Quercetin inhibits hypertonicity-induced inflammatory injury in human corneal epithelial cells via the PTEN/PI3K/AKT pathway

Dry eye is a prevalent ophthalmic disease. Ocular surface inflammation in the hyperosmolar environment of the tear film is critical in dry eye progression. Quercetin has strong anti-inflammatory effects; however, its exact mechanism of action in dry eye is not fully understood. Therefore, this study investigated whether quercetin could inhibit the damage sustained to human corneal epithelial cells (HCECs) in a hyperosmolar environment through its anti-inflammatory effects. HCECs were cultured in a complete medium and were divided into four groups: normal, model, quercetin, and inhibitor. The proliferation of HCECs was detected by Ki67 staining; the expression levels of PTEN, p-PI3K and p-AKT were detected by Western blotting and immunofluorescence staining; the relative mRNA expression levels of PTEN, PI3K, AKT, IL-6 and TNF-ɑ were detected by quantitative real-time PCR; the relative expression levels of IL-6 and TNF-α were detected by enzyme-linked immunosorbent assay. In this study, the proliferation of HCECs in the model group was found to be significantly inhibited compared with that in the normal group; however, quercetin was effective in improving the proliferation of HCECs, decreasing the relative expression of p-PI3K, p-AKT, IL-6, TNF-ɑ as well as increasing PTEN. In conclusion, this study demonstrated that quercetin could promote the proliferation of HCECs and reduce the expression of inflammatory factors by inhibiting the PTEN/PI3K/AKT pathway in the hyperosmolarity-induced HCECs model.