Mitochondrial toxicity of aluminium nanoparticles in comparison to its ionic form on isolated rat brain mitochondria

OBJECTIVES: The aim of this study was to evaluate the toxic effect of AlNPs on rat brain mitochondria and compare it with that of aluminium's ionic form. METHODS: Mitochondria were isolated from rat brain. Isolated mitochondria were treated with normal saline (Control) and different concentrations of aluminium ions (AlIs) and AlNPs (50, 100 and 200 mu M). Then, the effect of AlNPs on electron transport chain complexes as well as various endpoints such as mitochondrial oxidative damage (reactive oxygen species, lipid peroxidation, glutathione, and protein carbonyl) and mitochondrial function were assessed. Also, apoptosis was evaluated by cytochrome c release, mitochondrial membrane potential and swelling. RESULTS: When compared to the control group, the exposure to AlNPs showed a marked elevation in oxidative stress markers and inhibition of complex III which was accompanied by disturbance in mitochondrial function. Also, AlNPs induced a significant collapse of mitochondrial membrane potential, mitochondrial swelling, and cytochrome c release. CONCLUSIONS: The comparison of mitochondrial toxicity markers between both forms of aluminium revealed that the toxic effect of AlNPs on isolated brain mitochondria was substantially greater than that that caused by AlIs, which can probably be ascribed to its higher reactivity (Tab. 1, Fig. 8, Ref. 45).