RESUMEN
The efficacy of a UV-A light emitting diode system (LED) to reduce the concentrations of aflatoxin B1, aflatoxin M1 (AFB1, AFM1) in pure water was studied. This work investigates and reveals the kinetics and main mechanism(s) responsible for the destruction of aflatoxins in pure water and assesses the cytotoxicity in liver hepatocellular cells. Irradiation experiments were conducted using an LED system operating at 365 nm (monochromatic wave-length). Known concentrations of aflatoxins were spiked in water and irradiated at UV-A doses ranging from 0 to 1,200 mJ/cm2. The concentration of AFB1 and AFM1 was determined by HPLC with fluorescence detection. LC-MS/MS product ion scans were used to identify and semi-quantify degraded products of AFB1 and AFM1. It was observed that UV-A irradiation significantly reduced aflatoxins in pure water. In comparison to control, at dose of 1,200 mJ/cm2 UV-A irradiation reduced AFB1 and AFM1 concentrations by 70 ± 0.27 and 84 ± 1.95%, respectively. We hypothesize that the formation of reactive species initiated by UV-A light may have caused photolysis of AFB1 and AFM1 molecules in water. In cell culture studies, our results demonstrated that the increase of UV-A dosage decreased the aflatoxins-induced cytotoxicity in HepG2 cells, and no significant aflatoxin-induced cytotoxicity was observed at UV-A dose of 1,200 mJ/cm2. Further results from this study will be used to compare aflatoxins detoxification kinetics and mechanisms involved in liquid foods such as milk and vegetable oils.
Asunto(s)
Aflatoxinas/análisis , Rayos Ultravioleta/efectos adversos , Purificación del Agua/métodos , Aflatoxina B1/análisis , Aflatoxina B1/toxicidad , Aflatoxina M1/análisis , Aflatoxina M1/toxicidad , Aflatoxinas/toxicidad , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida/métodos , Células Hep G2 , Humanos , Cinética , Espectrometría de Masas en Tándem/métodos , AguaRESUMEN
Peanut allergy is usually lifelong and accidental exposure impose formidable risk. The aim of this study was to assess the capacity of peanut proteins complexed to polyphenol extracts to reduce allergic response in C3H/HeJ mice. Mice were sensitized to peanut flour followed by exposure to amino acid diets fortified with peanut protein-polyphenol aggregates of either with low (15%; w/w) or high (40%; w/w) complexation ratios of blueberry (BB-Low and BB-High) and cranberry (CB-Low and CB-High) extracts. Treatment groups on diets with high complexation ratios of blueberry and cranberry aggregates showed significant reduction in peanut specific plasma Immunoglobulin E (IgE). Western blot analysis of spleen lysates showed CD63 protein expression was reduced in a dose-dependent manner in blueberry and cranberry complexed peanut protein supplemented diet groups. Our results demonstrate for the first time that complexation of polyphenols to peanut flour can potentially lower plasma IgE of peanut-sensitized C3H/HeJ mice.
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Arachis/química , Arachis/inmunología , Inmunoglobulina E/inmunología , Hipersensibilidad al Cacahuete/prevención & control , Proteínas de Plantas/química , Proteínas de Plantas/inmunología , Polifenoles/química , Animales , Femenino , Ratones , Ratones Endogámicos C3H , Especificidad de la EspecieRESUMEN
This study investigates the anti-allergic properties of peanut skin polyphenols (PSP)-enriched peanut (PN) protein aggregates. PSP was blended with PN flour at concentrations of 5, 10, 15, 30, and 40% (w/w). Rat basophil leukemia cells (RBL-2H3) were sensitized with either anti-DNP-IgE or PN-allergic plasma followed by co-exposure to unmodified PN flour (control) or PSP-PN protein aggregates and Ca2+ ionophore, ionomycin. Immunoblotting and staining were performed to measure the IgE binding capacity of PSP-PN aggregates. Results showed that 30% PSP-PN aggregate significantly reduced ß-hexosaminidase and histamine levels by 54.2% and 49.2%, respectively compared with control. Immunoblotting results revealed 40% PSP-PN aggregates significantly decreased IgE binding by 19%. The phosphorylation of p44/42 MAPK was significantly reduced while phosphorylation of p38 MAPK and SAPK/JNK increased upon PSP-PN protein aggregate exposure to the cells. Our results show that aggregation of PSP to PN proteins reduces allergic response by inhibiting Ca2+-induced MAPK-dependent cell degranulation.
Asunto(s)
Arachis/química , Degranulación de la Célula/efectos de los fármacos , Inmunoglobulina E/inmunología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Polifenoles/farmacología , Alérgenos/inmunología , Alérgenos/metabolismo , Animales , Arachis/metabolismo , Basófilos/citología , Basófilos/efectos de los fármacos , Basófilos/metabolismo , Línea Celular Tumoral , Ensayo de Inmunoadsorción Enzimática , Histamina/metabolismo , Inmunoglobulina E/análisis , Proteínas de Plantas/inmunología , Proteínas de Plantas/metabolismo , Polifenoles/química , RatasRESUMEN
In this proof-of-concept study, the efficacy of a medium-pressure UV (MPUV) lamp source to reduce the concentrations of aflatoxin B1, aflatoxin B2, and aflatoxin G1 (AFB1, AFB2, and AFG1) in pure water is investigated. Irradiation experiments were conducted using a collimated beam system operating between 200 to 360 nm. The optical absorbance of the solution and the irradiance of the lamp are considered in calculating the average fluence rate. Based on these factors, the UV dose was quantified as a product of average fluence rate and treatment time. Known concentrations of aflatoxins were spiked in water and irradiated at UV doses ranging from 0, 1.22, 2.44, 3.66, and 4.88 J cm-2. The concentration of aflatoxins was determined by HPLC with fluorescence detection. LC-MS/MS product ion scans were used to identify and semi-quantify degraded products of AFB1, AFB2, and AFG1. It was observed that UV irradiation significantly reduced aflatoxins in pure water (p < 0.05). Irradiation doses of 4.88 J cm-2 reduced concentrations 67.22% for AFG1, 29.77% for AFB2, and 98.25% for AFB1 (p < 0.05). Using this technique, an overall reduction of total aflatoxin content of ≈95% (p < 0.05) was achieved. We hypothesize that the formation of ËOH radicals initiated by UV light may have caused photolysis of AFB1, AFB2, and AFG1 molecules. In cell culture studies, our results demonstrated that the increase of UV dosage decreased the aflatoxin-induced cytotoxicity in HepG2 cells. Therefore, our research finding suggests that UV irradiation can be used as an effective technique for the reduction of aflatoxins.
Asunto(s)
Aflatoxinas/efectos de la radiación , Aflatoxina B1/análisis , Aflatoxina B1/efectos de la radiación , Aflatoxinas/análisis , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Humanos , Espectrometría de Masas en Tándem , Rayos UltravioletaRESUMEN
Herein, we investigated the effects of grape pomace (GP) in diet on body weight, blood lipid profile, and expression of liver genes associated with lipid metabolism using a young rat model. In this study, twenty female Sprague-Dawley rats at 7 weeks of age were randomly divided into 4 groups, which were fed modified AIN-93G diets containing 0% (control), 6.9%, 13.8%, and 20.7% of GP for 10 weeks. Feed consumption and body weight were weekly determined. Blood samples were obtained at the beginning and end of the feeding period for cholesterol, alanine aminotransferase (ALT), and glucose analysis. At the end of the feeding period, all rats were fasted overnight and euthanized. Heart, kidney, and liver samples were obtained and weighed. Liver tissues were used for gene expression analysis. GP-containing diet did not influence the body weight of the rats. As GP content increased, blood triglyceride and very low density lipoprotein (VLDL) decreased (P < 0.05), high density lipoprotein (HDL) slightly increased but was not statistically significant, total cholesterol (TC) and low density lipoprotein (LDL) significantly increased (P < 0.05), blood glucose decreased, and ALT level slightly increased. The expressions of liver genes associated with fatty acid synthesis and lipid hydrolysis/metabolism were moderately downregulated by the GP diet. The study suggests that regular consumption of a diet containing appropriate amount of GP may help in the reduction of body fat accumulation and prevention of obesity. This is the first study revealing the change in gene expression caused by long-term consumption of GP-containing diet.
Asunto(s)
Lípidos/sangre , Hígado/metabolismo , Vitis/metabolismo , Factores de Edad , Alanina Transaminasa/genética , Alanina Transaminasa/metabolismo , Animales , Glucemia/metabolismo , HDL-Colesterol/sangre , VLDL-Colesterol/sangre , Metabolismo de los Lípidos , Lípidos/química , Hígado/enzimología , Masculino , Ratas , Ratas Sprague-Dawley , Triglicéridos/sangre , Residuos/análisisRESUMEN
Peanut allergy is a worldwide health concern. In this study, the natural binding properties of plant-derived polyphenols to proteins was leveraged to produce stable protein-polyphenol complexes comprised of peanut proteins and cranberry (Vaccinium macrocarpon Ait.) or lowbush blueberry (Vaccinium angustifolium Ait.) pomace polyphenols. Protein-bound and free polyphenols were characterized and quantified by multistep extraction of polyphenols from protein-polyphenol complexes. Immunoblotting was performed with peanut-allergic plasma to determine peanut protein-specific IgE binding to unmodified peanut protein, or to peanut protein-polyphenol complexes. In an allergen model system, RBL-2H3 mast cells were exposed to peanut protein-polyphenol complexes and evaluated for their inhibitory activity on ionomycin-induced degranulation (ß-hexosaminidase and histamine). Among the evaluated polyphenolic compounds from protein-polyphenol complex eluates, quercetin, - in aglycone or glycosidic form - was the main phytochemical identified to be covalently bound to peanut proteins. Peanut protein-bound cranberry and blueberry polyphenols significantly decreased IgE binding to peanut proteins at p < 0.05 (38% and 31% decrease, respectively). Sensitized RBL-2H3 cells challenged with antigen and ionomycin in the presence of protein-cranberry and blueberry polyphenol complexes showed a significant (p < 0.05) reduction in histamine and ß-hexosaminidase release (histamine: 65.5% and 65.8% decrease; ß-hexosaminidase: 60.7% and 45.4% decrease, respectively). The modification of peanut proteins with cranberry or blueberry polyphenols led to the formation of peanut protein-polyphenol complexes with significantly reduced allergenic potential. Future trials are warranted to investigate the immunomodulatory mechanisms of these protein-polyphenol complexes and the role of quercetin in their hypoallergenic potential.
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Alérgenos/inmunología , Arachis/inmunología , Degranulación de la Célula/efectos de los fármacos , Inmunoglobulina E/inmunología , Mastocitos/efectos de los fármacos , Hipersensibilidad al Cacahuete/tratamiento farmacológico , Extractos Vegetales/farmacología , Proteínas de Plantas/inmunología , Polifenoles/farmacología , Vaccinium/química , Frutas/química , Humanos , Mastocitos/inmunología , Mastocitos/fisiología , Hipersensibilidad al Cacahuete/inmunologíaRESUMEN
Proanthocyanidins are oligomeric flavonoids found in plant sources, most notably in apples, cinnamon, grape skin and cocoa beans. They have been also found in substantial amounts in cranberry, black currant, green tea, black tea and peanut skins. These compounds have been recently investigated for their health benefits. Proanthocyanidins have been demonstrated to have positive effects on various metabolic disorders such as inflammation, obesity, diabetes and insulin resistance. Another upcoming area of research that has gained widespread interest is microRNA (miRNA)-based anticancer therapies. MicroRNAs are short non-coding RNA segments, which plays a crucial role in RNA silencing and post-transcriptional regulation of gene expression. Currently, miRNA based anticancer therapies are being investigated either alone or in combination with current treatment methods. In this review, we summarize the current knowledge and investigate the potential of naturally occurring proanthocyanidins in modulating miRNA expression. We will also assess the strategies and challenges of using this approach as potential cancer therapeutics.
RESUMEN
Peanut skin is a rich source of polyphenols, such as proanthocyanidins. Peanut skin proanthocyanidins mainly consist of a subgroup called procyanidins. Peanut-based procyanidins contain oligomers of both type A and type B procyanidins. Recent studies have shown that peanut skin extracts exert protection against hepatic steatosis induced on rats fed with a high-fat diet. Studies have shown that proanthocyanidins protect against cardiovascular diseases (CVDs). The mechanism of CVD protection and hypolipidemic effect of peanut skin procyanidins has been gradually revealed in recent years. Due to the high molecular weight of procyanidins, they are not readily absorbed through the gut barrier. It is hypothesized that procyanidins exert their effect by inhibiting the absorption of dietary lipid and chylomicron secretion by enterocytes. In this review, we aim to highlight the hypolipidemic effects of peanut skin polyphenols and discuss the various molecular mechanisms, with which the polyphenols may exert the lipid-lowering function observed by weighing the absorption characteristics as well as gene expression mechanism responsible for lipid homeostasis.
Asunto(s)
Arachis/química , Enfermedades Cardiovasculares/prevención & control , Hipolipemiantes/farmacología , Lípidos/sangre , Extractos Vegetales/farmacología , Polifenoles/farmacología , Proantocianidinas/farmacología , Animales , Disponibilidad Biológica , Enfermedades Cardiovasculares/sangre , Humanos , Hipolipemiantes/farmacocinética , Hipolipemiantes/uso terapéutico , Fitoterapia , Extractos Vegetales/farmacocinética , Extractos Vegetales/uso terapéutico , Polifenoles/farmacocinética , Polifenoles/uso terapéutico , Proantocianidinas/farmacocinética , Proantocianidinas/uso terapéutico , Semillas/químicaRESUMEN
Peanut skin is a rich source of polyphenols including procyanidins and is shown to have hypolipidemic properties. This study investigated the bioavailability of peanut skin polyphenols using a rat model. First, the bioavailability of peanut skin polyphenols in rat plasma was evaluated. Our results showed procyanidin A2 levels in plasma peaked within 30 min of ingestion. The results of a second study show that peanut skin extract supplemented in addition to oil gavage resulted in significant decrease in plasma triglyceride and VLDL within 5h. In the third study, rats were given a Western type diet for 5 weeks with peanut skin extract at a dose of 150 and 300 mg/kg body weight. The main effects observed were lowering of total blood lipid and reduction of the plasma fatty acids profile. Our results suggest that procyanidin A may impart a key role of hypolipidemic effect seen in peanut skin polyphenols.
Asunto(s)
Arachis/química , Hipolipemiantes/farmacocinética , Lípidos/sangre , Extractos Vegetales/farmacocinética , Polifenoles/farmacocinética , Semillas/química , Animales , Disponibilidad Biológica , Ácidos Grasos/sangre , Hipolipemiantes/sangre , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Extractos Vegetales/sangre , Polifenoles/sangre , Proantocianidinas/sangre , Proantocianidinas/farmacocinética , Ratas , Ratas Wistar , Triglicéridos/sangreRESUMEN
Activated carbons are a byproduct from pyrolysis and have value as a purifying agent. The effectiveness of activated carbons is dependent on feedstock selection and pyrolysis conditions that modify their surface properties. Therefore, pecan shell-based activated carbons (PSACs) were prepared by soaking shells in 50% (v/v) HPO or 25 to 50% of KOH-NaHCO followed by pyrolysis at 400 to 700°C under a N atmosphere. Physically activated PSACs were produced by pyrolysis at 700°C under N followed by activation with steam or CO at 700 to 900°C. Physicochemical, surface, and adsorption properties of the PSACs were compared with two commercially available activated carbons. The average mass yield of PSACs with respect to the initial mass of the biomass was about 20 and 34% for physically activated and chemically activated carbons, respectively. Acid-activated carbons exhibited higher surface area, higher bulk density, and lower ash content compared with steam- or CO-activated carbons and the two commercial products. Base activation led to the development of biochar with moderate to high surface area with surface charges suitable for adsorption of anionic species. Regardless of the activation method, PSACs had high total surface area ranging from 400 to 1000 m g, better pore size distribution, and more surface charges than commercial samples. Our results also showed that PSACs were effective in removing inorganic contaminants such as Cu and NO as well as organic contaminants such as atrazine and metolachlor. This study showed that pyrolysis conditions and activation had a large influence on the PSAC's surface characteristics, which can limit its effectiveness as a custom sorbent for targeted water contaminants.
Asunto(s)
Carya , Agua , Adsorción , Carbono/química , Purificación del AguaRESUMEN
Angiogenesis is a process of new blood vessel generation and under pathological conditions, lead to tumor development, progression, and metastasis. Many bioactive components have been studied for its antiangiogenic properties as a preventive strategy against tumor development. This study is focused on the effects of cinnamon extract in modulating the pathway involved in angiogenesis. Human umbilical vein endothelial cells (HUVEC) were treated with cinnamon extract at a concentration of 25 µg/mL for 1, 3, or 6 h followed by treatment with phorbol ester (TPA) at a concentration of 10 nmol/L to induce mitogen-activated protein kinase (MAPK) expression. Results show that cinnamon extract inhibited TPA-induced phosphorylation of MAPK and AKT in a dose-dependent manner. Gene expression results in HUVEC showed that cinnamon extract treatment inhibited TPA induction of protein kinase C, PKCα and PKCη messenger RNA (mRNA) expression in a dose-dependent manner along with suppression of vascular endothelial growth factor receptor 1 (VEGFR1/Flt1) and vascular endothelial growth factor receptor 2 (VEGFR2/KDR/Flk1) mRNA expression. Cinnamon extract was administered to zebrafish embryos during gastrulation at 6-8 h post fertilization (hpf). The embryos were observed for changes in morphology, toxicity, and blood vessel development. The intersegmental vessels in the zebrafish embryos were attenuated and underdeveloped at an effective cinnamon extract dose of 250 µg/mL compared with the DMSO-treated control. Exposure to cinnamon extract for 36 h resulted in gross morphological deformities. The results suggest the effect of cinnamon extract on angiogenesis is mediated by PKC-dependent phosphorylation of MAPK.
RESUMEN
The effect of water soluble polyphenolic extract of peanut skin (PE) was investigated for its hypolipidemic properties in rats on Western diet. Seven-weeks old Wistar rats received control diet (AIN-93G), Western diet with and without a bolus of PE five times a week for 10weeks. Group which received 300mg/kg body weight showed significantly reduced body weight and epididymal fat. Plasma and liver triglyceride (TG) and cholesterol (TC) levels were significantly reduced while faecal secretion of TG and TC was greatly increased upon PE administration. Liver mRNA expression of enzymes involved in fatty acid synthesis, such as fatty acid synthase (FAS), sterol receptor element binding protein (SREBP)-1c, acetyl-CoA carboxylase (ACC1) and lipid uptake genes, such as PPARγ, were decreased, while PPARα was up-regulated by administration of PE. These data suggest that administration of PE may contribute to the improved lipid homoeostasis in rats on diets high in cholesterol and lipids.
Asunto(s)
Arachis/química , Hipolipemiantes/administración & dosificación , Metabolismo de los Lípidos/efectos de los fármacos , Extractos Vegetales/administración & dosificación , Polifenoles/administración & dosificación , Semillas/química , Acetil-CoA Carboxilasa/genética , Acetil-CoA Carboxilasa/metabolismo , Animales , Colesterol/metabolismo , Grasas de la Dieta/administración & dosificación , Evaluación Preclínica de Medicamentos , Humanos , Masculino , PPAR gamma/genética , PPAR gamma/metabolismo , Ratas , Ratas Wistar , Triglicéridos/metabolismoRESUMEN
To explore the role of leptin in PKCß action and to determine the protective potential of PKCß deficiency on profound obesity, double knockout (DBKO) mice lacking PKCß and ob genes were created, and key parameters of metabolism and body composition were studied. DBKO mice had similar caloric intake as ob/ob mice but showed significantly reduced body fat content, improved glucose metabolism, and elevated body temperature. DBKO mice were resistant to high-fat diet-induced obesity. Moreover, PKCß deficiency increased ß-adrenergic signaling by inducing expression of ß1- and ß3-adrenergic receptors (ß-ARs) in white adipose tissue (WAT) of ob/ob mice. Accordingly, p38(MAPK) activation and expression of PGC-1α and UCP-1 were increased in WAT of DBKO mice. Consistent with results of in vivo studies, inhibition of PKCß in WAT explants from ob/ob mice also increased expression of above ß-ARs. In contrast, induction of PGC-1α and UCP-1 expression in brown adipose tissue of DBKO mice was not accompanied by changes in the expression of these ß-ARs. Collectively, these findings suggest that PKCß deficiency may prevent genetic obesity, in part, by remodeling the catabolic function of adipose tissues through ß-ARs dependent and independent mechanisms.
Asunto(s)
Tejido Adiposo Blanco/metabolismo , Obesidad/metabolismo , Proteína Quinasa C/deficiencia , Proteína Quinasa C/metabolismo , Tejido Adiposo Pardo/metabolismo , Animales , Western Blotting , Dieta Alta en Grasa/efectos adversos , Ingestión de Alimentos/genética , Ingestión de Alimentos/fisiología , Genotipo , Técnicas In Vitro , Masculino , Ratones , Ratones Noqueados , Ratones Obesos , Obesidad/inducido químicamente , Obesidad/genética , Consumo de Oxígeno/genética , Consumo de Oxígeno/fisiología , Proteína Quinasa C/genética , Proteína Quinasa C beta , Receptores Adrenérgicos beta/genética , Receptores Adrenérgicos beta/metabolismo , Termogénesis/genética , Termogénesis/fisiología , Triglicéridos/metabolismoRESUMEN
The activity of N-hexanoyl-D-erythro-sphingosine, a C6-ceramide against angiogenesis was tested in vitro and in vivo. The effect of ceramide in inhibiting MCF-7 cancer cells was also determined. The aim of this study was to potentiate the effect of ceramide as anti-angiogenic compound that can regulate tumor induced angiogenesis.C6-ceramide inhibited vascular endothelial growth factor (VEGF)-induced human umbilical vein endothelial cells (HUVEC) tube formation in a dose-dependent manner within 24 hours. Ceramide at concentrations between 12.5 and 25 µM inhibited the viability of MCF-7 cells and reduced VEGF-induced cell migration in 24 hours. At 50 µM, ceramide induced MCF-7 cell death via autophagy as demonstrated by accumulation of MDC in ceramide-treated MCF-7 vacuoles. The expression of VEGF was reduced and the levels of cathepsin D in MCF-7 increased. In vivo, 50 µM ceramide caused a 40% reduction of new vessel formation in the CAM assay within 24 hours. Zebrafish exposed to 100 - 400 µM ceramide had a distinct disruption of blood vessel development at 48 hours post-fertilization. Ceramide-exposed embryos also had primary motoneurons exhibiting abnormal axonal trajectories and ectopic branching. Ceramide induced cell-death was not detected in the zebrafish assay. Collectively, these data indicate that ceramide is a potent anti-angiogenic compound and that the mechanism underlying its anti-angiogenic capabilities does not rely upon the induction of apoptosis.
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Inhibidores de la Angiogénesis/farmacología , Autofagia/efectos de los fármacos , Ceramidas/farmacología , Animales , Apoptosis/efectos de los fármacos , Línea Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Embrión de Pollo , Ensayo de Inmunoadsorción Enzimática , Humanos , Transducción de Señal/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/metabolismo , Pez CebraRESUMEN
The protein kinase C (PKC) family of Ca(2+) and/or lipid-activated serine-threonine protein kinases is implicated in the pathogenesis of obesity and insulin resistance. We recently reported that protein kinase Cß (PKCß), a calcium-, diacylglycerol-, and phospholipid-dependent kinase, is critical for maintaining whole body triglyceride homeostasis. We now report that PKCß deficiency has profound effects on murine hepatic cholesterol metabolism, including hypersensitivity to diet-induced gallstone formation. The incidence of gallstones increased from 9% in control mice to 95% in PKCß(-/-) mice. Gallstone formation in the mutant mice was accompanied by hyposecretion of bile acids with no alteration in fecal bile acid excretion, increased biliary cholesterol saturation and hydrophobicity indices, as well as hepatic p42/44(MAPK) activation, all of which enhance susceptibility to gallstone formation. Lithogenic diet-fed PKCß(-/-) mice also displayed decreased expression of hepatic cholesterol-7α-hydroxylase (CYP7A1) and sterol 12α-hydroxylase (CYP8b1). Finally, feeding a modified lithogenic diet supplemented with milk fat, instead of cocoa butter, both increased the severity of and shortened the interval for gallstone formation in PKCß(-/-) mice and was associated with dramatic increases in cholesterol saturation and hydrophobicity indices. Taken together, the findings reveal a hitherto unrecognized role of PKCß in fine tuning diet-induced cholesterol and bile acid homeostasis, thus identifying PKCß as a major physiological regulator of both triglyceride and cholesterol homeostasis.
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Ácidos y Sales Biliares/metabolismo , Colesterol/metabolismo , Cálculos Biliares/enzimología , Hígado/enzimología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Animales , Ácidos y Sales Biliares/genética , Colesterol/genética , Colesterol 7-alfa-Hidroxilasa/genética , Colesterol 7-alfa-Hidroxilasa/metabolismo , Activación Enzimática/genética , Cálculos Biliares/genética , Masculino , Ratones , Ratones Noqueados , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteínas Proto-Oncogénicas c-akt/genéticaRESUMEN
Metabolic syndrome is common in the general population, but there is little information available on the underlying signaling mechanisms regulating triglyceride (TG) content in the body. In the current study, we have uncovered a role for protein kinase Cbeta (PKCbeta) in TG homeostasis by studying the consequences of a targeted disruption of this kinase. PKCbeta(-/-) mutant mice were considerably leaner and the size of white fat depots was markedly decreased compared with wild-type littermates. TG content in the liver and skeletal muscle of PKCbeta(-/-) mice was also significantly low. Interestingly, mutant animals were hyperphagic and exhibited higher food intake and reduced feed efficiency versus wild type. The protection from obesity involves elevated oxygen consumption/energy expenditure and increased fatty acid oxidation in adipose tissue with concurrent increased mitochondria genesis, up-regulation of PGC-1alpha and UCP-2, and down-regulation of perilipin. The ability of PKCbeta deficiency to promote fat burning in adipocytes may suggest novel therapeutic strategies for obesity and obesity-related disorders.
Asunto(s)
Grasas/metabolismo , Ácidos Grasos/metabolismo , Proteína Quinasa C/metabolismo , Adipocitos/citología , Adipocitos/metabolismo , Adipocitos/ultraestructura , Tejido Adiposo/metabolismo , Tejido Adiposo/ultraestructura , Adiposidad , Animales , Peso Corporal , Dióxido de Carbono/metabolismo , Leptina/sangre , Hígado/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Microscopía Electrónica de Transmisión , Mitocondrias/metabolismo , Mitocondrias/ultraestructura , Músculo Esquelético/metabolismo , Ácido Oléico/metabolismo , Oxidación-Reducción , Consumo de Oxígeno , Proteína Quinasa C/deficiencia , Proteína Quinasa C/genética , Proteína Quinasa C beta , Triglicéridos/metabolismoRESUMEN
The potential cytotoxic and anti-proliferative activities of ellagic acid (a naturally occurring bioactive compound in berries, grapes, and nuts) was evaluated using human umbilical vein endothelial cells (HUVEC), normal human lung fibroblast cells HEL 299, Caco-2 colon, MCF-7 breast, Hs 578T breast, and DU 145 human prostatic cancer cells. Ellagic acid at concentration in the range 10-100 micromol/L did not affect the viability of normal fibroblast cells during a 24-hour incubation. An increase in adenosine triphosphate (ATP) bioluminescence of approximately 18-21% was observed in normal cells incubated with ellagic acid. In contrast, ellagic acid at 1-100 micromol/L dose-dependently inhibited HUVEC tube formation and proliferation on a reconstituted extracellular matrix and showed strong anti-proliferative activity against the colon, breast, and prostatic cancer cell lines investigated. The most sensitive cells were the Caco-2, and the most resistant were the breast cancer cells. Ellagic acid induced cancer cell death by apoptosis as shown by the microscopic examination of cell gross morphology. Ellagic acid induced reduced cancer cell viability as shown by decreased ATP levels of the cancer cells. After 24 hours incubation of 100 micromol/L of ellagic acid with Caco-2, MCF-7, Hs 578T, and DU 145 cancer cells, ellagic acid suppressed fetal bovine serum (FBS) stimulation of cell migration. The apoptosis induction was accompanied by a decreased in the levels of pro-matrix metalloproteinase-2 (pro-MMP-2 or gelatinase A), pro-matrix metalloproteinase-9 (pro-MMP-9 or gelatinase B), and vascular endothelial growth factor (VEGF(165)) in conditioned media. The results suggest that ellagic acid expressed a selective cytotoxicity and anti-proliferative activity, and induced apoptosis in Caco-2, MCF-7, Hs 578T, and DU 145 cancer cells without any toxic effect on the viability of normal human lung fibroblast cells. It was also observed that the mechanism of apoptosis induction in ellagic acid-treated cancer cells was associated with decreased ATP production, which is crucial for the viability of cancer cells.
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Proliferación Celular/efectos de los fármacos , Ácido Elágico/farmacología , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Humanos , Técnicas In Vitro , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Neovascularización Fisiológica/efectos de los fármacos , Células Tumorales Cultivadas/efectos de los fármacos , Factores de Crecimiento Endotelial Vascular/biosíntesis , Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Inductively coupled plasma analysis of soybean Bowman-Birk inhibitor (BBI) indicated that BBI was a metalloprotein which contained magnesium, calcium, and zinc at 0.40, 0.43 and 0.008 atom/mol BBI, respectively. Heparin-enhanced gelatin zymography, quenched fluorescence substrate hydrolysis analysis, and the Biotrak assay of the interaction of BBI with the matrix metalloproteinase-1 (MMP-1) demonstrated that demineralized BBI at 30 nM inhibited MMP-1 activity whereas mineralized BBI was inhibitory at 115 nM.
Asunto(s)
Metaloproteinasa 1 de la Matriz/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Inhibidor de la Tripsina de Soja de Bowman-Birk/química , Activación Enzimática , Inhibidores Enzimáticos/química , Hidrólisis , Inhibidores de la Metaloproteinasa de la MatrizRESUMEN
Prolamin extracted from rice flour using 55% n-propanol contained protein impurities. Reverse phase high-performance liquid chromatography (HPLC) on a perfusion column R2/H was used to separate rice prolamin from other proteins in less than 5 min. Prolamin eluted as the major peak. The isolated prolamin migrated as a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis using a 4-12% Bis-Tris gel. Matrix-assisted laser desorption ionization mass spectrometry identified the rice prolamin as a 15 013 Da protein. The surface hydrophobicity (S(o)) of the HPLC-separated protein fractions was measured using the hydrophobic fluorescent probe PRODAN. A comparison was made with the surface hydrophobicity (S(o)) of corn prolamin and bovine serum albumin. Surface hydrophobicity values and solubility in 90% ethanol assisted in rice prolamin identification from other chromatographic peaks. The advantage of perfusion chromatography in purifying rice prolamin from other rice proteins included the reduced separation time, the speed at which the separation was carried, and the ability to regenerate the column in a short period of time and allow for more samples to be purified and separated.