Abstract
Male Sprague-Dawley rats were fed 5% and 25% levels of coconut fiber to examine the effect of fiber on cholesterol metabolism. Rats fed fiber showed a significant lowering of serum total cholesterol and (LDL+VLDL) cholesterol, and an increase in HDL cholesterol. A hypocholesterolemic effect was observed in the aorta and other tissues. There was increased cholesterogenesis in the liver, as was evident from increased incorporation of radioactive acetate into cholesterol and increased activity of β-hydroxy-β-methylglutaryl-coenzyme A reductase (HMG-CoA reductase). Rats fed fiber showed an increased concentration of hepatic bile acids, increased the fecal excretion of neutral sterols and bile acids, and lower release of lipoproteins into the circulation. Increased incorporation of radioactive acetate into hepatic bile acids was also observed in these groups. Activities of plasma lecithin:cholesterol acyl transferase (LCAT) and lipoprotein lipase (LPL) were increased, while glucose-6-phosphate dehydrogenase and malic enzyme showed a decrease, in rats fed the coconut fiber.
