RESUMO
SCOPE: Wakame is an edible seaweed that is a common constituent in the Japanese diet. Previous studies showed that wakame consumption is associated with the prevention of metabolic syndrome, but the molecular mechanisms underlying the protective effects are poorly understood. METHODS AND RESULTS: To determine if the expression of hepatic genes is affected by ingestion of the brown seaweed Undaria pinnatifida (wakame), rats were fed a diet containing 0, 0.1, or 1.0 g per 100 g dried wakame powder for 28 days. Administration of 1% wakame significantly decreased serum total cholesterol levels. Hepatic gene expression was investigated using DNA microarray analysis, and the results showed that wakame suppresses the lipogenic pathway by downregulating SREBF-1. Moreover, bile acid biosynthesis and gluconeogenesis were promoted by upregulation of the PPAR signaling pathway, which leads to a reduction in the accumulation of cholesterol and promotion of ß-oxidation. CONCLUSIONS: These results suggest that wakame ingestion affects glucose and lipid metabolism by altering the expression of SREBF-1 and PPAR signal-related genes.
Assuntos
Fármacos Antiobesidade/farmacologia , Glucose/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Alga Marinha , Undaria , Administração Oral , Animais , Colesterol/sangue , Suplementos Nutricionais , Regulação da Expressão Gênica/efeitos dos fármacos , Ontologia Genética , Fígado/efeitos dos fármacos , Fígado/fisiologia , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Receptores Ativados por Proliferador de Peroxissomo/genética , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Ratos Sprague-Dawley , Proteína de Ligação a Elemento Regulador de Esterol 1/genéticaRESUMO
It is well known that ultraviolet B irradiation leads to dermal inflammation. In this study, we found that Mekabu fucoidan suppressed edema, decreased the thickness of the prickle cell layer, and decreased matrix metalloproteinase 1 in the skin of mice irradiated with ultraviolet B. Moreover, we found that the mean level of interferon gamma of Mekabu fucoidan-treated, ultraviolet B-irradiated mice (approximately 2.2 ng/mL) was not significantly different from that in normal mice (approximately 2.5 ng/mL). In contrast, a significant decrease in the mean level of interferon gamma (approximately 1.3 ng/mL) in ultraviolet B-irradiated control mice was observed compared with that in Mekabu fucoidan-treated, ultraviolet B-irradiated mice. The mean thickness of the prickle cell layer in the skin of Mekabu fucoidan-treated, ultraviolet B-irradiated mice was less than that in the ultraviolet B-irradiated control mice. Metalloproteinase 1 activity was significantly higher in the skin of ultraviolet B-irradiated mice than in the skin of untreated, nonirradiated normal mice. Metalloproteinase 1 in the skin of ultraviolet B-irradiated, Mekabu fucoidan- or L(+)-ascorbic acid (vitamin C)-treated mice was significantly lower than that in the ultraviolet B-irradiated control mice. Mitigation of the morphological changes in Mekabu fucoidan-treated mice was correlated with a decrease in metalloproteinase 1 levels. These data indicate that Mekabu fucoidan is an effective suppressor of inflammation in an ultraviolet B-irradiated mouse model.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Dermatite/prevenção & controle , Metaloproteinase 13 da Matriz/biossíntese , Polissacarídeos/farmacologia , Pele/efeitos dos fármacos , Raios Ultravioleta , Animais , Anti-Inflamatórios não Esteroides/isolamento & purificação , Ácido Ascórbico/farmacologia , Dieta , Imunidade/efeitos dos fármacos , Terapia de Imunossupressão , Camundongos , Pele/efeitos da radiação , Undaria/químicaRESUMO
Fucoidan from Mekabu (sporophyll of Undaria pinnatifida), a dietary alga, exerts antitumor activity possibly through enhancing the immune response. The present report describes the effects of dietary Mekabu fucoidan on the tumor growth of mouse A20 leukemia cells and on T cell-mediated immune responses in T cell receptor transgenic (DO-11 - 10 - Tg) mice. The animals were fed with a diet containing 1% Mekabu fucoidan (0.034 +/- 0.003 g/mouse/day) for 10 days and subcutaneously (s. c.) inoculated with A20 leukemia cells. Thereafter, the mice were fed with the diet containing fucoidan for 40 days. Mekabu fucoidan inhibited tumors by 65.4 %. We studied how the killer activities of T cell-mediated and natural killer (NK) cells are augmented in DO-11 - 10 mice fed with Mekabu fucoidan. The cytolytic activities of ovalbumin (OVA), which is specific against OVA-transfected A20 (OVA-A20) B lymphoma cells, and NK cells against YAC-1 were significantly enhanced in the mice fed with fucoidan compared with a basic diet. Thus, these findings suggested that Mekabu fucoidan mediates tumor destruction through Th1 cell and NK cell responses.
Assuntos
Anticarcinógenos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Células Matadoras Naturais/efeitos dos fármacos , Fitoterapia , Polissacarídeos/farmacologia , Undaria , Animais , Anticarcinógenos/administração & dosagem , Anticarcinógenos/uso terapêutico , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/uso terapêutico , Apoptose , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/imunologia , Suplementos Nutricionais , Feminino , Células Matadoras Naturais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia , Polissacarídeos/administração & dosagem , Polissacarídeos/uso terapêutico , Organismos Livres de Patógenos Específicos , Células Th1/imunologiaRESUMO
BACKGROUND: We showed that fucoidan, extracted from dietary seaweed, could inhibit tumor growth. However, the mechanism of Mekabu (Sporophyll of Undaria pinnatifida) fucoidan antitumor activity and how it enhances the immune response remains unknown. MATERIALS AND METHODS: We examined the effect of Mekabu fucoidan in P-388 tumor-bearing mice and in T cell-mediated NK cell activity in normal mice. RESULTS: The survival of mice was prolonged when Mekabu fucoidan was administered for 4 days before tumor cell inoculation, compared with non-treated mice. Fucoidan significantly enhanced the cytolytic activity of NK cells and increased the amount of IFN-gamma produced by T cells up to about 2-fold compared with non-treated mice. CONCLUSION: The anti-tumor effect of Mekabu fucoidan appears to be mediated by IFN-gamma-activated NK cells.
Assuntos
Anticarcinógenos/uso terapêutico , Antineoplásicos/uso terapêutico , Células Matadoras Naturais/imunologia , Leucemia P388/tratamento farmacológico , Leucemia P388/imunologia , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Polissacarídeos/uso terapêutico , Undaria , Animais , Esquema de Medicação , Japão , Células Matadoras Naturais/efeitos dos fármacos , Camundongos , Análise de Sobrevida , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Fatores de TempoRESUMO
1. We showed that a nutritional factor was able to attenuate the development of hypertension and its related diseases in stroke-prone spontaneously hypertensive rats (SHRSP). In the present study, the effect of Wakame, an edible brown seaweed, on the development of stroke was examined in SHRSP. 2. We studied the treatment with 5% (w/w in a diet) Wakame powder in salt-loaded (0.5% NaCl in drinking water) SHRSP. Salt-loaded animals treated with 5% cellulose or kaolin were used as controls. Wakame significantly delayed the development of stroke signs (P < 0.05) and significantly improved the survival rate of salt-loaded SHRSP (P < 0.05). There was no significant difference in the elevation of blood pressure among the three groups during the observation period. 3. We isolated fucoxanthin, a carotinoid, from Wakame powder and studied its preventive effect on ischaemic cultured neuronal cell death. Fucoxanthin significantly attenuated neuronal cell injury in hypoxia and re-oxygenation (P < 0.05). 4. Based on these results, we conclude that Wakame has a beneficial effect on cerebrovascular diseases in SHRSP, independent of hypertension. It is possible that fucoxanthin in Wakame may have a preventive effect against ischaemic neuronal cell death seen in SHRSP with stroke.