RESUMEN
The purpose of the present study was to investigate molecular compositions of lipid droplets changing in live hepatic cells stimulated with major fatty acids in the human body, i.e., palmitic, stearic, oleic, and linoleic acids. HepG2 cells were used as the model hepatic cells. Morphological changes of lipid droplets were observed by optical microscopy and transmission electron microscopy (TEM) during co-cultivation with fatty acids up to 5 days. The compositional changes in the fatty chains included in the lipid droplets were analyzed via Raman spectroscopy and chemometrics. The growth curves of the cells indicated that palmitic, stearic, and linoleic acids induced cell death in HepG2 cells, but oleic acid did not. Microscopic observations suggested that the rates of fat accumulation were high for oleic and linoleic acids, but low for palmitic and stearic acids. Raman analysis indicated that linoleic fatty chains taken into the cells are modified into oleic fatty chains. These results suggest that the signaling pathway of cell death is independent of fat stimulations. Moreover, these results suggest that hepatic cells have a high affinity for linoleic acid, but linoleic acid induces cell death in these cells. This may be one of the causes of inflammation in nonalcoholic fatty liver disease (NAFLD).
Asunto(s)
Muerte Celular/efectos de los fármacos , Medios de Cultivo/química , Ácidos Grasos/efectos adversos , Hepatocitos/metabolismo , Gotas Lipídicas/química , Espectrometría Raman , Ácidos Grasos/metabolismo , Células Hep G2 , Hepatocitos/efectos de los fármacos , Hepatocitos/patología , Humanos , Ácido Linoleico/farmacología , Ácido Linoleico/toxicidad , Gotas Lipídicas/metabolismo , Metabolismo de los Lípidos , Microscopía Electrónica de Transmisión , Ácido Oléico/farmacología , Ácido Palmítico/farmacología , Ácido Palmítico/toxicidad , Transducción de Señal/efectos de los fármacos , Ácidos Esteáricos/farmacología , Ácidos Esteáricos/toxicidadRESUMEN
Different fatty acids have distinct effects on the survival of breast cancer cells, which could be mediated by fatty acid binding proteins (FABPs), a family of lipid chaperones. Due to the diverse structures of the members of FABP family, each FABP demonstrates distinct binding affinities to different fatty acids. Of note, FABP7 is predominantly expressed in triple negative breast cancer (TNBC), the most aggressive subtype of breast cancer. Yet, the role of FABP7 in modulating the effects of fatty acids on TNBC survival was unclear. In contrast to the high expression of FABP7 in human TNBC tumours, FABP7 protein was undetectable in TNBC cell lines. Hence, a FABP7 overexpression model was used for this study, in which the transduced TNBC cell lines (MDA-MB-231 and Hs578T) were treated with various mono- and polyunsaturated fatty acids. Oleic acid (OA), docosahexaenoic acid (DHA) and arachidonic acid (AA) inhibited TNBC cell growth at high concentrations, with no differences resulted from FABP7 overexpression. Interestingly, overexpression of FABP7 augmented linoleic acid-induced cell death in MDA-MB-231 cells. The increased cell death may be explained by a decrease in 13-HODE, a pro-tumorigenic oxidation product of linoleic acid. The phenotype was, however, attenuated with a rescue treatment using 25 nM 13-HODE. The decrease in 13-HODE was potentially due to fatty acid partitioning modulated by FABP7, as demonstrated by a 3-fold increase in fatty acid oxidation. Our findings suggest that linoleic acid could be a potential therapeutic strategy for FABP7-overexpressing TNBC patients.
Asunto(s)
Proteína de Unión a los Ácidos Grasos 7/genética , Proteína de Unión a los Ácidos Grasos 7/metabolismo , Ácidos Linoleicos/genética , Ácidos Linoleicos/metabolismo , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/metabolismo , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Araquidonato 15-Lipooxigenasa/genética , Araquidonato 15-Lipooxigenasa/metabolismo , Muerte Celular/genética , Línea Celular Tumoral , Supervivencia Celular/genética , Regulación hacia Abajo , Ácidos Grasos/metabolismo , Humanos , Ácido Linoleico/toxicidad , Gotas Lipídicas/metabolismo , Gotas Lipídicas/ultraestructuraRESUMEN
Microbial biofilms are associated with persistent infections because of their high tolerance to antimicrobial agents and host defenses. The effects of centipede oil from Scolopendra subspinipes mutilans and its main components were investigated to identify non-toxic biofilm inhibitors. Centipede oil and linoleic acid at 20 µg ml-1 markedly inhibited biofilm formation by two fluconazole-resistant Candida albicans strains and three Staphylococcus aureus strains without affecting their planktonic cell growth. Also, both centipede oil and linoleic acid inhibited hyphal growth and cell aggregation by C. albicans. In addition, centipede oil and linoleic acid showed anti-biofilm activities against mixed C. albicans and S. aureus biofilms. Transcriptomic analysis showed that centipede oil and linoleic acid downregulated the expressions of several hypha/biofilm-related genes in C. albicans and α-hemolysin in S. aureus. Furthermore, both compounds effectively reduced C. albicans virulence in a nematode infection model with minimal toxicity.
Asunto(s)
Antiinfecciosos/farmacología , Biopelículas/efectos de los fármacos , Candida albicans/efectos de los fármacos , Ácido Linoleico/farmacología , Aceites Volátiles/farmacología , Staphylococcus aureus/efectos de los fármacos , Animales , Antiinfecciosos/toxicidad , Artrópodos/química , Biopelículas/crecimiento & desarrollo , Caenorhabditis elegans/efectos de los fármacos , Caenorhabditis elegans/microbiología , Candida albicans/crecimiento & desarrollo , Candida albicans/patogenicidad , Hifa/crecimiento & desarrollo , Ácido Linoleico/toxicidad , Pruebas de Sensibilidad Microbiana , Aceites Volátiles/toxicidad , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/patogenicidad , Virulencia/efectos de los fármacosRESUMEN
In this study, we evaluated the ability of Scutellaria baicalensis Georgi to protect lipid-peroxidation (LPO) in lung tissue after free radical-induced injury. We prepared S. baicalensis root (SBR) extracts using different solvents. The total flavonoid and total phenol contents of each extract were measured, and the ROS damage protection was evaluated by analyzing linoleic acid hydroperoxide (LHP)-induced LPO in rat lung mitochondria. Moreover, evaluating diphenylpicrylhydrazyl (DPPH), hydrogen peroxide, superoxide anion radical, and hydroxyl radical scavenging abilities and using metal chelating assays were used to determine in vitro antioxidant activity. The ethyl acetate (EtOAc) extract showed high ROS scavenging ability, and four compounds were subsequently isolated and purified from this extract: baicalin, baicalein, wogonin, and oroxylin A. Baicalein in rat lung mitochondria the most significant LHP-induced LPO inhibition was shown and extracted with EtOAc that contained the highest amount of baicalein. Thus, baicalein and the EtOAc extract of SBR may be efficient in conferring ROS damage protection and inhibiting LHP-induced LPO in rat lung mitochondria. Additional studies are warranted to investigate their use as antioxidant therapy for respiration infections, nutrition supplements, and lead compounds in pharmaceuticals.
Asunto(s)
Peroxidación de Lípido/efectos de los fármacos , Pulmón/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Scutellaria baicalensis/química , Animales , Antioxidantes/farmacología , Flavonoides/química , Flavonoides/aislamiento & purificación , Depuradores de Radicales Libres/química , Humanos , Peróxido de Hidrógeno/toxicidad , Ácido Linoleico/toxicidad , Pulmón/patología , Mitocondrias/patología , Fenoles/química , Fenoles/aislamiento & purificación , Extractos Vegetales/química , Extractos Vegetales/farmacología , Raíces de Plantas/química , Ratas , Ratas WistarRESUMEN
Acute lipolysis of visceral fat or circulating triglycerides may worsen acute pancreatitis (AP)-associated local and systemic injury. The pancreas expresses pancreatic triacylglycerol lipase (PNLIP), pancreatic lipase-related protein 2 (PNLIPRP2), and carboxyl ester lipase (CEL), which may leak into the visceral fat or systemic circulation during pancreatitis. We, thus, aimed to determine the pancreatic lipase(s) regulating lipotoxicity during AP. For this AP, associated fat necrosis was analyzed using Western blot analysis. Bile acid (using liquid chromatography-tandem mass spectrometry) and fatty acid (using gas chromatography) concentrations were measured in human fat necrosis. The fat necrosis milieu was simulated in vitro using glyceryl trilinoleate because linoleic acid is increased in fat necrosis. Bile acid requirements to effectively hydrolyze glyceryl trilinoleate were studied using exogenous or overexpressed lipases. The renal cell line (HEK 293) was used to study lipotoxic injury. Because dual pancreatic lipase knockouts are lethal, exocrine parotid acini lacking lipases were used to verify the results. PNLIP, PNLIPRP2, and CEL were increased in fat necrosis. Although PNLIP and PNLIPRP2 were equipotent in inducing lipolysis and lipotoxic injury, CEL required bile acid concentrations higher than in human fat necrosis. The high bile acid requirements for effective lipolysis make CEL an unlikely mediator of lipotoxic injury in AP. It remains to be explored whether PNLIP or PNLIPRP2 worsens AP severity in vivo.
Asunto(s)
Necrosis Grasa/enzimología , Grasa Intraabdominal/enzimología , Lipasa/metabolismo , Pancreatitis/enzimología , Animales , Necrosis Grasa/inducido químicamente , Necrosis Grasa/genética , Necrosis Grasa/patología , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Grasa Intraabdominal/patología , Ácido Linoleico/toxicidad , Lipasa/genética , Masculino , Ratones , Pancreatitis/inducido químicamente , Pancreatitis/genética , Pancreatitis/patologíaRESUMEN
Cardiac ischemia/reperfusion injury is associated with the formation and action of lipid mediators derived from polyunsaturated fatty acids. Among them, linoleic acid (LA) is metabolized to epoxyoctadecanoic acids (EpOMEs) by cytochrome P450 (CYP) epoxygenases and further to dihydroxyoctadecanoic acids (DiHOMEs) by soluble epoxide hydrolase (sEH). We hypothesized that EpOMEs and/or DiHOMEs may affect cardiac post-ischemic recovery and addressed this question using isolated murine hearts in a Langendorff system. Hearts from C57Bl6 mice were exposed to 12,13-EpOME, 12,13-DiHOME, or vehicle (phosphate buffered sodium; PBS). Effects on basal cardiac function and functional recovery during reperfusion following 20 min of ischemia were investigated. Electrocardiogram (ECG), left ventricular (LV) pressure and coronary flow (CF) were continuously measured. Ischemia reperfusion experiments were repeated after administration of the sEH-inhibitor 12-(3-adamantan-1-yl-ureido)dodecanoic acid (AUDA). At a concentration of 100 nM, both EpOME and DiHOME decreased post-ischemic functional recovery in murine hearts. There was no effect on basal cardiac parameters. The detrimental effects seen with EpOME, but not DiHOME, were averted by sEH inhibition (AUDA). Our results indicate that LA-derived mediators EpOME/DiHOME may play an important role in cardiac ischemic events. Inhibition of sEH could provide a novel treatment option to prevent detrimental DiHOME effects in acute cardiac ischemia.
Asunto(s)
Epóxido Hidrolasas/metabolismo , Ácido Linoleico/toxicidad , Daño por Reperfusión Miocárdica/enzimología , Miocardio/enzimología , Ácidos Oléicos/toxicidad , Función Ventricular Izquierda/efectos de los fármacos , Adamantano/análogos & derivados , Adamantano/farmacología , Animales , Modelos Animales de Enfermedad , Inhibidores Enzimáticos/farmacología , Epóxido Hidrolasas/antagonistas & inhibidores , Preparación de Corazón Aislado , Ácidos Láuricos/farmacología , Ácido Linoleico/metabolismo , Masculino , Ratones Endogámicos C57BL , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/fisiopatología , Ácidos Oléicos/metabolismo , Recuperación de la Función , Transducción de Señal , Presión Ventricular/efectos de los fármacosRESUMEN
Linoleic acid (LA), is the product of secondary metabolism secreted from Microcystis aeruginosa, and it exhibits allelopathic activity against eukaryotic algae. However, information about on the mechanisms associated with the inhibition of algal activity by LA is limited. In this study, Chlorella pyrenoidosa was treated with LA (20-120⯵gâ¯L-1) for 4â¯days, and its growth inhibition and physiological responses were examined for potential toxic mechanisms. The photosynthetic efficiency of C. pyrenoidosa was inhibited by LA treatments, and the Fv/Fm parameter decreased significantly compared to that of controls; however, the photosynthetic pigment content did not change significantly. Peroxidase activity was enhanced, relieving oxidative damage in algae after LA treatments. However, superoxide dismutase and catalase were suppressed, ultimately leading to the aggravation of lipid peroxidation. Transcriptome-based gene expression analysis revealed that the 120⯵gâ¯L-1 LA treatment significantly inhibited the transcription of genes related to photosynthesis, carbon metabolism, and amino acid metabolism in C. pyrenoidosa, suggesting that these genes might be key LA targets in C. pyrenoidosa. Moreover, the expression of genes involved in vitamin, lipid, nitrogen cycling, terpenoid, and ascorbate metabolism was also affected, suggesting that LA inhibits algal cell growth through multiple pathways. The identification of LA-responsive genes in C. pyrenoidosa provides new insight into LA stress responses in eukaryotic algae.
Asunto(s)
Chlorella/efectos de los fármacos , Ácido Linoleico/toxicidad , Contaminantes Químicos del Agua/toxicidad , Catalasa/metabolismo , Peroxidación de Lípido , Microcystis , Fotosíntesis/efectos de los fármacos , Superóxido Dismutasa/metabolismoRESUMEN
Over the past century, soybean oil (SBO) consumption in the United States increased dramatically. The main SBO fatty acid, linoleic acid (18:2), inhibits in vitro the growth of lactobacilli, beneficial members of the small intestinal microbiota. Human-associated lactobacilli have declined in prevalence in Western microbiomes, but how dietary changes may have impacted their ecology is unclear. Here, we compared the in vitro and in vivo effects of 18:2 on Lactobacillus reuteri and L. johnsonii. Directed evolution in vitro in both species led to strong 18:2 resistance with mutations in genes for lipid biosynthesis, acid stress, and the cell membrane or wall. Small-intestinal Lactobacillus populations in mice were unaffected by chronic and acute 18:2 exposure, yet harbored both 18:2- sensitive and resistant strains. This work shows that extant small intestinal lactobacilli are protected from toxic dietary components via the gut environment as well as their own capacity to evolve resistance.
Asunto(s)
Microbioma Gastrointestinal/efectos de los fármacos , Intestino Delgado/microbiología , Lactobacillus johnsonii/efectos de los fármacos , Limosilactobacillus reuteri/efectos de los fármacos , Ácido Linoleico/toxicidad , Aceite de Soja/toxicidad , Animales , Farmacorresistencia Bacteriana , Lactobacillus johnsonii/crecimiento & desarrollo , Limosilactobacillus reuteri/crecimiento & desarrollo , Ratones , Mutación , Selección GenéticaRESUMEN
Nonalcoholic fatty liver is characterized by the abnormal accumulation of triglycerides within hepatocytes, resulting in a steatotic liver. Glucagon-like peptide 1 and its analog exendin-4 can ameliorate certain aspects of this syndrome by inducing weight loss and reducing hepatic triglyceride accumulation, but it is unclear whether these effects result from the effects of glucagon-like peptide 1 on the pancreas, or from direct action on the liver. This study investigated the direct action and putative cellular mechanism of exendin-4 on steatotic hepatocytes in culture. Steatosis was induced in cultured HepG2 human hepatoma cells by incubation in media supplemented with 2 mM each of linoleic acid and oleic acid. Steatotic hepatocytes were then pre-incubated in the protein kinase A inhibitor H89 for 30 min, then treated with exendin-4 over a period of 24 h. Cell viability and triglyceride content were characterized by a TUNEL assay and AdipoRed staining, respectively. Our results showed that steatotic cells maintained high levels of intracellular triglycerides (80%) compared to lean controls (25%). Exendin-4 treatment caused a significant reduction in intracellular triglyceride content after 12 h that persisted through 24 h, while protein kinase A inhibitors abolished the effects of exendin-4. The results demonstrate the exendin-4 induces a partial reduction in triglycerides in steatotic hepatocytes within 12 h via the GLP-1 receptor-mediated activation of protein kinase A. Thus, the reduction in hepatocyte triglyceride accumulation is likely driven primarily by downregulation of lipogenesis and upregulation of ß-oxidation of free fatty acids.
Asunto(s)
Carcinoma Hepatocelular/tratamiento farmacológico , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Hígado Graso/tratamiento farmacológico , Péptido 1 Similar al Glucagón/metabolismo , Péptidos/metabolismo , Ponzoñas/metabolismo , Carcinoma Hepatocelular/inducido químicamente , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Supervivencia Celular/efectos de los fármacos , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Exenatida , Hígado Graso/inducido químicamente , Hígado Graso/metabolismo , Hígado Graso/patología , Péptido 1 Similar al Glucagón/genética , Células Hep G2 , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/patología , Humanos , Isoquinolinas/administración & dosificación , Ácido Linoleico/toxicidad , Lipogénesis/efectos de los fármacos , Lipogénesis/genética , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Ácido Oléico/toxicidad , Páncreas/efectos de los fármacos , Páncreas/microbiología , Péptidos/administración & dosificación , Péptidos/antagonistas & inhibidores , Sulfonamidas/administración & dosificación , Triglicéridos/metabolismo , Ponzoñas/administración & dosificaciónRESUMEN
The biological activities of fatty acids (FAs) can differ with size even for lipids of similar compositions. The aim of this study was to develop size-controlled FA particles and to evaluate their toxicity as a function of size. Well-stabilized nano- and microscale linoleic acid (LA) were fabricated based on specific physical factors. Then, resulting LAs were characterized by size distribution, surface charge, assembly structure, composition, and serum effects. The sizes of the nano- (LAnano) and microscale (LAmicro) LAs, determined by electron microscopy, were 109 nm and 12 µm, respectively. LAnano, a multilamellar structure as determined by cryo-electron microscopy, was rapidly internalized into cells via free fatty acid receptor 3. After internalization, LAnano, but not LAmicro, induced nuclear translocation of fatty acid binding protein 4 (FABP4). Translocation of FABP4 into the nucleus then induced expression of the FA metabolism-related genes InsR and AdipoR1. Their expression was significantly increased in the presence of only LAnano. Cytotoxicity was also significantly increased in cells treated with LAnano, but not LAmicro, as indicated by the endoplasmic reticulum stress markers CHOP and GRP78. Therefore, our results demonstrated that FAs with the same composition but varying in size can cause different cellular responses.
Asunto(s)
Supervivencia Celular/efectos de los fármacos , Estrés del Retículo Endoplásmico/efectos de los fármacos , Ácido Linoleico/química , Ácido Linoleico/toxicidad , Lípidos/análisis , Macrófagos/efectos de los fármacos , Animales , Western Blotting , Células Cultivadas , Microscopía por Crioelectrón , Chaperón BiP del Retículo Endoplásmico , Proteínas de Unión a Ácidos Grasos/genética , Proteínas de Unión a Ácidos Grasos/metabolismo , Citometría de Flujo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Técnicas para Inmunoenzimas , Técnicas In Vitro , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Tamaño de la Partícula , Reacción en Cadena en Tiempo Real de la Polimerasa , Factor de Transcripción CHOP/genética , Factor de Transcripción CHOP/metabolismoRESUMEN
Cyanobacterial mutants defective in acyl-acyl carrier protein synthetase (Aas) secrete free fatty acids (FFAs) into the external medium and hence have been used for the studies aimed at photosynthetic production of biofuels. While the wild-type strain of Synechocystis sp. PCC 6803 is highly sensitive to exogenously added linolenic acid, mutants defective in the aas gene are known to be resistant to the externally provided fatty acid. In this study, the wild-type Synechocystis cells were shown to be sensitive to lauric, oleic, and linoleic acids as well, and the resistance to these fatty acids was shown to be enhanced by inactivation of the aas gene. On the basis of these observations, we developed an efficient method to isolate aas-deficient mutants from cultures of Synechocystis cells by counter selection using linoleic acid or linolenic acid as the selective agent. A variety of aas mutations were found in about 70 % of the FFA-resistant mutants thus selected. Various aas mutants were isolated also from Synechococcus sp. PCC 7002, using lauric acid as a selective agent. Selection using FFAs was useful also for construction of markerless aas knockout mutants from Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002. Thus, genetic engineering of FFA-producing cyanobacterial strains would be greatly facilitated by the use of the FFAs for counter selection.
Asunto(s)
Ligasas de Carbono-Azufre/deficiencia , Eliminación de Gen , Synechococcus/enzimología , Synechocystis/enzimología , Farmacorresistencia Bacteriana , Ácidos Láuricos/toxicidad , Ácido Linoleico/toxicidad , Mutación , Selección Genética , Synechococcus/efectos de los fármacos , Synechococcus/genética , Synechocystis/efectos de los fármacos , Synechocystis/genéticaRESUMEN
Hidden blood loss typically occurs following total hip arthroplasty (THA) and total knee arthroplasty (TKA) and is thought to be related to free fatty acid (FFA). To study the effect of linoleic acid on red blood cells and to examine the pathogenesis of hidden blood loss in vivo, we generated an animal model by injecting linoleic acid into the tail veins of rats. We collected blood samples and determined red blood cell count (RBC) and levels of hemoglobin (Hb), as well as the oxidation and reducing agents in the blood, including glutathione peroxidase (GSH-PX), total superoxide dismutase (T-SOD), hydrogen peroxide (H2O2), and ferryl hemoglobin (Fe4+=O2-), which is generated by the oxidation of Hb. Hidden blood loss occurred when linoleic acid was administered at a concentration of 60 mmol/L; RBC and Hb levels were significantly reduced by 24 h post-injection. This was followed by erythrocyte deformation, reduced activity of GSH-PX and T-SOD, and decreased levels of H2O2. This was accompanied by an increase in ferryl species, which likely contributes to oxidative stress in vivo. Our findings suggest that linoleic acid enhances acute red blood cell injury. Hb and RBC began to increase by 72 h, potentially resulting from linoleic acid metabolism. Thus, elevated levels of linoleic acid in the blood cause acute oxidative damage to red blood cells, eventually leading to partial acute anemia. These findings highlight the pathophysiology underlying hidden blood loss.
Asunto(s)
Anemia/inducido químicamente , Eritrocitos/efectos de los fármacos , Hemoglobinas/metabolismo , Ácido Linoleico/toxicidad , Estrés Oxidativo/efectos de los fármacos , Anemia/sangre , Anemia/patología , Animales , Biomarcadores/sangre , Deformación Eritrocítica/efectos de los fármacos , Eritrocitos/metabolismo , Eritrocitos/patología , Glutatión Peroxidasa/sangre , Peróxido de Hidrógeno/sangre , Inyecciones Intravenosas , Ácido Linoleico/administración & dosificación , Masculino , Oxidación-Reducción , Ratas Sprague-Dawley , Superóxido Dismutasa/sangre , Factores de TiempoRESUMEN
BACKGROUND: Autophagy has emerged as a potentially important factor in the pathogenesis of atherosclerosis. Dehydroepiandrosterone (DHEA) is an adrenal steroid of great recent interest due to its anti-aging and anti-atherogenic effects; however, little is known about its role in autophagy and endothelial senescence. OBJECTIVE: The aim of this study was to investigate whether DHEA prevents linoleic acid (LA)-induced endothelial senescence by enhancing autophagy. MATERIALS/METHODS: After pre-treatement with or without DHEA prior to LA treatment in human aortic endothelial cells (HAECs), the level of senescence was compared by senescence-associated acidic ß-galactosidase (SA-ß-Gal) staining and hyperphosphorylated pRB (ppRB) protein level. Autophagy was detected by LC3 conversion and measuring the level of p62/SQSTM1 (sequestosome 1), a protein degraded by autophagy. The fusion of autophagosome and lysosome was confirmed by fluorescence microscopy. RESULTS: Pre-treatment with DHEA inhibited LA-induced endothelial senescence. DHEA increased the conversion of LC3-I to LC3-II and decreased the level of p62 in a time- and dose-dependent manner. Although both DHEA and LA treatment increased the conversion of LC3-I to LC3-II, treatment of LA increased p62 and decreased fusion of autophagosome and lysosome, which reflected decreased autophagic flux. However, pre-treatment with DHEA restored autophagic flux inhibited by LA. When we evaluated signaling pathways, we found that JNK activation involved in LC3 conversion induced by DHEA. CONCLUSION: DHEA prevents LA-induced endothelial senescence by restoring autophagy and autophagic flux through JNK activation.
Asunto(s)
Autofagia/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Deshidroepiandrosterona/farmacología , Células Endoteliales/efectos de los fármacos , Ácido Linoleico/antagonistas & inhibidores , Ácido Linoleico/toxicidad , Relación Dosis-Respuesta a Droga , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/farmacología , Lisosomas/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Fagosomas/metabolismo , ARN Interferente Pequeño , beta-Galactosidasa/metabolismoRESUMEN
Chitosan is well known for its positive properties in wound healing. Also unsaturated fatty acids are described as able to accelerate tissue repairing mechanisms. In this work hydrophobically modified chitosan was obtained by ionic interaction with either oleic or linoleic acid. In aqueous environment self-assembling into nanoparticles occurred. The presence of hydrophobic domains, similar to those present in polymeric micelles, was demonstrated by changes in pyrene spectra. Both oleate and linoleate derivatives showed mucoadhesion behaviour. Cytotoxicity tests on human dermal fibroblasts demonstrated good biocompatibility of especially oleate derivatives. Clarithromycin, a poorly soluble model drug proposed for use in infected wounds was successfully encapsulated in both oleic and linoleic based polymeric micelles. The ionic structure of the carriers is responsible for their loosening at neutral pH and in the presence of salts. This behaviour should impair parenteral administration of the systems, but can be useful for topical delivery where the micelle components, chitosan and fatty acid, can play a positive role in dermal regeneration and tissue repairing.
Asunto(s)
Quitosano/química , Portadores de Fármacos/química , Ácido Linoleico/química , Ácido Oléico/química , Cicatrización de Heridas , Antibacterianos/administración & dosificación , Antibacterianos/química , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Quitosano/farmacología , Quitosano/toxicidad , Claritromicina/administración & dosificación , Claritromicina/química , Portadores de Fármacos/farmacología , Portadores de Fármacos/toxicidad , Composición de Medicamentos , Fibroblastos/efectos de los fármacos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Ácido Linoleico/farmacología , Ácido Linoleico/toxicidad , Micelas , Nanopartículas , Ácido Oléico/farmacología , Ácido Oléico/toxicidad , Tamaño de la Partícula , Cicatrización de Heridas/efectos de los fármacosRESUMEN
The dairy protein ß-lactoglobulin (ßlg) is known to form a complex with fatty acids (FA). Due to industrial processing, ßlg is often in its non-native form in food products, which can modify the FA/ßlg complex properties. We investigated the interaction of bovine ßlg, in selected structural forms (native ßlg, a covalent dimer and as nanoparticles), with linoleate (C18:2). Using fluorescence and Isothermal Titration Calorimetry, linoleate was found to bind ßlg at two different binding sites. Regardless of the structural state of ßlg, association constants remained in the same order of magnitude. However, the stoichiometry increased up to 6-fold for nanoparticles, compared to that of native ßlg. The impact of these structural changes on linoleate uptake in vitro was measured by cytotoxicity assays on Caco-2 cells. The order of cytotoxicity of linoleate was as follows: free>complexed to dimers>complexed to nanoparticles>complexed to native ßlg. Therefore, the in vitro cytotoxicity of linoleate could be modulated by altering the state of ßlg aggregation, which in turn affects its binding capacity to the FA.
Asunto(s)
Lactoglobulinas/química , Ácido Linoleico/química , Animales , Sitios de Unión , Células CACO-2 , Bovinos , Proliferación Celular/efectos de los fármacos , Dimerización , Humanos , Concentración de Iones de Hidrógeno , Cinética , Lactoglobulinas/metabolismo , Lactoglobulinas/toxicidad , Ácido Linoleico/metabolismo , Ácido Linoleico/toxicidad , Unión Proteica , Pliegue de ProteínaRESUMEN
Alcohol and dietary fat both play an important role in alcohol-mediated multi-organ pathology, including gut and liver. In the present study we hypothesized that the combination of alcohol and dietary unsaturated fat (USF) would result in intestinal inflammatory stress and mucus layer alterations, thus contributing to disruption of intestinal barrier integrity. C57BL/6N mice were fed Lieber-DeCarli liquid diets containing EtOH and enriched in USF (corn oil/linoleic acid) or SF (medium chain triglycerides: beef tallow) for 8 weeks. Intestinal histology, morphometry, markers of inflammation, as well as levels of mucus protective factors were evaluated. Alcohol and dietary USF triggered an intestinal pro-inflammatory response, characterized by increase in Tnf-α, MCP1, and MPO activity. Further, alcohol and dietary USF, but not SF, resulted in alterations of the intestinal mucus layer, characterized by decreased expression of Muc2 in the ileum. A strong correlation was observed between down-regulation of the antimicrobial factor Cramp and increased Tnf-α mRNA. Therefore, dietary unsaturated fat (corn oil/LA enriched) is a significant contributing factor to EtOH-mediated intestinal inflammatory response and mucus layer alterations in rodents.
Asunto(s)
Aceite de Maíz/toxicidad , Enteritis/patología , Etanol/toxicidad , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/patología , Ácido Linoleico/toxicidad , Animales , Aceite de Maíz/administración & dosificación , Grasas Insaturadas en la Dieta/administración & dosificación , Grasas Insaturadas en la Dieta/toxicidad , Enteritis/inducido químicamente , Etanol/administración & dosificación , Ácido Linoleico/administración & dosificación , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Glycidol fatty acid esters (GEs) have been identified as contaminants in refined edible oils. Although the possible release of glycidol (G) from GEs is a concern, little is known about the conversion of GEs to G in the human body. This study addressed the toxicokinetics of glycidol linoleate (GL) and G in male Crl:CD(SD) rats and cynomolgus monkeys. Equimolar amounts of GL (341 mg/kg) or G (75 mg/kg) were administered by gavage to each animal. G was found in both species after the G and GL administration, while plasma GL concentrations were below the lower limit of quantification (5 ng/ml) in both species. In rats, the administration of GL or G produced similar concentration-time profiles for G. In monkeys, the C(max) and AUC values after GL administration were significantly lower than those after G administration. The oral bioavailability of G in monkeys (34.3%) was remarkably lower than that in rats (68.8%) at 75 mg/kg G administration. In addition, plasma G concentrations after oral administration at three lower doses of GL or G were measured in both species. In monkeys, G was detected only at the highest dose of G. In contrast, the rats exhibited similar plasma G concentration-time profiles after GL or G administration with significantly higher G levels than those in monkeys. In conclusion, these results indicate that there are remarkable species differences in the toxicokinetics of GEs and G between rodents and primates, findings that should be considered when assessing the human risk of GEs.
Asunto(s)
Compuestos Epoxi/farmacocinética , Compuestos Epoxi/toxicidad , Ácido Linoleico/farmacocinética , Ácido Linoleico/toxicidad , Ácidos Linoleicos/farmacocinética , Ácidos Linoleicos/toxicidad , Propanoles/farmacocinética , Propanoles/toxicidad , Administración Oral , Animales , Área Bajo la Curva , Disponibilidad Biológica , Diglicéridos/química , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Compuestos Epoxi/sangre , Ácido Linoleico/sangre , Ácidos Linoleicos/sangre , Macaca fascicularis , Masculino , Propanoles/sangre , Ratas , Ratas Sprague-Dawley , Especificidad de la EspecieRESUMEN
PURPOSE: Novel surfactants made of diglutamic acid (DG) polar head linked to lithocholic, arachidonic, linoleic or stearic acids were designed for drug solubilization. METHODS: Surfactants 3-D conformer and packing parameter were determined by molecular modelling and self-assembling properties by pyrene fluorescence measurements. Cytotoxicity was assessed on Human Umbilical Vein Endothelial Cells (HUVEC) and haemolyitic activity on rat red blood cells. Drug solubilization was quantified and its interaction with hydrophobic moieties was characterized using differential scanning calorimetry and X-ray diffraction. Self organisation of stearoyl-DG was observed by cryogenic transmission electron microscopy. Toxicity after repeated injections of stearoyl-DG was investigated in Wistar rats. RESULTS: DG-based surfactants self-assemble into water and their critical micellar concentrations are comprised between 200 and 920 µg/mL. Cytotoxicity and haemolysis were lower than for polysorbate 80. At best, stearoyl-DG solubilized the drug up to 22% (w/w). Solid-state characterization evidenced drug/lipid interactions leading to the formation of a new complex. Stearoyl-DG formed spherical micelles of 20 nm, as predicted by packing parameter calculation. However, it induced a possible liver toxicity after intravenous administration in rats. CONCLUSIONS: Among the surfactants tested, stearoyl-DG is the more efficient for drug solubilization but its use is limited by its possible liver toxicity.
Asunto(s)
Antineoplásicos/química , Ácido Glutámico/análogos & derivados , Ácido Glutámico/toxicidad , Tensoactivos/química , Tensoactivos/toxicidad , Animales , Ácido Araquidónico/química , Ácido Araquidónico/toxicidad , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Ácido Linoleico/química , Ácido Linoleico/toxicidad , Ácido Litocólico/química , Ácido Litocólico/toxicidad , Micelas , Modelos Moleculares , Ratas , Ratas Wistar , Solubilidad , Ácidos Esteáricos/química , Ácidos Esteáricos/toxicidadRESUMEN
Taxa of the Alternaria infectoria species group are the predominant Alternaria spp. found in cereals in Northern Europe. While several pyrones have been isolated from A. infectoria and described as taxonomical markers for species identification, information about the bioactivity of metabolites from the fungus is missing. Bioassay-guided fractionation of rice culture extracts from several strains of A. infectoria linked the observed toxicity of the extracts in MRC-5 cells to free fatty acids, i.e. linoleic acid and alpha-linolenic acid. The fungus also produced a cytotoxic pyrone, which upon isolation and NMR spectroscopic analysis was identified as a mixture of phomenins A and B (approximately 10:1), which have not previously been isolated from an Alternaria species.
Asunto(s)
Alternaria/metabolismo , Contaminación de Alimentos/análisis , Ácido Linoleico/metabolismo , Oryza/microbiología , Ácido alfa-Linolénico/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Medios de Cultivo Condicionados/química , Medios de Cultivo Condicionados/toxicidad , Fibroblastos/efectos de los fármacos , Microbiología de Alimentos , Humanos , Ácido Linoleico/análisis , Ácido Linoleico/toxicidad , Pironas/análisis , Pironas/metabolismo , Pironas/toxicidad , Ácido alfa-Linolénico/análisis , Ácido alfa-Linolénico/toxicidadRESUMEN
An extract of roots of Centaurea diffusa (diffuse knapweed) yielded caryophyllene oxide and linoleic acid which were shown to be phytotoxic. Also isolated were germacrene B, a previously-known phytotoxin as well as the inactive polyene aplotaxene. A combination of these compounds, if transferred to the soil, could be one factor in the invasive behavior of this weed. Contrary to a literature report, 8-hydroxyquinoline was not detected in root exudates of in vitro grown C. diffusa nor could it be identified in the root extract. However, a recent report from a different group maintains that 8-hydroxyquinoline can be released from roots of C. diffusa following a diurnal rhythm.