Effects of phenolic constituents of Luffa cylindrica on UVB-damaged mouse skin and on dome formation by MDCK I cells

We showed that Luffa cylindrica extract prevented transepidermal water loss in UVB-irradiated hairless mice. Phenolic constituents were detected in L. cylindrica by high-performance liquid chromatography, and 12 phenylpropanoids were isolated and confirmed by NMR and negative-ion mode mass spectroscopy. 4-O-caffeoyl-glucose, 6-O-caffeoyl-glucose, 4-O-p-coumaroyl-glucose, 6-O-p-coumaroyl-glucose, 4-O-feruloyl-glucose, 6-O-feruloyl-glucose, caffeic acid, and ferulic acid were isolated from L. cylindrica for the first time. The L. cylindrica extract and phenylpropanoids were found to promote the dome formation by Madin-Darby canine kidney I epithelial cells, with p-coumaric acid being the most effective. Furthermore, p-coumaric acid upregulated the expression of aquaporin-3 (AQP3) mRNA in a dose- and time-dependent manner. These results suggested that L. cylindrica extract enhances the water permeability of the skin, owing to the AQP3 expression induced by p-coumaric acid. Therefore, L. cylindrica extract might contribute to the treatment of diseases such as dry syndrome, which cause the tissue's inability to retain moisture.