Comparative bio-effect of gadolinium with alternative contrast medium of magnesium chloride and zinc oxide nanoparticles on single-strand DNA following exposure to magnetic resonance imaging

Gadolinium (Gd) is a widely used MRI contrast agent that improves visibility and aids in accurate diagnosis. However, conflicting reports exist regarding its genotoxic effects. This study investigates the bio-effects of Gd and alternative contrast media, magnesium chloride (MgCl2), and zinc oxide nanoparticles (ZnO NPs) on DNA single-strand breaks.

In this in-vitro comparative experiment, 12 adult New Zealand rabbits (males aged between 4.5 to 5.5 months, weighing 2.5 to 3.0 kg) were utilized. The rabbits received intravenous injections of different contrast agents, namely Gd (n=3), MgCl2 (n=3), ZnO NPs (n=3), and a control group (n=3). Following this, all the rabbits were subjected to MRI at 1.5 Tesla (T) with an RF of 64 MHz for 20 minutes. The alkaline comet assay assessed the presence of single-strand breaks (SSB).

The results of the study revealed a statistically significant increase in DNA SSB in both the Gd (p<0.010) and ZnO NPs (p=0.006) treated groups compared to the normal control group. However, the alternative MgCl2 treatment did not elicit a statistically significant effect on the DNA single-strand compared to the control group (p=0.277).

The contrast medium Gd and alternative ZnO NPs were demonstrated to cause significant DNA single-strand breaks, with the Gd causing more damage than ZnO NPs. However, the alternative contrast MgCl2 was safer with no effect on DNA single-strand. This suggests that MgCl2 is more suitable as an alternative contrast media in MRI scanning.