1. Neurotoxic Effects of Salsolinol Jung Hoon Kang Department of Genetic Engineering Cheongju University

2. Endogenous dopaminergic neurotoxin (1-metyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline)  Detection in urine of parkinsonian patients administered with L-DOPA (Sandler et.al., 1973)  The progression of disease characterized by dysfunction of dopaminergic neuron  A neuromodulator of dopaminergic neurotransmission

3. Role of salsolinol in catecholamine system  Selective neuronal cell death through reactive oxygen species (ROS)  Inhibition of mitochondrial complex II activity  Alteration of protein synthesis in the endoplasmic reticulum

4. Role of salsolinol in Parkinson´s disease (PD)  Salsolinol and its metabolites involved in the etiopathogenesis of PD  Increased activity of N-methyl transferase, catalyzing the synthesis of N-methyl-salsolinol from salsolinol  Salsolinol derivatives as a biological marker for PD  The regulation of the nigrostriatal system activity  Increase or decrease the formation of hydroxyl radicals

5. The role of salsolinol in addiction  Salsolinol is a condensation product of the alcohol metabolite acetaldehyde and dopamine  Involvement of salsolinol in the balance of the reward system and the opio system  Decrease of pro-opiomelanocortin gene expression  Involvement of salsolinol in the establishment of opioid deficiency in alcoholism  It is not a sufficient marker for distinguish between alcoholics and a non-alcoholics

6. Biosynthesis of salsolinol

7. Derivatives of salsolinol

9. Role of salsolinol as a generator of ROS  Selective neuronal cell death through ROS  Increase the formation of hydroxyl radicals  Hydroxyl radicals induced DNA damage, protein modification and lipid peroxidation ● Transition metal ions (Fe 2+, Cu 2+ ) reduce H 2 O 2 to yield hydroxyl radicals

10. OC LN SC 1 2 3456789 10 SAL(μM) Cu 2+ (μM) Fe 3+ (μM) −−−−300 −− − −−−− 100 −−− − 1050 100 1050 100 1050 100 DNA cleavage by salsolinol and transition metal ions

11. Some typical chromosomal aberrations Jung, Y.J. et.al.,(2001) Mutation Research, 474, 25-33.

12. Analysis of salsolinol-mediated cell death with or without copper Kim, H.J. et.al., (2001) Molecular Phamacology, 60, 440-449. Control SAL SAL + Cu 2+

13. Antioxidant system Superoxide dismutase, Glutathione peroxidase, Catalase, etc. α-Tocopherol, Ascorbate, Carotinoids, Glutathione, etc.

14. Superoxide dismutase (SOD) Cu,Zn-SOD (cytosol) Mn-SOD (mitochondria) Fe-SOD (plant, microorganism)  EC-SOD (plasma)

15. (A) (B) Modification of Cu,Zn-SOD by salsolinol

16. (A) (B) Carbonyl compound and Radical scavengers

17. (A) (B) Catalase and Copper chelators

18. (A) (B) Scavenger/chelator (mM) TBARS (nmole/mL) Inhibition of formation of TBARS (%) No addition Mannitol (100) Ethanol (100) Thiourea (20) DDC (5) 2.18  0.2 0.32  0.1 1.20  0.2 0.36  0.1 0.56  0.1 85  4.6 52  9.2 84  5.1 74  5.9 Reaction mixture containing 15 μM Cu,Zn-SOD, 1 mM salsolinol in 10 mM potassium phosphate buffer at pH 7.4, in the presence of each scavenger and copper chelator. Generation of hydroxyl radicals

19. (A) (B) (C) DNA strand breakage

20. (A) (B) Radical scavengers and Copper chelator

21. Modification of cytochrome c and ferritin

22. (A) (B) Aggregations of α-synuclein and neurofilament-L

23. Salsolinol O2O2 O 2 MnMn M n-1 MnMn Semiquinone radical O-Quinone M n = Cu 2+ or Fe 3+ Possible scheme of metal-mediated salsolinol toxicity Covalent adducts - protein - DNA - RNA Oxidative Damage of DNA & Neural protein /cell death SOD