Shimada Tsutomu, Tanaka Katsuhiro, Takenaka Shigeo, Foroozesh Maryam K, Murayama Norie, Yamazaki Hiroshi, Guengerich F Peter, Komori Masayuki
Laboratory of Cellular and Molecular Biology, Department of Veterinary Science, Osaka Prefecture University, 1-58 Rinku-Orai-Kita, Izumisano, Osaka 598-8531, USA.
Chem Res Toxicol. 2009 Jul;22(7):1325-33. doi: 10.1021/tx900127s.
Fifty-one chemicals including derivatives of 16 flavonoids, three stilbenes, six pyrenes, seven naphthalenes, seven phenanthrenes, 10 biphenyls, 17beta-estradiol, and estrone were examined for their abilities to induce reverse type I binding spectra with human cytochrome P450 (P450) 1B1 and to inhibit 7-ethoxyresorufin O-deethylation (EROD) activities catalyzed by P450 1B1. Forty-nine chemicals showed reverse type I spectra with P450 1B1, and we found that 3,5,7-trihydroxyflavone, 3',4'-dimethoxy-5,7-dihydroxyflavone, 4'-methoxy-5,7-dihydroxyflavone, alpha- and beta-naphthoflavones, 2,4,3',5'-tetramethoxystilbene, pyrene, and several acetylenic pyrenes and phenanthrenes were strong inducers of the spectra and also potent inhibitors of EROD activities catalyzed by P450 1B1. The spectral dissociation constant (K(s)) and the magnitude of the binding (DeltaA(max)/K(s)) of 49 chemicals were correlated with the inhibition potencies of EROD activities by these chemicals [correlation coefficients (r) of 0.72 and 0.74, respectively]. The K(s) and DeltaA(max)/K(s) values were more correlated with IC(50) values when compared in a group of derivatives of flavonoids, stilbenes, and estrogens (r = 0.81 and 0.88, respectively) or a group of derivatives of pyrenes, naphthalenes, phenanthrenes, and biphenyls (r = 0.88 and 0.91, respectively). Among 14 flavonoids examined, 3,5,7-trihydroxyflavone and 4'-methoxy- and 3',4'-dimethoxy-5,7-dihydroxyflavone were more active than flavone in interacting with P450 1B1, but the respective 7,8-dihydroxyflavones were less active. Pyrene itself was highly active in interacting with P450 1B1, but its binding was slightly decreased when substituted with acetylenic groups. In contrast, substitution of naphthalene with methyl and ethyl propargyl ethers led to more interaction with P450 1B1 than with naphthalene itself. Similarly, substitution on phenanthrene or biphenyl with acetylenic groups and propargyl ethers increased affinities to P450 1B1. These results suggest that the reverse type I binding of chemicals to P450 1B1 may determine how they interact with and inhibit the catalytic activity of the enzyme. Substitutions on the compounds with various acetylenic groups and propargyl ethers cause an increase or decrease of their affinities to P450 1B1, depending on the parent compound used.
对51种化学物质进行了检测，这些物质包括16种黄酮类化合物的衍生物、3种芪类化合物、6种芘类化合物、7种萘类化合物、7种菲类化合物、10种联苯类化合物、17β-雌二醇和雌酮，检测它们诱导人细胞色素P450（P450）1B1产生I型逆向结合光谱的能力以及抑制由P450 1B1催化的7-乙氧基异吩恶唑酮O-脱乙基酶（EROD）活性的能力。49种化学物质与P450 1B1呈现I型逆向光谱，并且我们发现3,5,7-三羟基黄酮、3',4'-二甲氧基-5,7-二羟基黄酮、4'-甲氧基-5,7-二羟基黄酮、α-和β-萘黄酮、2,4,3',5'-四甲氧基芪以及芘和几种炔基芘及菲类化合物是该光谱的强诱导剂，也是P450 1B1催化的EROD活性的有效抑制剂。49种化学物质的光谱解离常数（K(s)）和结合强度（ΔA(max)/K(s)）与这些化学物质对EROD活性的抑制效力相关[相关系数（r）分别为0.72和0.74]。当在一组黄酮类、芪类和雌激素衍生物（r分别为0.81和0.88）或一组芘类、萘类、菲类和联苯类衍生物（r分别为0.88和0.91）中进行比较时，K(s)和ΔA(max)/K(s)值与IC(50)值的相关性更强。在所检测的14种黄酮类化合物中，3,5,7-三羟基黄酮以及4'-甲氧基和3',4'-二甲氧基-5,7-二羟基黄酮在与P450 1B1相互作用时比黄酮更具活性，但相应的7,8-二羟基黄酮活性较低。芘本身在与P450 1B1相互作用时具有高活性，但其结合在被炔基取代时略有降低。相反，萘被甲基和乙基炔丙基醚取代后与P450 1B1的相互作用比萘本身更强。同样，菲或联苯被炔基和炔丙基醚取代后对P450 1B1的亲和力增加。这些结果表明，化学物质与P450 1B1的I型逆向结合可能决定它们如何与该酶相互作用并抑制其催化活性。用各种炔基和炔丙基醚对化合物进行取代会导致它们对P450 1B1的亲和力增加或降低，这取决于所使用的母体化合物。
