Evaluation of the antioxidant activity of donepezil - in vitro study

[...]in this study, we have evaluated the antioxidant potential of drug using 1,1 diphenyl 2 picrylhydrazine (DPPH) and nitric oxide (NO) synthase assay. [14,15] Most of the currently known antioxidants have limited ability to cross blood-brain barrier. [...]the development of smaller molecules which are readily/easily crosses the barrier into the brain offers much promise. [...]this aspect has not been properly investigated. [...]the present study was aimed at in vitro antioxidant effect of donepezil by 1,1 diphenyl 2 picrylhydrazine (DPPH) and NO assay method. Griess reagent contains 1% sulfanilamide, 2% phosphoric acid, and 0.1% naphthyl ethylenediamine dihydrochloride in 100 ml of distilled water. 3 ml of a reaction mixture containing sodium nitroprusside (10 mM in phosphate buffer saline) and various concentrations (10, 50, 100, 200, 400, and 800 pg/ml) ofthe test drug were incubated at 37°C for 4 h. To the incubation solution, 0.5 ml of Griess reagent was added, and the absorbance was read at 546 nm using a spectrophotometer.