Effect of TJ-960 (a Japanese herbal medicine) on free radical changes within an iron-induced focal epileptogenic region in rat brain measured by in vivo L-band electron spin resonance.

In vivo L-band electron spin resonance (ESR) system was used to measure the decay of nitroxide radicals in the living rat cerebrum containing a cortical area with an iron-induced epileptogenic region. Carbamoyl-PROXYL (3-carbamoyl-2,2,5,5-tetramethyl-1-pyrrolinyloxy) was injected intraperitoneally. The decay of nitroxide radicals in the iron-injected regions at the subacute stage of epileptogenesis was prolonged. The Japanese herbal medicine, sho-saiko-to-go-keishi-ka- shakuyakuto (TJ-960), a compound known to have free radical scavenging activity, inhibited the delay of nitroxide radical decay in the rat cerebrum with an iron-induced epileptic focus following injection of carbamoyl-PROXYL. TJ-960 did not affect the decay of nitroxide radicals in the control rats' brain. These data show that TJ-960 has the scavenging activity for free radicals generated within an iron-induced epileptogenic regions of rat brain.