Osthole attenuated cytotoxicity induced by 6-OHDA in SH-SY5Y cells through inhibition of JAK/STAT and MAPK pathways

Natural coumarin called osthole is regarded as a medicinal herb with widespread applications in Traditional Chinese Medicine. It has various pharmacological properties, including antioxidant, anti-inflammatory, and anti-apoptotic effects. In some neurodegenerative diseases, osthole also shows neuroprotective properties. In this study, we explored how osthole protects human neuroblastoma SH-SY5Y cells from the cytotoxicity of 6-hydroxydopamine (6-OHDA). 

Using the MTT assay and DCFH-DA methods, respectively, the viability of the cells and the quantity of intracellular reactive oxygen species (ROS) were evaluated. Signal Transducers and Activators of Transcription (STAT), Janus Kinase (JAK), extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and caspase-3 activation levels were examined using western blotting.

In SH-SY5Y cells, the results showed that a 24-hour exposure to 6-OHDA (200 µM) lowered cell viability but markedly elevated ROS, p-JAK/JAK, p-STAT/STAT, p-ERK/ERK, p-JNK/JNK ratio, and caspase-3 levels. Interestingly, osthole (100 µM) pretreatment of cells for 24 hr prevented 6-OHDA-induced cytotoxicity by undoing all effects of 6-OHDA. 

In summary, our data showed that osthole protects SH-SY5Y cells against 6-OHDA-induced cytotoxicity by inhibiting ROS generation and reducing the activity of the JAK/STAT, MAPK, and apoptotic pathways.