Comparison of antiproliferative effects of trichothecene mycotoxins, nivalenol and deoxynivalenol, in cultured cells

摘要

To elucidate the mechanisms underlying the toxicities of nivalenol (NIV) and deoxynivalenol (DON), their potencies on cell proliferation in cultured cells were investigated. Assays were performed after 24 h of treatment. Both toxins re-tarded proliferation of all 4 cell lines tested. NIV was more potent than DON in the human promyelocytic leukemia cell line HL60, the human lymphoblastic leukemia cell line MOLT-4, and the rat aortic myoblast cell line A-10. In contrast, both toxins exhibited almost the same potencies in the human hepatoblastoma cell line HepG2. If both toxins exert their toxicities through the same mechanism, ratios of the 50 % inhibitory concentration (IC_(50)) of DON to NIV are expected to be constant regardless of the types of cells used in the assays. However, the ratios of each IC_(50) varied, indicating differ-ences in the mechanism of action of these toxins.%二バレノール（NIV）とデオキシ二バレノール（DON） の毒性発現機構を解明するために，培養細胞の増殖に 対する両毒素の阻害効果を検討した．毒素処理24時間 後に試験を行った．両毒素は試験に供した4つの培養 細胞の増殖を遅らせた．ヒト前骨髄球白血病細胞HL 60とヒトリンパ芽球白血病細胞MOLT-4，ラット大動 脈筋芽細胞A-10においては，DONよりもNIVの方が 効果が強かった．これに対し，ヒト肝芽腫細胞HepG 2では両毒素ともほぼ同じ効果を示した．もし両毒素rnが同一の毒性発現機構で毒性を発揮しているのであれrnば，細胞の種類にかかわらずDONとNIVの50％阻害rn濃度（IC_(50)）の比は一定になると考えられるが，各々rnの細胞のIC_(50)の比は一様でないことから，両毒素の毒rn性発現機構には違いがあると考えられた．