (WAT), suggesting its role in triggering WAT-beige switch. In summary, this study uncovers novel function of IL-4 in mediating food-intake behaviors and metabolic efficiency by regulating hypothalamic appetite-control and WAT browning activities. These findings support the therapeutic potential of targeting hypothalamic inflammation and reducing adiposity through IL-4 intervention for tackling the pandemic increasing prevalence of obesity and associated metabolic disorders.

Anti-Obesity Effect of Jeju Roasted Citrus Peel Extract in High-Fat Diet-Induced Obese Mice and 3T3-L1 Adipocytes Via Lipid Metabolism Regulation.

Lipid accumulation in adipocytes occurs through multifactorial effects such as overnutrition due to unbalanced eating habits, reduced physical activity, and genetic factors. In addition, obesity can be intensified by the dis-regulation of various metabolic systems such as differentiation, lipogenesis, lipolysis, and energy metabolism of adipocytes. In this study, the Jeju roasted peel extract from Citrus unshiu S.Markov. (JRC), which is discarded as opposed to the pulp of C. unshiu S.Markov., is commonly consumed to ameliorate obesity. To investigate the anti-obesity effect of JRC, these studies were conducted on differentiated 3T3-L1 cells and in high-fat diet-induced mice, and related methods were used to confirm whether it decreased lipid accumulation in adipocytes. The mechanism of inhibiting obesity by JRC was confirmed through mRNA expression studies. JRC suppressed lipid accumulation in adipocytes and adipose tissue, and significantly improved enzymes such as alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase and serum lipid profiles. In addition, it effectively modulated the expression of genes related to lipid and energy metabolism in adipose tissue. As a result, these findings suggest that JRC could be a therapeutic regulator of body fat accumulation by significantly alleviating the dis-regulation of intracellular lipid metabolism in adipocytes and by enhancement of energy metabolism (Approval No. CNU IACUC-YB-2023-98).

Anti-Obesity Effects of GABA in C57BL/6J Mice with High-Fat Diet-Induced Obesity and 3T3-L1 Adipocytes.

Obesity is the excessive accumulation of body fat resulting from impairment in energy balance mechanisms. In this study, we aimed to investigate the mechanism whereby GABA (γ-aminobutyric acid) prevents high-fat diet-induced obesity, and whether it induces lipolysis and browning in white adipose tissue (WAT), using high-fat diet (HFD)-fed obese mice and 3T3-L1 adipocytes. We demonstrated that GABA substantially inhibits the body mass gain of mice by suppressing adipogenesis and lipogenesis. Consistent with this result, histological analysis of WAT demonstrated that GABA decreases adipocyte size. Moreover, we show that GABA administration decreases fasting blood glucose and improves serum lipid profiles and hepatic lipogenesis in HFD-fed obese mice. Furthermore, Western blot and immunofluorescence analyses showed that GABA activates protein kinase A (PKA) signaling pathways that increase lipolysis and promote uncoupling protein 1 (UCP1)-mediated WAT browning. Overall, these results suggest that GABA exerts an anti-obesity effect via the regulation of lipid metabolism.

The Hexane Extract of Citrus sphaerocarpa Ameliorates Visceral Adiposity by Regulating the PI3K/AKT/FoxO1 and AMPK/ACC Signaling Pathways in High-Fat-Diet-Induced Obese Mice.

Obesity is an emerging global health issue with an increasing risk of disease linked to lifestyle choices. Previously, we reported that the hexane extract of Citrus sphaerocarpa (CSHE) suppressed lipid accumulation in differentiated 3T3-L1 adipocytes. In this study, we conducted in vivo experiments to assess whether CSHE suppressed obesity in zebrafish and mouse models. We administered 10 and 20 µg/mL CSHE to obese zebrafish juveniles. CSHE significantly inhibited visceral fat accumulation compared to untreated obese fish. Moreover, the oral administration (100 µg/g body weight/day) of CSHE to high-fat-diet-induced obese mice significantly reduced their body weight, visceral fat volume, and hepatic lipid accumulation. The expression analyses of key regulatory genes involved in lipid metabolism revealed that CSHE upregulated the mRNA expression of lipolysis-related genes in the mouse liver (Pparα and Acox1) and downregulated lipogenesis-related gene (Fasn) expression in epididymal white adipose tissue (eWAT). Fluorescence immunostaining demonstrated the CSHE-mediated enhanced phosphorylation of AKT, AMPK, ACC, and FoxO1, which are crucial factors regulating adipogenesis. CSHE-treated differentiated 3T3L1 adipocytes also exhibited an increased phosphorylation of ACC. Therefore, we propose that CSHE suppresses adipogenesis and enhances lipolysis by regulating the PI3K/AKT/FoxO1 and AMPK/ACC signaling pathways. These findings suggested that CSHE is a promising novel preventive and therapeutic agent for managing obesity.

Starch-entrapped microspheres enhance gut microbiome-mediated anti-obesity effects of resistant starch in high-fat diet induced obese C57BL/6J mice.

The prevalence of obesity is growing worldwide and has been extensively linked to gut microbiota dysbiosis. In addition to exercise and physical activity, fiber-rich foods may be a first-line prophylactic to manage obesity. This study investigated in vivo dietary intervention with high-amylose maize starch (HAMS) and starch-entrapped microspheres (MS) to treat high-fat diet induced metabolic disorder and gut microbiome dysbiosis in mice. MS more efficiently controlled body weight as well as adipose tissue mass compared to HAMS. Furthermore, MS significantly reduced blood glucose, insulin, lipid and pro-inflammatory cytokine levels compared to the high-fat diet, while the effects of HAMS were less pronounced. The MS-altered gut microbiota composition favoring Streptococcaceae, Bacilli, Firmicutes and unclassified Clostridiales was predicted to promote fatty acid, pantothenate and Coenzyme A biosynthesis. In line with this, elevated fecal short chain fatty acid (SCFA), in particular, propionate concentration was observed in MS-fed mice. Our study provides novel insights into the mechanistic action of MS on intestinal homeostasis, providing a basis for future dietary therapeutic applications.

Dietary Inclusion of Yellow Mealworms (T. molitor) and Lesser Mealworms (A. diaperinus) Modifies Intestinal Microbiota Populations of Diet-Induced Obesity Mice.

BACKGROUND: Insect-based proteins are high-quality alternatives to support the shift toward more sustainable and healthy diets. Additionally, insects contain chitin and have unique fatty acid profiles. Studies have shown that mealworms may beneficially affect metabolism, but limited information is known regarding their effects on gut microbiota. OBJECTIVES: We determined the effects of defatted yellow mealworm (Tenebrio molitor) and whole lesser mealworm (Alphitobius diaperinus) meals on the intestinal microbiota of diet-induced obesity mice. METHODS: Male C57BL/6J mice were fed a high-fat diet (HFD; 46% kcal) to induce obesity. Obese mice were then randomly assigned to treatments (n = 10/group) and fed for 8 wk: HFD, HFD with casein protein; B50, HFD with 50% protein from whole lesser mealworm; B100, HFD with 100% protein from whole lesser mealworm; Y50, HFD with 50% protein from defatted yellow mealworm; Y100, HFD with 100% protein from defatted yellow mealworm. Lean mice (n = 10) fed a low-fat-diet (10% kcal) were included. Fresh feces were collected at baseline and every 2 wk, with cecal digesta collected at kill. Fecal and cecal DNA was analyzed for microbiota using 16S rRNA MiSeq Illumina sequencing. RESULTS: In feces and cecal digesta, mice fed mealworms had greater (P < 0.05) bacterial alpha diversity, with changes occurring in a time-dependent manner (P < 0.05). Beta diversity analyses of cecal samples showed a clear separation of treatments, with a time-based separation shown in fecal samples. Widespread microbial differences were observed, with over 45 genera altered (P < 0.05) by diet in cecal digesta. In feces, over 50 genera and 40 genera were altered (P < 0.05) by diet and time, respectively. CONCLUSION: Mealworm consumption changes the intestinal microbiota of obese mice, increasing alpha diversity measures and shifting bacterial taxa. More investigation is required to determine what mealworm components are responsible and how they may be linked with the metabolic benefits observed in mealworm-fed mice.

Ophiopogonin D ameliorates non­alcoholic fatty liver disease in high­fat diet­induced obese mice by improving lipid metabolism, oxidative stress and inflammatory response.

Lipid metabolic disorders, oxidative stress and inflammation in the liver are key steps in the progression of non-alcoholic fatty liver disease (NAFLD). Ophiopogonin D (OP-D), the main active ingredient of Ophiopogon japonicus, exhibits several pharmacological activities such as antioxidant and anti-inflammatory activities. Therefore, the current study aimed to explore the role of OP-D in NAFLD in a high-fat diet (HFD)-induced obesity mouse model. To investigate the effect of OP-D on NAFLD in vivo, a NAFLD mouse model was established following feeding mice with HFD, then the mice were randomly treated with HFD or HFD + OP-D for 4 weeks. Subsequently, primary mouse hepatocytes were isolated, and enzyme-linked immunosorbent assay, reverse transcription-quantitative PCR western blotting and immunofluorescence analysis were used for assessment to explore the direct effect of OP-D in vitro. The results of the present study indicated that OP-D could ameliorate NAFLD in HFD-induced obese mice by regulating lipid metabolism and antioxidant and anti-inflammatory responses. Additionally, OP-D treatment decreased lipogenesis and inflammation levels in vitro, suggesting that the NF-κB signaling pathway may be involved in the beneficial effects of OP-D on NAFLD.

Effects of Modified Dietary Fiber from Fresh Corn Bracts on Obesity and Intestinal Microbiota in High-Fat-Diet Mice.

The effects of insoluble dietary fiber from fresh corn bracts modified by dynamic high-pressure micro-fluidization (DHPM) on the pathological characteristics of obesity, intestinal microflora distribution and production of short-chain fatty acids in high-fat-diet C57BL/6 mice were evaluated. The results show that the DHPM-modified dietary fiber from fresh corn bracts significantly reduces weight gain, insulin resistance and oxidative damage caused by a high-fat diet, and promotes the production of SCFAs, especially acetic acid, propionic acid and butyric acid. These modified dietary fibers also change the proportion of different types of bacteria in the intestinal microflora of mice, reduce the ratio of Firmicutes and Bacteroidota and promote the proliferation of Bifidobacteriales. Therefore, the DHPM-modified dietary fiber from fresh corn bracts can be used as a good intestinal microbiota regulator to promote intestinal health, thereby achieving the role of preventing and treating obesity.

Yellow Mealworm (Tenebrio molitor) and Lesser Mealworm (Alphitobius diaperinus) Proteins Slowed Weight Gain and Improved Metabolism of Diet-Induced Obesity Mice.

BACKGROUND: High-protein diets not only meet amino acid needs but also modulate satiety and energy metabolism. Insect-based proteins are sustainable, high-quality proteins. Mealworms have been studied, but limited information is known about their ability to impact metabolism and obesity. OBJECTIVE: We determined the effects of defatted yellow mealworm (Tenebrio molitor)- and whole lesser mealworm (Alphitobius diaperinus)-based proteins on the body weight (BW), serum metabolites, and liver and adipose tissue (AT) histology and gene expression of diet-induced obesity mice. METHODS: Male C57BL/6J mice were fed a high-fat diet (HFD; 46% kcal) to induce obesity and metabolic syndrome. Obese mice were then assigned to treatments (n = 10/group) and fed for 8 wk: HFD: HFD with casein protein; B50: HFD with 50% protein from whole lesser mealworm; B100: HFD with 100% protein from whole lesser mealworm; Y50: HFD with 50% protein from defatted yellow mealworm; Y100: HFD with 100% protein from defatted yellow mealworm. Lean mice (n = 10) fed a low-fat-diet (LFD; 10% kcal) were included. Longitudinal food intake, BW, body composition, and glucose response were measured. At time of killing, serum metabolites, tissue histopathology and gene expression, and hepatic triglycerides were analyzed. RESULTS: After 8 wk, HFD, B50, and B100 had greater (P < 0.05) weight gain than LFD, whereas Y50 and Y100 did not. Y50, B100, and Y100 had a lower (P < 0.05) BW change rate than HFD. Mealworm-based diets led to increased (P < 0.05) serum high-density lipoprotein (HDL) and reduced (P < 0.05) serum low-density lipoprotein (LDL) concentrations and reduced (P<0.05) LDL/HDL ratio. Mealworm-based diets led to increased (P < 0.05) hepatic expression of genes related to energy balance, immune response, and antioxidants and reduced (P < 0.05) AT expression of genes associated with inflammation and apoptosis. Mealworm-based diets altered (P < 0.05) hepatic and AT expression of glucose and lipid metabolism genes. CONCLUSIONS: In addition to serving as an alternative protein source, mealworms may confer health benefits to obese patients.

The Chinese herbal medicine Dai-Zong-Fang promotes browning of white adipocytes in vivo and in vitro by activating PKA pathway to ameliorate obesity.

Introduction: The global prevalence of obesity is rising rapidly. Conversion of white adipose tissue (WAT) into beige adipose tissue with heat-consuming characteristics, i.e., WAT browning, effectively inhibits obesity. Dai-Zong-Fang (DZF), a traditional Chinese medicine formula, has long been used to treat metabolic syndrome and obesity. This study aimed to explore the pharmacological mechanism of DZF against obesity. Methods: In vivo, C57BL/6J mice were fed high-fat diets to establish the diet-induced obese (DIO) model. DZF (0.40 g/kg and 0.20 g/kg) and metformin (0.15 g/kg, positive control drug) were used as intervention drugs for six weeks, respectively. The effects of DZF on body size, blood glucose and lipid level, structure and morphology of adipocytes and browning of inguinal WAT (iWAT) in DIO mice were observed. In vitro, mature 3T3-L1 adipocytes were used as the model. Concentrations of DZF (0.8 mg/mL and 0.4 mg/mL) were selected according to the Cell Counting Kit-8 (CCK8). After 2d intervention, lipid droplet morphology was observed by BODIPY493/503 staining, and mitochondria number was observed by mito-tracker Green staining. H-89 dihydrochloride, a PKA inhibitor, was used to observe the change in browning markers' expression. The expression levels of browning markers UCP1 and PGC-1α and key molecules of PKA pathway were detected in vivo and in vitro. Results: In vivo, compared with vehicle control group, 0.40 g/kg DZF significantly reduced obesity in DIO mice from body weight, abdomen circumference, Lee's index, and WAT/body weight (p < 0.01 or p < 0.001). 0.40 g/kg DZF also significantly reduced fasting blood glucose (FBG), serum triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) (p < 0.01 or p < 0.001). The iWAT's morphology and mitochondria were browning after DZF intervention. In HE-staining, the lipid droplets became smaller, and the number of mitochondria increased. The mitochondrial structure was remodeled under the electron microscope. The expression of UCP1, PGC-1α and PKA was elevated in iWAT detected by RT-qPCR (p < 0.05 or p < 0.001). In vitro, compared with the control group, 0.8 mg/mL DZF intervention significantly increased the number of mitochondria and expression of UCP1, PGC-1α, PKA, and pCREB (p < 0.05 or p < 0.01). In contrast, UCP1 and PGC-1α expression were significantly reversed after adding PKA inhibitor H-89 dihydrochloride. Conclusion: DZF can promote UCP1 expression by activating the PKA pathway, thereby promoting browning of WAT, attenuating obesity, and reducing obesity-related glucose and lipid metabolism abnormalities, indicating that DZF has the potential to be selected as an anti-obesity drug to benefit obese patients.

Fatty Acid Induced Hypermethylation in the Slc2a4 Gene in Visceral Adipose Tissue Is Associated to Insulin-Resistance and Obesity.

De novo lipogenesis (DNL) in visceral adipose tissue (VAT) is associated with systemic insulin sensitivity. DNL in VAT is regulated through ChREBP activity and glucose uptake through Glut4 (encoded by Slc2a4). Slc2a4 expression, ChREBP activity, and DNL are decreased in obesity, the underlying cause however remains unidentified. We hypothesize that increased DNA methylation in an enhancer region of Slc2a4 decreases Slc2a4 expression in obesity and insulin resistance. We found that SLC2A4 expression in VAT of morbidly obese subjects with high HbA1c (>6.5%, n = 35) is decreased, whereas DNA methylation is concomitantly increased compared to morbidly obese subjects with low HbA1c (≤6.5%, n = 65). In diet-induced obese (DIO) mice, DNA methylation of Slc2a4 persistently increases with the onset of obesity and insulin resistance, while gene expression progressively decreases. The regulatory impact of DNA methylation in the investigated enhancer region on SLC2A4 gene expression was validated with a reporter gene assay. Additionally, treatment of 3T3 pre-adipocytes with palmitate/oleate during differentiation decreased DNA methylation and increased Slc2a4 expression. These findings highlight a potential regulation of Slc2a4 by DNA methylation in VAT, which is induced by fatty acids and may play a role in the progression of obesity and insulin resistance in humans.

Naringin reduces fat deposition by promoting the expression of lipolysis and ß-oxidation related genes.

AIMS: Naringin, a flavonoid present in citrus fruits, has been known for the capacity to reduce lipid synthesis and anti-inflammatory. In this study, we investigated whether naringin increases lipolysis and fatty acid ß-oxidation to change fat deposition. METHODS: In in vivo experiment, obese adult mice (20-weeks-old, n = 18) were divided into control group fed with normal diet and naringin-treated group fed with naringin-supplemented diet (5 g/kg) for 60 days, respectively. In in vitro experiment, differentiated 3T3-L1 adipocytes were treated for four days with or without naringin (100 µg/mL). RESULTS: Supplementing naringin significantly reduced the body weight, abdominal fat weight, blood total cholesterol content of mice, but did not affect food intake. In addition, naringin decreased levels of pro-inflammatory factors in adipose tissue including interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and monocyte chemotactic protein 1 (MCP-1). Naringin increased the expression of AMP-activated protein kinase (AMPK), a key factor in cellular energy metabolism, and raised the ratio of p-AMPK/AMPK in mouse liver tissue. The protein expression of hormone-sensitive lipase (HSL), phospho-HSL563 (p-HSL563), p-HSL563/HSL, and adipocyte triglyceride lipase (ATGL) was significantly increased in the adipose tissue of naringin-treated mice. Furthermore, naringin enhanced the expression of fatty acid ß-oxidation genes, including carnitine palmitoyl transferase 1 (CPT1), uncoupling protein 2 (UCP2), and acyl-coenzyme A oxidase 1 (AOX1) in mouse adipose tissue. In in vitro experiment, similar findings were observed in differentiated 3T3-L1 adipocytes with naringin treatment. The treatment remarkably reduced intracellular lipid content, increased the number of mitochondria and promoted the gene expression of HSL, ATGL, CPT1, AOX1, and UCP2 and the phosphorylation of HSL protein. CONCLUSION: Naringin reduced body fat in obese mice and lipid content in differentiated 3T3-L1 adipocytes, which was associated with enhanced AMPK activation and upregulation of the expression of the lipolytic genes HSL, ATGL, and ß-oxidation genes CPT1, AOX1, and UCP2.

Validating the Health Benefits of Coffee Berry Pulp Extracts in Mice with High-Fat Diet-Induced Obesity and Diabetes.

The effects of coffee (Coffea arabica L.) berry pulp extracts (CBP extracts) on the improvement of diabetes, obesity, and non-alcoholic fatty liver disease (NAFLD) were evaluated using various in vitro antioxidant activity assays and through a high-fat diet-induced mild diabetic obese mouse model. After an 84-day oral administration of CBP extracts (400-100 mg/kg), bioactivities were evaluated. The in vitro analysis showed the highest DPPH● scavenging activity of 73.10 ± 4.27%, ABTS● scavenging activity of 41.18 ± 1.14%, and SOD activity of 56.24 ± 2.81%, at a CBP extract concentration of 1000 µg/mL. The in vivo analysis of the CBP extracts showed favorable and dose-dependent anti-obesity, anti-diabetic, NAFLD, nephropathy, and hyperlipidemia refinement effects through hepatic glucose enzyme activity, 5'-AMP-activated protein kinase (AMPK) up-regulation, antioxidant activity, lipid metabolism-related gene expression, and pancreatic lipid digestion enzyme modulatory activities. This study shows that an appropriate oral dosage of CBP extracts could function as a potent herbal formulation for a refinement agent or medicinal food ingredient to control type 2 diabetes and related complications.

Anti-diabetic effect of hesperidin on palmitate (PA)-treated HepG2 cells and high fat diet-induced obese mice.

The present study examined the relationship between the anti-diabetic effect of hesperidin (HES) and the differential gene expression in HES treated high fat diet (HFD)-induced obese mice. Based on the glucose uptake assay, the treatment of HES restored the glucose uptake to control level in an insulin-independent manner in PA-treated HepG2 cells. Western blot analysis confirmed that the treatment of HES increased the insulin-stimulated phosphorylation of Akt and GSK3ß in insulin-resistant PA-treated HepG2 cells. HFD-induced obese mice treated with HES significantly reduced serum insulin, blood glucose, and homeostatic model assessment for insulin resistance (HOMA-IR) values. In addition, both glucose tolerance and insulin tolerance were significantly improved to normal level by HES in HFD-induced obese mice. RNA sequencing analysis disclosed that the expression levels of up-regulated 12 genes and down-regulated 6 genes related to insulin signaling and glucose metabolism were restored to normal level by HES in the liver of HFD-induced obese mice. A protein-protein interaction (PPI) network was constructed via search tool for the retrieval of interacting genes/proteins (STRING) analysis, and Eno1, Pik3cd, Hk2, Trib3, Myc, Nos3, Ppargc1a, and Igf2 were located in the functional hubs of the PPI network of glucose metabolism. Furthermore, Western blot analysis confirmed that HES improved insulin sensitivity and glucose homeostasis by normalizing the expression levels of hexokinase-II, enolase-1, and PI3 kinase p110δ to normal level. The overall results suggest that HES possess a potential anti-diabetic effect by normalizing the expression levels of the insulin signaling and glucose metabolism related genes which were perturbed in the liver of HFD-induced obese mice.

MC-LR Aggravates Liver Lipid Metabolism Disorders in Obese Mice Fed a High-Fat Diet via PI3K/AKT/mTOR/SREBP1 Signaling Pathway.

Obesity, a metabolic disease caused by excessive fat accumulation in the body, has attracted worldwide attention. Microcystin-LR (MC-LR) is a hepatotoxic cyanotoxin which has been reportedly to cause lipid metabolism disorder. In this study, C57BL/6J mice were fed a high-fat diet (HFD) for eight weeks to build obese an animal model, and subsequently, the obese mice were fed MC-LR for another eight weeks, and we aimed to determine how MC-LR exposure affects the liver lipid metabolism in high-fat-diet-induced obese mice. The results show that MC-LR increased the obese mice serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT), indicating damaged liver function. The lipid parameters include serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and liver TG, which were all increased, whilst the high-density lipoprotein cholesterol (HDL-c) was decreased. Furthermore, after MC-LR treatment, histopathological observation revealed that the number of red lipid droplets increased, and that steatosis was more severe in the obese mice. In addition, the lipid synthesis-related genes were increased and the fatty acid ß-oxidation-related genes were decreased in the obese mice after MC-LR exposure. Meanwhile, the protein expression levels of phosphorylation phosphatidylinositol 3-kinase (p-PI3K), phosphorylation protein kinase B (p-AKT), phosphorylation mammalian target of rapamycin (p-mTOR), and sterol regulatory element binding protein 1c (SREBP1-c) were increased; similarly, the p-PI3K/PI3K, p-AKT/AKT, p-mTOR/mTOR, and SREBP1/ß-actin were significantly up-regulated in obese mice after being exposed to MC-LR, and the activated PI3K/AKT/mTOR/SREBP1 signaling pathway. In addition, MC-LR exposure reduced the activity of superoxide dismutase (SOD) and increased the level of malondialdehyde (MDA) in the obese mice's serum. In summary, the MC-LR could aggravate the HFD-induced obese mice liver lipid metabolism disorder by activating the PI3K/AKT/mTOR/SREBP1 signaling pathway to hepatocytes, increasing the SREBP1-c-regulated key enzymes for lipid synthesis, and blocking fatty acid ß-oxidation.

Effect of Structured Phenolic Lipids with EPA/DHA and Gallic Acid against Metabolic-Associated Fatty Liver Disease (MAFLD) in Mice.

Obesity is the leading risk factor for developing metabolic (dysfunction)-associated fatty liver disease (MAFLD). The food industry has an essential role in searching for new strategies to improve primary food sources to revert some of the metabolic alterations induced by obesity. There is consistent evidence that long-chain polyunsaturated fatty acids (n-3 LCPUFA) belonging to the n-3 series, i.e., eicosapentaenoic (20:5n-3, EPA) and docosahexaenoic (22:6n-3, DHA) acids, could revert some alterations associated with obesity-induced metabolic diseases. A relevant tool is the synthesis of structured acylglycerols (sAG), which include EPA or DHA at the sn-2 position. On the other hand, it has been reported that a crucial role of antioxidants is the reversion of MAFLD. In this work, we studied the effects of new molecules incorporating gallic acid (GA) into EPA/DHA-rich structured lipids. Mice were fed with a high-fat diet (60%) for three months and were then divided into five groups for supplementation with sAG and sAG structured with gallic acid (structured phenolic acylglycerols, sPAG). sPAG synthesis was optimized using a 2²-screening factorial design based on the response surface methodology (RSM). Our results show that treatment of sPAG was effective in decreasing visceral fat, fasting glycemia, fasting insulin, suggesting that this new molecule has a potential use in the reversal of MAFLD-associated alterations.

In vivo morphological study of obese development in mice model guided by swept-source optical coherence tomography (SSOCT).

This article shows the adequacy of the custom-built optical imaging system in the advancement investigation of obese mice. Obesity is defined as increased adipose/fatty mass resulting from a chronic imbalance between energy intake and expenditure. The in vivo investigation was performed for the tissue characterization of obese mice utilizing swept-source optical coherence tomography (SSOCT) for in situ examination and histology of delicate tissues in mice skin. It provides a noninvasive, painless visualization of the subsurface in life systems. Our SSOCT system's data is comparable to the regular invasive histology. Cross-assessment is done in various skin layers in obese mice like epidermis, papillary dermis, dermis, and fat tissue, which are likewise separated from the nonobese mice group. Histopathology results were further assessed with the obtained SSOCT results. This high precision of characterizing tissues using SSOCT helps us perform in vivo imaging and can also be used for the variable purpose of clinical practice.

[Effects of bifid triple viable on chronic low-grade inflammation in obese mice induced by high fat diet].

OBJECTIVE: To explore the effects and possible mechanism of bifid triple viable(BTV) on chronic low-grade inflammation and insulin resistance in obese mice induced by high fat diet(DIO). METHODS: A total of 18 male C57 BL/6 J mice aged 6 weeks were randomly divided into two groups according to their body weight after adaptive feeding for 2 weeks. Six mice in one group were fed with normal rodent diet as control group. Twelve mice in the other group were fed with high fat diet(60% kcal% fat)(HF). After 8 weeks, it was confirmed that body weight and fasting blood glucose of the mice fed with high fat diet were significantly higher than those of the control group(P<0.001), and then they were randomly divided into HF group and HF+BTV group according to the body weight and fasting blood glucose. Six mice in the HF group continued to be fed with high fat diet. Six mice in the HF+BTV group were fed with high fat diet and administered bifid triple viable suspension by gavage(24 mg/kg body weight), once a day. Mice in the control group and HF group were given equal volume of water as control treatment. After 4 weeks of treatment, blood was collected from tail vein, and the fasting blood glucose was measured by automatic glucose meter. Then the animals were killed and collected blood, distal ileum, liver and epididymal white adipose tissue. The tight junctions between the epithelial cells of ileum mucosa were observed by transmission electron microscopy. Serum endotoxin(also called lipopolysaccharide, LPS) levels were determined by limulus amebocyte lysate assay. Immunohistochemical staining was used to observe the macrophage marker F4/80 in liver and epididymal white adipose tissue. Serum fasting insulin levels, tumor necrosis factor-α(TNF-α), interlukin-6(IL-6) and monocyte chemotactic protein-1(MCP-1) in liver and/or epididymal white adipose tissue were detected by ELISA. The index of homeostasis model assessment of insulin resistance(HOMA-IR) was calculated by formula. RESULTS: Compared with the mice fed with normal rodents diet, the tight junctions between the epithelial cells of ileum mucosa were loose, the levels of serum endotoxin, live TNF-α and IL-6, epididymal white adipose tissue TNF-α, IL-6, MCP-1 were significantly elevated(P<0.05), the number of macrophages increased in liver and epididymal white adipose tissue, fasting glucose, fasting insulin levels and HOMA-IR were significantly up-regulated(P<0.01) in the HF group. In comparison with the HF group, the structures of tight junctions between the epithelial cells of ileum mucosa were normalized, the levels of serum endotoxin, liver TNF-α, IL-6 and epididymal white adipose tissue TNF-α, IL-6, MCP-1 were obviously decreased(P<0.05), the number of macrophages reduced in liver and epididymal white adipocytes, fasting insulin levels and HOMA-IR were significantly down-regulated(P<0.05), but had no effect on fasting blood glucose levels in HF+BTV group. CONCLUSION: Bifid triple viable may protect intestinal mucosa barrier, alleviate metabolic endotoxemia, thus improve chronic low-grade inflammation in liver and adipose tissue, and partially restore insulin sensitivity in DIO mice by regulating gut microbiota.