In this study, we investigate the protective effects of the Chinese herbal medicine prescription Zhujing pill (ZJP) on the development of diabetic retinopathy (DR) and explore the potential mechanisms.

Zhujing pill extract (ZJPE) was prepared, and the main components were identified by high-performance liquid chromatography (HPLC). Several serum and tissue (retina) parameters were measured, such as levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), intercellular adhesion molecule 1 (ICAM-1), vascular endothelial growth factor (VEGF), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), advanced glycation end products (AGEs), and high sensitivity C-reactive protein (hsCRP). Aldose reductase (AR) activity and blood-retinal barrier (BRB) breakdown were determined. Finally, retinal electrophysiology and morphological changes were assayed.

In STZ-induced DM rats, ZJPE treatment restored the body weight decrease. DM rats showed decreased levels of SOD and GSH-Px and increased levels of IL-6, TNF-α, hsCRP, and MDA, whereas all these changes were significantly reversed by ZJPE administration. ZJPE alleviated BRB breakdown. Furthermore, ZJPE also alleviated the retinal electrophysiology changes and impaired morphology of the retina and lowered the high levels of TNF-α, IL-1β, ICAM-1, VEGF, AGEs, and AR in the retina.

ZJPE treatment attenuated the progression of DR in STZ-induced diabetic rats.