Fast repair of oxidizing oh radical adduct of dGMP by hydroxycinnamic acid derivatives. A pulse radiolytic study

Jiang, Yue; Yao, Side; Lin, Nianyun

doi:10.1016/s0969-806x(96)00167-3

Cited by 20 publications

(3 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…O'Neill (1983) firstly reported that natural compounds, such as thiols and ascorbate, can repair hydroxyl radical adducts of dGMP and dG with high rate constants (3.6 Â 10 7 e8.4 Â 10 8 M À1 s À1 ) in chemical systems without any repair enzymes (O'Neill, 1983;O'Neill and Chapman, 1985). Jiang et al (1997) found that the dGMP-OH adduct can be repaired non-enzymatically by hydroxycinnamic acid derivatives. In our laboratory we have systematically studied the fast repair activities of a variety of natural polyphenols, including verbascoside (VER), towards the oxidative damage of dGMP, dAMP, dCMP, TMP, deoxythymine radical anion, polyA, polyC, polyG, ssDNA and dsDNA (Huang et al, 2003;Shi et al, 1999Shi et al, , 2008Zhao et al, 2001Zhao et al, , 2003a.…”

Section: Introductionmentioning

confidence: 99%

Non‐enzymatic fast repair of DNA oxidative damage might also exist in cells

Zhang

Pan

Zhao

et al. 2008

Cell Biology International

View full text Add to dashboard Cite

Many studies have shown that in a chemical system natural polyphenols can rapidly repair DNA oxidative damage. In this paper we report that in a cellular system the non-enzymatic fast repair activities of two natural polyphenols might also exist. The viability of a Chinese hamster ovary cell line (AA8) highly expressing the XRCC1 gene (a DNA repairing protein) treated with H2O2 is significantly higher than that of a normal Chinese hamster ovary cell line (CHO). Following inhibition of the enzymatic repair system by different inhibitors--methoxyamine (MX), 3-aminobenzamide (3AB) or nicotinamide (NIC)--DNA oxidative damage by H2O2 increased 2-5-fold in both cell lines. However, when natural polyphenols--rosmarinic acid (RA) or verbascoside (VER)--were added, DNA oxidative damage was significantly reduced. This decrease of DNA oxidative damage by RA or VER is not due to their scavenging activity for reactive oxygen species (ROS) because cells suffered from heavy ROS throughout the whole experimental process. Therefore, the decrease of DNA damage might be due to their non-enzymatic fast repair mechanisms. Further investigation showed that H2O2 induced a drop in the mitochondrial membrane potential (MMP), and that RA and VER were able to attenuate the drop. Previous studies have shown that H2O2 initiates a chain of events in cells, involving mtDNA damage, a drop in MMP and loss of repair activity. These results, taken together with our present results, suggest that the non-enzymatic fast repair mechanism exists not only in chemical systems but also might exist in cells.

show abstract

Section: Introductionmentioning

confidence: 99%

Non‐enzymatic fast repair of DNA oxidative damage might also exist in cells

Zhang

Pan

Zhao

et al. 2008

Cell Biology International

View full text Add to dashboard Cite

show abstract

“…O'Neill (1983) and O'Neill and Chapman (1985) reported that the endogenous thiols and ascorbate can react with oxidizing hydroxyl radical adducts of dGMP and dG with high rate-constants. Jiang et al (1997) showed that hydroxycinnamic acid derivatives could react very fast with hydroxyl radical adduct of dGMP. The rapid electron transfer reaction between the thymidine anion and caffeic acid has been reported by Zou et al (1995).…”

Section: Introductionmentioning

confidence: 99%

In vivo non‐enzymatic repair of DNA oxidative damage by polyphenols

Tan¹,

Zhao²,

Pan³

et al. 2009

Cell Biology International

View full text Add to dashboard Cite

The non-enzymatic repair of DNA oxidative damage can occur in a purely chemical system, but data show that it might also occur in cells. Human hepatoma cells (SMMC-7721) and human hepatocyte cells (LO2) were treated with 200microM H(2)O(2) for 30min to induce oxidative DNA damage quantified by amount of 8-OHdG and degree of DNA strand breaks, without inducing enzymatic repair. The dynamics of enzymatic repair activity quantified by unscheduled DNA synthesis, within 30min after removal of H(2)O(2) enzymatic repair mechanism has not been initiated. However, pre-incubation with low micromolar level polyphenols, quercetin or rutin can significantly attenuate DNA damage in both cell lines, indicating that the polyphenols did not work through an enzymatic mechanism. Unscheduled DNA synthesis after removal of H(2)O(2) was also markedly decreased by quercetin and rutin. Combined with our previous studies of fast reaction chemistry, the inhibitory effect of polyphenols have to be assigned to non-enzymatic repair mechanism rather than to enzymatic repair mechanism or antioxidant mechanism.

show abstract

“…Cinnamic acid *For correspondence derivatives inhibit oxidative modification of human low density lipoprotein. 6 It has been demonstrated 11,17,18 that the interaction of the oxidising OH adduct of DNA, poly A and poly G with hydroxycinnamic acid derivatives proceed via electron transfer . .…”

Section: Introductionmentioning

confidence: 99%