The antioxidative activity of traditional Japanese herbs.

The objective of this research was to examine the radical scavenging activity of traditional Japanese herbs. Samples used in the experiments were gennoshoko (Geranium nepalense var. thunbergii), yomogi (Artemisia vulgaris var.indica), senburi (Swertia japonica), iwa-tobacco (Conandron ramondioides), sarunokoshikake (Elfvingia applanata), kanzo (Glycyrrhiza uralensis Fisch) and matatabi (Actinidia polygama). The water-soluble components of the herbs were extracted in boiling water, and the volatile oil was extracted by a distillation apparatus or steeping in some organic solvents such as petroleum ether and ethyl ether. The radical scavenging activity was determined by the decrease of free radicals of DPPH detected by both colorimetric assay and HPLC method at 517 nm. The extracts of gennoshoko, yomogi and iwa-tobacco showed remarkable radical scavenging activity. The volatile oil of yomogi obtained by distillation or steeping in organic solvents had especially strong antioxidative activity.