Abstract Background Agastache rugosa (Fisch.& C.A.
Mey.) Kuntze (Korean mint) is used to treat diverse types of human disorders in traditional medicine.In recent years, its non-fermented leaf extract (ARE) has been shown to possess protective properties against ultraviolet-B (UV-B) radiation-induced photooxidative stress.
The present work aimed to examine whether probiotic bacterial fermentation would potentiate the skin anti-photoaging activity of ARE or not, by comparing the protective properties of ARE and corresponding fermented extract (ARE-F) against UV-B radiation-induced photooxidative stress in HaCaT keratinocytes.Methods ARE-F was produced from ARE by the fermentation with Lactobacillus rhamnosus Hair Cream HK-9, a type of Gram-positive probiotic bacterial strain.Anti-photoaging activities were evaluated by analyzing reactive oxygen species (ROS), promatrix metalloproteinases (proMMPs), total glutathione (GSH) and total superoxide dismutase (SOD) in UV-B-irradiated HaCaT keratinocytes.
Antiradical activity was determined using 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) Easel Calendar radical scavenging assay.Results ARE-F contained higher attenuating activity on the UV-B-induced ROS generation than ARE.Similarly, ARE-F was able to diminish the UV-B-induced proMMP-9 and -2 more effectively than ARE.
ARE-F displayed higher tendencies to augment the UV-B-reduced total GSH content and SOD activity than ARE.However, there were no significant difference between ARE and ARE-F in ABTS radical scavenging activities.Conclusions The findings suggest that the UV-B radiation-protective activity of ARE is enhanced by probiotic bacterial fermentation, which might improve the therapeutic and cosmetic values of A.
rugosa leaves.