Abstract
The hypocholesterolemic effects of cellulose, hemicellulose and lignin were examined in rats fed a 0.5% cholesterol-supplemented diet. 1) To compare these effects, diets each containing 3% added cellulose, hemicellulose or lignin in a cholesterol-supplemented basal diet were prepared, and also a 3% cellulose diet without cholesterol was prepared. These diets were given to male S.D. rats for 4 weeks and the latter diet was fed to a control rat group. Lignin showed a tendency to decrease the plasma and liver cholesterol levels. 2) Organo solve (OS-) lignin, obtained by 90% CH3COOH treatment, and exploded (EX-) lignin were prepared, and cellulose, OS-lignin or EX-lignin was mixed at 3% with 0.5% cholesterol-supplemented basal diets. These diets were fed to male S.D. rats for 4 weeks. The EX-lignin preparation significantly prevented the elevation of plasma cholesterol. 3) To confirm the relationship between the molecular weight of lignin and its cholesterol-reducing effect, EX-lignin was separated in o three fractions according to molecular size, i. e., high-molecular-weight (HM-), middlemolecular-weight (MM-), and low-molecular-weight (LM-) lignin. Diets, each containing cellulose, hemicellulose, EX-lignin, HM-lignin, MM-lignin or LM-lignin (2% level) were fed for 3 weeks, and to one group, liriodendrin (syringaresinol-diglucoside), extracted from the tulip-tree, was added to the basal diet at 0.5%, as this compound is a derivative of lignin and its molecular weight was smaller than that of LM-lignin. Only LM-lignin showed depression of plasma and liver cholesterols, confirming that molecular size has some relationship to this effect.
