Neuroprotective effect of alpha-lipoic acid on hydrostatic pressure-induced damage of retinal ganglion cells in vitro.

Background: Recently, alpha-lipoic acid (ALA) has been reported to afford protection against neurodegenerative disorders in humans and experimental animals, yet little study elucidates whether it works in glaucomatous optic neuropathy.

Objective: This study aims to investigate whether ALA possesses neuroprotection against hydrostatic pressure-induced damage and explore its possible protective mechanism in cultured retinal ganglion cells (RGCs) in vitro.

Methods: RGC-5 cells were differentiated using staurosporine and pre-treated with different concentrations of ALA, then subjected to 50mm Hg hydrostatic pressure for 6h. After elevated hydrostatic pressure, cell viability was measured using MTT assay and apoptosis was evaluated using flow cytometry with Annexin V/PI staining. Intracellular reactive oxygen species (ROS) changes were determined by flow cytometry based on 2',7'-dichlorofluorescein diacetate (DCFH-DA). The expression of manganese superoxide dismutase (MnSOD) was measured via quantitative real-time PCR and Western blotting analysis.

Results: Increases of apoptotic rate and ROS production were observed in pressure-treated RGC-5 cells compared to normal control cells. In contrast, pretreatment of ALA significantly reduced the production of ROS, increased the expression of MnSOD and prevented apoptosis in pressure-treated RGC-5 cells.

Conclusions: These findings suggest that there are protective effects of ALA against elevated hydrostatic pressure-induced damage in RGC-5 cells, indicating ALA might be a potential therapeutic agent for glaucomatous optic neuropathy.