Evaluation of antioxidant activity of sour cherry stalk extracts by in vitro methods

In this study, the antioxidant activities of sour cherry (Prunus cerasus L.) stalk extracts were investigated using β-caroten/linoleic acid, metal chelating, reducing power, DPPH radical scavenging, ABTS method and TEAC method. For this purpose the stalks were extracted separately by using distilled water, methanol, ethyl acetate and hexane solvents following dried and ground to fine powder. The antioxidant activities of extracts prepared at the different concentration (100-1000 μg/mL) were compared with α-tocopherol, ascorbic acid, BHT and BHA standards. The methanol extract of stalk had the highest yield (22%). Chelating activities (Fe2+) of methanol extract at 100-1000 μg/mL concentrations ranged between 18.45 and 67.75%. However, chelating activities of all test extracts were found lower than standards. The reducing power of all extracts except hexane increased depending upon the increase in concentration. DPPH radical scavenging activity of methanol extract varied in the range of 14.57 to 85.78%. The lowest EC50 value was determined as 0.494 μg/mL for methanol extract. But, the highest inhibition percentage of linoleic acid oxidation was found in hexane extract (57.22%). TEAC values of methanol extract ranged from 15.43 to 20.54 μM Trolox equivalent/10 g. It was determined that methanol extract showed a dose-dependent inhibition on the antioxidant activities.