Iron-reducing and free-radical-scavenging properties of apomorphine and some related benzylisoquinolines.
The scavenging and iron-reducing properties of a series of benzylisoquinolines of natural and synthetic origin have been studied. Bulbocapnine, boldine, glaucine, and stepholidine acted as scavengers of hydroxyl radical in the deoxyribose degradation by Fe(3+)-EDTA + H2O2. On the contrary, laudanosoline, apomorphine, protopapaverine, anonaine, and tetrahydroberberine increased deoxyribose degradation by a mechanism related to generation of superoxide anion. Only apomorphine had a stimulating effect in the system using citrate instead of ethylenediaminetetraacetic acid (EDTA) as well as in the absence of chelator. Apomorphine also stimulated DNA damage by Cu2+. The iron-ion reducing ability of apomorphine and laudanosoline was confirmed using cytochrome c. Both compounds scavenged peroxyl radicals in an aqueous medium, while in Fe(3+)-induced microsomal lipid peroxidation apomorphine acted as an inhibitor and laudanosoline stimulated the process. It is suggested that in microsomes the chain-breaking antioxidant properties of apomorphine overcome its possible influence on redox cycling of iron, or prooxidant properties.
Departamento de Farmacologia, Facultad de Farmacia, Valencia, Spain.
A
A
Ubeda
C
C
Montesinos
M
M
Payá
M J
MJ
Alcaraz
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D003855:Deoxyribose / Q000378:metabolism; D004492:Edetic Acid / Q000378:metabolism; D005290:Ferric Compounds / Q000378:metabolism; D016166:Free Radical Scavengers; D005609:Free Radicals; D006861:Hydrogen Peroxide / Q000378:metabolism; D006878:Hydroxides / Q000378:metabolism; D017665:Hydroxyl Radical; D007501:Iron / Q000378:metabolism* / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008862:Microsomes, Liver / Q000378:metabolism; D010084:Oxidation-Reduction; D010545:Peroxides / Q000378:metabolism; D051381:Rats; D013481:Superoxides / Q000378:metabolism / Q000494:pharmacology
D003574:Cytochrome c Group; D005290:Ferric Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D006878:Hydroxides; D007546:Isoquinolines; D010545:Peroxides; D013481:Superoxides; C049375:perhydroxyl radical; D017665:Hydroxyl Radical; D003855:Deoxyribose; D003300:Copper; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D007501:Iron; C019179:Fe(III)-EDTA; D001058:Apomorphine