Age-Related Effects of Orthovanadate Nanoparticles Involve Activation of GSH-Dependent Antioxidant System in Liver...

Vanadium is an important ultra-trace element nowadays attracting attention with particular emphasis on medical application. But the therapeutic application of vanadium-based drugs is still questionable and restricted due to some toxic side effects. It was found that unique redox properties of vanadium in nanoform provided antioxidant activity and prevented oxidative disturbance in cells in vitro. Though, on the organism level, ambiguous effects of vanadium-based nanoparticles were observed. In this study, the age-related features of prooxidant/antioxidant balance in blood serum and liver mitochondrial and postmitochondrial fractions of 3 and 18-month-old Wistar male rats treated with orthovanadate nanoparticles (GdVO₄/Eu³⁺, 8 × 25 nm) within 2 months have been investigated. Prooxidant potential-related indexes were the content of lipid hydroperoxides as well as aconitase activity. Activity of glutathione peroxidase, glutathione-S-transferase, glutaredoxin, glutathione reductase, glucose-6-phosphate dehydrogenase, and NADPH-dependent isocitrate dehydrogenase designated the tissue antioxidant potential. Based on the obtained values, the integral index of the prooxidant/antioxidant balance-the reliability coefficient (Kr) has been calculated. The data show that due to activation some chain links of GSH-dependent antioxidant system, GdVO₄/Eu³⁺ nanoparticles increase the reliability of the prooxidant-antioxidant balance in tissues and especially in the liver mitochondria of old animals (Kr in mitochondria of young rats was 2.94, and in mitochondria of old ones-9.83 conventional units). Detected in vitro glutathione peroxidase-like activity of the GdVO₄/Eu³⁺ nanoparticles is supposed to be among factors increasing the reliability of the system. So, for the first time, the beneficial effect of the long-term orthovanadate nanoparticle consumption in old males has been discovered.