Biological and Pharmaceutical Bulletin
Online ISSN : 1347-5215
Print ISSN : 0918-6158
Effects of Soyasaponins on Lipid Peroxidation through the Secretion of Thyroid Hormones
Yasuko IshiiHisayuki Tanizawa
Author information

2006 Volume 29 Issue 8 Pages 1759-1763


We investigated how soyasaponins (SS), which had been isolated from soybeans (Glycine max Merrill, seeds), influenced lipid peroxidation. The in vivo reduction in hepatic lipid peroxidation in mice intraperitoneally injected with total soyasaponins (TSS) was comparable to that which has been observed for α-tocopherol (VE). However, TSS and its five main constituent saponins (I, II, III, A1, and A2) had a much weaker in vitro inhibitory effect on lipid peroxidation induced by NADPH in mouse liver microsomes than VE. Therefore, we were not able to explain the in vivo effect of SS on lipid peroxidation level through direct antioxidative effects. We also demonstrated that TSS increased the levels of serum thyroid hormones. The effect of serum thyroid hormones on in vitro lipid peroxidation was much stronger than that observed for VE. Furthermore, the effects of TSS on levels of serum thyroid hormones and LPO were markedly decreased by propylthiouracil, an antithyroid drug. These results indicate that the effects of SS on lipid peroxidation levels appear to be mediated through the secretion of thyroid hormones.

Information related to the author
© 2006 The Pharmaceutical Society of Japan
Previous article Next article