PARP1 and diabetes mellitus: It is possible to observe the protection of curcumin in pancreatic islet cells exposed to streptozotocin, the compound can decrease the formation of reactive oxygen species (ROS) and inhibit the activation of the poly ADP-ribose polymerase-1 enzyme, encoded by the PARP1 gene, and can also prevent the reduction of ROS levels of free radical scavenging enzymes. In HUVECs cells, it was observed that flavonoids (rutin, quercetin, and flavone) can inhibit PARP activation and improve diabetes complications. These compounds can interact with transcription factors and regulate gene expression.