RESUMO
Fucoidan extracted from brown algae has multiple beneficial functions. In this study, we investigated the effects of low-molecular-weight fucoidan (oligo-FO) on renal fibrosis under in vitro and in vivo diabetic conditions, and its molecular mechanisms. Advanced glycation product (AGE)-stimulated rat renal proximal tubular epithelial cells (NRK-52E) and diabetic mice induced by high-fat diet and intraperitoneal injection of streptozotocin and nicotinamide were used. Oligo-FO treatment significantly inhibited anti-high mobility group box 1 (HMGB1)/RAGE/ anti-nuclear factor-kappa B (NF-κB)/transforming growth factor-ß1 (TGF-ß1)/TGF-ß1R/Smad 2/3/fibronectin signaling pathway and HIF-1α activation in AGE-stimulated NRK-52E cells. Conversely, the expression and activity of Sirt-1; the levels of ubiquitin-specific peptidase 22 (USP22), p-AMPK, glucagon-like peptide-1 receptor (GLP-1R), and heme oxygenase-1 (HO-1); and Nrf2 activation were remarkably increased by oligo-FO in AGE-stimulated cells. However, the above effects of oligo-FO were greatly diminished by inhibiting Sirt-1, HO-1, or GLP-1R activity. Similar changes of these pro-fibrotic genes in the kidney and a marked attenuation of renal injury and dysfunction were observed in oligo-FO-treated diabetic mice. These findings indicated that the inhibitory effects of the oligo-FO on diabetes-evoked renal fibrosis are mediated by suppressing TGF-ß1-activated pro-fibrogenic processes via Sirt-1, HO-1, and GLP-1R dependence. Collectively, fucoidan-containing foods or supplements may be potential agents for ameliorating renal diseases due to excessive fibrosis.
Assuntos
Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/genética , Suplementos Nutricionais , Expressão Gênica/efeitos dos fármacos , Receptor do Peptídeo Semelhante ao Glucagon 1/genética , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Rim/patologia , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Fenômenos Fisiológicos da Nutrição/fisiologia , Phaeophyceae/química , Fitoterapia , Polissacarídeos/farmacologia , Sirtuína 1/genética , Sirtuína 1/metabolismo , Animais , Células Cultivadas , Fibrose/tratamento farmacológico , Fibrose/genética , Masculino , Camundongos Endogâmicos C57BL , Peso Molecular , Polissacarídeos/administração & dosagem , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , RatosRESUMO
Antrodia camphorata, unique fungal specie, has been used as a folk medicine in Taiwan for many years. The purpose of this study was to compare the extracts from the solid-state culture of A. camphorata co-fermented with Chinese medicinal herb (AC-CF) with two other extracts from fruiting bodies (AC-FB) or solid-state culture (AC-SS), for their anti-tumor effects in human hepatoma HepG2 cells. We measured in vitro cell proliferation, percentage of apoptosis, population distribution of cell cycles, Western blot analysis of multiple drugs resistance-1 (MDR-1), and apoptosis-related proteins in HepG2 cells treated with three different preparations of A. camphorate extracts. Our results showed that AC-CF had better anti-proliferation effect on human hepatoma HepG2 cells than AC-FB or AC-SS dose-dependently. In addition, AC-CF in combination with anti-tumor agents (mitomycin C or methotrexate) showed better adjuvant anti-tumor effects than AC-FB or AC-SS. We further demonstrated the augmented adjuvant anti-tumor effects of AC-CF not only through down regulation of MDR-1 expression but also through a COX-2 dependent apoptosis pathway, involving down-regulation of COX-2 and p-AKT and up-regulation of PARP-1. In conclusion, in this study, we have demonstrated a novel strategy of fermenting A. camphorata with Chinese medicinal herb (AC-CF), which augmented their anti-tumor effects in human hepatoma HepG2 cells as compared to the traditional ones (AC-FB or AC-SS).