Effect of Depolymerized Sodium Alginate on the Excretion of Cholesterol from Rats

Abstract

The minimum effective dose and dose response of depolymerized sodium alginate (DSA, average molecular weight of 5×10⁴) on the acceleration of sterol excretion into feces after the oral administration of ³H-cholesterol were investigated with rats. The radioactivity levels of the neutral sterol fraction and acidic sterol fraction were separately determined to elucidate the mechanism for this accelerated sterol excretion.
After administering 100mg of DSA/kg of body weight, the isotope level in the neutral and/or acidic sterol fraction increased on the 1st day after the DSA dose. With a dose of 300mg/kg, the isotope level in the fecal neutral sterol fraction increased, and the absorption of cholesterol was dose-dependently suppressed. The ratio of fecal acidic sterols to absorbed cholesterol during 4 days was also significantly greater in the 300 mg group than in the control group.
These results indicate that the minimum effective dose of DSA to accelerate cholesterol excretion into the feces was 100 mg of DSA/kg of body weight, a dose-response effect being apparent in the cholesterol excretion. DSA had an accelerating effect on the excretion of neutral sterols, and possibly an indirect effect on the metabolism of acidic sterols.