Antioxidant properties of hydro-alcoholic extract and extract of nepeta crispa in Lorestan province

Introduction: antioxidants protect body against the oxidative stress caused by free radicals. this study aims at comparing the antioxidant properties of hydro-alcoholic extract and extract of nepeta crispa (from its shoot part). methods: the study was carried out in lorestan university of medical sciences in 2012. both hydro-alcoholic extract and essence of nepeta crispa were prepared and antioxidant properties of samples were assessed using different methods. the ability to inhibit free radicals production was measured through 2, 2-diphenyl-1-picrylhydrazyl (dpph) method. total antioxidant capacity was measured using phosphomolybdate method. likewise, phenol and flavonoid compounds of samples were measured using folinciocalteu zishen method. results: the results showed that the total antioxidant capacity of hydro-alcoholic extract and essence of nepeta crispa were equal to 0.23±0.12 and 0.82±0.40 nmol ascorbic acid per gram extract or essence. the phenol content of hydro-alcoholic extract and essence of nepeta crispa were 254.63±15.75 and 6.94±1.37 mg gallic acid per gram extract or essence, respectively. flavonoid content of hydro-alcoholic extract and essence of nepeta crispa were equal to 5.53±0.34 and 0.36±0.06 mg quercetin per gram extract or essence, respectively. ic50 value (concentration that will inhibit 50% of free radicals production), hydro-alcoholic extract, essence of plant and butylated hydroxytoluene (bht), as positive control, were equal to 2.09±0.11, 6.05, and 3.88±1 μg/ml, respectively. conclusion: the results showed that the hydro-alcoholic extract has better antioxidant properties in contrast to essence of nepeta crispa. as a result, hydro-alcoholic extract of nepeta crispa is a good and available source of antioxidant compounds which can be used, if useful, in food, pharmaceutical and industrial products.