Mutagenic and cytotoxic activity of benzol[a]pyrene 4,5-, 7,8-, and 9,10-oxides and the six corresponding phenols.

Abstract

May 27,1975 ABSTRACT The benzo[alpyrene 45-,, 7,8-, and 9,10-ox-ides and the six corresponding phenols (4-, 7-, 9-,, and 10-hydroxybenzo[alpyrene) have' been tested for mutagenic and cytotoxic activity in bacteria and in a mammalian cell culture system. Benzo[alpyIene 4,5-oxide (K-region) was highly mutagenic in two histidine-dependent strains (TA1537 and TA1538) of Salmonella typhimurium which detect frameshift mutagens. In contrast, benzo a1pyrene 7,8-and 9,10-oxides were less than 1% as mutagenic as the 4,5-oxide. Benzo [alpyrene 7,8-and 9,10- Recent studies have indicated that much of the biologic activity of polycyclic aromatic hydrocarbons and the covalent binding of these compounds to macromolecules can be attributed to metabolic products. The end products of aromatic hydrocarbon metabolism, which include phenols, quinones, trans-dihydrodiols, and thiol conjugates, result from reactive arene oxide intermediates (1, 2). The ability of certain K-region arene oxides to bind covalently to DNA (3-5), to induce malignant transformations in cell culture (6-10), and to elicit mutations in both bacteria (11) and in cultured mammalian cells (12), suggests that arene oxides may be proximate or ultimate carcinogens of polycyclic hydrocarbons. Unfortunately, studies with arene oxides have generally been limited to the more stable K-region arene oxides.Since metabolic oxidation of polycyclic hydrocarbons occurs at multiple sites in these molecules, it is important to systematically study the biologic activity of all of the potential metabolites.In this communication, we report the mutagenic properties of the chemically synthesized 4,5-, 7,8-, and 9,10-oxides of benzo[a]pyrene (BP) and the six corresponding phenols (4-, 5-, 7-, 8-, 9-, and 10-hydroxybenzo[a]pyrene) in histidine-dependent auxotrophs of Salmonella typhimurium and in V79 Chinese hamster cells. Neither the bacteria (13) nor the V79 cells (14) contain enzymes that metabolize polycyclic hydrocarbons. We have chosen initially to study the mutagenic properties of BP derivatives because the mutation test systems are generally well characterized, relatively rapid, and provide an index of an interaction of the BP derivatives with genetic material under conditions that result in an altered phenotype.MATERIALS AND METHODS Synthesis and Handling of BP Derivatives. The unequivocal synthesis of the BP 4,5-, 7,8-, and 9,10-oxides (15, 16) and the six corresponding phenols § have been reported, as have structural proofs and criteria of purity. All compounds used in this study were greater than 98% pure. Arene oxides were dissolved in acetone/NH40H (1000:1), while BP and phepols were dissolved in acetone. Derivatives were stored at -900 in amberized glass tubes, and their stability was confirmed prior to each experiment by chromatography on silica gel thin layer sheets (Eastman 13181) using a benzene/chloroform/ethylacetate (1:1:1) solvent system. Decomposition of the arene oxides on silica gel was prevented by adding triethylamine to the solvent system (5% v/v) an...

The Friedreich's ataxia protein frataxin modulates DNA base excision repair in prokaryotes and mammals

“…Benzo[ a ]pyrene 4,5-oxide, a metabolite of benzo[ a ]pyrene, is a well-characterized mutagen [ 39 ] and was tested in both frataxin-overexpressing strains TA1538-hFX and TA104-hFX, as well as the corresponding control strains TA1538-Neo and TA104-Neo. In all strains, a dose-dependent increase in the number of revertants was detected.…”

Induction by cigarette smoke of aryl hydrocarbon hydroxylase activity in the rat kidney and lung1

“…The concept that many chemicals must be activated into reactive metabolites (Ames ef al., 1972, Felton andNebert, 1975;Grover et al, 1971;Heidelberger, 1973 ;Jerina and Daly, 1974;Miller, 1970;Sims and Grover, 1974;Wood et al, 1975) in order to interact with the cellular macromolecules (Baird et al, 1975;Daudel et al, 1975) has directed our attention to the enzymatic systems involved in their biotransformations. The polycyclic hydrocarbons constitute an important class of potentially hazardous chemicals which are ubiquitous in our environment.…”

“…That those epoxides are most likely the ultimate or proximate carcinogens is supported by several experimental facts, such as: (1) their ability to bind covalently to the cellular macromolecules (Baird et al, 1975;Daudel et al, 1975;Miller, 1970); (2) their mutagenic activity in bacteria (Ames, 1972;Felton and Nebert, 1975) and (3) their malignant transformation activity in cell culture (Grover et al, 1971;Heidelberger, 1973). Important differences have been demonstrated regarding the mutagenic as well as the cytotoxic activities of a number of benzo(a)pyrene epoxides (Wood et al, 1975). On the other hand, it is largely documented that the pattern of metabolites produced from a single polycyclic hydrocarbon varies both quantitatively and qualitatively as a function of biological and biochemical parameters such as the activity of the various enzymes involved in the metabolic pathway (Holder et al, 1974;Yang et al, 1975), the polycyclic hydrocarbon used as a substrate (Felton and Nebert, 1975), the animal species or the tissue analyzed .…”

Potential carcinogenic and mutagenic industrial chemicals. I. Alkylating agents

“…(Bartsch, 1976;Bartsch et al, 1976;Fishbein, 1976a;Malaveille et a!., 1975;McCann et al, 1975aMcCann et al, , 1975bMcCann et al, , 1975cWood et al, 1975). A number of epoxides also transform cells in culture to malignancy (Huberman et al, 1972(Huberman et al, , 1975Wood et al, 1975). By analogy with the biotransformation of arene oxides from aromatic compounds (Daly et al, 1972), it is assumed that aliphatic epoxides (alkene oxides) are active intermediates in the metabolism of alkene compounds.…”

“…In a study of the epidermal carcinogenicity of the epoxy resin monomers bis(2,3-epoxycyclopentyl) ether (1) and 2,2-bis(p-glycidyloxyphenyl)propane (II), which were assessed relative to benzo[o]pyrene by application to the skin of male and female C3H and C57B1/6 mice three times a week for 24 mo, a comparison of dose responses showed that benzo[fl]pyrene was 107 X 10 3 , 161 X 10 3 , and 51 X 10 3 more potent as a skin carcinogen than I, II, or their mixture, respectively (Holland et al, 1979). (Bartsch, 1976;Bartsch et al, 1976;Fishbein, 1976a;Malaveille et a!., 1975;McCann et al, 1975aMcCann et al, , 1975bMcCann et al, , 1975cWood et al, 1975). A number of epoxides also transform cells in culture to malignancy (Huberman et al, 1972(Huberman et al, , 1975Wood et al, 1975).…”