Consumption of salt leads to ameliorate symptoms of metabolic disorder and change of gut microbiota.

PURPOSE: Metabolic diseases caused by high-carbohydrate and/or high-salt diets are becoming major public health concerns. However, the effects of salt on high-carbohydrate diet-induced obesity are unclear. Accordingly, in this study, we investigated the effects of high-salt intake on high-carbohydrate diet-induced obesity. METHODS: We performed a 12-week study on gut microbiota and metabolic changes in high-rice diet (HRD) or HRD supplemented with high-salt (HRS)-fed C57BL/6 J mice by 16S rRNA analysis, glucose and insulin tolerance testing, gut barrier function, western blot and histological analysis. Moreover, the effects of salt on lipid metabolism were confirmed in vitro using 3T3-L1 cells. RESULTS: High salt intake decreased HRD-induced increases in body and white adipose tissue (WAT) weight. Alternatively, HRS did not reverse the observed increases in glucose intolerance and insulin resistance. Moreover, HRD caused changes in the gut microbiota, thereby impairing gut barrier function and increasing inflammation in the liver. HRS altered HRD-induced microbial composition, however, did not ameliorate gut barrier dysfunction or hepatic inflammation. HRS diets regulated the HRD-induced increase in peroxisome proliferator-activated receptor-γ (PPAR-γ) and lipid metabolism-related protein expression. Moreover, within WAT, HRS was found to reverse the observed decrease in adiponectin and increase in PPAR-γ expression induced by HRD. In vitro, high NaCl concentration also significantly reduced 3T3-L1 cell differentiation and modulated lipid metabolism without causing cytotoxicity. CONCLUSION: These results indicate that high salt intake ameliorates metabolic changes associated with a high-rice diet, including changes in fecal microbiota composition.

Syzygium aromaticum Reduces Diabetes-induced Glucotoxicity via the NRF2/Glo1 Pathway.

Advanced glycation end products and methylglyoxal are known to show increased levels in diabetic conditions and induce diverse metabolic disorders. However, the antiglycation ability of the bark of Syzygium aromaticum is not yet studied. In this study, we determined the inhibitory effects of S. aromaticum on AGE formation. Moreover, S. aromaticum showed breakage and inhibitory ability against the formation of AGE-collagen crosslinks. In SV40 MES13 cells, treatment with the S. aromaticum extract significantly ameliorated MG-induced oxidative stress as well as cytotoxicity. Furthermore, in the S. aromaticum extract-treated group, there was a reduction in levels of several diabetic markers, such as blood glucose, kidney weight, and urinary albumin to creatinine ratio in streptozotocin-induced diabetic rats. Treatment with the S. aromaticum extract significantly increased the expression of nuclear factor erythroid 2-related factor 2, a transcription factor involved in the expression of antioxidant enzymes. Moreover, the treatment significantly upregulated the expression of glyoxalase 1 and downregulated the expression of receptor for AGEs. These results suggest that the S. aromaticum extract might ameliorate diabetes-induced renal damage by inhibiting the AGE-induced glucotoxicity and oxidative stress through the Nrf2/Glo1 pathway.

Lespedeza bicolor Extract Improves Amyloid Beta25 - 35-Induced Memory Impairments by Upregulating BDNF and Activating Akt, ERK, and CREB Signaling in Mice.

Lespedeza bicolor, a traditional herbal medicine widely used in Australia, North America, and Eastern Asia, has various therapeutic effects on inflammation, nephritis, hyperpigmentation, and diuresis. In this study, to evaluate the effects of L. bicolor on cognitive function, we examined whether L. bicolor improved amyloid beta-induced memory impairment and assessed the possible mechanisms in mice. Catechin, rutin, daidzein, luteolin, naringenin, and genistein were identified in the powdered extract of L. bicolor by HPCL-DAD analyses. In behavioral experiments, L. bicolor (25 and 50 mg/kg, p. o.) significantly improved amyloid beta25 - 35 (6 nmol, intracerebroventricular)-induced cognitive dysfunction in the Y-maze, novel recognition, and passive avoidance tests. Our molecular studies showed L. bicolor (25 and 50 mg/kg, p. o.) significantly recovered the reduced glutathione content as well as increased thiobarbituric acid reactive substance and acetylcholinesterase activities in the hippocampus. Furthermore, we found that L. bicolor significantly increased the expression of brain-derived neurotrophic factor, and phospho-Akt, extracellular signal-regulated kinase, and cAMP response element binding caused by amyloid beta25 - 35 in the hippocampus. In conclusion, L. bicolor exerts a potent memory-enhancing effect on cognitive dysfunction induced by amyloid beta25 - 35 in mice.

Spatholobus suberectus Ameliorates Diabetes-Induced Renal Damage by Suppressing Advanced Glycation End Products in db/db Mice.

Spatholobus suberectus (SS) is a medicinal herb commonly used in Asia to treat anemia, menoxenia and rheumatism. However, its effect of diabetes-induced renal damage and mechanisms of action against advanced glycation end-products (AGEs) are unclear. In this study, we evaluated the effects of SS on diabetes-induced renal damage and explored the possible underlying mechanisms using db/db type 2 diabetes mice. db/db mice were administered SS extract (50 mg/kg) orally for 6 weeks. SS-treated group did not change body weight, blood glucose and glycated hemoglobin (HbA1c) levels. However, SS treatment reversed diabetes-induced dyslipidemia and urinary albumin/creatinine ratio in db/db mice. Moreover, SS administration showed significantly increased protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2), which is a transcription factor for antioxidant enzyme. SS significantly upregulated glyoxalase 1 (Glo1) and NADPH quinine oxidoreductase 1 (NQO1) expression but reduced CML accumulation and downregulated receptor for AGEs (RAGE). Furthermore, SS showed significant decrease of periodic acid⁻Schiff (PAS)-positive staining and AGEs accumulation in histological and immunohistochemical analyses of kidney tissues. Taken together, we concluded that SS ameliorated the renal damage by inhibiting diabetes-induced glucotoxicity, dyslipidemia and oxidative stress, through the Nrf2/antioxidant responsive element (ARE) stress-response system.

Antimicrobial and anti-inflammatory effects of BenTooth: A natural product blend of burdock root, persimmon leaf extracts, and quercetin on periodontal disease.

Periodontal disease represents a condition that exhibits substantial global morbidity, and is characterized by the infection and inflammation of the periodontal tissue effectuated by bacterial pathogens. The present study aimed at evaluating the therapeutic efficacy of BenTooth, an edible natural product mixture comprising burdock root extract, persimmon leaf extract and quercetin, against periodontitis both in vitro and in vivo. BenTooth was examined for antimicrobial properties and its impact on cellular responses related to inflammation and bone resorption. Its effects were also assessed in a rat model of ligature-induced periodontitis. BenTooth demonstrated potent antimicrobial activity against P. gingivalis and S. mutans. In RAW264.7 cells, it notably diminished the expression of inducible nitric oxide synthase and cyclooxygenase-2, as well as reduced interleukin-6 and tumor necrosis factor-α levels triggered by P. gingivalis-derived lipopolysaccharide. Furthermore, BenTooth inhibited osteoclastogenesis mediated by the receptor activator of nuclear factor κB ligand. In the rat model, BenTooth consumption mitigated the ligature-induced expansion in distance between the cementoenamel junction and the alveolar bone crest and bolstered the bone volume fraction. These results present BenTooth as a potential therapeutic candidate for the prevention and remediation of periodontal diseases.

Animal efficacy study of a plant extract complex (BEN815) as a potential treatment for COVID-19.

In a short time, several types of injectable and oral therapeutics have been developed and used to effectively manage patients with coronavirus disease 2019 (COVID-19). BEN815 is an improved mixture of three extracts (Psidium guajava, Camellia sinensis, and Rosa hybrida) recognized by the Ministry of Food and Drug Safety of Korea as a health food ingredient that alleviates allergic rhinitis. The current animal efficacy study was performed to assess its probability of improving COVID-19 symptoms. BEN815 treatment significantly increased the survival of K18-hACE2 transgenic mice and reduced viral titers in the lungs at 5 days post infection (DPI). Furthermore, the lungs of the treated mice showed mild tissue damage at 5 DPI and nearly complete recovery from COVID-19 at 14 DPI. BEN815 appears to be an effective and minimally toxic anti-SARS-CoV-2 agent in mice and has potential for clinical applications.

Gellan gum prevents non-alcoholic fatty liver disease by modulating the gut microbiota and metabolites.

Gellan gum (GG) is an anionic polysaccharide used as an additive in the food industry. However, the effect of GG on gut microbiota regulation and nonalcoholic fatty liver disease (NAFLD) has not yet been investigated. In vitro fermentation experiments have demonstrated that GG promoted the growth of probiotic strains such as Lactiplantibacillus rhamnosus and Bifidobacterium bifidum, producing metabolites beneficial to gut health. In mice, GG reduced hepatic triglyceride content, serum biomarkers, and body fat mass and weight gain induced by a high fat diet. Additionally, GG regulated the gut microbiota including Desulfovibrionales, Deferribacterales, Bacteroidales, and Lactobacillales at the order level and also promoted short-chain fatty acid production. Moreover, GG improved the expression of proteins related to hepatic inflammation and lipid metabolism. Taken together, GG ameliorated NAFLD, possibly by acting on the gut-liver axis via improving the gut health, indicating its potential as a food supplement and/or prebiotic against NAFLD.

Bifidobacterium animalis ssp. lactis MG741 Reduces Body Weight and Ameliorates Nonalcoholic Fatty Liver Disease via Improving the Gut Permeability and Amelioration of Inflammatory Cytokines.

Diet-induced obesity is one of the major causes of the development of metabolic disorders such as insulin resistance and nonalcoholic fatty liver disease (NAFLD). Recently, specific probiotic strains have been found to improve the symptoms of NAFLD. We examined the effects of Bifidobacterium animalis ssp. lactis MG741 (MG741) on NAFLD and weight gain, using a mouse model of high-fat-diet (HFD)-induced obesity. HFD-fed mice were supplemented daily with MG741. After 12 weeks, MG741-administered mice exhibited reduced fat deposition, and serum metabolic alterations, including fasting hyperinsulinemia, were modulated. In addition, MG741 regulated Acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), sterol regulatory element-binding protein 1 (SREBP-1), and carbohydrate-responsive element-binding protein (ChREBP) expression and lipid accumulation in the liver, thereby reducing the hepatic steatosis score. To determine whether the effects of MG741 were related to improvements in gut health, MG741 improved the HFD-induced deterioration in gut permeability by reducing toxic substances and inflammatory cytokine expression, and upregulating tight junctions. These results collectively demonstrate that the oral administration of MG741 could prevent NAFLD and obesity, thereby improving metabolic health.

A water soluble extract of radish greens ameliorates high fat diet-induced obesity in mice and inhibits adipogenesis in preadipocytes.

Radish (Raphanus sativus L.) is a rich source of nutrients and its greens have reported functionalities. This study aimed to investigate the effects of a water-soluble extract from radish greens (WERG) on adipogenesis in 3T3-L1 adipocytes and high-fat diet-induced obesity in model mice. We also quantified the phytochemical composition of WERG such as glucoraphenin and ferulic acid. These findings show that treatment with 100 µg mL-1 WERG reduced lipid accumulation in 3T3-L1 adipocytes, whereas in mice, the administration of 100 mg kg-1 WERG reduced weight gain and hepatic lipid accumulation and improved the levels of serum lipid biomarkers. Furthermore, WERG treatment improved intestinal permeability and suppressed the activities of harmful intestinal enzymes in feces, thus improving gut health. It also inhibited metabolic endotoxemia and inflammatory marker levels in serum. Moreover, WERG reduced the expression of lipid-metabolism-related proteins in the liver and white adipose tissue. Collectively, these results indicate that WERG may potentiate the anti-obesity effect by improving gut health and regulating lipid metabolism.

Dietary rhamnogalacturonan-â rich extracts of molokhia ameliorate high fat diet-induced obesity and gut dysbiosis.

Obesity is a global health issue associated with increased prevalence of disease and mortality. Molokhia (Corchorus olitorius L.) leaves, used as vegetables in Asia and Africa, comprise abundant water-soluble mucilage polysaccharides. The present study aimed to evaluate the effects of molokhia leaf polysaccharide fraction (MPF) on high-fat diet (HFD)-induced obesity and gut dysbiosis in mice. A significant decrease was observed in the body weight, adipocyte size, triglyceride serum, and low-density lipoprotein cholesterol levels, as well as in the expression of lipid synthesis-related proteins in mice treated with 4 mg/kg of MPF (MPF4). Moreover, the expression of the tight junction protein increased significantly; however, gut permeability and related inflammatory marker levels decreased in the MPF4 group. Furthermore, MPF ameliorated gut dysbiosis, whereas the MPF4 group presented a decreased Firmicutes to Bacteroidetes ratios and an increased abundance of Akkermansia during exposure to HFD. Our findings reveal that rhamnogalacturonan-Ⅰ rich MPF attenuates obesity in mice subjected to HFD by modulating the gut microbiota.

Morinda citrifolia Extract Prevents Alcoholic Fatty Liver Disease by Improving Gut Health.

Alcoholic liver disease (ALD) is a major chronic liver disease. Chronic alcohol consumption induces dysbiosis, disruption of gut barrier function, oxidative stress, inflammation, and changes in lipid metabolism, thereby leading to ALD. In this study, we investigated whether the commercial Morinda citrifolia extract Nonitri can ameliorate ALD symptoms through the gut-liver axis. We used mice chronically administered EtOH and found a marked increase in serum endotoxin levels and biomarkers of liver pathology. Moreover, the EtOH-treated group showed significantly altered gut microbial composition particularly that of Alistipes, Bacteroides, and Muribaculum and disrupted gut barrier function. However, Nonitri improved serum parameters, restored the microbial proportions, and regulated levels of zonula occludens1, occludin, and claudin1. Furthermore, Nonitri suppressed inflammation by inhibiting endotoxin-triggered toll-like receptor 4-signaling pathway and fat deposition by reducing lipogenesis through activating AMP-activated protein kinase in the liver. Furthermore, Pearson's correlation analysis showed that gut microbiota and ALD-related markers were correlated, and Nonitri regulated these bacteria. Taken together, our results indicate that the hepatoprotective effect of Nonitri reduces endotoxin levels by improving gut health, and inhibits fat deposition by regulating lipid metabolism.

Polysaccharide fraction from greens of Raphanus sativus alleviates high fat diet-induced obesity.

Radish (Raphanus sativus) greens are commonly used as a vegetable in Korea; however, their anti-obesity effect has not been reported yet. We prepared the polysaccharide fraction of radish greens (PRG) and assessed its anti-obesity activity in high fat diet (HFD)-induced obese C57BL/6J mice. Supplementation with 4 mg/kg PRG reduced weight gain and body fat percentage, and regulated serum biomarkers against HFD-induced obesity. Moreover, PRG treatment improved gut permeability by increasing tight junction protein expression and colon length shortening. HFD intake increased the proportion of Firmicutes and decreased the proportion of Bacteroidetes and Verrucomicrobia; however, PRG supplementation maintained gut microbial composition to normal diet condition. Moreover, PRG reduced HFD-induced increase of lipid metabolism-related protein expression, along with adipocyte size in white adipose tissue. These results indicated that PRG as a potential prebiotic, has anti-obesity properties by improving gut barrier function, modulating gut microbiota and regulating lipid metabolism.

Amelioration of Hepatic Steatosis in Mice through Bacteroides uniformis CBA7346-Mediated Regulation of High-Fat Diet-Induced Insulin Resistance and Lipogenesis.

Dietary habits and gut microbiota play an essential role in non-alcoholic fatty liver disease (NAFLD) and related factors such as insulin resistance and de novo lipogenesis. In this study, we investigated the protective effects of Bacteroides uniformis CBA7346, isolated from the gut of healthy Koreans, on mice with high-fat diet (HFD)-induced NAFLD. Administration of B. uniformis CBA7346 reduced body and liver weight gain, serum alanine aminotransferase and aspartate aminotransferase levels, liver steatosis, and liver triglyceride levels in mice on an HFD; the strain also decreased homeostatic model assessment for insulin resistance values, as well as serum cholesterol, triglyceride, lipopolysaccharide, leptin, and adiponectin levels in mice on an HFD. Moreover, B. uniformis CBA7346 controlled fatty liver disease by attenuating steatosis and inflammation and regulating de novo lipogenesis-related proteins in mice on an HFD. Taken together, these findings suggest that B. uniformis CBA7346 ameliorates HFD-induced NAFLD by reducing insulin resistance and regulating de novo lipogenesis in obese mice.

The Effects of Gelatinized Wheat Starch and High Salt Diet on Gut Microbiota and Metabolic Disorder.

Diets high in gelatinized starch and high in gelatinized starch supplemented with salt-induced metabolic disorders and changes in gut microbiota have scarcely been studied. In this study, mice on wheat starch diets (WD) exhibited significantly higher body weight, white adipose tissue (WAT), and gut permeability compared to those on normal diet (ND). However, gelatinized wheat starch diet (GWD) and NaCl-supplemented gelatinized wheat starch diet (SGW) mice did not increase body and WAT weights or dyslipidemia, and maintained consistent colon pH at ND levels. WD mice showed higher levels of Desulfovibrio, Faecalibaculum, and Lactobacillus and lower levels of Muribaculum compared to ND mice. However, GWD and SGW mice showed a significantly different gut microbial composition, such as a lower proportion of Lactobacillus and Desulfovibrio, and higher proportion of Faecalibaculum and Muribaculum compared to WD mice. High starch diet-induced dysbiosis caused increase of lipid accumulation and inflammation-related proteins' expression, thereby leading to non-alcoholic fatty liver disease. However, GWD and SGW showed lower levels than that, and it might be due to the difference in the gut microbial composition compared to WD. Taken together, diets high in gelatinized starch and high in gelatinized starch supplemented with salt induced mild metabolic disorders compared to native starch.

Molokhia leaf extract prevents gut inflammation and obesity.

ETHNOPHARMACOLOGICAL RELEVANCE: Molokhia is highly consumed in Egypt as edible and medicinal plants, and its leaves are used for the treatment of pain, fever, and inflammation. AIM OF THE STUDY: High-fat diet (HFD) induces gut dysbiosis, which is closely linked to metabolic diseases including obesity and leaky gut. The effects of molokhia (Corchorus olitorius L.) on anti-obesity and gut health were investigated in this study. MATERIALS AND METHODS: The effects of a water-soluble extract from molokhia leaves (WM) on lipid accumulation in 3T3-L1 adipocytes and on body weight, gut permeability, hormone levels, fecal enzyme activity of the intestinal microflora, and gut microbiota in HFD-induced C57BL/6J mice were examined. RESULTS: WM treatment significantly inhibited lipid accumulation in 3T3-L1 adipocytes. Mice treated with 100 mg/kg WM had 13.1, 52.4, and 17.4% significantly lower body weights, gut permeability, and hepatic lipid accumulation than those in the HFD group, respectively. In addition, WM influenced gut health by inhibiting metabolic endotoxemia and colonic inflammation. It also altered the composition of the gut microbiota; in particular, it increased the abundance of Lactobacillus and decreased that of Desulfovibrio. CONCLUSION: Our results extend our understanding of the beneficial effects of WM consumption, including the prevention of gut dysbiosis and obesity.

Isosamidin from Peucedanum japonicum Roots Prevents Methylglyoxal-Induced Glucotoxicity in Human Umbilical Vein Endothelial Cells via Suppression of ROS-Mediated Bax/Bcl-2.

Methylglyoxal (MGO) is a highly reactive metabolite of glucose. Elevated levels of MGO induce the generation of reactive oxygen species (ROS) and cause cell death in endothelial cells. Vascular endothelial cell damage by ROS has been implicated in the progression of diabetic vascular complications, cardiovascular diseases, and atherosclerosis. In this study, the protective effect of isosamidin, isolated from Peucedanum japonicum roots, on MGO-induced apoptosis was investigated using human umbilical vein endothelial cells (HUVECs). Among the 20 compounds isolated from P. japonicum, isosamidin showed the highest effectiveness in inhibiting MGO-induced apoptosis of HUVECs. Pretreatment of HUVECs with isosamidin significantly prevented the generation of ROS and cell death induced by MGO. Isosamidin prevented MGO-induced apoptosis in HUVECs by downregulating the expression of Bax and upregulating the expression of Bcl-2. MGO treatment activated mitogen-activated protein kinases (MAPKs), such as p38, c-Jun N terminal kinase (JNK), and extracellular signal-regulated kinase (ERK). In contrast, pretreatment with isosamidin strongly inhibited the activation of p38 and JNK. Furthermore, isosamidin caused the breakdown of the crosslinks of the MGO-derived advanced glycation end products (AGEs). These findings suggest that isosamidin from P. japonicum may be used as a preventive agent against MGO-mediated endothelial dysfunction in diabetes. However, further study of the therapeutic potential of isosamidin on endothelial dysfunction needs to explored in vivo models.

Molecular mechanisms of methylglyoxal-induced aortic endothelial dysfunction in human vascular endothelial cells.

Methylglyoxal (MGO)-induced cellular apoptosis, oxidative stress, inflammation, and AGE formation are specific events that induce vascular endothelial cell (EC) toxicity in endothelial dysfunction (ED). MGO accumulates quickly in various tissues and plays a prominent role in the pathogeneses of several diabetic complications. Unbalanced angiogenesis is a gateway to the development of diabetic complications. EC apoptosis and autophagy work together to regulate angiogenesis by interacting with different angiogenic factors. In addition to understanding the deep mechanism regarding MGO-dependent autophagy/apoptosis may provide new therapeutic applications to treat diabetes and diabetic complications. Therefore, the present study aimed to investigate the regulatory effects of MGO-induced autophagy and apoptosis on angiogenesis in HAoEC and to elucidate the molecular mechanisms to discover new target base therapy for diabetes and diabetic complications. In MGO-stimulated HAoEC, protein expression was identified using a western blot, autophagosomes were observed by bio-transmission electron microscopy (TEM), and cell autophagic vacuoles and flux were measured using a confocal microscope. We found that MGO significantly induced autophagy, declined the pro-angiogenic effect, decreased proliferation, migration, and formation of tube-like structures, and increased autophagic vacuoles, flux and autophagosomes in the HAoEC in a dose-dependent manner. We observed that MGO-induced autophagic cell death and inhibited the ROS-mediated Akt/mTOR signaling pathway. MGO also triggered apoptosis by elevating the cleaved caspase-3 to Bax/Bcl-2 ratio and through activation of the ROS-mediated MAPKs (p-JNK, p-p38, and p-ERK) signaling pathway. Collectively, these findings suggest that autophagy and apoptosis inhibit angiogenesis via the ROS-mediated Akt/mTOR and MAPKs signaling pathways, respectively, when HAoEC are treated with MGO.

Therapeutic Potential of Lespedeza bicolor to Prevent Methylglyoxal-Induced Glucotoxicity in Familiar Diabetic Nephropathy.

Lespedeza bicolor (LB) is often used in traditional medicine to remove toxins, replenish energy stores, and regulate various symptoms of diabetes. This study aimed to explore the use of LB as a therapeutic to prevent diabetic nephropathy in methylglyoxal (MGO)-treated models in vitro and in vivo. Western blotting, immunostaining, and biochemical assays were used to obtain several experimental readouts in renal epithelial cells (LLC-PK1) and BALB/c mice. These include: production of reactive oxygen species (ROS), formation of advanced glycation end-products (AGEs), expression of receptor for advanced glycation end-products (RAGE), apoptotic cell death, glucose levels, fatty acid and triglyceride levels, expression of pro-inflammatory cytokines IL-1ß and TNF-α, glyoxalase 1 (Glo1), and nuclear factor erythroid 2-related factor 2 (Nrf2). Pretreatment with LB significantly reduced MGO-induced cellular apoptosis, intracellular production of ROS, and formation of AGEs to ameliorate renal dysfunction in vitro and in vivo. Interestingly, administering LB in MGO-treated cells and mice upregulated the expression of Nrf2 and Glo1, and downregulated the expression of IL-1ß and TNF-α. Moreover, LB reduced MGO-induced AGE accumulation and RAGE expression in the kidneys, which subsequently reduced AGE-RAGE interactions. Overall, LB ameliorates renal cell apoptosis and corrects renal dysfunction in MGO-treated mice. These findings extend our understanding of the pathogenic mechanism of MGO-induced nephrotoxicity and regulation of the AGE/RAGE axis by Lespedeza bicolor.

High-Glucose or -Fructose Diet Cause Changes of the Gut Microbiota and Metabolic Disorders in Mice without Body Weight Change.

High fat diet-induced changes in gut microbiota have been linked to intestinal permeability and metabolic endotoxemia, which is related to metabolic disorders. However, the influence of a high-glucose (HGD) or high-fructose (HFrD) diet on gut microbiota is largely unknown. We performed changes of gut microbiota in HGD- or HFrD-fed C57BL/6J mice by 16S rRNA analysis. Gut microbiota-derived endotoxin-induced metabolic disorders were evaluated by glucose and insulin tolerance test, gut permeability, Western blot and histological analysis. We found that the HGD and HFrD groups had comparatively higher blood glucose and endotoxin levels, fat mass, dyslipidemia, and glucose intolerance without changes in bodyweight. The HGD- and HFrD-fed mice lost gut microbial diversity, characterized by a lower proportion of Bacteroidetes and a markedly increased proportion of Proteobacteria. Moreover, the HGD and HFrD groups had increased gut permeability due to alterations to the tight junction proteins caused by gut inflammation. Hepatic inflammation and lipid accumulation were also markedly increased in the HGD and HFrD groups. High levels of glucose or fructose in the diet regulate the gut microbiota and increase intestinal permeability, which precedes the development of metabolic endotoxemia, inflammation, and lipid accumulation, ultimately leading to hepatic steatosis and normal-weight obesity.

Lespedeza cuneata protects the endothelial dysfunction via eNOS phosphorylation of PI3K/Akt signaling pathway in HUVECs.

BACKGROUND: Lespedeza cuneata G.Don (LCE), which belongs to the genus Lespedeza (Leguminosae), is a traditional oriental medicine known to prevent diabetes and cardiovascular diseases. However, no scientific studies about the effectiveness of LCE, their responsible bioactive constituents, and its mechanisms against endothelial dysfunction have been performed. PURPOSE: This study was performed to investigate the role of LCE and its chemical components in ameliorating endothelial dysfunction. METHODS: The production of nitric oxide (NO) was evaluated after LCE treatment in HUVECs. Cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reagent. Western blot analysis was performed to determine the protein expression of endothelial nitric oxide synthase (eNOS) and protein kinase B (PKB, also known as Akt) in human umbilical vein endothelial cells (HUVECs). RESULTS: Pretreatment with L-NAME and LY294002 significantly decreased the LCE-induced NO production, as well as eNOS and Akt phosphorylation. ß-Sitosterol and ß-Sitosterol 6'-linolenoyl-3-O-ß-D-glucopyranoside are the bioactive constituents increase NO production as well as eNOS phosphorylation. CONCLUSION: Our findings suggest that LCE increase NO production via eNOS phosphorylation of PI3K/Akt signaling pathway.