T. Sekine et al., EVALUATION OF SUPEROXIDE ANION-RADICAL SCAVENGING ACTIVITY OF SHIKONIN BY ELECTRON-SPIN-RESONANCE, International journal of pharmaceutics, 174(1-2), 1998, pp. 133-139
The scavenging activity of shikonin (SK) for superoxide anion radical
(O-2(.-)) was evaluated by electron spin resonance (ESR) to clarify th
e mechanism of the enhancing effect of SK on wound healing and its ant
i-inflammatory effect. SK quenched O-2(.-) in a dose-dependent manner.
Values for the O-2(.-) scavenging activity of SK were converted to va
lues representing the equivalent activity of superoxide dismutase (SOD
) and were termed SOD-like activity values. SK exhibited potent O-2(.-
) quenching activity and its SOD-like activity was calculated to be ab
out 920 U/mg. These results suggested that the O-2(.-) scavenging acti
vity of SK played an important role in enhancing wound healing and in
the anti-inflammatory effect of SK. No difference in O-2(.-) scavengin
g activity was observed between SK and its optical isomer alkannin. SK
was reduced to SK semiquinone radical by O-2(.-). The SK semiquinone
radical may be responsible for the anti-tumor and anti-bacterial effec
ts of SK. (C) 1998 Elsevier Science B.V. All rights reserved.