Assessment of neuroprotective properties of Rhus coriaria L. ethanol extract in an in vitro model of retinal degeneration

Neuroprotection refers to the use of any therapeutic modality that prevents, retards, or reverses neuronal cell death during the degenerative process. The aim of the present study was to determine the neuroprotective effects of Rhus coriaria L. (R. coriaria) fruit extract. Ethanol extract of the R. coriaria fruit was prepared via maceration technique and tested for its neurotoxic properties on retinal photoreceptor cells (RGC-5). Cell viability (MTT), Hoechst staining and caspase levels were measured following 48 h serum deprivation. The role of ethanol extract of R. coriaria (ERC) in attenuating oxidative stress conditions was evaluated by testing its ability to increase glutathione (GSH) and glutathione-S-transferase (GST) levels. Ethanol extract was non-toxic (IC50 of 249.99 ± 0.17 μg/mL). The in vitro retinal degeneration study revealed ERC at 5 μg/mL was effective in rescuing RGC-5 cells from the detrimental effect of serum deprivation by significantly maintaining viability, decreasing apoptotic markers caspases 3/7, 8 and 9 and significantly reducing the number of Hoechst-positive apoptotic RGC-5 cells. The extract also significantly increased the levels of GSH and GST. ERC therefore exhibits its neuroprotective activities by modulating caspase-dependent apoptosis in an in vitro model of retinal degeneration and enhancing radical scavenging properties in simulated oxidative stress conditions.