The effect of cordycepin on brain oxidative stress and protein expression in streptozotocin-induced diabetic mice

Abstract

Diabetes mellitus (DM) is characterized by metabolic disorders and psychological deficits, including cognitive decline. Here, we investigated the effect of cordycepin on oxidative stress and protein expression in the brains of diabetic mice. Twenty-four mice were divided into four groups, one comprising untreated healthy mice (N); one comprising healthy mice treated with cordycepin (24 mg/kg body weight) (N+Cor); one comprising untreated DM mice; and one comprising DM mice treated with cordycepin (24 mg/kg body weight) (DM+Cor). After 14 days of treatment, cognitive behavior was assessed using the novel object recognition (NOR) test. The brain levels of oxidative stress markers (glutathione, catalase, and superoxide dismutase) were examined using the respective detection kits. Protein expression in brain tissues was assessed by liquid chromatography with tandem mass spectrometry (LC–MS/MS); the functions of the identified proteins were annotated by PANTHER, while major protein–protein interactions were assessed using STITCH. We found that cordycepin treatment significantly decreased body weight and food and water intake in the DM+Cor group compared with that in the DM group; however, no differences in blood glucose levels were found between the two groups. Cordycepin treatment significantly reversed cognitive decline in diabetic mice in the NOR test and ameliorated antioxidant defenses. Additionally, we identified ULK1 isoform 2, a protein associated with cognitive function via the activated AMPK and autophagic pathways, as being uniquely expressed in the DM+Cor group. Our findings provide novel insights into the cellular mechanisms underlying how cordycepin improves cognitive decline in diabetic mice.