are colchicine metabolites chain-breaking antioxidants?
Effective scavenging of reactive radicals and low reactivity of generated secondary antioxidant radicals towards vital intracellular components are two critical requirements for a chain-breaking antioxidant. Tubulin-binding properties aside, colchicine metabolites remain largely untested for other possible biological activities, including antioxidant activity. Mourelle et al. [Life Sci. 45 (1989) 891] proposed that colchiceine (EIN) acts as an antioxidant and protective agent against lipid peroxidation in a rat model of liver injury. Since EIN as well as two other colchicine metabolites, 2-demethylcolchicine (2DM) and 3-demethylcolchicine (3DM), possess a hydroxy-group on their carbon ring that could participate in radical scavenging, we tested whether they can act as chain-breaking antioxidants. Using our fluorescence-HPLC assay with metabolically incorporated oxidation-sensitive cis-parinaric acid (PnA) we studied the effects of colchicine metabolites on peroxidation of different cla
