Antioxidative Functions of Natto, A Kind of Fermented Soybeans:  Effect on LDL Oxidation and Lipid Metabolism in Cholesterol-Fed Rats

Abstract

Natto water-soluble fractions, low-molecular-weight viscous substance, and soybean water extract, which had an inhibitory effect on the oxidation of low-density lipoproteins (LDL) in vitro, were fed to rats for 3 weeks. These fractions had no influence on the growth of rats, which were fed a basal diet containing 1% cholesterol, but lowered plasma triglyceride and total cholesterol. Inhibition of copper-oxidation of plasma and LDL ex vivo, and a reduction in lipid peroxidation in liver and aorta in vivo, were also observed. The antioxidant enzymes were not induced in rats fed natto fraction diets. These results demonstrate that ingestion of the natto fractions led to inhibition of LDL oxidation, and that the fractions perform direct antioxidant action in the body. It is suggested that natto fractions might help to prevent arteriosclerosis, as they appear to reduce lipid peroxidation and improve lipid metabolism.

Effect of Cheonggukjang Made from Sword Bean on Serum Lipid Profile and Tissue Change in Rats

“…Given the results, it was confirmed that the intake of CS diet would be superior lowering TG than that of TC diet. This result was similar to the reduced effect of TG by soy protein intake reported to the existing (Iwai et al, 2002;Liao et al, 2007). Especially, according to Liao et al, it determined that protein ingredient in soybean had an effect on the serum TG reduction (Liao et al, 2007).…”

“…For example, the obesity by the increase of TG concentration and the circulatory disease (Arteriosclerosis and Table 5 Effects of experimental diets on serum TG/PL, T-C/PL or T-C/HDL-C and LDL-C/HDL-C ratios in rats See footnote Table 1 2) a-f: Means with the same letter superscript in histograms are not significantly different at the 5% level by Duncan's multiple range test heart disease etc.) by increase of T-C and LDL-C can be given (Ando et al, 1998;Iwai et al, 2002). However, the rats fed on Cheonggukjang increased HDL-C and decreased for LDL-C, TG, and T-C.…”

Changes in the Radical Scavenging Activity of Bacterial-Type Douchi, a Traditional Fermented Soybean Product, during the Primary Fermentation Process

“…22) This indicates that molecules other than isoflavones might have synergistic effects on the in vivo antioxidant enzyme induction of tofu. Moreover, aqueous extracts of natto and tempeh also have strong antioxidant potential in vivo, 23,24) while soybean protein inhibits lipid peroxidation in the plasma. 25) Our results indicate that peptides and amino acids were liberated during douchi fermentation, and that the antioxidant activity of the douchi depended on the increase in peptides with fermentation, rather than on the increase in isoflavone aglycons.…”

Treatment of Natto, a Fermented Soybean Preparation, to Prevent Excessive Plasma Vitamin K Concentrations in Patients Taking Warfarin

“…Recent surveys have demonstrated that isoflavones in soybeans act as antioxidants (11,12), improve lipoprotein profiles (13), delay osteoporosis in the elderly (14,23) and may protect against cancer (15). These effects are independent of vitamin K action as a cofactor of ␥-glutamyl carboxylase.…”