Shimada Hideaki, Ohtaguro Misa, Miura Kazumi, Imamura Yorishige
Faculty of Education, Kumamoto University, 2-40-1, Kurokami, Kumamoto, 860-8555, Japan.
J Enzyme Inhib Med Chem. 2007 Aug;22(4):445-9. doi: 10.1080/14756360601162113.
The inhibitory effects of diesel exhaust components and flavonoids on 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) activity were examined in cytosolic fractions from the liver, kidney and lung of male mice. 9,10-Phenanthrenequinone (9,10-PQ) and 1,2-naphthoquinone (1,2-NQ), which are contained in diesel exhaust particles (DEPs), potently inhibited 20alpha-HSD activity in liver cytosol. 9,10-PQ also inhibited the enzyme activity in lung cytosol. However, 20alpha-HSD activity in kidney cytosol was little inhibited by 9,10-PQ or 1,2-NQ. Flavonoids such as quercetin, fisetin and kaempferol exhibited high inhibitory potencies for 20alpha-HSD activity in liver cytosol, whereas these flavonoids were poor inhibitors for the enzyme activity in kidney cytosol. It is likely that several diesel exhaust components and flavonoids augment the signaling of progesterone in the liver cells, by potently inhibiting 20alpha-HSD activity in mouse liver cytosol. The possibility that there are distinct enzymes catalyzing 20alpha-HSD activity in the non-reproductive tissues of male mice is also discussed.
研究了柴油废气成分和类黄酮对雄性小鼠肝脏、肾脏和肺胞质组分中20α-羟基类固醇脱氢酶（20α-HSD）活性的抑制作用。柴油废气颗粒（DEP）中含有的9,10-菲醌（9,10-PQ）和1,2-萘醌（1,2-NQ）可有效抑制肝脏胞质溶胶中的20α-HSD活性。9,10-PQ也抑制肺胞质溶胶中的酶活性。然而，9,10-PQ或1,2-NQ对肾脏胞质溶胶中的20α-HSD活性几乎没有抑制作用。槲皮素、非瑟酮和山奈酚等类黄酮对肝脏胞质溶胶中的20α-HSD活性表现出高抑制效力，而这些类黄酮对肾脏胞质溶胶中的酶活性是弱抑制剂。几种柴油废气成分和类黄酮可能通过有效抑制小鼠肝脏胞质溶胶中的20α-HSD活性来增强肝细胞中孕酮的信号传导。还讨论了在雄性小鼠的非生殖组织中存在催化20α-HSD活性的不同酶的可能性。
