RESUMO
UNLABELLED: O BJECTIVE: Venlafaxine (VLF) was examined as a potential donor of H atom(s) to scavenge hydroxyl and peroxy-type radicals generated under aerobic conditions by catalytic oxidation of ascorbate with Cu²âº ions. Kinetics of the electron-donor property of VLF was investigated by standard ABTS and DPPH assays. Electron paramagnetic resonance measurements were applied to prove/disprove the VLF ability to scavenge superoxide anion radical. RESULTS: Results indicated that the drug venlafaxine was slightly capable of donating ·H, this way VLF scavenged the in situ generated hydroxyl radicals. Under the experimental conditions VLF was not able to inhibit/retard the propagation of the peroxy-type radicals. Regarding to the drug electron donating property, VLF did not show any ABTS·âº or DPPH· radical quenching property. Venlafaxine was not effective in scavenging O2·â». CONCLUSION: Results of ABTS and DPPH assay showed a negligible redox activity of venlafaxine to both DPPH· and ABTS·âº. Venlafaxine was not capable of scavenging the superoxide anion radical generated in KO2/DMSO system, which indicates that VLF is not an efficient electron/proton donor molecule.
Assuntos
Sequestradores de Radicais Livres/farmacologia , Cloridrato de Venlafaxina/farmacologia , Espectroscopia de Ressonância de Spin Eletrônica , Elétrons , Sequestradores de Radicais Livres/química , Radical Hidroxila/química , Oxirredução , Superóxidos/química , Fatores de Tempo , Cloridrato de Venlafaxina/químicaRESUMO
OBJECTIVES: To assess protective effects of the tara (Caesalpinia spinosa) extract against hyaluronan (HA) degradation evoked by cupric ions and ascorbate. METHODS: Uninhibited/inhibited HA degradation was assayed by a decrease in dynamic viscosity of the HA solutions, whereas as a method rotational viscometry was used. To determine radical scavenging capacity of the tara extract, the ABTS and DPPH assays were performed. RESULTS: The results of rotational viscometry showed remarkable protective effects of the tara extract against the degradation of HA. In the ABTS and DPPH assays the IC50 values of the tara extract 1.59 and 30.8 µg/mL indicated quite high radical scavenging properties. CONCLUSION: The tara extract is an efficient antioxidant as demonstrated by the methods used.
