BIO-ANTICLASTOGENIC EFFECTS OF UNSATURATED FATTY-ACIDS INCLUDED IN FISH-OIL, DOCOSAHEXAENOIC ACID, DOCOSAPENTAENOIC ACID, AND EICOSAPENTAENOIC ACID, IN CULTURED CHINESE-HAMSTER CELLS

Bio-anticlastogenic effects of unsaturated fatty acids - cis-4,7,10,13 ,16,19-docosahexaenoic acid (DHA), cis-7,10,13,16,19-docosapentaenoic acid (DPA), and cis-5,8,11,14,17-eicosapentaenoic acid (EPA) - on chem ically induced chromosome aberrations were studied in cultured Chinese hamster cells. The induction of chromosome aberrations by the crossli nking agents mitomycin C (MMC) and cisplatin (DDP), the S-N-1 type alk ylating agents N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG), methyl nitr osourea (MNU), and ethyl nitrosourea (ENU), and the S-N-2 type alkylat ing agent ethyl methanesulfonate (EMS), but not by the S-N-1 type alky lating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and the S-N-2 type alkylating agent methyl methanesulfonate (MMS), was suppressed b y post-treatment with DHA, DPA, and EPA. Since there was no opportunit y to inactivate mutagens by desmutagenic mechanisms under the post-tre atment schedule used, the results demonstrate the bio-anticlastogenici ty of unsaturated fatty acids. Suppression by the unsaturated fatty ac ids was observed when cells were treated during the G2 phase, suggesti ng that G2 events were responsible for the bio-anticlastogenic effects . Two saturated fatty acids with the same number of carbons as the stu died unsaturated fatty acids - docosanoic acid and eicosanoic acid - d id not affect chromosome aberration induction, suggesting the necessit y of unsaturation for fatty acid bio-anticlastogenicity.