Antioxidant potential of new pyrazoline derivatives to prevent oxidative damage.

摘要

The antioxidant capacity of a series of six novel synthetic pyrazoline derivatives (i) 5-hydroxy-3-methyl-5-trifluoromethyl-4,5-dihydro-1H-carbaldehyde-pyrazole, (ii) 5-hydroxy-3-methyl-5-trifluoromethyl-4,5-dihydro-1H-1-acetyl-pyrazole, (iii) 5-hydroxy-3-methyl-5-trifluoromethyl-4,5-dihydro-1H-carboxyamide-pyrazole, (iv) 5-hydroxy-3-methyl-5-trifluoromethyl-4,5-dihydro-1H-1-benzoyl-pyrazole, (v) 5-hydroxy-3-methyl-5-trifluoromethyl-4,5-dihydro-1H-1-(2-hydroxybenzoyl)-pyrazole and (vi) 5-hydroxy-3-methyl-5-trifluoromethyl-4,5-dihydro-1H-1-(4-methoxybenzoyl)-pyrazole was evaluated as the capacity of compounds to transfer a hydrogen atom (protection against brain lipid peroxidation and glutathione oxidation) and their capacity to transfer a single electron [ferric-reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging (DPPH) assays]. Compound 5 had the highest free radical scavenging capacity in the DPPH assay, while compound 2 had the highest FRAP value (P < 0.05). Only compounds 1, 4 and 5 protected against lipid peroxidation in rat brain homogenate. However, compound 5 was the most effective to prevent basal and iron-, sodium nitroprusside- and H(2)O(2)-stimulated lipid peroxidation (IC(50) < 15 microM) and the only one effective to block glutathione oxidation-mediated by H(2)O(2) (at 150 microM). Our results indicate that compound 5 has the greatest potential to prevent oxidative damage in brain homogenates.