Affiliations: National Institute of Advanced Industrial Science and
Technology (AIST), Human Stress Signal Research Center, Ikeda 563-8577,
Japan
Note: [] Address for correspondence: Yasukazu Yoshida, AIST, Human Stress
Signal Research Center, 1-8-31 Midorigaoka, Ikeda 563-8577, Japan. Tel.: +81 72
751 8183; Fax: +81 72 751 9964; E-mail: yoshida-ya@aist.go.jp
Abstract: The biological role of lipid peroxidation products has continued to
receive a great deal of attention not only for the elucidation of pathological
mechanisms but also for their practical application to clinical use as
bio-markers. In the last fifty years, lipid peroxidation has been the subject
of extensive studies from the viewpoints of mechanisms, dynamics, product
analysis, involvement in diseases, inhibition, and biological signaling. Lipid
hydroperoxides are formed as the major primary products, however they are
substrates for various enzymes and they also undergo various secondary
reactions. In this decade, F2-isoprostanes from arachidonates and
neuroprostanes from docosahexanoates have been proposed as bio-markers.
Although these markers are formed by a free radical-mediated oxidation, the
yields from the parent lipids are minimal. Compared to these markers,
hydroperoxy octadecadienoates (HPODE) from linoleates and oxysterols from
cholesterols are yielded by much simpler mechanisms from more abundant parent
lipids in vivo. Recently, the method in which both free and ester forms of
hydroperoxides and ketones as well as hydroxides of linoleic acid and
cholesterol are measured as total hydroxyoctadecadienoic acid (tHODE) and
7-hydroxycholesterol (t7-OHCh), respectively, was proposed. The concentrations
of tHODE and t7-OHCh determined by GC-MS analysis from physiological samples
were much higher than that of 8-iso-prostagrandin
F_{2α}. In addition to this advantage, hydrogen-donor
activity of antioxidants in vivo could be determined by the isomeric-ratio of
HODE (9- and 13-(Z,E)-HODE/9- and 13-(E,E)-HODE).
