Effect of acetyl L-carnitine on human retinal pigment epithelium-19 cells in hypoxic conditions

AIM: To investigate the effect of acetyl-L-carnitine(ALCAR)on cell viability, morphological integrity, and vascular endothelial growth factor(VEGF)expression in human retinal pigment epithelium(ARPE-19)cells using a hypoxic model.METHODS: In the first set of experiments, the optimal CoCl2 dose was determined by exposing ARPE-19 cell cultures to different concentrations. To evaluate the effect of ALCAR on cell viability, five groups of ARPE-19 cell culture were established that included a control group, a sham group(200 μM CoCl2), and groups that received 1, 10 and 100 mM doses of ALCAR combined with 200 μM CoCl2, respectively. The cell viability was measured by MTT assay. The morphological characteristics of cells were observed by an inverted phase contrast microscope. The levels of VEGF and HIF-1α secretion by ARPE-19 cells were detected by enzyme linked immunosorbent assay(ELISA)assay.RESULTS: ARPE-19 cells were exposed to different doses of CoCl2 in order to create a hypoxia model. Nevertheless, when exposed to a concentration of 200 μM CoCl2, a notable decrease in viability to 83% was noted. ALCAR was found to increase the cell viability at 1 mM and 10 mM concentrations, while the highest concentration(100 mM)did not have an added effect. The cell viability was found to be significantly higher in the groups treated with a concentration of 1 mM and 10 mM ALCAR compared to the Sham group(P=0.041, P=0.019, respectively). The cell viability and morphology remained unaffected by the greatest dose of ALCAR(100 mM). The administration of 10 mM ALCAR demonstrated a statistically significant reduction in the levels of VEGF and HIF-1α compared with the Sham group(P=0.013, P=0.033, respectively).CONCLUSION: The findings from the current study indicate that ALCAR could represent a viable therapeutic option with the potential to open up novel treatment pathways for retinal diseases, particular relevance for age-related macular degeneration(AMD). However, to fully elucidate ALCAR's application potential in retinal diseases, additional investigation is necessary to clearly define the exact mechanisms involved.