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Chromatography 2016
September 21-23, 2016
Volume 7, Issue 5(Suppl) J Chromatogr Sep Tech 2016
ISSN: 2157-7064 JCGST, an open access journal
conferenceseries .com
September 21-23, 2016 Amsterdam, Netherlands
World Congress on Chromatography
A link between aberrant methylation level and AA adducts: Fact or coincidence
Dalia El-Zeihery1 , Mohamed Abd El Kawy1, Oliver Schmitz2, Cai Zongwei3 and Heinz Schmeiser4
1Beni-Suef University, Egypt
2Essen-Duisburg University, Germany
3Hong Kong Baptist University, China
4German Cancer Research Center, Germany
Themainaimof this study istoestimate theeffectof aristolochicacid(AA)onthegenomicmethylationlevel (5-methylcytosine,
5mc) of Sprague-Dawley rats subjected to a single oral dose of 30 mg AA/kg over three weeks-period, and to detect AA-
DNA adducts in tissues of rodents. Our analytical method involves hydrolyzing the DNA extracted from different organs to
2-deoxyribose-3’-phosphate, labeling the nucleotides with a fluorescence marker, thenmeasuring the genome wide methylation
level with micellar electrokinetic chromatography using laser-induced fluorescence detector (MEKC-LIF). The results had
shown different behavior patterns in the methylation level according to the tested organ. An obvious hypermethylation was
observed in kidney, stomach and colon of rats dosed with AA, in comparison with their respective controls. Individual 5mc
levels are (3.97±0.05, 3.90±0.04 and 4.46±0.04%) for organs, respectively. Bladder, small intestine and liver did not exhibit
either hyper- or hypo- methylation. We further studied the samples for detection of AA-adducts in two complementary studies.
The deoxyadenosine-AA-adducts were identified in kidney (Adduct level, 2.63 to 5.16/106 nucleotides) and colon tissues (0.28
to 1.01/106 nucleotides) among several tissues analyzed by the 32P-postlabeling method. While control samples were free from
DNA adducts spots. As well, the highest AA-DNA adduct concentration was detected in kidneys of the AA-dosed rats by
LC-ESI-MS method. Our study highlights the relation between the exposure to this carcinogen belonging to natural product
group (AA) and the aberration of methylation level that contributes to understanding the involvement of AA-adducts in cancer
development via epigenetic modification.
Biography
Dalia Mohamed El-Zeihery received her PhD from the Bergische Universitaet Wuppertal in Germany and completed Post-doctoral studies at CRO in Germany.
She is lecturer of Analytical Chemistry at Beni Suef University in Egypt. She has strong footing in teaching and research, in depth theoretical knowledge and
hands-on experience in analytical techniques: like capillary electrophoresis, HPLC-MS and UV-VIS spectroscopy. She was awarded third prize of Pharmaceutical
and Bio-analysis from Pfizer for her poster at the 2009 34th International Symposium on HPLC Separations and Related Techniques. His research interests are
development and validation of bio-analytical methods for analysis of drugs, proteins and biomarkers.
Dalia El-Zeihery et al., J Chromatogr Sep Tech 2016, 7:5(Suppl)