Neuroprotective Effects of Methyl 3,4-dihydroxybenzoate Against H₂O₂-Induced Apoptosis in RGC-5 Cells

Abstract

In the present study, we investigated the protective effect of methyl 3,4-dihydroxybenzoate (MDHB) against H₂O₂-induced apoptosis in RGC-5 cells. The RGC-5 cells were cultured in plates for 24 h, which were then pretreated with dimethyl sulfoxide, different concentrations of MDHB, or probucol for 12 h prior to addition of 300 μM H₂O₂ for 24 h. The cell viability was detected by MTT assay. The rate of apoptosis, level of lipid peroxidation, and mitochondrial membrane potential (MMP) were detected by flow cytometry. Western blot analysis was also used to measure the expression level of Bcl-2, Bax, caspase 9, and caspase 3 proteins in H₂O₂-treated RGC-5 cells. Our study showed that the cell viability of RGC-5 cells significantly decreased after treatment with 300 μM H₂O₂ for 24 h, but MDHB (8, 16, 32 μM) increased RGC-5 cell survival, suppressed the rate of apoptosis, scavenged reactive oxygen species, and restored MMP. MDHB also obstructed H₂O₂-induced apoptosis by regulating the expression of Bcl-2 and Bax, as well as suppressing the activation of caspase 9 and caspase 3. Our results showed that MDHB is an effective neuroprotective compound that mitigates oxidative stress and inhibits apoptosis in RGC-5 cells.