The potential toxicity of fucoidan from Undaria pinnatifida was investigated in vitro and in vivo. By the Ames test, fucoidan showed no mutagenicity up to 500 microL/plate, and inhibited the mutagenicity induced by 4-nitro-quinoline-1-oxide, by up to 71%, compared with controls. In the bone marrow micronucleus test, fucoidan, at all levels tested, did not change the micronucleated polychromatic erythrocyte percentage ratio in mouse bone marrow cells. As an acute in vivo toxicity test, fucoidan from 0 to 2000 mg/kg body weight per day was administered orally to Sprague-Dawley rats for 28 days. No significant toxicological change was induced by fucoidan treatment up to 1000 mg/kg body weight per day in biochemical analyses, hematological analyses, necropsy and liver histopathology. The plasma ALT level was slightly, but significantly, increased in male rats at 2000 mg/kg/day. The consumption of fucoidan from Undaria pinnatifida, up to 1000 mg/kg body weight per day, may be safe in rodents, with no sign of toxicity after up to 28 days of daily administration.

To investigate the hypocholesterolemic mechanism of barley in vivo, six-week-old C57BL/6J mice were fed a high-fat diet (HFD) or high-fat diet containing barley (HFD-B) for seven weeks. Total and LDL cholesterol concentrations were significantly reduced in the HFD-B group while fecal cholesterol and bile acid was increased. Real-time PCR and immunoblot analysis revealed the induction of FXR expression, which in turn suppressed the expression of ASBT and NPC1L1 in the HFD-B group compared with the controls. In the liver, the expression of HMG-CoA reductase was significantly reduced while LDL receptor expression was unaltered in the HFD-B group compared with the controls. Our data suggest that the hypocholesterolemic effects of barley are primarily the result of reduced dietary cholesterol uptake and bile acid resorption. Reduced expression of intestinal ASBT and NPC1L1 may play a key role in the regulation of dietary cholesterol and bile acid metabolism in mice consuming a diet containing barley.

No abstract

No abstract

No abstract