Screening of antioxidant properties of seven Umbelliferae fruits from Iran.

Antioxidative activities (IC(50)) of ethanol extracts from seven Umbelliferae fruits (Bunium persicum, Coriandrum sativum, Cuminum cyminum, Foeniculum vulgare, Heracleum persicum, Pimpinella anisum and Trachyspermum copticum) have been studied by the DPPH (2,2'-diphenyl-1-picrylhydrazyl) radical scavenging test. All the studied extracts showed antioxidant capability and P. anisum extract exhibited the strongest activity. The scavenging activity of the extracts in decreasing order was: P. anisum> T. copticum> C. cyminum> F. vulgare > or = B. persicum > or = C. sativum> H. persicum. The extracts were also investigated regarding their total flavonoid contents by the AlCl3 technique. The decreasing order of the flavonoid content of the extracts was: C. cyminum > T. copticum> P. anisum > or = H. persicum > or = B. persicum > or = F. vulgare > or = C. sativum. However, a favorable correlation was not found between the antioxidant activity and the total flavonoid content of the extracts. As well, the most active extract (i.e. P. anisum) was partitioned with n-hexane, chloroform and ethyl acetate to yield three organic fractions together with the remaining aqueous fraction. The antioxidative activities (IP%) and flavonoid contents of the fractions were also determined. The ethyl acetate fraction exhibited the highest activity and content. A positive correlation was found between the antioxidant potency and flavonoid content of the fractions.