The effects of ellagic acid-coated gold nanoparticles on oxidative stress in experimentally induced inflammation.

Background. Oxidative stress, the result of the oxidant/antioxidant imbalance, is involved in the pathogenesis of different diseases associated with inflammation. Aims. The study aimed to investigate the effects of orally administered gold nanoparticles phytoreduced with ellagic acid (AuNPs-EA) on oxidative stress in carrageenan-induced paw oedema, in Wistar rats. Methods. Paw oedema and oxidative stress parameters were investigated in rats after intraplantar carrageenan injection (0.2 ml 1% solution). Prior to this, the animals, randomly allocated into four groups, received, for 15 days, vehicle (1% carboxymethyl cellulose –CMC) (group C), 1 mg/kg/day indomethacin (group I), 40 mg/kg/day ellagic acid (group II) or 0.3 mg/kg/day AuNPs-EA (group III). The paw oedema was evaluated through plethysmometry before and at 2, 6 and 24 hours after carrageenan injection and blood samples, paw tissues and kidneys fragments were collected for oxidative stress investigation. Results. AuNPs-EA and indomethacin administration produced significant decreases of the paw oedema, compared to the control group. Lipid peroxidation was reduced significantly by the tested medication in the paw tissues, but it was increased significantly by AuNPs-EA in the kidneys. The antioxidant protection, evaluated through the GSH/GSSG ratio, was amplified significantly in all rats that received AuNPs-EA and indomethacin, in paw tissues and in serum. Ellagic acid provided antioxidant protection only in the serum. In the kidneys, only indomethacin administration increased significantly GSH/GSSG ratio. Conclusions. AuNPs-EA reduced the paw oedema and oxidative stress in inflamed tissue and in serum, in carrageenaninduced inflammation model. [ABSTRACT FROM AUTHOR]