RESUMO
Metabolic syndrome (MetS) is a multifactorial chronic metabolic disorder that affects approximately one billion people worldwide. Recent studies have evaluated whether targeting the gut microbiota can prevent MetS. This study aimed to assess the ability of dietary fiber to control MetS by modulating gut microbiota composition. Sodium alginate (SA) is a seaweed-derived dietary fiber that suppresses high-fat diet (HFD)-induced MetS via an effect on the gut microbiota. We observed that SA supplementation significantly decreased body weight gain, cholesterol levels, and fat weight, while improving glucose tolerance in HFD-fed mice. SA changed the gut microbiota composition and significantly increased the abundance of Bacteroides. Antibiotic treatment completely abolished the suppressive effects of SA on MetS. Mechanistically, SA decreased the number of colonic inflammatory monocytes, which promote MetS development, in a gut microbiota-dependent manner. The abundance of Bacteroides was negatively correlated with that of inflammatory monocytes and positively correlated with the levels of several gut metabolites. The present study revealed a novel food function of SA in preventing HFD-induced MetS through its action on gut microbiota.
Assuntos
Alginatos/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Síndrome Metabólica/metabolismo , Monócitos/efeitos dos fármacos , Alga Marinha , Animais , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Fibras na Dieta/farmacologia , Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BLRESUMO
The active form of vitamin D3, 1,25(OH)2D3 has been found to exert multiple effects on the suppression of progression of inflammatory bowel disease (IBD). Vitamin D3 has been gathering attention as a therapy for IBD. However, the clinical trials conducted to date revealed that a relatively high dosage of vitamin D3 was required to see a significant therapeutic effect. Thus, effective formulation and delivery of vitamin D3 to colonic inflammatory lesions will be required. Herein we describe the preparation of a nanostructured lipid carrier (NLC) for the encapsulation of 1,25(OH)2D3 for colonic delivery via oral administration. The optimized fabrication procedure enabled the incorporation of 1,25(OH)2D3 in the NLC by minimizing the destruction of chemically unstable 1,25(OH)2D3. The obtained NLCs orally delivered 1,25(OH)2D3 to the colon in mice and maintained a high concentration of 1,25(OH)2D3 in the colonic tissue for at least 12â¯h. The NLC showed multiple effects on the suppression of symptoms of colitis induced by dextran sodium sulfate, namely maintaining crypt structure, reducing the tissue concentration of inflammatory cytokines, suppressing the infiltration of polymorphonuclear leukocytes, and augmenting anti-inflammatory CX3CR1high macrophages. Our NLCs containing 1,25(OH)2D3 may be an alternative treatment for IBD therapy.
Assuntos
Colecalciferol/administração & dosagem , Portadores de Fármacos/química , Doenças Inflamatórias Intestinais/tratamento farmacológico , Lipídeos/química , Nanoestruturas/química , Vitaminas/administração & dosagem , Administração Oral , Animais , Colecalciferol/uso terapêutico , Colo/efeitos dos fármacos , Colo/patologia , Doenças Inflamatórias Intestinais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células RAW 264.7 , Vitaminas/uso terapêuticoRESUMO
Mutations of genes encoding alpha4, beta2, or alpha2 subunits (CHRNA4, CHRNB2, or CHRNA2, respectively) of nAChR [neuronal nicotinic ACh (acetylcholine) receptor] cause nocturnal frontal lobe epilepsy (NFLE) in human. NFLE-related seizures are seen exclusively during sleep and are characterized by three distinct seizure phenotypes: "paroxysmal arousals," "paroxysmal dystonia," and "episodic wandering." We generated transgenic rat strains that harbor a missense mutation S284L, which had been identified in CHRNA4 in NFLE. The transgenic rats were free of biological abnormalities, such as dysmorphology in the CNS, and behavioral abnormalities. The mRNA level of the transgene (mutant Chrna4) was similar to the wild type, and no distorted expression was detected in the brain. However, the transgenic rats showed epileptic seizure phenotypes during slow-wave sleep (SWS) similar to those in NFLE exhibiting three characteristic seizure phenotypes and thus fulfilled the diagnostic criteria of human NFLE. The therapeutic response of these rats to conventional antiepileptic drugs also resembled that of NFLE patients with the S284L mutation. The rats exhibited two major abnormalities in neurotransmission: (1) attenuation of synaptic and extrasynaptic GABAergic transmission and (2) abnormal glutamate release during SWS. The currently available genetically engineered animal models of epilepsy are limited to mice; thus, our transgenic rats offer another dimension to the epilepsy research field.