Scavenging Effect of Korean Medicinal Plants on the Peroxynitrite and Total ROS

To discover the sources with antioxidative activity in traditional medicines, 100 extracts of Korean medicinal plants were screened for their scavenging effect on peroxynitrite $(ONOO^{-})$ and total reactive oxygen species (ROS). The potency of total ROS scavenging activity was shown in the extracts of 25 plants, and 4 of their species, Macleaya cordata R. Br., Salvia plebeia R. Br., Cassia tora L. and Angelica gigas Nakai, had a greater effect with $IC_{50}$ values of $1.7{\pm}0.36$, $4.3{\pm}1.08$, $4.9{\pm}0.17$ and $5.8{\pm}1.01\;{\mu}g/ml$, respectively, than that of trolox, positive control $(7.61{\pm}0.12\;{\mu}g/ml)$. Another 35 extracts exhibited inhibitory effect of below 50 percent at $100\;{\mu}g/ml$ of sample concentrations on total ROS, while the rest observed total ROS generators rather than scavengers. The peroxynitrite scavenging activities were observed in the greater part of the plants tested. Five of them, Schisandra chinensis Baill, Campsis grandiflora (Thunb.) K. Schum., Cedrela sinensis A. Juss., Pleuropterus multiflorus Turcz. and Veronica linariaefolia Pall represented scavenging activities on peroxynitrite twice as strong with $IC_{50}$ Values of $0.48{\pm}0.10$, $0.59{\pm}0.15$, $0.60{\pm}0.10$, $0.64{\pm}0.10$ and $0.91{\pm}0.23\;{\mu}g/ml$, respectively, as that of penicillamine $(1.72{\pm}0.05\;{\mu}g/ml)$, positive control. Consequently, 25 species of the entire plants tested, exhibited scavenging activities on total ROS and $ONOO^{-}$, Salvia plebeia R. Br., Macleaya cordata R. Br., Cassia tora L. and Angelica gigas Nakai exerted potent scavenging activities on both radicals.