XDH and type 2 diabetes mellitus: Based on these results, subsequently, the authors showed that in STZ-T2DM rats, NSO (2.0 ml/Kg) and anti-diabetic drugs (metformin and glimepiride) alone and/or in combination, were able to suppress brain levels of oxidative stress markers such as xanthine oxidase (XO) and NOS, through the product of lipid peroxidation [e.g., thiobarbituric acid reactive substances (TBARS)] (Balbaa et al., 2017).