DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity of crude extract and various fractions of Crocus sativus

Abstract

Oxidative stress is one of the major etiologic factors that form the basis of wide range of chronic and degenerative diseases. The antioxidant compounds found in medicinal plants have, therefore, gained an extensive academic interest because of their potential therapeutic value. In the DPPH (2,2-diphenyl-1-picrylhydrazyl), assay, the radical-scavenging activity of the crude methanolic extract and solvent-partitioned extracts of the dried stigmas of Crocus sativus L. were examined. The crude extract was then subjected to consecutive liquid liquid partitioning using n- hexane, chloroform, ethyl acetate, methanol and n-butanol to give separate fractions. Antioxidant activity was assessed at concentrations ranging from 10 to 100 µg/mL. All the fractions had concentration-dependent radical-scavenging activity. The polar fractions including the n-butanol and methanol fractions showed the greatest percentage scavenging of up to 91.35%. Conversely, the non-polar fractions had relatively low activity. These results highlight the central role of solvent polarity in the effectiveness of bioactive compound extraction. The strong antioxidant activity of the polar fractions of saffron is an indicator of the potential of the fractions as natural sources of antioxidants with possible uses in the nutraceutical and pharmaceutical industries.