Salsolinol, a Dopamine-derived Tetrahydroisoquinoline, Occur in Dopaminergic SH-SY5Y Cells Induced by Dopamine

The dopamine-derived salsolinol (Sal), 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, has been considered a potential endogenous neurotoxin involved in the etiology of PD. In the present study, 150 muM dopamine (DA) was applied to be the treatment concentration on account of that 150 muM DA decreased cell viability to 44.8%. The level of salsolinol in human dopaminergic SH-SY5Y cells treated with 150 muM DA for 24 h was measured using high-performance liquid chromatography with electrochemical detection (HPLC-ECD), and the possible mechanism of salsolinol formation in SH-SY5Y cells was discussed. DA significantly increased the production of hydroxyl radicals quantitatively measured after derivatization as 2, 3-and 2, 5-DHBA by reaction with salicylic acid, and malonaldehyde (MDA), a marker of lipid peroxidation. Salsolinol increased remarkably in DA-induced cells compared to control cells. These results suggest that DA incubation and oxidative stress induced by excessive dopamine contribute to the synthesis of salsolinol in SH-SH5Y cells.