Reference

Inhibition of the mutagenicity of bay-region diol-epoxides of polycyclic aromatic hydrocarbons by phenolic plant flavonoids

Inhibition of the mutagenicity of bay-region diol-epoxides of polycyclic aromatic hydrocarbons by phenolic plant flavonoids. Huang, Mou Tuan; Wood, Alexander W.; Newmark, Harold L.; Sayer, Jane M.; Yagi, Haruhiko; Jerina, Donald M.; Conney, Allan H. (Dep. Biochem. Drug Metab., Hoffmann-La Roche Inc., Nutley, NJ 07110, USA). Carcinogenesis (London), 4(12), 1631-7 (English) 1983. CODEN: CRNGDP. ISSN: 0143-3334. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) Myricetin [529-44-2], robinetin [490-31-3], and luteolin [491-70-3] inhibited the mutagenic activity resulting from the metabolic activation of benzo[a]pyrene (I) [50-32-8] and (±)-trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene [61443-57-0] by rat liver microsomes. These naturally occurring plant flavonoids and 17 addnl. flavonoids and related derivs. with phenolic hydroxyl groups inhibited the mutagenic activity of (±)-7b,8a-dihydroxy-9a,10a-epoxy-7,8,9,10-tetrahydrobenzo[a]pyren e (B[a]P 7,8-diol-9,10-epoxide-2) [58917-67-2], which is an ultimate mutagenic and carcinogenic metabolite of I. Several flavonoids without phenolic hydroxyl groups of methylated phenolic hydroxyl groups were inactive. The mutagenic activity of 0.05 nmol BP 7,8-diol-9,10-epoxide-2 towards strain TA 100 of Salmonella typhimurium was inhibited 50% by incubation of the bacteria and the diol-epoxide with myricetin (2nmol), luteolin (5 nmol), quercetin [117-39-5] (5 nmol), 7-methoxyquercetin [90-19-7] (5 nmol), rutin [153-18-4] (5 nmol), quercitrin [522-12-3] (5 nmol), delphinidin chloride [528-53-0] (5 nmol), morin [480-16-0] (10 nmol), myricitrin [17912-87-7] (10 nmol), kaempferol [520-18-3] (10 nmol), diosmetin [520-34-3] (10 nmol), fisetin [528-48-3] (10 nmol), or apigenin [520-36-5] (10 nmol). Considerably less antimutagenic activity was obsd. for dihydroquercetin [480-18-2], naringenin [480-41-1], robinin [301-19-9], D-catechin [154-23-4], genistein [446-72-0], kaempferide [491-54-3], and chrysin [480-40-0]. Pentamethoxyquercetin [1247-97-8], tangeretin [481-53-8], nobiletin [478-01-3], 7,8-benzoflavone [604-59-1], 5,6-benzoflavone [6051-87-2], and flavone [525-82-6], which lack free phenolic groups, were inactive. The antimutagenic activity of hydroxylated flavonoids results from their direct interaction with B[a]P 7,8-diol-9,10-epoxide-2 since the rate of disappearance of the diol-epoxide from cell-free solns. in 1:9 dioxane:water was markedly stimulated by myricetin, robinetin, and quercetin. Myricetin was a highly potent inhibitor of the mutagenic activity of bay-region diol-epoxides of I, dibenzo[a,h]pyrene and dibenzo[a,i]pyrene, but higher concns. of myricetin were needed to inhibit the mutagenicity of the chem. less reactive benzo[a]pyrene 4,5-oxide and bay region diol-epoxides of benz[a]anthracene, chrysene, and benzo[c]phenanthrene.

Effect of flavonoids on the platelet adhesiveness in repeatedly bred rats

Effect of flavonoids on the platelet adhesiveness in repeatedly bred rats. Sempinska, Elzbieta; Kostka, Barbara; Krolikowska, Maria; Kalisiak, Elzbieta (Inst. Environ. Res. Bioanal., Med. Acad., Lodz, Pol.). Pol. J. Pharmacol. Pharm., 29(1), 7-10 (English) 1977. CODEN: PJPPAA. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacodynamics) Decrease of blood platelet adhesiveness in rats by flavonoids was demonstrated by the method of glass wool filter. The antiadhesive activity of isorhamnetin 5,7,4'-trimethyl ether 3B-D-glucoside (I) [16727-54-1] was greater than that of isorhamnetin 3-glucoside [5041-82-7], but these activities were less than that of nobiletin [478-01-3]. The methylation of isorhamnetin-3-glucoside OH groups increased its antiadhesive activity.