Using Elevated Temperature as an Assay to Determine the Importance of Various SODs and the Life Extending Properties of Various Manganese Salts in C. elegans

Abstract

C. elegans have a similar aging mechanism as humans, including the presence of superoxide scavenging enzymes, SODs (Superoxide Dismutase). This study focused only on two out of five different forms of SODs, a manganese SOD (SOD-3) and a copper-zinc SOD (SOD-4), to uncover the most important one for combating oxidative stress. In addition, this current study extended on the previous findings that ionic manganese supplementation provides life-span extending benefit, to uncover a preferred chemical form of manganese that has superior efficacy compared to previously utilized MnSO4. The various worm strains were grown as a synchronous population from eggs at 22°C for 48 hours. They were then subjected to thermal stress at 35°C, which elevates free radical levels in vivo to a lethal limit. The results showed that a form of manganese SOD (SOD-3) is vital in combating oxidative stress, that MnSO4 supplementation rescued the reduced thermotolerance seen in SOD-3 knockout worms and that MnSO4 is the preferential form for worm supplementation studies compared to other simple salts based on thermotolerance assay. Future studies will include manganese containing complexes, some of which are known to have antioxidant properties, to examine if simple manganese salts can be as efficacious as the complexes using both thermotolerance and life-span as assays.