SOD1 and metabolic dysfunction-associated steatohepatitis: To investigate the effect of kinins on oxidative stress in NASH, the activities of the antioxidant enzymes catalase (CAT), glutathione S-transferase (GST), and superoxide dismutase (SOD) were analyzed (Figure 3), in addition to lipid peroxidation markers such as malondialdehyde and protein oxidation as carbonyl protein (Figure 4).