Effect of the rhizomes of Astilbe chinensis on UVB-induced inflammatory response

The EtOH extract from the rhizomes of Astilbe chinensis (Saxifragaceae) exhibited potent antioxidant activity in preliminary screening. Since oxidative stress is known to be involved in the inflammatory response after UVB exposure, the ability of an A. chinensis extract to inhibit UVB-induced PGE(2) and NO production was examined. UVB irradiation (35 mJ/cm(2)) increased PGE(2) and NO production, which were significantly decreased by pre-administration of the extract in a dose-dependent manner. The A. chinensis extract also preserved the cellular antioxidant capacity after UVB irradiation, which was determined by the GSH content. UVB irradiation enhanced the formation of ROS in the keratinocytes, which was determined using DCFH-DA, a redox sensitive dye. The levels of intracellular ROS were also significantly reduced by pre-treatment of the extract in a dose-dependent manner measured 9 h after UVB irradiation. The results suggest that the A. chinensis extract may have a protective effect on the UVB-injured keratinocytes by inhibiting PGE(2) and NO production, possibly through the inhibition of intracellular ROS accumulation. Copyright (C) 2004 John Wiley Sons, Ltd.