To investigate the effects of zingerone (ZO) on the retina in diabetic rats.

A total of 70 rats were randomly selected and divided into seven groups [diabetic group (Dm+; n=10), diabetic+metformin group (Dm+Met; n=10), diabetic+ZO25 group (Dm+ZO25; n=10), diabetic+ZO50 group (Dm+ZO50; n=10), diabetic+metformin group+ZO 50 Group (Dm+Met+ZO50; n=10)]. Diabetes was induced by streptozotocin (STZ), and metformin and two different doses of ZO were administered via gavage. Retinal tissues were evaluated by histopathological and immunohistochemical analyses.

In diabetic rats, severe retinal inflammation, tissue necrosis, and increased tumor necrosis factor-α (TNF-α) expression were observed. ZO administration reduced these effects in a dose-dependent manner. Protective effects of metformin alone were limited, and no synergistic benefit was observed in ZO+Met groups. Administration of 50 mg/kg ZO to non-diabetic rats caused no retinal toxicity. Additionally, elevated 8-OHdG and c-Jun N-terminal kinase (JNK) expressions in diabetic retinopathy models were significantly reduced by ZO treatment.

ZO can markedly reduce the pathological effects of the retina in a diabetic rat model.