Hippophae rhamnoides L. leaf extracts alleviate diabetic nephropathy via attenuation of advanced glycation end product-induced oxidative stress in db/db mice.

Diabetes mellitus leads to chronic complications, such as nephropathy. Diabetic complications are closely related to advanced glycation end products (AGEs). Excessive formation and accumulation of AGEs in diabetic renal diseases lead to excessive oxidative stress, resulting in chronic renal failure. The leaves of Hippophae rhamnoides L. (sea buckthorn leaves; SBL) show biological benefits, including antioxidant effects. This study aimed to evaluate the effect of SBL on kidney damage in db/db mice. The SBL extract was orally administered at 100 and 200 mg kg-1 for 12 weeks to db/db mice. Histological changes and the urine albumin/creatinine ratio were relieved, and the accumulation of AGEs in kidney glomeruli decreased following SBL treatment. Moreover, the SBL extract reduced the expression of AGEs, the receptor for AGEs, and NADPH oxidase 4, but upregulated glyoxalase 1 in the diabetic renal tissue. Urinary excretion levels and expression of 8-hydroxy-2'-deoxyguanosine as a biomarker of oxidative stress decreased after SBL treatment in the renal tissue. Furthermore, SBL attenuated oxidative stress in diabetic kidneys by reducing AGE accumulation, thereby ameliorating renal damage. Therefore, from these results, we infer that the SBL extract can act as a potential therapeutic agent for diabetic renal complications caused by AGEs.

Anti-obesity effects of red pepper (Capsicum annuum L.) leaf extract on 3T3-L1 preadipocytes and high fat diet-fed mice.

Patients with obesity mostly have metabolic syndrome and this can lead to multiple health problems. In the present study, we evaluated the anti-obesity effect of water-soluble red pepper (Capsicum annuum L.) leaf extract (PLE) on 3T3-L1 adipocytes and high-fat diet (HFD)-fed mice. The adipocyte lipid content was determined using Oil Red O staining, which revealed that 100 µg mL-1 PLE markedly reduced fat accumulation without affecting the cell viability. PLE exhibited high prebiotic activity scores by modulating probiotic strains, contributing to host health improvement. In vivo investigation in HFD-fed mice revealed that PLE supplementation significantly decreased the HFD-induced increases in the body weight, amount of white adipose tissue, and serum triglyceride, total cholesterol, leptin, and insulin levels. Consistent with its effects on reduced lipid droplet formation in the liver, PLE supplementation suppressed the expression of lipid synthesis-related proteins including SREBP-1, FAS, and PPAR-γ in the liver and increased that of PGC-1α, CPT1, and adiponectin in epididymal WAT. PLE treatment improved intestinal barrier function and inflammation and reduced harmful intestinal enzyme activities in the feces. Collectively, these results indicate that PLE inhibits fat accumulation in HFD-fed mice via the suppression of adipogenesis and lipogenesis, suggesting its potential in preventing obesity.

Peanut shell extract inhibits the development of dextran sulfate sodium (DSS)-induced colitis.

Inflammatory bowel diseases (IBD) induce inflammation in the colon and small intestine. IBD include ulcerative colitis and Crohn's disease, with such common symptoms as severe diarrhea, fever, and blood in the stool. In the current study, we explored the ability of peanut shell extract (PSE) to alleviate IBD in an experimental colonic inflammation model. Colitis was induced by orally administered dextran sulfate sodium (DSS) in mice. Peanut shell extract was prepared using a method of aqueous ethanol. DSS treatment reduced the colon length and mouse body weight, and aggravated disease condition compared with untreated control mice. Oral administration of 400 mg/kg PSE alleviated colon shortening, body weight loss, DAI, and colon injury score in DSS-induced colitis. These physiological improvements were validated by reduced levels of proinflammatory cytokines and infiltrating macrophage accumulation in the inflamed colon in the PSE administered group. These observations suggest that PSE may be developed as an alternative natural extract for the prevention or treatment of IBD.

Enzymatic Synthesis of Structured Monogalactosyldiacylglycerols Enriched in Pinolenic Acid.

We enzymatically prepared structured monogalactosydiacylglycerols (MGDGs) enriched in pinolenic acid (PLA). PLA-enriched free fatty acids (FFAs) containing ∼86 mol % PLA were produced from an FFA fraction obtained from pine nut oil (PLA content, ∼13 mol %) by urea crystallization. Commercial MGDGs (5 mg) were acidolyzed with PLA-enriched FFAs using four commercial immobilized lipases as biocatalysts. The reaction was performed in acetone (4 mL) in a stirred-batch reactor. Lipozyme RM IM (immobilized Rhizomucor miehei lipase) was the most effective biocatalyst for the reaction. Structured MGDGs containing 42.1 mol % PLA were obtained under optimal reaction conditions: temperature, 25 °C; substrate molar ratio, 1:30 (MGDGs/PLA-enriched FFAs); enzyme loading, 20 wt % of total substrates; and reaction time, 36 h. The structured MGDGs were separated from the reaction products at a purity of 96.6 wt % using silica column chromatography. The structured MGDGs could be possibly used as emulsifiers with appetite-suppression effects.

Immunomodulatory effects of polysaccharide fraction isolated from Fagopyrum esculentum on innate immune system.

The present study investigates the immunomodulatory activities of buckwheat polysaccharide fraction (BPF) from the seed of Fagopyrum esculentum on RAW 264.7 macrophage cell line and Cyclophosphamide-induced immunosuppressed conditions in mice models. The results of in vitro showed that treatment with 0.5-10 µg/mL of BPF can modulate immune responses. MTT assay and nitric oxide production and immune-related cytokine levels were conducted. Treatment with BPF at a dose of 10 µg/mL of BPF increased immune responses on macrophages. Moreover, natural killer (NK) cell cytotoxicity was conducted. The apoptosis of YAC-1 cells increased as the co-culture ratio between spleen cells and YAC-1 cells increased approximately 4- fold compared to the control group from 12.5:1 to 50.0:1. The in-vivo immunomodulatory effects of BPF were evaluated by cyclophosphamide-induced mice model. The immune response of BPF was determined against cyclophosphamide (100 mg/kg) immunosuppressed mice at doses of 50 mg/kg and 100 mg/kg of BPF as compared to control. The results of this study showed that BPF administration increased spleen and thymus indices as well as the leukocytes count in the blood of immunosuppressed mice. All of results suggested that BPF are potentially acts as immunomodulator for activation of immune responses.

Lespedeza bicolor ameliorates endothelial dysfunction induced by methylglyoxal glucotoxicity.

BACKGROUND: Lespedeza species have been used as a traditional medicine to treat nephritis, azotemia, inflammation, energy depletion, diabetes, and diuresis. PURPOSE: The purpose of this study is to screen the most potent Lespedeza species against methylglyoxal (MGO)-induced glucotoxicity, and to elucidate the mechanisms of action. Also, we will attempt to identify small chemical metabolites that might be responsible for such anti-glucotoxicity effects. METHODS: Firstly, the protective effect of 26 different Lespedeza species against MGO-induced toxicity in human umbilical vein endothelial cells was investigated. The chemical metabolites of the most potent species (Lespedeza bicolor 1 (LB1) were identified by high pressure liquid chromatography quadrupole time-of-flight tandem mass spectrometry (HPLC-Q-TOF-MS/MS), then quantified by HPLC. The effects of LB1 on MGO-induced apoptosis were measured by annexin V-FITC staining and western blot. Inhibitory effects of LB1 on MGO-induced ROS generation, and effect of LB1 on advanced glycation end products (AGEs) inhibitor or a glycated cross-link breaker are also measured. RESULTS: Among different Lespedeza species, LB1 extract was shown to reduce intracellular reactive oxidative species, exhibit anti-apoptotic effects, strongly inhibit all the mitogen-activated protein kinase signals, inhibit MGO-induced AGEs formation, and break down preformed AGEs. We tentatively identified 17 chemical constituents of LB1 by HPLC-Q-TOF-MS/MS. Among those, some components, such as genistein and quercetin, significantly reduced the AGEs formation and increased the AGEs-breaking activity, resulting in the reduction of glucotoxicity. CONCLUSION: LB1 extract has shown to be effective in preventing or treating MGO-induced endothelial dysfunction.

Melandrii Herba Extract Attenuates H2O2-Induced Neurotoxicity in Human Neuroblastoma SH-SY5Y Cells and Scopolamine-Induced Memory Impairment in Mice.

Oxidative stress plays a significant role in the etiology of a variety of neurodegenerative diseases. In this study, we found that Melandrii Herba extract (ME) attenuated oxidative-induced damage in cells. Mechanistically, ME exhibited protection from H2O2-induced neurotoxicity via caspase-3 inactivation, Bcl-2 downregulation, Bax upregulation, and MAPK activation (ERK 1/2, JNK 1/2, and p38 MAPK) in vitro. Moreover, our in vivo data showed that ME was able to attenuate scopolamine-induced cognitive impairment. These results provide in vitro and in vivo evidence that ME exhibits neuroprotective properties against oxidative stress, which suggests that ME is worthy of further investigation as a complementary, or even as an alternative, product for preventing and treating neurodegenerative disorders.

Pinolenic Acid in Structured Triacylglycerols Exhibits Superior Intestinal Lymphatic Absorption As Compared to Pinolenic Acid in Natural Pine Nut Oil.

The positional distribution pattern of fatty acids (FAs) in the triacylglycerols (TAGs) affects intestinal absorption of these FAs. The aim of this study was to compare lymphatic absorption of pinolenic acid (PLA) present in structured pinolenic TAG (SPT) where PLA was evenly distributed on the glycerol backbone, with absorption of pine nut oil (PNO) where PLA was predominantly positioned at the sn-3 position. SPT was prepared via the nonspecific lipase-catalyzed esterification of glycerol with free FA obtained from PNO. Lymphatic absorption of PLA from PNO and from SPT was compared in a rat model of lymphatic cannulation. Significantly (P < 0.05) greater amounts of PLA were detected in lymph collected for 8 h from an emulsion containing SPT (28.5 ± 0.7% dose) than from an emulsion containing PNO (26.2 ± 0.6% dose), thereby indicating that PLA present in SPT has a greater capacity for lymphatic absorption than PLA from PNO.

Conjugated Linoleic Triacylglycerols Exhibit Superior Lymphatic Absorption Than Free Conjugate Linoleic Acids and Have Antiobesity Properties.

This study aimed to compare lymphatic absorption of conjugated linoleic acids (CLAs) in the triacylglycerol (TAG) or free fatty acid (FFA) form and to examine the antiobesity effects of different doses of CLAs in the TAG form in animals. Conjugated linoleic TAGs (containing 70.3 wt% CLAs; CLA-TAG) were prepared through lipase-catalyzed esterification of glycerol with commercial CLA mixtures (CLA-FFA). Lymphatic absorption of CLA-TAG and CLA-FFA was compared in a rat model of lymphatic cannulation. Greater amounts of cis-9,trans-11 and trans-10,cis-12 CLAs were detected in the collected lymph from a lipid emulsion containing CLA-TAG. This result suggests that CLA-TAG has greater capacity for lymphatic absorption than does CLA-FFA. The antiobesity efficacy of CLA-TAG at different doses was examined in mice with diet-induced obesity. A high-fat diet (HFD) for 12 weeks caused a significant increase in body weight and epididymal and retroperitoneal fat weights, which were significantly decreased by 2% dietary supplementation (w/w) with CLA-TAG. CLA-TAG at 2% significantly attenuated the HFD-induced upregulation of serum TAG, but led to hepatomegaly and exacerbated HFD-induced hypercholesterolemia. CLA-TAG at 1% significantly attenuated upregulation of retroperitoneal fat weight and significantly increased liver weight, which was decreased by the HFD. Nonetheless, the liver weight in group "HFD +1% CLA-TAG" was not significantly different from that of normal diet controls. CLA-TAG at 1% significantly reduced serum TAG levels and did not exacerbate HFD-induced hypercholesterolemia. Thus, 1% dietary supplementation with CLA-TAG reduces retroperitoneal fat weight without apparent hepatomegaly, a known side-effect of CLAs in mouse models of obesity.

Microtechnology-based organ systems and whole-body models for drug screening.

After drug administration, the drugs are absorbed, distributed, metabolized, and excreted (ADME). Because ADME processes affect drug efficacy, various in vitro models have been developed based on the ADME processes. Although these models have been widely accepted as a tool for predicting the effects of drugs, the differences between in vivo and in vitro systems result in high attrition rates of drugs during the development process and remain a major limitation. Recent advances in microtechnology enable more accurate mimicking of the in vivo environment, where cellular behavior and physiological responses to drugs are more realistic; this has led to the development of novel in vitro systems, known as "organ-on-a-chip" systems. The development of organ-on-a-chip systems has progressed to include the reproduction of multiple organ interactions, which is an important step towards "body-on-a-chip" systems that will ultimately predict whole-body responses to drugs. In this review, we summarize the application of microtechnology for the development of in vitro systems that accurately mimic in vivo environments and reconstruct multiple organ models.

A microfluidic device with 3-d hydrogel villi scaffold to simulate intestinal absorption.

The absorption of drugs via oral route is a subject of a great interest in drug development process. The current in vitro method for measuring the kinetics of drug absorption relies on 2-D monolayer culture of Caco-2 cells on a porous membrane, but physiologically unrealistic environment provided by this method often results in inaccurate drug absorption kinetics. Here we report a novel microfluidic system which better mimics the physiological environment of the human small intestine. Three dimensional geometries of villi of the small intestine were reproduced via novel hydrogel microfabrication technique, and the fluid flow in the apical and basolateral sides of intestinal tract was reproduced with a two-layer microfluidic device. A wide range of flow rates was achieved by using gravity-induced flow, potentially facilitating easier high-throughput implementation. The kinetics of diffusion process through the 3-D villi scaffold in the microfluidic device was measured and mathematically modeled. When combined with intestinal cell culture model, this novel 3-D microfluidic system can serve as an in vitro platform that better mimics the in vivo environment.

The effects of biopolymer encapsulation on total lipids and cholesterol in egg yolk during in vitro human digestion.

The purpose of this study was to examine the effect of biopolymer encapsulation on the digestion of total lipids and cholesterol in egg yolk using an in vitro human digestion model. Egg yolks were encapsulated with 1% cellulose, pectin, or chitosan. The samples were then passed through an in vitro human digestion model that simulated the composition of mouth saliva, stomach acid, and the intestinal juice of the small intestine by using a dialysis tubing system. The change in digestion of total lipids was monitored by confocal fluorescence microscopy. The digestion rate of total lipids and cholesterol in all egg yolk samples dramatically increased after in vitro human digestion. The digestion rate of total lipids and cholesterol in egg yolks encapsulated with chitosan or pectin was reduced compared to the digestion rate of total lipids and cholesterol in other egg yolk samples. Egg yolks encapsulated with pectin or chitosan had lower free fatty acid content, and lipid oxidation values than samples without biopolymer encapsulation. Moreover, the lipase activity decreased, after in vitro digestion, in egg yolks encapsulated with biopolymers. These results improve our understanding of the effects of digestion on total lipids and cholesterol in egg yolk within the gastrointestinal tract.

Narirutin fraction from citrus peels attenuates alcoholic liver disease in mice.

This study aimed to demonstrate protective activities of the narirutin fraction from peels of Citrus unshiu against ethanol-induced hepatic damage through an animal study. Citrus narirutin fraction (CNF), contained 75% of narirutin, was obtained by an ultra-sonicated extraction and further purification. ICR mice were divided into four groups; normaldiet control, ethanol control (6.5g ethanol/kg), low-CNF (ethanol+150mg CNF/kg) and high-CNF (ethanol+300mg CNF/kg) groups. Consumption of alcohol for 8weeks induced severe liver damage with increases in prognostic indicators such as aspartate transaminase, alanine transaminase in serum whereas co-administration of CNF suppressed their increases. Excessive accumulations in liver TG and TC in ethanol control group were also suppressed by co-administration of CNF. Co-administration of CNF maintained SOD activity, GSH and malondialdehyde levels close to those of the normal diet group. Chronic consumption of alcohol also stimulated abrupt increases in pro-inflammatory cytokines such as nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α and interleukin (IL)-1ß in liver otherwise co-administration of CNF effectively suppressed production of these cytokines dose-dependently. These results indicate that co-administration of CNF with alcohol can alleviate alcohol induced liver damage through preventing lipid formation, protecting antioxidant system and suppressing productions of pro-inflammatory cytokines.

Narirutin fraction from citrus peels attenuates LPS-stimulated inflammatory response through inhibition of NF-κB and MAPKs activation.

In this study, we examined the regulatory activity of narirutin fraction from citrus peels on the production of inflammatory mediators managing acute or chronic inflammatory diseases in macrophages. Narirutin fraction inhibited the release, by lipopolysaccharide (LPS)-stimulated macrophages, of nitric oxide (NO) and prostaglandin E2 (PGE2) through suppressing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively. The release, by LPS stimulated macrophages, of interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) was also reduced by narirutin fraction in a dose-dependent manner. Furthermore, narirutin fraction inhibited the LPS-mediated activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs), which are signaling molecules involved in production of pro-inflammatory factors. As a result of these properties, narirutin fraction has the potential to be used as a functional dietary supplement and effective anti-inflammatory agent.

Effects of wild ginseng (Panax ginseng C.A. Meyer) leaves on lipid peroxidation levels and antioxidant enzyme activities in streptozotocin diabetic rats.

The aim of this study was to examine the possible antioxidant activities of wild Panax ginseng leaf extract intake in streptozotocin (STZ)-induced diabetic rats (WGLE). Initial blood glucose levels increased abruptly after streptozotocin injection. After 4 weeks of WGLE supplementation, blood glucose levels were lower in animals fed 40 mg/kg (266 mg/dL) and 200 mg/kg (239 mg/dL) than those in no-WGLE fed diabetic rats (464 mg/dL). The concentration of blood TBARS, which are considered the main products of glucose oxidation in blood, was also lowered by WGLE supplementation. These results indicate that WGLE supplementation is involved in suppressing a sudden increase in blood glucose levels and a consequent decrease in TBARS levels in diabetic rats. TBARS levels in the liver, kidney and spleen of WGLE-fed diabetic groups were also significantly lower than in the control diabetic group indicating that oral administration of WGLE effectively suppresses lipid peroxidation that occurs in the organs of diabetic rats. Antioxidant activities of WGLE supplementation further extend in suppressing activities of antioxidant related enzymes, such as glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD), in organs of diabetic rats. These results confirm the effectiveness of WGLE supplementation in detoxifying free radicals that are produced excessively in diabetic-induced complications.