NOS2 and Cognitive impairment: In addition, it has been found that HYP significantly inhibited the oxidative damage observed in the brain of T2DM rats, such as significantly decreasing the concentrations of MDA and inducible nitric oxide synthase (iNOS) and correspondingly increasing the activities of GSH-Px, CAT, SOD and the tricarboxylic acid cycle (TAC), thereby improving cognitive impairment in T2DM rats (71).