Substances in the aqueous fraction of cigarette smoke inhibit lipid peroxidation in synaptosomes of rat cerebral cortex.

The effects of water-soluble substances in cigarette smoke on lipid peroxidation were investigated using nerve terminals prepared from the rat cerebral cortex. The prepared smoke-substances significantly reduced the spontaneous increase in thiobarbituric acid-reactive substances in synaptosomes in a dilution factor-dependent manner. Furthermore, the aqueous extract also inhibited the elevation of lipid peroxidation induced by 2,2'-azobis (2-amidinopropane) dihydrochloride, a peroxyl radical generator. Smoke-substances scavenged superoxide radicals generated from stimulated human leukocytes and from the xanthine/xanthine oxidase system. These effects were not mimicked by nicotine. The antioxidant effects of smoke-substances were preserved for several days at 5 degrees or -80 degrees C. The results suggest that the smoke-substances may possess long half-lives and scavenge the radicals which cause lipid-peroxidation in synaptosome membranes.