Research of prilocaine-induced inflammation in human retinal pigment epithelial cells

Objectives: Prilocaine (PRL) is a commonly used local anesthetic. Despite the successful use of regional anaesthesia for intraocular surgery, toxic effects of local anesthetics can occur on the retina in cases of accidental intravitreal injection. This study examined signal transduction pathways activated by PRL toxicity and determined the protective role of nitric oxide synthase-2 (NOS2) inhibition in human retinal pigment epithelial (ARPE-19) cells. Materials and Methods: Toxicity analysis (MTT test) was performed to determine both the toxic dose of PRL and the protective efficacy of ASP, a NOS2 inhibitor. Nuclear factor kappa B p65 (NF–B p65), phosphorylated NF-B p65, phospho AKT, NOS2, nitrotyrosine, cleaved caspase-3 protein levels were evaluated by immunofluorescence staining and/or western blot analysis. Interleukin-6 (IL-6) and nitrated protein levels were quantified by immunoassay, while caspase -3 activity and nitrite/nitrate levels were measured via a fluorometric method. Results: It was observed that NF-B p65, phosphorylated NF-B p65 and phosphorylated AKT were significantly increased in PRL toxicity. Likewise, IL-6, NOS2, nitrite/nitrate and nitrotyrosine levels were significantly higher in PRL-treated cells compared to controls. Application of ASP to PRL treated cells significantly reduced NF-B p65, phosphorylated NF-B p65 and phosphorylated AKT to basal levels. IL-6, NOS2, nitrite/nitrate and nitrotyrosine levels were also considerably decreased following ASP treatment in PRL-induced toxicity. No activation was observed in the caspase-3-dependent apoptotic pathway. Conclusions: NF-B p65-mediated signal transduction pathway is activated due to PRL toxicity and can be down regulated by ASP. Supported by a grant from TUBİTAK #121S194 and BAP# TYL-2022-5989.