(R)- α-Lipoic acid treatments for preserving indocyanine green and light-induced oxidative damage in ARPE-19 cells under clinical vitrectomy conditions

Abstract

Purpose: To evaluate the co-administration and pre-treatment with (R)-α-Lipoic acid as protective agent against indocyanine green (ICG) and light-induced oxidative damage in ARPE-19 cells using a Constellation apparatus as light source in order to mimick clinical vitrectomy conditions.

Methods: ARPE-19 cells were co-incubated along with ICG (0.5% in culture medium) and subjected to light for 30 min following either a (R)-α-Lipoic acid co-administration or pre-treatment (0.05mM in culture medium) and compared with (R)-α-Lipoic acid-untreated cells under the same conditions (control). Cell viability was measured colorimetrically (WST-8 reagent) at 0 and 24 h. The determination of intracellular levels of reactive oxygen species (ROS) and mitochondrial membrane potential (Ψm) was carried out using, respectively, the fluorescent probes tetramethylrhodamine methyl ester (TMRM) and 5-(and 6)-chloromethyl-dichlorodihydrofluorescein diacetate (CM-H2DCFDA) at 0 and 24 h.

Results: The results demonstrated that both the (R)-α-Lipoic acid co-administration and pre-treatment significantly decreased ROS levels at 24 h (*p<0.05). However, the Ψm was significantly decreased only with the (R)-α-Lipoic acid pre-treatment at times 0 and 24 h (***p<0.001), but did not vary with the co-administration of the (R)-α-Lipoic acid (p>0.05).

Conclusions: These results demonstrate the (R)-α-Lipoic acid effectively preserves against ICG and light-induced oxidative damage under clinical vitrectomy conditions. Whilst reducing ROS levels, (R)-α-Lipoic acid pre-treatment induced a significant Ψm reduction in ARPE-19 cells, suggesting a co-administration of (R)-α-Lipoic acid during vitrectomy might be desirable in order to preserve long-term cell damage.

Keywords: 424 antioxidants • 688 retina • 762 vitreoretinal surgery