SOD1 and parasitic infectious disease: One study investigated the effects of dietary with 10-20 mg/kg grape seed extracts (GSPE) on coccidia-challenged broilers and found that significantly improved the growth performance, since GSPE addition into the poultry diet could decrease the concentration of plasma malondiadehyde and increased SOD activity, thus restoring the balance of the antioxidant/oxidant system that was exerted by the oxidative stress after the parasite infection (Wang et al., 2008).