Effect of caffeine on in vivo processing of alkylated bases in proliferating plant cells

Abstract

DNA damage was induced by either 2 mM ethylmethanesulfonate or 1 Gy of gamma-irradiation in Allium cepa L. root meristems. The percentage of DNA that migrated towards the anode during microelectrophoresis after alkali denaturation (pH approximately 13.5) of the isolated nuclei (comet assay) reflects the amount of single strand breaks present in them. There was some DNA migration (12.8+/-2.4%) in untreated roots. This percentage doubled at the end of 1.5 h treatment with the mono-functional alkylating agent 2 mM ethylmethanesulfonate, and trebled after a single exposure to 1 Gy of gamma-rays. A proportion of the DNA migration caused by these two treatments was reversed (repaired) by a 2 h long period of in vivo recovery. However, when 5 mM caffeine was applied after removal of the alkylating agent, the amount of DNA migrating to the comet tail over the same 2 h period was almost double that at the onset of recovery. In both control and irradiated nuclei, caffeine also increased the initial level of DNA migration in the comet assay, but to a lesser extent. These results indicate that caffeine increases the DNA damage that accumulates during the processing of alkylated bases and, to a lesser extent, of the DNA bases damaged by gamma-irradiation. Thus, the potentiation effect of caffeine on induced chromosomal damage may not just be due to caffeine-induced cancellation of the G2 checkpoint, but also to a direct effect this methylxantine has on the processing of DNA damage.

Effect of Copper on the Toxicity and Genotoxicity of Cadmium in Duckweed (Lemna Minor L.)

“…This is supported by a drop in DNA damage in plants exposed to Cu/Cd combinations on day 7, which correlates with lower MDA level (Figure 1). The drop may also be attributed to DNA repair (41).…”

Degradation of caffeine by Pseudomonas monteilii KRM9

“…However, some studies have shown that caffeine negatively impact plants growth. These plants include onions, sunflowers, and lettuces (Pincheira et al, 2003;Khursheed et al, 2009;Gomes et al, 2013). Therefore, the concentration of the caffeine in coffee pulp waste must be reduced before it is used as an organic fertilizer.…”

Evaluation of DNA damage in the root cells of Allium cepa seeds growing in soil of high background radiation areas of Ramsar – Iran

“…Higher plants, sensitive to soil, water and air pollutants, have been widely used for the biomonitoring of DNA damage induced by genotoxic agents. The comet assay in the nuclei of various higher plants has been applied before, such as in Vicia faba (Koppen and Verschaeve, 1996;Koppen and Angelis, 1998;Koppen et al, 1999), Allium cepa (Navarrete et al, 1997;Pincheira et al, 2003), Nicotiana tabacum (Koppen et al,1999;Stavreva et al,1998;Gichner et al, 2000;Ptacek et al, 2001;Stavreva and Gichner, 2002;Restivo et al, 2002), Calamagrostis epigejos (Ptacek et al, 2002), Impatiens balsamina (Poli et al, 2003), Arabidopsis thaliana and barley (Jovtchev et al, 2001). We measured the DNA damage in nuclei of the root cells of A. cepa seeds germinated in the soil of high background radiation areas (HBRAs) of Ramsar.…”