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Olive (Olea europaea Linn) leaves contain a phenolic compound oleuropein (Ole) has antioxidant, anti-inflammatory, and immunomodulatory activities. However, whether Ole might be an effective treatment for atopic dermatitis (AD) remains unknown.This study investigated the functional role of oleuropein in a 2,4-dinitrochlorobenzene-induced AD-like mouse model, with a focus on allergic inflammation.We evaluated cytokine gene expression, COX-2 inflammatory protein production, and Th2 related cytokine regulation of mast cells and eosinophils that infiltrated AD-like skin lesions.A topical application of Ole significantly reduced Th2-related cytokine gene expression (IL-4 and IL-5) and inflammatory COX-2 protein production in AD-like skin lesions. Additionally, Ole suppressed serum IgE levels. Furthermore, Ole effectively reduced ear swelling and epidermal and dermal thickening.These results suggested that, mechanistically, Ole treatment improved allergic inflammation by blocking the Th2-driven inflammatory axis. In conclusion, our findings indicated that Ole showed promise in treating AD by regulating serum IgE and Th2 cytokine levels. Although the effects of Ole on AD in humans require clinical trials, our results provided insights into how AD treatments might be improved.

The occurrence of nonalcoholic fatty liver disease (NAFLD) is associated with type 2 diabetes mellitus (T2DM). The activation of nucleotide‐binding domain and leucine‐rich‐containing family, pyrin domain‐containing 3 (NLRP3) inflammasome in the liver may lead to hepatic fat accumulation. Alpha‐lipoic acid (ALA) has been reported to improve IR in a T2DM rodent model. We investigated the effects of ALA on NLRP3 inflammasome activation and fat accumulation in the liver of a high‐fat diet (HFD) plus streptozotocin (STZ)‐induced T2DM rats. The HFD/STZ‐induced T2DM rats were orally administered ALA (50, 100, or 200 mg/kg BW) once a day for 13 weeks. The results showed that the liver triglyceride contents of T2DM rats were 11.35 ± 1.84%, whereas the administration of 50, 100, and 200 mg/kg BW ALA significantly reduced the liver triglyceride contents of T2DM rats to 4.14 ± 0.59%, 4.02 ± 0.41%, and 3.01 ± 1.07%, respectively. Moreover, 200 mg/kg BW ALA significantly decreased the hepatic levels of NLRP3 inflammasome activation‐related proteins NLRP3, caspase‐1, and interleukin‐1β expression by 40.0%, 60.1%, and 24.5%, respectively, in T2DM rats. Furthermore, the expression levels of hepatic fat synthesis‐related proteins decreased, namely a 45.4% decrease in sterol regulatory element‐binding protein‐1c, whereas the expression of hepatic lipid oxidation‐related proteins increased, including a 27.5% increase in carnitine palmitoyltransferase, in T2DM rats after 200 mg/kg BW ALA treatment. We concluded that ALA treatment may suppress hepatic NLRP3 inflammasome activation, consequently alleviating NAFLD and excess hepatic lipid accumulation in HFD/STZ‐induced T2DM rats., Alpha‐lipoic acid alleviates hepatic triglyceride accumulation by suppressing the NLRP3 inflammasome pathway, suppressing lipid generation, and promoting lipid oxidation in high‐fat diet and streptozotocin‐induced type 2 diabetic rats.

Ruellia tuberosa L. (RTL) has been used as a folk medicine to cure diabetes in Asia. RTL was previously reported to alleviate hyperglycemia, insulin resistance (IR), abnormal hepatic detoxification, and liver steatosis. However, the potential bioactive compounds of RTL have still not been identified. The aim of this study was to investigate the bioactive compounds in RTL ethyl acetate (EA) fractions by using a glucose uptake assay in TNF-α-treated mouse FL83B hepatocytes to discover a mechanism by which to improve IR. The bioactive compounds were identified by the high-performance liquid chromatography (HPLC) assay. Using the Sephadex LH20 gel packing chromatography column, the EAF5 fraction was isolated from RTL and significantly increased glucose uptake in TNF-α-treated FL83B cells. Moreover, the MCI gel packing chromatography column separated EAF5 into five subfractions and had no significant cytotoxic effect in FL83B cells when treated at the concentration of 25 μg/ml. Among the subfractions, EAF5-5 markedly enhanced glucose uptake in TNF-α-treated FL83B cells. The possible bioactive compounds of the EAF5-5 fraction that were identified by the HPLC assay include syringic acid, p-coumaric acid, and cirsimaritin. The bioactive compound with the best effect of increasing glucose uptake was p-coumaric acid, but its effect alone was not as good as the combined effect of all three compounds of the EAF5-5 fraction. Thus, we speculate that the antidiabetic effect of RTL may be the result of multiple active ingredients.

We previously demonstrated that acacetin reduces adipogenesis in adipocytes, and decreases lipid accumulation in visceral adipocyte tissue. Here we investigated whether acacetin regulated the mechanisms of lipogenesis and inflammation in non-alcoholic fatty liver disease (NAFLD) in obese mice. Male C57BL/6 mice were fed a high-fat diet (HFD), and then administered acacetin by intraperitoneal injection. Acacetin reduced body weight and liver weight in obese mice. Acacetin-treated obese mice exhibited decreased lipid accumulation, increased glycogen accumulation, and improved hepatocyte steatosis. Acacetin regulated triglycerides and total cholesterol in the liver and serum. Acacetin decreased low-density lipoprotein and leptin concentrations, but increased high-density lipoprotein and adiponectin levels in obese mice. Acacetin effectively weakened the gene expressions of transcription factors related to lipogenesis, and promoted the expressions of genes related to lipolysis and fatty acid β-oxidation in liver. Acacetin also reduced expressions of inflammation-related cytokines in the serum and liver. Oleic acid induced lipid accumulation in murine FL83B hepatocytes, and the effects of acacetin treatment indicated that acacetin may regulate lipid metabolism through the AMPK pathway. Acacetin may protect against hepatic steatosis by modulating inflammation and AMPK expression.

Asian children are increasingly being diagnosed with type 1 diabetes (T1D) or type 2 diabetes (T2D), and the presence of coexisting islet autoimmune antibodies complicate diagnosis. Here, we aimed to determine the prevalence of islet cell autoantibodies (ICAs) and glutamic acid decarboxylase 65 autoantibodies (GADAs) in children with T1D versus T2D living in Vietnam. This cross-sectional study included 145 pediatric patients aged 10.3 ± 3.6 years, with 53.1% and 46.9% having T1D and T2D, respectively. ICAs were reported in only 3.9% of pediatric T1Ds, which was not significantly different from the 1.5% of those with T2D. Older children with T1D were positive for either ICAs, or ICAs and GADAs (5–9 and 10–15 years), whereas only a small proportion of children aged 0–4 years were positive for GADAs (18%). Notably, 27.9% of children with T2D aged 10–15 were positive for GADAs, and all were classified as overweight (n = 9) or obese (n = 10). GADAs were more commonly observed in T1D patients younger than four years than ICAs, which were more prevalent in older children (5–15 years). Even though few children with T2D carried ICAs and GADAs, finding a better biomarker or an appropriate time to confirm diabetes type may require further investigation.

Background and objectives: This study aimed to investigate the enhancing effect of vitamin-like alpha-lipoic acid (ALA) on phagocytosis of oligomeric beta-amyloid (oAβ)1–42 in BV-2 mouse microglial cells. Methods: An in vitro model was established to investigate phagocytosis of oAβ1–42 in BV-2 cells. Transmission electron microscopy images indicated that the morphology of prepared oAβ1–42 was spherical particles. BV-2 cells treated with ALA were incubated with 5(6)-carboxyfluorescein-labeled oAβ1–42 (FAM-oAβ1–42) for 24 h, followed by flow cytometer analysis, western blotting, real-time quantitative PCR, and immunocytochemistry (ICC) analysis to assess the in vitro phagocytosis ability of oAβ1–42. Results: Alpha-lipoic acid significantly increased messenger RNA (mRNA) expression of the CD36 receptor in BV-2 cells. ICC analysis showed that ALA significantly elevated CD36 protein expression in BV-2 cells both with and without oAβ1–42 treatment. Results from the flow cytometry analysis indicated that the CD36 receptor inhibitor significantly attenuated ALA-promoted phagocytosis of FAM-oAβ1–42 in BV-2 cells. Moreover, ICC analysis revealed that ALA caused the translocation of peroxisome proliferator-activated receptor-γ (PPAR-γ), which is known to regulate the expression of CD36 mRNA in BV-2 cells. ALA also elevated both the mRNA and protein expression of cyclooxygenase-2 (COX-2), which is a key enzyme involved in the synthesis of 15-deoxy-Δ12,14-prostaglandin J2 in BV-2 cells. Conclusion: We postulated that ALA enhances oAβ1–42 phagocytosis by upregulating the COX-2/15-deoxy-Δ12,14-prostaglandin J2/PPAR-γ/CD36 pathway in BV-2 cells. Finally, future studies should be conducted with an in vivo study to confirm the findings.

Hyperglycemia plays crucial roles in vascular disease development, including macrovascular and microvascular diseases from diabetes mellitus (DM). Our previous study demonstrated that Ruellia tuberosa L. (RTL) aqueous and ethanol extracts alleviate hyperglycemia and inhibit insulin resistance in diabetic rats. This study investigated the protective effect of RTL ethanol extract against aorta dysfunction in high‐fat diet (HFD) and streptozotocin (STZ)‐induced type 2 DM (T2DM) rats. Results showed that RTL ethanol extract (100 and 400 mg/kg BW/day) ameliorated serum lipid profiles, including triglyceride, free fatty acid, low‐density lipoprotein cholesterol, very low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol levels. It also significantly reduced the level of serum cytokines such as tumor necrosis factor‐α (TNF‐α) and interleukin‐6 in T2DM rats. Additionally, RTL extract decreased endothelin‐1 and endothelial nitric oxide contents, reduced the level of cell adhesion factors, including monocyte chemoattractant protein‐1 and cell adhesion factor vascular cell adhesion molecule‐1, while decreasing content of damage factors, namely tissue factor and von Willebrand factor in aortic tissues of diabetic rats. Equally noteworthy is that RTL extract enhanced the activity of aorta antioxidative enzymes, including superoxidase dismutase and catalase in diabetic rats, suggesting that RTL ethanol extract may ameliorate aorta dysfunction via enhancing aortic antioxidative enzyme activity, which subsequently suppresses aorta endothelial damage‐associated factors in HFD with STZ‐induced T2DM rats.

This study investigated the alleviative effect of caffeic acid (CA) on Alzheimer's disease (AD) pathogenesis and associated mechanisms in high-fat (HF) diet-induced hyperinsulinemic rats. The results of a Morris water maze indicated that, by administrating CA (30 mg/kg b.w./day) for 30 weeks, the memory and learning impairments in HF-induced hyperinsulinemic rats were significantly ameliorated. CA also enhanced superoxide dismutase and glutathione free radical scavenger activity in hyperinsulinemic rats. The Western blot data further confirmed that protein expressions of phosphorylated-glycogen synthase kinase 3β (GSK3β) were significantly increased, whereas the expression of phosphorylated-tau protein decreased in the hippocampus of rats administered with CA in comparison with the HF group. Moreover, the expression of amyloid precursor protein (APP) and β-site APP cleaving enzyme were attenuated, subsequently lowering the level of β-amyloid 1-42 (Aβ 1-42) in the hippocampus of CA-treated hyperinsulinemic rats. CA also significantly increased the expression of synaptic proteins in HF rats.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease, and most patients with T2DM develop nonalcoholic fatty liver disease (NAFLD). Both diseases are closely linked to insulin resistance (IR). Our previous studies demonstrated that Ruellia tuberosa L. (RTL) extract significantly enhanced glucose uptake in the skeletal muscles and ameliorated hyperglycemia and IR in T2DM rats. We proposed that RTL might be via enhancing hepatic antioxidant capacity. However, the potent RTL bioactivity remains unidentified. In this study, we investigated the effects of RTL on glucose uptake, IR, and lipid accumulation in vitro to mimic the T2DM accompanied by the NAFLD paradigm. FL83B mouse hepatocytes were treated with tumor necrosis factor-α (TNF-α) to induce IR, coincubated with oleic acid (OA) to induce lipid accumulation, and then, treated with RTL fractions, fractionated with n-hexane or ethyl acetate (EA), from column chromatography, and analyzed by thin-layer chromatography. Our results showed that the ethyl acetate fraction (EAf2) from RTL significantly increased glucose uptake and suppressed lipid accumulation in TNF-α plus OA-treated FL83B cells. Western blot analysis showed that EAf2 from RTL ameliorated IR by upregulating the expression of insulin-signaling-related proteins, including protein kinase B, glucose transporter-2, and peroxisome proliferator-activated receptor alpha in TNF-α plus OA-treated FL83B cells. The results of this study suggest that EAf2 from RTL may improve hepatic glucose uptake and alleviate lipid accumulation by ameliorating and suppressing the hepatic insulin signaling and lipogenesis pathways, respectively, in hepatocytes.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease, and most patients with T2DM develop nonalcoholic fatty liver disease (NAFLD). Both diseases are closely linked to insulin resistance (IR). Our previous studies demonstrated that Ruellia tuberosa L. (RTL) extract significantly enhanced glucose uptake in the skeletal muscles and ameliorated hyperglycemia and IR in T2DM rats. We proposed that RTL might be via enhancing hepatic antioxidant capacity. However, the potent RTL bioactivity remains unidentified. In this study, we investigated the effects of RTL on glucose uptake, IR, and lipid accumulation in vitro to mimic the T2DM accompanied by the NAFLD paradigm. FL83B mouse hepatocytes were treated with tumor necrosis factor-α (TNF-α) to induce IR, coincubated with oleic acid (OA) to induce lipid accumulation, and then, treated with RTL fractions, fractionated with n-hexane or ethyl acetate (EA), from column chromatography, and analyzed by thin-layer chromatography. Our results showed that the ethyl acetate fraction (EAf2) from RTL significantly increased glucose uptake and suppressed lipid accumulation in TNF-α plus OA-treated FL83B cells. Western blot analysis showed that EAf2 from RTL ameliorated IR by upregulating the expression of insulin-signaling-related proteins, including protein kinase B, glucose transporter-2, and peroxisome proliferator-activated receptor alpha in TNF-α plus OA-treated FL83B cells. The results of this study suggest that EAf2 from RTL may improve hepatic glucose uptake and alleviate lipid accumulation by ameliorating and suppressing the hepatic insulin signaling and lipogenesis pathways, respectively, in hepatocytes.

Background Phloretin is isolated from apple trees and could increase lipolysis in 3T3-L1 adipocytes. Previous studies have found that phloretin could prevent obesity in mice. In this study, we investigated whether phloretin ameliorates non-alcoholic fatty liver disease (NAFLD) in high-fat diet (HFD)-induced obese mice, and evaluated the regulation of lipid metabolism in hepatocytes. Methods HepG2 cells were treated with 0.5 mM oleic acid to induce lipid accumulation, and then treated with phloretin to evaluate the molecular mechanism of lipogenesis. In another experiment, male C57BL/6 mice were fed normal diet or HFD (60% fat, w/w) for 16 weeks. After the fourth week, mice were treated with or without phloretin by intraperitoneal injection for 12 weeks. Results Phloretin significantly reduced excessive lipid accumulation and decreased sterol regulatory element-binding protein 1c, blocking the expression of fatty acid synthase in oleic acid-induced HepG2 cells. Phloretin increased Sirt1, and phosphorylation of AMP activated protein kinase to suppress acetyl-CoA carboxylase expression, reducing fatty acid synthesis in hepatocytes. Phloretin also reduced body weight and fat weight compared to untreated HFD-fed mice. Phloretin also reduced liver weight and liver lipid accumulation and improved hepatocyte steatosis in obese mice. In liver tissue from obese mice, phloretin suppressed transcription factors of lipogenesis and fatty acid synthase, and increased lipolysis and fatty acid β-oxidation. Furthermore, phloretin regulated serum leptin, adiponectin, triglyceride, low-density lipoprotein, and free fatty acid levels in obese mice. Conclusions These findings suggest that phloretin improves hepatic steatosis by regulating lipogenesis and the Sirt-1/AMPK pathway in the liver.

Marinating meat with alcohol, such as wine and beer, is a common culinary practice in cultures worldwide. In this study we use a model marination solution comprising 0.2 mol L-1 glucose-0.2 mol L-1 glycine buffered to pH 4.3 containing either 0 or 50% ethanol and mimicked the cooking process by heating for 12 h. Antioxidative and antimutagenic characteristics of Maillard reaction products (MRPs) were investigated. Reducing power, antioxidant activity (ferrous ion chelating ability), and free radical neutralization ability generated from 1,1-diphenyl-2-pichrylhydrazyl and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) were determined. Ames testing was performed.; Results: Results indicate that MRPs from aqueous and alcoholic solution exhibit four antioxidative assays in a dose-dependent manner from 0.16 to 10.00 mg mL-1 . However, MRPs from the alcoholic model were superior. In Ames testing, MRPs from both models are neither toxic nor mutagenic at the test concentrations of 0.63-10.00 mg/plate. However, MRPs from the alcoholic model exhibited a higher inhibitory effect on the direct-acting mutagen 4-nitroquinoline-N-oxide compared with the aqueous model. This result is consistent with the observation that MRPs with higher antioxidative capacity exhibit superior antimutagenic activity, suggesting that there are more different products in the alcoholic model.; Conclusion: Our results add to the current knowledge about the antioxidative and antimutagenic properties of MRPs arising when food is cooked in the presence of ethanol. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.

Ruellia tuberosa L. (RTL) has been used as a folk medicine for curing diabetes mellitus in East Asia decades. This study investigated the effect of RTL on hepatic detoxification enzyme expression in diabetic rats. Male Wistar rats were fed a high fat diet (HFD) and intraperitoneally injected with streptozotocin (STZ) to induce diabetes. Subsequently, rats received oral administrations of 100 or 400 mg kg−1 body weight RTL extract, in either water (RTLW) or ethanol (RTLE), once a day for 4 weeks. The real-time PCR analyses showed that abnormality of hepatic phase I and II detoxification enzyme expression was observed in diabetic rats. However, both RTLW and RTLE significantly normalized the expression of hepatic phase I detoxification enzymes such as CYP 2E1, and expression of phase II detoxification enzymes such as UGT 1A7 and GST M1 in diabetic rats. Furthermore, we found that fasting serum glucose, hemoglobin A1C (HbA1C) and the area under the curve of oral glucose tolerance test (AUCOGTT) levels were significantly reduced in both RTLW and RTLE treated diabetic rats. Moreover, both RTLW and RTLE significantly increased the activity of hepatic anti-oxidative enzymes such as superoxide dismutase (SOD) in diabetic rats. The present study suggests that RTL may ameliorate abnormal hepatic detoxification function via alleviating hyperglycemia and enhancing hepatic antioxidant capacity in HFD/STZ-induced diabetic rats.

Ruellia tuberosa L. (RTL) exhibits phytochemical activities and has been used as a folk medicine for curing diabetes mellitus in East Asia for decades. This study investigated the effect of RTL aqueous and ethanolic extracts on nonalcoholic fatty liver disease (NAFLD) and hepatic lipid accumulation in high‐fat diet (HFD) and streptozotocin (STZ)‐induced type 2 diabetes mellitus (T2DM) rats. Administration of RTL aqueous extract (RTLW) or ethanolic extract (RTLE) at dosage of 100 or 400 mg/kg body weight for 4 weeks was carried out in HFD/STZ‐induced T2DM rats. Liver weight, adipose (epididymal and perirenal adipose tissues) weight, hepatic triglyceride level, and de novo lipogenesis (DNL)‐associated protein expression were monitored after scarification. The results revealed that RTLW and RTLE reduced relative liver weight and relative fat weights in HFD/STZ‐induced T2DM rats. RTLW and RTLE also ameliorated NAFLD and hepatic triglyceride (TG) accumulation in diabetic rats. Moreover, hepatic DNL‐regulated enzymes such as sterol regulatory element‐binding protein‐1 (SREBP1) and fatty acid synthase (FAS) expression were significantly suppressed by RTLE (100 and 400 mg/kg body weight) in diabetic rats. The evidences of this study suggest that RTL possesses potential on alleviating NAFLD and lipid accumulation via regulating DNL in the liver of HFD/STZ‐induced T2DM rats., This study investigated the effect of RTL aqueous and ethanolic extracts on nonalcoholic fatty liver disease (NAFLD) and hepatic lipid accumulation in high‐fat diet (HFD) and streptozotocin (STZ)‐induced type 2 diabetes mellitus (T2DM) rats. Liver weight, adipose (epididymal and perirenal adipose tissues) weight, hepatic triglyceride level, and de novo lipogenesis (DNL)‐associated protein expression were monitored after scarification. The evidences of this study suggest that RTL possesses potential on alleviating NAFLD and lipid accumulation via regulating DNL in the liver of HFD/STZ‐induced T2DM rats.

Licochalcone A was isolated from Glycyrrhiza uralensis and previously reported to have antitumor and anti-inflammatory effects. Licochalcone A has also been found to inhibit the levels of Th2-associated cytokines in the bronchoalveolar lavage fluid (BALF) of asthmatic mice. However, the molecular mechanism underlying airway inflammation and how licochalcone A regulates oxidative stress in asthmatic mice are elusive. In this study, we investigated whether licochalcone A could attenuate inflammatory and oxidative responses in tracheal epithelial cells, and whether it could ameliorate oxidative stress and airway inflammation in asthmatic mice. Inflammatory human tracheal epithelial (BEAS-2B) cells were treated with licochalcone A to evaluate oxidative responses and inflammatory cytokine levels. In addition, BALB/c mice were sensitized with ovalbumin (OVA) and injected intraperitoneally with licochalcone A (5 or 10 mg/kg). Licochalcone A significantly inhibited reactive oxygen species, eotaxin, and proinflammatory cytokines in BEAS-2B cells. Licochalcone A also decreased intercellular adhesion molecule 1 levels in inflammatory BEAS-2B cells, blocking monocyte cell adherence. We also found that licochalcone A significantly decreased oxidative responses, reduced malondialdehyde levels, and increased glutathione levels in the lungs of OVA-sensitized mice. Furthermore, licochalcone A decreased airway hyper-responsiveness, eosinophil infiltration, and Th2 cytokine production in the BALF. These findings suggest that licochalcone A alleviates oxidative stress, inflammation, and pathological changes by inhibiting Th2-associated cytokines in asthmatic mice and human tracheal epithelial cells. Thus, licochalcone A demonstrated therapeutic potential for improving asthma.

Tomatidine is isolated from the leaves and green fruits of some plants in the Solanaceae family, and has been reported to have anti-inflammatory and antitumor effects. Previous studies have found that tomatidine decreases hepatic lipid accumulation via regulation of vitamin D receptor and activation of AMP-activated protein kinase (AMPK) phosphorylation. However, whether tomatidine reduces weight gain and improves nonalcoholic fatty liver disease (NAFLD) remains unclear. In this study, we investigated how tomatidine ameliorates NAFLD in obese mice and evaluated the regulatory mechanism of lipogenesis in hepatocytes. Male C57BL/6 mice were fed a high-fat diet (HFD) to induce obesity and NAFLD, and treated with tomatidine via intraperitoneal injection. In vitro, FL83B hepatocytes were incubated with oleic acid and treated with tomatidine to evaluate lipid metabolism. Our results demonstrate that tomatidine significantly decreases body weight and fat weight compared to HFD-fed mice. In addition, tomatidine decreased hepatic lipid accumulation and improved hepatocyte steatosis in HFD-induced obese mice. We also found that tomatidine significantly regulated serum total cholesterol, fasting blood glucose, low-density lipoprotein, and triglyceride levels, but the serum high-density lipoprotein and adiponectin concentrations were higher than in the HFD-fed obese mice. In vivo and in vitro, tomatidine significantly suppressed the expression of fatty acid synthase and transcription factors involved in lipogenesis, and increased the expression of adipose triglyceride lipase. Tomatidine promoted the sirtuin 1 (sirt1)/AMPK signaling pathway to increase lipolysis and β-oxidation in fatty liver cells. These findings suggest that tomatidine potentially ameliorates obesity and acts against hepatic steatosis by regulating lipogenesis and the sirt1/AMPK pathway.

Ruellia tuberosa L. (RTL) exhibits a wide range of phytochemical activities, for example, on treatment of diabetes mellitus (DM), in Orient. There is, however, few study regarding the effect of RTL on glycemic‐related homeostasis in type 2 DM (T2DM). We investigated the effect of RTL aqueous and ethanolic extracts on hypoglycemia in high‐fat diet (HFD)‐fed plus streptozotocin (STZ)‐induced T2DM rats, and examined the effect of RTL on glucose uptake in tumor necrosis factor‐α‐induced insulin‐resistant mouse C2C12 myoblasts, a mouse skeletal muscle cell line. The administration of 100 or 400 mg kg BW−1 day−1 of RTL aqueous or ethanolic extracts once a day for 4 weeks significantly ameliorated hyperglycemia, hyperinsulinemia, and the insulin resistance (IR) index in diabetic rats. RTL either aqueous or ethanolic extract at a concentration of 25–800 μg/ml significantly improved glucose uptake in insulin‐resistant mouse C2C12 myoblasts, indicating inhibiting the IR in skeletal muscles. These evidences suggest that RTL ameliorates hyperglycemia in HFD/STZ‐induced T2DM rats may be attributed to the alleviation of IR in skeletal muscles.

This study investigates the ameliorative effect of vescalagin (VES) isolated from Pink wax apple fruit on hepatic insulin resistance and abnormal carbohydrate metabolism in high-fructose diet (HFD)-induced hyperglycemic rats. The results show that in HFD rats, VES significantly reduced the values of the area under the curve for glucose in an oral glucose tolerance test and the homeostasis model assessment of insulin resistance index. VES significantly enhanced the activity of hepatic antioxidant enzymes while reducing thiobarbituric acid-reactive substances in HFD rats. Western blot assay revealed that VES reduced hepatic protein expression involved in inflammation pathways while up-regulating expression of hepatic insulin signaling-related proteins. Moreover, VES up-regulated the expression of hepatic glycogen synthase and hepatic glycolysis-related proteins while down-regulating hepatic gluconeogenesis-related proteins in HFD rats. This study suggests some therapeutic potential of VES in preventing the progression of diabetes mellitus.

Herein, we investigated the hypoglycemic effect of plant gallic acid (GA) on glucose uptake in an insulin-resistant cell culture model and on hepatic carbohydrate metabolism in rats with a high-fructose diet (HFD)-induced diabetes. Our hypothesis is that GA ameliorates hyperglycemia via alleviating hepatic insulin resistance by suppressing hepatic inflammation and improves abnormal hepatic carbohydrate metabolism by suppressing hepatic gluconeogenesis and enhancing the hepatic glycogenesis and glycolysis pathways in HFD-induced diabetic rats. Gallic acid increased glucose uptake activity by 19.2% at a concentration of 6.25 μg/mL in insulin-resistant FL83B mouse hepatocytes. In HFD-induced diabetic rats, GA significantly alleviated hyperglycemia, reduced the values of the area under the curve for glucose in an oral glucose tolerance test, and reduced the scores of the homeostasis model assessment of insulin resistance index. The levels of serum C-peptide and fructosamine and cardiovascular risk index scores were also significantly decreased in HFD rats treated with GA. Moreover, GA up-regulated the expression of hepatic insulin signal transduction-related proteins, including insulin receptor, insulin receptor substrate 1, phosphatidylinositol-3 kinase, Akt/protein kinase B, and glucose transporter 2, in HFD rats. Gallic acid also down-regulated the expression of hepatic gluconeogenesis-related proteins, such as fructose-1,6-bisphosphatase, and up-regulated expression of hepatic glycogen synthase and glycolysis-related proteins, including hexokinase, phosphofructokinase, and aldolase, in HFD rats. Our findings indicate that GA has potential as a health food ingredient to prevent diabetes mellitus.

Excess free fatty acid accumulation from abnormal lipid metabolism results in the insulin resistance in peripheral cells, subsequently causing hyperinsulinemia, hyperglycemia and/or hyperlipidemia in diabetes mellitus (DM) patients. Herein, we investigated the effect of phenolic acids on glucose uptake in an insulin-resistant cell-culture model and on hepatic insulin resistance and inflammation in rats fed a high-fat diet (HFD). The results show that vanillic acid (VA) demonstrated the highest glucose uptake ability among all tested phenolic acids in insulin-resistant FL83B mouse hepatocytes. Furthermore, rats fed HFD for 16 weeks were orally administered with VA daily (30 mg/kg body weight) at weeks 13–16. The results show that levels of serum insulin, glucose, triglyceride, and free fatty acid were significantly decreased in VA-treated HFD rats (p &lt, 0.05), indicating the protective effects of VA against hyperinsulinemia, hyperglycemia and hyperlipidemia in HFD rats. Moreover, VA significantly reduced values of area under the curve for glucose (AUCglucose) in oral glucose tolerance test and homeostasis model assessment-insulin resistance (HOMA-IR) index, suggesting the improving effect on glucose tolerance and insulin resistance in HFD rats. The Western blot analysis revealed that VA significantly up-regulated expression of hepatic insulin-signaling and lipid metabolism-related protein, including insulin receptor, phosphatidylinositol-3 kinase, glucose transporter 2, and phosphorylated acetyl CoA carboxylase in HFD rats. VA also significantly down-regulated hepatic inflammation-related proteins, including cyclooxygenase-2 and monocyte chemoattractant protein-1 expressions in HFD rats. These results indicate that VA might ameliorate insulin resistance via improving hepatic insulin signaling and alleviating inflammation pathways in HFD rats. These findings also suggest the potential of VA in preventing the progression of DM.

This study investigated the effect of phenolic acid on memory decline and cerebral carbohydrate metabolism in rats fed a high-fat diet (HFD), which induced hyperinsulinemia. First, among eleven tested phenolic acids, caffeic acid (CA) was demonstrated to induce the highest glucose uptake capacity in insulin-resistant Neuro 2a mouse neuroblastoma cells. Next, male rats fed a HFD were treated with daily oral CA (30 mg/kg body weight) for 30 weeks. Cognitive performance trials were conducted to investigate the effect of CA on ameliorating memory impairment. Cerebral tissues were analyzed to determine whether CA affected brain carbohydrate metabolism and/or alleviated insulin and leptin resistance. Our results suggested that CA significantly reduced plasma glucose and insulin levels, and it alleviated insulin resistance (HOMA-IR) in HFD-induced hyperinsulinemic rats. Concurrently, passive avoidance tests revealed that orally administered CA significantly improved memory impairments in HFD rats. Western blot analysis demonstrated that CA significantly increased the expression of insulin signaling-related proteins, including the insulin receptor, phosphatidylinositol-3-kinase, Akt/protein kinase B, and insulin degrading enzyme. CA also increased the expression of leptin signaling-related proteins, including leptin receptor and pJAK2Tyr813/JAK2 in the cortex of HFD rats. These findings demonstrated that CA showed promise as a drug or food supplement for preventing the progression of dementia.

This study investigated the ameliorative effect of gallic acid (GA) on hypertriglyceridemia and fat accumulation in perirenal adipose tissues of high-fructose diet (HFD)-induced diabetic rats. The previous results showed that orally administered GA (30 mg/kg body weight) for four weeks significantly reduced the levels of plasma glucose and triglyceride (TG) in HFD rats. GA also markedly decreased the perirenal adipose tissues weight of HFD rats in present study (p < 0.05). Western blot assay indicated that GA restored expression of insulin signaling-related proteins, such as insulin receptor (IR), protein kinase C-zeta (PKC-ζ), and glucose transporter-4 (GLUT4) in the perirenal adipose tissues of HFD rats. Moreover, GA enhanced expression of glycolysis-related proteins, such as phosphofructokinase (PFK) and pyruvate kinase (PK), and increased the expression of lipolysis-related proteins, such as adipose triglyceride lipase (ATGL), which is involved in lipolysis in the perirenal adipose tissues of HFD rats. This study revealed that GA may alleviate hypertriglyceridemia and fat accumulation through enhancing glycolysis and lipolysis pathways in perirenal adipose tissues of HFD rats. These findings also suggest the potential of GA in preventing the progression of diabetes mellitus (DM) complications.

Ruellia tuberosa L. (RTL) exhibits a wide range of phytochemical activities, for example, on treatment of diabetes mellitus (DM), in Orient. There is, however, few study regarding the effect of RTL on glycemic‐related homeostasis in type 2 DM (T2DM). We investigated the effect of RTL aqueous and ethanolic extracts on hypoglycemia in high‐fat diet (HFD)‐fed plus streptozotocin (STZ)‐induced T2DM rats, and examined the effect of RTL on glucose uptake in tumor necrosis factor‐α‐induced insulin‐resistant mouse C2C12 myoblasts, a mouse skeletal muscle cell line. The administration of 100 or 400 mg kg BW−1 day−1 of RTL aqueous or ethanolic extracts once a day for 4 weeks significantly ameliorated hyperglycemia, hyperinsulinemia, and the insulin resistance (IR) index in diabetic rats. RTL either aqueous or ethanolic extract at a concentration of 25–800 μg/ml significantly improved glucose uptake in insulin‐resistant mouse C2C12 myoblasts, indicating inhibiting the IR in skeletal muscles. These evidences suggest that RTL ameliorates hyperglycemia in HFD/STZ‐induced T2DM rats may be attributed to the alleviation of IR in skeletal muscles.

Marinating meat with alcohol, such as wine and beer, is a common culinary practice in cultures worldwide. In this study we use a model marination solution comprising 0.2 mol LResults indicate that MRPs from aqueous and alcoholic solution exhibit four antioxidative assays in a dose-dependent manner from 0.16 to 10.00 mg mLOur results add to the current knowledge about the antioxidative and antimutagenic properties of MRPs arising when food is cooked in the presence of ethanol. © 2018 Society of Chemical Industry.

FL83B mouse hepatocytes were treated with tumor necrosis factor-α (TNF-α) to induce insulin resistance to investigate the effect of a wax apple aqueous extract (WAE) in insulin-resistant mouse hepatocytes. The uptake of 2-[N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino]-2-deoxyglucose (2 NBDG), a fluorescent d-glucose derivative, was performed, and the metabolism of carbohydrates was evaluated by examining the expression of glycogenesis or glycolysis-related proteins in insulin-resistant hepatocytes. The results show that WAE significantly improves the uptake of glucose and enhances glycogen content in insulin-resistant FL83B mouse hepatocytes. The results from Western blot analysis also reveal that WAE increases the expression of glycogen synthase (GS), hexokinase (HXK), glucose-6-phosphate dehydrogenase (G6PD), phosphofructokinase (PFK) and aldolase in TNF-α treated cells, indicating that WAE may ameliorate glucose metabolism by promoting glycogen synthesis and the glycolysis pathways in insulin-resistant FL83B mouse hepatocytes.

FL83B mouse hepatocytes were treated with tumor necrosis factor-α (TNF-α) to induce insulin resistance to investigate the effect of a wax apple aqueous extract (WAE) in insulin-resistant mouse hepatocytes. The uptake of 2-[N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino]-2-deoxyglucose (2 NBDG), a fluorescent d-glucose derivative, was performed, and the metabolism of carbohydrates was evaluated by examining the expression of glycogenesis or glycolysis-related proteins in insulin-resistant hepatocytes. The results show that WAE significantly improves the uptake of glucose and enhances glycogen content in insulin-resistant FL83B mouse hepatocytes. The results from Western blot analysis also reveal that WAE increases the expression of glycogen synthase (GS), hexokinase (HXK), glucose-6-phosphate dehydrogenase (G6PD), phosphofructokinase (PFK) and aldolase in TNF-α treated cells, indicating that WAE may ameliorate glucose metabolism by promoting glycogen synthesis and the glycolysis pathways in insulin-resistant FL83B mouse hepatocytes.

Vescalagin, an active component from Pink wax apple [Syzygium samarangense (Blume) Merrill and Perry cv. Pink] fruit, with glucose uptake enhancing ability in insulin-resistant FL83B mouse hepatocytes, as shown in our previous study, was further evaluated for its hypotriglyceridemic and hypoglycemic effects in high-fructose diet (HFD)-induced diabetic rats. Wistar rats were fed HFD for 16 weeks and orally administered with vescalagin from Pink wax apple daily during the last 4 weeks. The results of biochemical parameters showed that fasting blood glucose, C-peptide, fructosamine, triglyceride and free fatty acid contents decreased by 44.7%, 46.2%, 4.0%, 42.5%, and 10.8%, respectively, in the HFD-induced diabetic rats administered with vescalagin at 30 mg/kg body weight in comparison with those of control HFD-induced diabetic rats. However, high-density-lipoprotein-cholesterol content increased by 14.4% in the HFD rats treated with vescalagin. The present study reveals that vescalagin could have therapeutic value against diabetic progression via its anti-hypertriglyceridemic and anti-hyperglycemic effects.

Inflammation is associated with the development of insulin resistance in Type 2 diabetes mellitus. In the present study, mouse FL83B cells were treated with tumor necrosis factor-alpha (TNF-α) to induce insulin resistance, and then co-incubated with a fraction from wax apple fruit extract (FWFE). This fraction significantly increased the uptake of the nonradioactive fluorescent indicator 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose (2-NBDG) in insulin resistant cells. Western blot analysis revealed that, compared with the TNF-α-treated control group, FWFE increased the expression of the insulin receptor (IR), insulin receptor substrate-1 (IRS-1), protein kinase B (Akt/PKB), phosphatidylinositol-3 kinase (PI3K), and glucose transporter 2 (GLUT-2), and increased IR tyrosyl phosporylation, in insulin resistant FL83B cells. However, FWFE decreased phosphorylation of c-Jun N-terminal kinases (JNK), but not the expression of the intercellular signal-regulated kinases (ERK), in the same cells. These results suggest that FWFE might alleviate insulin resistance in TNF-α-treated FL83B cells by activating PI3K-Akt/PKB signaling and inhibiting inflammatory response via suppression of JNK, rather than ERK, activation.

This study investigated the glucose uptake activity of the water extracts from the leaves and fruit of edible Myrtaceae plants, including guava (Psidium guajava Linn.), wax apples [Syzygium samarangense (Blume) Merr. and L.M. Perry], Pu-Tau [Syzygium jambo (L.) Alston], and Kan-Shi Pu-Tau (Syzygium cumini Linn.) in FL83B mouse hepatocytes. The fluorescent dye 2-(n-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose was used to estimate the uptake ability of the cells. Glucose uptake test showed that pink wax apple fruit extract (PWFE) exhibits the highest glucose uptake activity, at an increment of 21% in the insulin-resistant FL83B mouse hepatocytes as compared with the TNF-α-treated control group. Vescalagin was isolated using column chromatography of PWFE. This compound, at the concentration of 6.25 µg/mL, exhibits the same glucose uptake improvement in insulin-resistant cells as PWFE at a 100-µg/mL dose. We postulate that vescalagin is an active component in PWFE that may alleviate the insulin resistance in mouse hepatocytes. Copyright © 2012 John Wiley & Sons, Ltd.

The present study mimics cooking meats in alcohol or distilled spirit marinades by using a 0.1 M creatinine/0.05 M sugars/0.1 M threonine ethanolic model solution, in an attempt to investigate the formation of the heterocyclic amines IQ and IQx, via Maillard reaction. The results showed that ethanol accelerated the formation of IQ and IQx, in a dose-dependent manner. In an aqueous model solution of 0.1 M creatinine/0.05 M glucose/0.1 M threonine after 8 h heating at 150 °C, the contents of IQ and IQx are 16.5 ± 2.2 and 26.2 ± 4.2 mg/kg, respectively. However, at a similar Maillard browning level in the equivalent 50% ethanolic model solution after heating at the same temperature for only 4 h, the contents of IQ and IQx significantly increase to 46.0 ± 5.5 and 69.2 ± 3.4 mg/kg, respectively.