Ameliorative effect of persimmon ( Diospyros kaki ) in cognitively impaired diabetic mice

The effects of ethanolic extract of Diospyros kaki (EED) on diabetic cognitive impairment were investigated in high-fat diet (HFD)-induced mouse. After HFD was fed to mouse for 16 weeks, EED was administrated to mouse for 4 weeks. EED reduced fasting blood glucose level and improved cognitive and behavioral dysfunction. EED improved serum biomarkers related to lipid and liver damage better than positive control (PC). In addition, EED ameliorated impaired cholinergic system, increased oxidative stress as well as mitochondrial dysfunction compared with HFD group. In the molecular study, EED downregulated the phosphorylation of c-Jun N-terminal kinase (p-JNK), which phosphorylates the serine residue of insulin receptor substrate-1 (IRS-1pSer). Finally, various physiological compounds such as tannin-based ingredients were identified using UPLC-QTOF/MS2. These results suggest that EED can help improve cognitive impairment caused by HFD. Practical applications Recently, cognitive impairment caused by type 2 diabetes mellitus (T2DM) has become a problem. T2DM, mainly derived from HFD, is characterized by hyperglycemia, which is associated with insulin resistance. In this study, EED not only improved hyperglycemia and insulin resistance, but also restored diabetes-related cognitive dysfunction in HFD-induced diabetic mice. Finally, the decrease in cholinergic and antioxidant systems related to cognitive impairment was recovered by consumption of EED via improvement of insulin signaling pathway. Therefore, this study suggests that persimmon (Diospyros kaki) containing diverse physiological compounds has potential and industrial value as a functional food material for cognitive improvement.