Attenuating properties of Agastache rugosa leaf extract against ultraviolet-B-induced photoaging via up-regulating glutathione and superoxide dismutase in a human keratinocyte cell line.

Agastache rugosa Kuntze, known as a Korean mint, is an herbal medicine that has been used for the treatment of diverse kinds of symptoms in traditional medicine. This work was undertaken to assess the protective properties of A. rugosa leaves against UV-B-induced photoaging in HaCaT keratinocytes. They were evaluated via analyzing reactive oxygen species (ROS), promatrix metalloproteinase-2 (proMMP-2) and -9 (proMMP-9), total glutathione (GSH), total superoxide dismutase (SOD), cellular viability, flavonoid content and in vitro radical scavenging activity. Total flavonoid content of ARE, a hot water extract of A. rugosa leaves, was 22.8±7.6mg of naringin equivalent/g ARE. ARE exhibited ABTS(+) radical scavenging activity with an SC50 of 836.9µg/mL. ARE attenuated the UV-B-induced ROS generation. It diminished the UV-B-induced elevation of proMMP-2 and -9 at both activity and protein levels. On the contrary, ARE was able to enhance the UV-B-reduced total GSH and total SOD activity levels. ARE, at the used concentrations, was unable to interfere with the cellular viabilities of HaCaT keratinocytes under UV-B irradiation. Taken together, ARE possesses a protective potential against UV-B-induced photoaging in HaCaT keratinocytes, possibly based upon up-regulating antioxidant components, including total GSH and SOD. These findings reasonably suggest the use of A. rugosa leaves as a photoprotective resource in manufacturing functional cosmetics.

Stereoselective suppressive effects of protopanaxadiol epimers on UV-B-induced reactive oxygen species and matrix metalloproteinase-2 in human dermal keratinocytes.

This study aimed to assess the skin-related anti-photoaging activities of the 2 epimeric forms of protopanaxadiol (PPD), 20(S)-PPD and 20(R)-PPD, in cultured human keratinocytes (HaCaT cells). The anti-photoaging activity was evaluated by analyzing the levels of reactive oxygen species (ROS) and matrix metalloproteinases (MMPs), as well as cell viability for HaCaT cells under UV-B irradiation. The activities for MMP-2 and -1 in conditioned medium were determined using gelatin zymography, and MMP-2 protein in the conditioned medium was detected using Western blot analysis. 20(S)-PPD, but not 20(R)-PPD, suppressed UV-B-induced ROS elevation. Neither of the epimers, at the concentrations used, exhibited cytotoxicity, irrespective of UV-B irradiation. 20(S)-PPD, but not 20(R)-PPD, exhibited an inhibitory effect on UV-B-induced MMP-2 activity and expression in HaCaT cells. In brief, only 20(S)-PPD, a major metabolic product of PPD-type ginsenosides, inhibits UV-B-induced ROS and MMP-2 elevation, implying its stereospecific anti-photoaging activity on the skin.