Research progress in the intervention of Chinese herb monomers on diabetic retinal neurodegeneration

Diabetic retinopathy(DR)has been traditionally considered a purely microvascular disease in the retina. Currently, mainstream therapies focus only on advanced vascular complications and a single molecular target-vascular endothelial growth factor(VEGF). However, the research is shifting towards a more comprehensive view that DR is a neurovascular disease caused by neurovascular unit(NVU)injury. In the early stage of DR, diabetic retinal neurodegeneration(DRN)dominates and may precede the retinal microvascular abnormalities. Moreover, neuronal apoptosis can further lead to microvascular injury and blood-retinal barrier(BRB)disruption. Therefore, it makes sense to develop new therapeutic strategies to prevent or reverse DRN. However, no drug targeting DRN has been approved for clinical use. In recent years, it has become a trend to study the protective effect of traditional Chinese medicine on the retina. The primary research focuses on Chinese herb monomers. This article reviews the research status of representative monomers in DRN to provide references for the early treatment of DR and development of new drugs.