Cytotoxic Effects of Imidacloprid Pesticide on HEK 293T Human Cells
S. M. Herwald, M. J. S. Falso, S. L. Hrizo
Slippery Rock University Department of Biology
Introduction

Figure 2. Estimated use of
imidacloprid in the US (5).

1.8
1.6

Figure 1. The chemical
structure of imidacloprid.
Imidacloprid is
potentially dangerous
because of its uptake and
translocation in plants,
unable to be rinsed off
and thus exposing
humans through intake
via consumption.
Previous studies using
imidacloprid on nonhuman cell types indicate
cellular stress and
damage on reproductive
and nervous system cells,
and inflammation in liver
and other organs (3).

Studies performed on human lymphocytes indicate DNA
fragmentation and damage (4). This experiment will utilize HEK 293T
human embryonic kidney cells treated with varying concentrations of
imidacloprid to determine levels of cell death after 24 hours of
exposure.

Average Abs490

The purpose of this study is to
examine the potential
cytotoxic effects of the
pesticide imidacloprid. This
compound is a neonicotinoid
and has been consistently
used for insect control on
crops in the United States
since the late 1980s despite
being banned in Europe (1,2).

Results

Technique

Figure 3. Reaction of MTS to Formazan by dehydrogenase enzymes
that occurs in a metabolically active cell. The presence of more
metabolically active cells results in a deeper color change that can be
quantified by collecting absorbance values.

1.4
1.2
1

0.8
0.6
0.4
0.2
0
(-)

DMSO

10mM H2O2 10uM IMI

100uM IMI

1mM IMI

Treatment

Human HEK 293T cells were cultured in DMEM with L-glutamine, fetal
bovine serum, and penicillin + streptomycin media and incubated at
37˚C and 5% CO2. For the assay, cells were plated into a 96 well plate
with 7,500 cells in 100𝜇L of media per well. After 24 hours, media was
aspirated off and cells were treated with 100𝜇L media containing
treatment. Designated cells were treated with untreated media, 10
mM H2O2 (positive control), 10 𝜇M imidacloprid, 100 𝜇M imidacloprid,
and 1 mM imidacloprid. A DMSO vehicle control was also included.
After 24 hours, 20 𝜇L of MTS reagent was added to each well and
absorbance values at 490 nm were collected after 1 hour and 2 hours.

Figure 4. Average absorbance values after 1 hour (blue) and 2 hours
(orange) post-MTS reagent addition. Imidacloprid (IMI) treatments show
no significant change in cellular metabolic activity upon treatment with
varying dosages. (-) is media only. DMSO is the vehicle control. Error bars
represent standard deviation among average absorbance values. Higher
absorbance values represent more conversion to the formazan end
product, indicating more metabolically active cells. n=5

References

Conclusion & Future Directions

1. Bass, C. Current Biology 28, R772-R773 (2018).
2. Douglas, M. R. & Tooker, J. F. Environ Sci Technol 49, 5088-5097, (2015).
3. Duzguner, V., & Erdogan, S. Pest Biochem Phys, 97, 13-18 (2010).
4. Costa, C., et al. Mut Res/Genet Tox Env Mut, 672(1), 40-44 (2009).
5. water.usgs.gov

Imidacloprid showed no cytotoxic effects on HEK 293T cells. When compared to
the hydrogen peroxide positive control, there is no significant cellular death as
represented by absorbance values. Future research directions include
treatments exceeding 24 hours, and treatment on other cell lines.