Neuroprotective effects of Salvia splendens extracts against rotenone-induced oxidative stress and cell death in SH-SY5Y cells

INTRODUCTION: Numerous studies in literature indicate that rotenone (ROT) has a cytotoxic effect on humans or animals, and it causes a neurodegenerative disease as Parkinson's Disease (PD). Our study showed that ROT can induce oxidative damage and cause neuronal loss in SH-SY5Y cells, an in vitro model of dopaminergic neuronal cells. Salvia splendens (S. splendens) can show an antioxidant, anti-inflammatory, and cholinergic effects on neuronal cells thanks to the phenolic compounds it contains.
METHODS: In this study, we investigated the neuroprotective effects of ethanol extracts prepared from aerial and root parts of S. splendens (AE and RE, respectively) against ROT-induced oxidative stress and neuronal loss in SH-SY5Y cells.
RESULTS: In the current study, ROT dose dependently increased neuronal cell loss in SH-SY5Y cells, and the IC50 value of ROT was determined as 40 µM. The optimum concentrations of AE and RE, which showed the maximum protective effect on SH-SY5Y viability, were determined as 195.3125 μg/mL in the presence of 40 µM ROT. AE and RE, at a concentration of 195.3125 μg/mL, in the presence of 40 µM ROT significantly increased the total antioxidant status (TAS) and did not create a significant difference in the total oxidant status (TOS). Additionally, AE and RE significantly decreased the oxidative stress index (OSI) value, as an indicator of total cellular oxidative stress, compared to the ROT group in the presence of ROT.
DISCUSSION AND CONCLUSION: In summary, AE and RE obtained from S. splendens protect the SH-SY5Y cells from ROT-induced damage through reducing oxidative stress and preventing neuronal cell loss.

Keywords: Salvia splendens, Rotenone, SH-SY5Y Neuroblastoma Cells, Oxidative Stress, Cell Death, Neuroprotective Effect