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Effect of co-existing biologically relevant molecules and ions on DNA photocleavage caused by pyrene and its derivatives.

Wang S, Yu H - Int J Environ Res Public Health (2005)

Bottom Line: Riboflavin, histidine, and mannitol enhance DNA photocleavage by all three compounds, except that mannitol has no effect on the photocleavage of DNA by pyrene.NAD enhances the DNA photocleavage by 1-AP, but has no effect on that by 1-HP and pyrene.These results show that the co-existing chemicals may have a profound effect on the toxicity of PAHs, or possibly on the toxicity of many other chemicals.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Jackson State University, Jackson, MS 39217, USA.

ABSTRACT
Inorganic ions, coenzymes, amino acids, and saccharides could co-exist with toxic environmental chemicals, such as polycyclic aromatic hydrocarbons (PAHs), in the cell. The presence of these co-existing chemicals can modulate the toxicity of the PAHs. One of the genotoxic effects by PAHs is light-induced cleavage, or photocleavage, of DNA. The effect of inorganic ions I-, Na+, Ca2+, Mg2+, Fe3+, Mn2+, Cu2+, and Zn2+ and biological molecules riboflavin, histidine, mannitol, nicotinamide adenine dinucleotide (NAD), glutathione, and glutamic acid on the DNA photocleavage by pyrene, 1-hydroxypyrene (1-HP), and 1-aminopyrene (1-AP), is studied. The non-transition metal ions Na+, Ca2+, and Mg2+, usually have very little inhibitory effects, while the transition metal ions Fe3+, Cu2+, and Zn2+ enhance, Mn2+ inhibits the DNA photocleavage. The effect by biological molecules is complex, depending on the photochemical reaction mechanisms of the compounds tested (1-AP, 1-HP and pyrene) and on the chemical nature of the added biological molecules. Riboflavin, histidine, and mannitol enhance DNA photocleavage by all three compounds, except that mannitol has no effect on the photocleavage of DNA by pyrene. Glutathione inhibits the DNA photocleavage by 1-AP and 1-HP, but has no effect on that by pyrene. NAD enhances the DNA photocleavage by 1-AP, but has no effect on that by 1-HP and pyrene. Glutamic acid enhances the DNA photocleavage by 1-AP and pyrene, but inhibits that by 1-HP. These results show that the co-existing chemicals may have a profound effect on the toxicity of PAHs, or possibly on the toxicity of many other chemicals. Therefore, if one studies the toxic effects of PAHs or other toxic chemicals, the effect of the co-existing chemicals or ions needs to be considered.

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Effect of biologically relevant molecules on light-induced DNA cleavage by pyrene. ΦX-174 plasmid DNA (27μM in base pairs) was mixed with 60μM pyrene and various biological chemicals and was irradiated for 1 h with a 100 W UVA lamp. Lane 1 is the dark control and lane 2 is the positive control with pyrene and DNA but without any added chemicals. Lanes 3, 5, 7, 9, 11, and 13 are the mixtures of DNA and pyrene irradiated for 1 h in the presence of riboflavin (5 mM), NAD (5mM), Histidine (5mM), Glutathione (0.5mM), Mannitol (0.5mM), and Glutamic acid (0.5mM), respectively. Lanes 4, 6, 8, 10, 12, 14 are the same as 3, 5, 7, 9, 11, and 13, respectively, but without pyrene.
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f2-ijerph-02-00132: Effect of biologically relevant molecules on light-induced DNA cleavage by pyrene. ΦX-174 plasmid DNA (27μM in base pairs) was mixed with 60μM pyrene and various biological chemicals and was irradiated for 1 h with a 100 W UVA lamp. Lane 1 is the dark control and lane 2 is the positive control with pyrene and DNA but without any added chemicals. Lanes 3, 5, 7, 9, 11, and 13 are the mixtures of DNA and pyrene irradiated for 1 h in the presence of riboflavin (5 mM), NAD (5mM), Histidine (5mM), Glutathione (0.5mM), Mannitol (0.5mM), and Glutamic acid (0.5mM), respectively. Lanes 4, 6, 8, 10, 12, 14 are the same as 3, 5, 7, 9, 11, and 13, respectively, but without pyrene.

Mentions: DNA photocleavage induced by the combination of 1-AP, 1-HP, or pyrene and light were carried out in the presence of some biologically important molecules. The rationale is that PAHs in the cell are likely to co-exist with these molecules and these molecules may affect the ability of PAHs to cause DNA photocleavage. Except riboflavin, which by itself can cause DNA photocleavage, all the other chemicals, histidine (5mM), mannitol (0.5mM), NAD (5mM), glutathione (0.5mM), and glutamic acid (0.5 mM) do not cause DNA cleavage upon light irradiation under these experimental conditions. The effect of these chemicals on DNA photocleavage is different for 1-AP, 1-HP or pyrene (Figure 2, Table 2). With 1-AP, all chemicals except glutathione, which inhibits the DNA photocleavage completely, enhance DNA photocleavage. For 1-HP, riboflavin, histidine and mannitol enhance DNA photocleavage, while glutathione and glutamic acid inhibit and NAD has no effect on DNA photocleavage. For pyrene, riboflavin, histidine and glutamic acid enhance DNA photocleavage, while NAD, glutathione, and mannitol have no effect on DNA photocleavage.


Effect of co-existing biologically relevant molecules and ions on DNA photocleavage caused by pyrene and its derivatives.

Wang S, Yu H - Int J Environ Res Public Health (2005)

Effect of biologically relevant molecules on light-induced DNA cleavage by pyrene. ΦX-174 plasmid DNA (27μM in base pairs) was mixed with 60μM pyrene and various biological chemicals and was irradiated for 1 h with a 100 W UVA lamp. Lane 1 is the dark control and lane 2 is the positive control with pyrene and DNA but without any added chemicals. Lanes 3, 5, 7, 9, 11, and 13 are the mixtures of DNA and pyrene irradiated for 1 h in the presence of riboflavin (5 mM), NAD (5mM), Histidine (5mM), Glutathione (0.5mM), Mannitol (0.5mM), and Glutamic acid (0.5mM), respectively. Lanes 4, 6, 8, 10, 12, 14 are the same as 3, 5, 7, 9, 11, and 13, respectively, but without pyrene.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814707&req=5

f2-ijerph-02-00132: Effect of biologically relevant molecules on light-induced DNA cleavage by pyrene. ΦX-174 plasmid DNA (27μM in base pairs) was mixed with 60μM pyrene and various biological chemicals and was irradiated for 1 h with a 100 W UVA lamp. Lane 1 is the dark control and lane 2 is the positive control with pyrene and DNA but without any added chemicals. Lanes 3, 5, 7, 9, 11, and 13 are the mixtures of DNA and pyrene irradiated for 1 h in the presence of riboflavin (5 mM), NAD (5mM), Histidine (5mM), Glutathione (0.5mM), Mannitol (0.5mM), and Glutamic acid (0.5mM), respectively. Lanes 4, 6, 8, 10, 12, 14 are the same as 3, 5, 7, 9, 11, and 13, respectively, but without pyrene.
Mentions: DNA photocleavage induced by the combination of 1-AP, 1-HP, or pyrene and light were carried out in the presence of some biologically important molecules. The rationale is that PAHs in the cell are likely to co-exist with these molecules and these molecules may affect the ability of PAHs to cause DNA photocleavage. Except riboflavin, which by itself can cause DNA photocleavage, all the other chemicals, histidine (5mM), mannitol (0.5mM), NAD (5mM), glutathione (0.5mM), and glutamic acid (0.5 mM) do not cause DNA cleavage upon light irradiation under these experimental conditions. The effect of these chemicals on DNA photocleavage is different for 1-AP, 1-HP or pyrene (Figure 2, Table 2). With 1-AP, all chemicals except glutathione, which inhibits the DNA photocleavage completely, enhance DNA photocleavage. For 1-HP, riboflavin, histidine and mannitol enhance DNA photocleavage, while glutathione and glutamic acid inhibit and NAD has no effect on DNA photocleavage. For pyrene, riboflavin, histidine and glutamic acid enhance DNA photocleavage, while NAD, glutathione, and mannitol have no effect on DNA photocleavage.

Bottom Line: Riboflavin, histidine, and mannitol enhance DNA photocleavage by all three compounds, except that mannitol has no effect on the photocleavage of DNA by pyrene.NAD enhances the DNA photocleavage by 1-AP, but has no effect on that by 1-HP and pyrene.These results show that the co-existing chemicals may have a profound effect on the toxicity of PAHs, or possibly on the toxicity of many other chemicals.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Jackson State University, Jackson, MS 39217, USA.

ABSTRACT
Inorganic ions, coenzymes, amino acids, and saccharides could co-exist with toxic environmental chemicals, such as polycyclic aromatic hydrocarbons (PAHs), in the cell. The presence of these co-existing chemicals can modulate the toxicity of the PAHs. One of the genotoxic effects by PAHs is light-induced cleavage, or photocleavage, of DNA. The effect of inorganic ions I-, Na+, Ca2+, Mg2+, Fe3+, Mn2+, Cu2+, and Zn2+ and biological molecules riboflavin, histidine, mannitol, nicotinamide adenine dinucleotide (NAD), glutathione, and glutamic acid on the DNA photocleavage by pyrene, 1-hydroxypyrene (1-HP), and 1-aminopyrene (1-AP), is studied. The non-transition metal ions Na+, Ca2+, and Mg2+, usually have very little inhibitory effects, while the transition metal ions Fe3+, Cu2+, and Zn2+ enhance, Mn2+ inhibits the DNA photocleavage. The effect by biological molecules is complex, depending on the photochemical reaction mechanisms of the compounds tested (1-AP, 1-HP and pyrene) and on the chemical nature of the added biological molecules. Riboflavin, histidine, and mannitol enhance DNA photocleavage by all three compounds, except that mannitol has no effect on the photocleavage of DNA by pyrene. Glutathione inhibits the DNA photocleavage by 1-AP and 1-HP, but has no effect on that by pyrene. NAD enhances the DNA photocleavage by 1-AP, but has no effect on that by 1-HP and pyrene. Glutamic acid enhances the DNA photocleavage by 1-AP and pyrene, but inhibits that by 1-HP. These results show that the co-existing chemicals may have a profound effect on the toxicity of PAHs, or possibly on the toxicity of many other chemicals. Therefore, if one studies the toxic effects of PAHs or other toxic chemicals, the effect of the co-existing chemicals or ions needs to be considered.

Show MeSH
Related in: MedlinePlus