Radical scavenging and antioxidant activities of the extracts of globe artichoke outer bracts

Abstract

This study investigates the antioxidant activities of extracts obtained from the outer bracts of globe artichoke using the Soxhlet extraction (SE) method. To investigate the polarity effect on antioxidant activity, the extracts were prepared in distilled water, ethanol, or ethyl acetate. Different antioxidant activity determination methods were applied. According to our results, the extracts prepared with ethanol (SE-Ethanol) showed the highest total phenolic compounds (182.19 mu g pyrocatechol equivalent/mg extract), the greatest sum chlorophyll amount (10.81 mu g/mL), the highest metal chelating activity (47.10 %), the highest reducing power, the highest ABTS'+ (85.47 %), and DPPH' scavenging activity (89.42 %). However, the extracts prepared using distilled water in Soxhlet extraction (SE-Water) showed the highest proline amount (41.75 mu g proline/mg extract) and the highest DMPD radical scavenging activity (93.32 %). The highest total flavonoid content (168.44 mu g catechin equivalent/mg extract) was observed in the extracts prepared with ethyl acetate (SE-Ethylacetate).