Dammarenediol II may have the ability to prevent diabetic microvascular complications, including diabetic retinopathy, it can inhibit vascular endothelial growth factor (VEGF)-induced intracellular reactive oxygen species generation and stress fiber formation and vascular endothelial-cadherin disruption. The medicinally important dammarenediol II can be ectopically produced in tobacco, and the production of dammarenediol-II in tobacco plants allows them to adopt a viral defense system.