In vivo genotoxicity assessment of aluminium oxide nanomaterials in rat peripheral blood cells using the comet assay and micronucleus test

Abstract

Advances in nanotechnology and its usage in various fields have led to the exposure of humans to engineered nanomaterials (NMs) and there is a need to tackle the potential human health effects before these materials are fully exploited. The main purpose of the current study was to assess whether aluminium oxide NMs (Al(2)O(3)-30 nm and Al(2)O(3)-40 nm) could cause potential genotoxic effects in vivo. Characterization of Al(2)O(3)-30 nm and Al(2)O(3)-40 nm was done with transmission electron microscopy, dynamic light scattering and laser Doppler velocimetry prior to their use in this study. The genotoxicity end points considered in this study were the frequency of micronuclei (MN) and the percentage of tail DNA (% Tail DNA) migration in rat peripheral blood cells using the micronucleus test (MNT) and the comet assay, respectively. Genotoxic effects were evaluated in groups of female Wistar rats (five per group) after single doses of 500, 1000 and 2000 mg/kg body weight (bw) of Al(2)O(3)-30 nm, Al(2)O(3)-40 nm and Al(2)O(3)-bulk. Al(2)O(3)-30 nm and Al(2)O(3)-40 nm showed a statistically significant dose-related increase in % Tail DNA for Al(2)O(3)-30 nm and Al(2)O(3)-40 nm (P < 0.05). However, Al(2)O(3)-bulk did not induce statistically significant changes over control values. The MNT also revealed a statistically significant (P < 0.05) dose-dependent increase in the frequency of MN, whereas Al(2)O(3)-bulk did not show any significant increase in frequency of MN compared to control. Cyclophosphamide (40 mg/kg bw) used as a positive control showed statistically significant (P < 0.001) increase in % Tail DNA and frequency of MN. The biodistribution of Al(2)O(3)-30 nm and Al(2)O(3)-40 nm and Al(2)O(3)-bulk in different rat tissues, urine and feces was also studied 14 days after treatment using inductively coupled plasma mass spectrometry. The data indicated that tissue distribution of Al(2)O(3) was size dependent. Our findings suggest that Al(2)O(3) NMs were able to cause size- and dose-dependent genotoxicity in vivo compared to Al(2)O(3)-bulk and control groups.

In vitro and in vivo toxicity assessment of nanoparticles

“…The results from the study indicated a decrease in the cell viability [134]. Another study investigated the effect of increasing concentration of aluminium nanoparticles on rat blood cells at 500-2000 mg/kg for 72 h. It was observed from the study that the toxicity was dose dependent [135]. A study conducted on mammalian cell lines suggested that at 0-5000 μg/mL, aluminium nanoparticles were responsible for DNA damage after treatment for 2 h [136].…”

Induction of Cytotoxicity by Selected Nanoparticles in Chinese Hamster Ovary-K1 Cells

“…Al2O3 and TiO2 nanoparticles have reported with internalization and cytotoxicity in CHO cells where it has been shown to induce vesicle formation and got trapped inside the vesicles along with free nanoparticles observed inside the cell (DiVirgilio et al, 2010). It is believed that nanoparticles with smaller size can easily enter into the biological system and the resulting cytotoxicity or genotoxicity is size-dependent (Balasubramanyam et al, 2009). However, titanium dioxide nanoparticles even in range of 150 nm can also internalized and elicit toxic responses as DNA damage and genetic instability (Trouiller et al, 2009).…”

Mangiferin activates the Nrf2-ARE pathway and reduces etoposide-induced DNA damage in human umbilical cord mononuclear blood cells

“…DNA damage was evaluated by a comet assay, which was performed according to the published protocol with minor modifications (Balasubramanyam et al, 2009). Briefly, 200 ml of low-melting agarose [1% (v/v) in phosphatebuffered saline (PBS, pH 7.4)] at 37 C mixed with 10 ml of PBS containing MNCs was transferred onto a precoated [0.5% (v/v) normal melting agarose in PBS (pH 7.4)] slide.…”