Antioxidant activity and total phenolic contents of three Bupleurum taxa.

Bupleuri Radix (Bupleurum spp. root) is one of the most important crude drugs in Korea, China and Japan. We investigated the total phenolic content and antioxidant activity of three Bupleurum taxa (B. falcatum, B. falcatum 'Mishima' and B. latissimum). The highest total phenolic content was found in B. latissimum (18.6 +/- 1.7 mg/g) and the least in B. falcatum 'Mishima' (9.4 +/- 0.5 mg/g). The ethyl acetate fractions obtained from B. falcatum and B. falcatum 'Mishima' showed higher DPPH radical scavenging activity than the other fractions. In the case of B. latissimum, the DPPH radical scavenging activity of the diethyl ether fraction was higher than that of the other fractions. These results suggest that the three Bupleurum plants may be used as a food additive as a natural antioxidant.