Figure 5.

The effect on antioxidant activity of SiO₂ NPs fed to mice.

Notes: C57BL/6 mice were treated with varying sizes (20 nm, 100 nm) and charges (SiO₂^EN[R]; negative, SiO₂^EN[−]) of 750 mg/kg colloidal SiO₂ NPs for 14 days. Spleens from mice were isolated aseptically and made into single-cell suspension splenocytes. (A) SOD activity and (B) GPx activity were measured in splenocyte lysate by an SOD activity assay kit and by a GPx activity colorimetric assay kit, according to the manufacturer’s instructions (BioVision, Inc., Milpitas, CA, USA). Data are presented as the mean ± standard deviation; n=5.

Abbreviations: SOD, superoxide dismutase; NC, normal control; SiO₂, silicon dioxide; SiO₂^EN(−), negatively charged silicon dioxide; SiO₂^EN(R), silicon dioxide modified with L-arginine; GPx, glutathione peroxidase; n, number.