Effects of Sodium Alginate or Partially Hydrolyzed LowMolecular Sodium Alginate on Serum and Liver Lipid Levels and Hepatic Lipogenesis in Rats

Male Sprague-Dawlay rats were fed a 0.5% cholesterol diet containing 5% cellulose, sodium alginate (SA) or partially hydrolyzed low-molecular sodium alginate (Low-SA), as dietary fiber source, for 4 weeks. Serum and liver cholesterol concentrations in rats fed the diet containing SA were comparable to those in rats fed the diet containing cellulose. But feeding of Low-SA increased serum and liver cholesterol levels when compared with feeding of SA. Fecal total steroid excretion was decreased in the Low-SA group. The concentration of triglyceride in serum and liver was significantly lower in the SA and Low-SA groups than in the cellulose group. Feeding of SA reduced hepatic fatty acid synthase activity and increased both hepatic carnitine palmitoyltransferase activity and excretion of fecal triglyceride. Low-SA increased only the activity of carnitine palmitoyltransferase. These results suggest that SA and Low-SA exert a triglyceride-lowering effect by the reduction of hepatic lipogenesis and/or the stimulation of fatty acid catabolism, although Low-SA, compared with SA, increased the levels of serum and liver cholesterol through the decrease of fecal steroid excretion.