Antioxidant and anti-inflammatory activities of Thunb. var. Hayata flower bud extracts prepared by water, ethanol and supercritical fluid extraction techniques.

Thunberg () has long been used as an antipyretic, anti-inflammatory and anti-infectious agent in East Asia. The subspecies Thunb. var. Hayata () is a variant that mainly grows in Taiwan. This study examined the antioxidant and anti-inflammatory activities of the extracts from the flower buds of these two species. The extracts were obtained by three extraction methods: water extraction, ethanol extraction, and supercritical-CO fluid extraction (SFE). The antioxidant activities of dry (dLJ) extracts were superior to those of extracts. Water extracts possessed higher activities than that prepared by ethanol or SFE. The total polyphenols content, total flavonoids content, and the amount of chlorogenic acid and luteolin-7--glucoside were all higher in the water extracts compared to the other two. The SFE extracts of these two species all exhibited excellent anti-inflammatory activities. Although the water and ethanol extracts of dLJ extracts had higher anti-inflammatory activity than that of extracts, the SFE extracts prepared from fresh flower buds (fLJv) exhibited the highest activity among all extracts. The SFE effectively isolates the bioactive components of and can obtain the extracts with high anti-inflammatory activity.