1992 Volume 33 Issue 6 Pages 593-598_1
Laminaria japonica is one of the major species of marine algae which has been utilized as a foodstuff since ancient times and generally believed to be good for health in Japan. The reason for the apparent benefit of algal foodstuff consumption has remained obscure, though these algae are rich in minerals. We describe in this report the possible desmutagenicity of L. japonica, and we show that L. japonica itself is harmless in terms of mutagenicity tested by Ames' method.
Dried leaves of L. japonica were pulverized and the boiling water extract and the insoluble fraction were prepared. When added to the assay plates with or without rat liver preparation (S-9 mixture), neither fraction caused an increase in the number of revertant colonies of Salmonella typhimurium strains TA98 or TA100. The insoluble fraction of L. japonica reduced the numbers of revertant colonies induced by a variety of mutagens existing in food, such as dinitropyrene, Trp-P-1, Trp-P-2, 2-aminoanthracene, and benzo[a]pyrene, and crude coffee extract. The insoluble fraction of L. japonica, which mainly consists of indigestible dietary fiber, adsorbed dinitropyrene quickly and stably, and may thus prevent the absorption of mutagenic substances present in food.
