[Protective effect of epalrestat against high glucose-induced endothelial cell injuries].

OBJECTIVE: To study the protective effect of epalrestat against endothelial cell injuries induced by high glucose.

METHODS: Human umbilical vein endothelial cells were pretreated with epalrestat (0.1 µmol/L) for 30 min followed by exposure to high glucose for 8 h. NO concentration in the cell culture supernatant was assayed using chemiluminescence method following the exposure. Real-time PCR and Western blotting were used to detect eNOS mRNA and protein expression levels and the protein expressions of AR gene (the target gene of epalrestat) and NOX4 (the upstream gene of NO).

RESULTS: Compared with mannitol treatment, an 8-h exposure to high glucose caused significantly decreased NO levels and eNOS mRNA and protein expression in the vascular endothelial cells (P<0.05). Pretreatment with epalrestat prior to high glucose exposure resulted in elevated eNOS mRNA and protein expression levels and NO up-regulation in the cell culture as compared with the glucose exposure alone group (P<0.05), causing also decreased expression of AR and NOX4 in the cells.

CONCLUSIONS: High glucose can induce endothelial cell damage characterized by a lowered level of NO secretion. Epalrestat can protect the endothelial cells against high glucose-induced injury by inhibiting the expression of AR and NOX4.