Qiming Granules Ameliorate Diabetic Retinopathy by Regulating the PI3K/Akt Signaling Pathway

To investigate the protective effect of Qiming granules on diabetic retinopathy (DR).

The diabetic model was established by intraperitoneal injection of streptozotocin. Histopathological alterations in the rat retina were examined using hematoxylin and eosin techniques. The TUNEL assay was utilized to identify apoptosis in retinal cells. Western blotting was used to investigate the expression of tight junction proteins and the phosphatidylinositol 3-kinase (PI3K/Protein Kinase B (Akt) signaling pathway within retinal tissues. TUNEL assay, immunofluorescence, and Western blot analysis were employed to examine cellular apoptosis, tight junction protein expression, and proteins related to the PI3K/Akt signaling pathway.

After Qiming intervention, it was alleviated compared with the model group. TUNEL staining showed an increase in the apoptosis rate of cells in retinal tissue. Western blotting analysis revealed that the Qiming group exhibited a marked upregulation in the expression levels of occludin, zonula occludens-1, p-PI3K/PI3K, and p-Akt/Akt proteins (P < 0.05). The results from the in vitro experiments indicated that the rate of apoptosis declined following Qiming intervention (P < 0.05). There was a noted reduction in the expression levels of B-cell lymphoma-2-associated X protein (Bax)/B-cell lymphoma-2 (Bcl-2) and cleaved Caspase-3 proteins, with the decrease being statistically significant (P < 0.05).

Qiming granules offered protection against damage to the blood-retinal barrier by preventing apoptosis, which in turn slowed the progression of DR. Its mode of action might be associated with modulating the PI3K/Akt signaling pathway.