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Journal of Clinical and Experimental Toxicology | Volume: 2
December 03-04, 2018 | Dubai, UAE
International Conference on
6
th
International Conference on
Toxicology, Clinical Toxicology & Pharmacology
Recycling & Waste Management
Joint Event
&
Genotoxicity induced by different brands of e-cigarette liquids
Ghofran Al-Qudaihi
King Faisal Specialist Hospital & Research Centre, Saudi Arabia
R
ecent studies have shown that e-cigarettes contain
carcinogenic compounds and nicotine that makes their
long-term safety questionable; however findings on their
genotoxic behaviour are still limited. We used in vitro single-cell
gel electrophoresis (comet) and micronucleus (MN) assays with
human lymphoblastoid TK6 cells to examine the genotoxicity
of different brands of e-cigarette refill liquids collected from
local e-cigarette smokers. As indicated in the label, these refills
contain 1 to 8 mg nicotine. We tested nicotine content in
these refills by Gas Chromatography/Mass Spectrometry and
the range was between 0.5 to 10.4 mg with poor correlation
(r=0.283, p=0.019). Six refills had nicotine ≥2 folds the label.
Human lymphoblastoid TK6 cells were exposed overnight
to 20 μl of e-cigarette liquids, and nicotine (4 mg). Negative
(untreated cells) and positive controls (cells treated with 100
mM H2O2) displayed respectively the absence and presence
of DNA damage. 14 samples induced ≥5 folds strand breaks
in DNA as depicted by tail moment higher than the negative
control. Nicotine in these samples was in the range of 0.96
to 10.4 mg. We exposed 23 refills that showed no positive
response for 3 hours to metabolic activation (liver microsomal
S9 fraction from Wistar rats). The introduction of S9 mix
made significant increase in DNA damage (p<0.001). Out of
23 refills, ≥5 folds increase in TM was observed in 13 refills.
Chromosome breakage expressed as MN frequency ≥3 folds
higher than in untreated cells was found in 20 refills out of 63
tested (31.7%) that contains nicotine in the range between
1.3 to 9.6 mg. There was significant positive correlation
between TM and MN (r=0.284, p=0.021). An evidence of
positive relationship was seen between nicotine and MN
(r=0.212, p=0.095) but not with TM. Our results suggest that
some other ingredients with mutagenic/genotoxic properties
in e-cigarette refill liquids might have induced DNA damage.
Further investigation is required confirming our observation.
Speaker Biography
Ghofran Al-Qudaihi was awarded her PhD degree in 2011 by Newcastle University,
United Kingdom. In 2014, she joined the Environmental Health Program at the King Faisal
Specialist Hospital &Research Centre. Currently her research interests are directed towards
the identification of genotoxic chemicals present in everyday life and the environment.
e:
galqudaihi76@kfshrc.edu.saGhofran Al-Qudaihi
, Toxicology 2018 & Recycling 2018, Volume 2
DOI: 10.4066/2630-4570-C1-003