Detoxification of paraoxon-ethyl by Lysiphyllum strychnifolium extracts in undifferentiated human neuroblastoma SH-SY5Y cells.

Context: Lysiphyllum strychnifolium (Craib) A. Schmitz. (Fabaceae) is a Thai traditional medicine used to remove food and alcohol toxins from the body.

Objective: This study investigates the molecular mechanism of L. strychnifolium extracts against paraoxon-ethyl-induced apoptosis in SH-SY5Y cells.

Materials and methods: The ethanol and water extracts of leaves and stems of L. strychnifolium were prepared at various concentrations (0-100 μg/mL) and co-treated to the cells with 0.375 mM paraoxon-ethyl for 24 and 48 h. Cell viability was performed using the PrestoBlue assay. ROS and caspase activity were detected using 2',7'-dichlorodihydrofluorecein diacetate and caspase-Glo® 3/7, 8, and 9 assay kits. Apoptotic and ER stress-related gene expression were determined by real-time PCR, and nuclear and mitochondrial morphology were observed using Hoechst 33342 and MitoTracker® Deep Red FM staining.

Results: The most effective concentrations of each extract against paraoxon-ethyl-induced cell death were 25 μg/mL of leaf ethanol, 12.5 μg/mL of stem ethanol, 100 μg/mL of leaf water, and 25 μg/mL of stem water extracts. The leaf ethanol extract was the most effective at detoxifying, while stem extracts were highly toxic in high doses. The detoxifying L. strychnifolium extracts against paraoxon-ethyl-induced oxidative stress decreased p53, BiP/GRP78, and CHOP gene expression and minimized caspase 9 and caspase 3, protecting cells from apoptosis. The extracts could also restore mitochondrial membrane potential and reduce the swollen globule mitochondrial shape.

Discussion and conclusion: These findings could potentially protect neuron cells from neurodegenerative issues due to oxidative damage, apoptosis, and other potential consequences.