Ameliorative effect of black raspberry anthocyanins on diabetes retinopathy by inhibiting axis protein tyrosine phosphatase 1B-endoplasmic reticulum stress

[Display omitted] •The amelioration DR of BRAs in vivo and vitro were evaluated for the first time.•BRAs improved blood glucose, lipid metabolism and retinopathy in DR rats.•BRAs significantly improved morphological changes and apoptosis of RPECs.•BRAs ameliorated ERS-induced DR by regulating PTP1B-ERS axis in vivo and vitro.•Molecular docking revealed cyanidin 3-O-rutinoside and GRP78 could combine weell. Diabetes retinopathy (DR) is a common complication associated with diabetes. This study aimed to investigate ameliorative effect of black raspberry anthocyanins (BRAs) on DR and underlying inhibition mechanism of protein tyrosine phosphatase 1B (PTP1B)-endoplasmic reticulum stress (ERS) with retinal pigment epithelial cells apoptosis exposed to high glucose and tunicamycin and DR rats induced by STZ and high-fat and high-sugar diet. The results showed that TG and TC levels were markedly decreased, and disarrangement of retinas was markedly improved after BRA administration. Moreover, after pre-incubation with BRAs, morphological changes and mitochondrial membrane potential were significantly improved, whereas the apoptosis rates, activities of PTP1B and Caspase-1, and reactive oxygen species levels were significantly decreased. Finally, BRAs exhibited an efficient combination with GRP78, and they significantly suppressed protein expression of axis PTP1B-ERS. The results offer a basis for mastering ameliorated DR with BRAs and further first enhanced the mechanism of inhibiting axis PTP1B-ERS.