Cytoprotective Effects of KIOM-79 on Streptozotocin Induced Cell Damage by Inhibiting ERK and AP-1

The present study investigated the potential cytoprotective properties of a combination of plant extracts (KIOM-79) obtained from Magnolia officinalis, Pueraria lobata, Glycyrrhiza uralensis, and Euphorbia pekinensis, against the oxidative stresses induced by streptozotocin (STZ) in a rat pancreatic beta-cells (RINm5F). KIOM-79 was found to scavenge intracellular reactive oxygen species (ROS), thereby preventing DNA damage and lipid peroxidation. The KIOM-79 inhibited apoptosis of the beta-cells exposed to STZ via radical scavenging activity and activation of antioxidant enzymes. KIOM-79 inhibited activation of extracellular regulated kinase (ERK) induced by STZ and inhibited DNA binding activity of an activator protein-1 (AP-1), a downstream transcription factor of ERK. Taken together, these findings suggest that KIOM-79 protects against STZ induced cell death in RINm5F cells by inhibiting ROS generation and the ERK pathway.