Euphorbiasteroid induces neurotoxicity through the FOXO/NF-κB/apoptosis signaling pathway

Background

Euphorbiasteroid, a bioactive compound from Euphorbia lathyris L., exhibits significant pharmacological effects, including anti-tumor activity and multi-drug resistance reversal. However, its potential neurotoxicity limits its clinical use. This study investigates the neurotoxic effects of euphorbiasteroid and elucidates the underlying mechanisms.

Methods

Neurotoxicity was evaluated in differentiated PC12 cells and primary astrocytes through cell viability and lactate dehydrogenase (LDH) assays. Transcriptomic analysis was employed to predict the involvement of the Forkhead box O (FOXO), nuclear factor-kappa B (NF-κB), and apoptosis pathways in euphorbiasteroid-induced cytotoxicity. Apoptosis was detected using TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, and western blot analysis of quantified apoptotic markers and key signaling proteins. Molecular docking studies explored the interaction between euphorbiasteroid and FOXO3A, while gene knockdown experiments assessed the role of FOXO3A.

Results

Euphorbiasteroid significantly induced cytotoxicity in differentiated PC12 cells and primary astrocytes, linked to the activation of the FOXO, NF-κB, and apoptosis pathways. Apoptosis was confirmed by TUNEL staining, Bax/Bcl-2 ratio, and cleaved caspase 3 levels. Additionally, euphorbiasteroid reduced phospho-FOXO3A levels, promoted FOXO3A nuclear translocation and enhanced NF-κBp65 phosphorylation. Molecular docking revealed direct binding of euphorbiasteroid to FOXO3A, and FOXO3A knockdown substantially mitigated its neurotoxicity.

Conclusion

Euphorbiasteroid induces neurotoxicity through the activation of the FOXO/NF-κB/apoptosis signaling pathway. These findings provide new insights into the mechanisms of euphorbiasteroid-induced neurotoxicity and suggest potential strategies to mitigate these effects, which is crucial for its therapeutic application.