Nitric Oxide Inhibition and Procollagen Type I Peptide Synthesis Activities of a Phenolic Amide Identified from the Stem of Miller.

The bioactivities of boxthron fruits, a source of oriental medicine, are well known, whereas phytochemical studies of the boxthorn stem are rare. In this study, the stem extract of boxthorn ( Miller) and its subfractions were evaluated for their effects on nitric oxide (NO) inhibition and procollagen type I peptide (PIP) synthesis. A phenolic amide isolated from the stem extract was also assayed for these effects. The compound, feruloyltyramine, was identified by H, C, and 2D-nuclear magnetic resonance analyses. In NO inhibition, the chloroform fraction (CF) exhibited the strongest inhibitory activity (MIC = 24.69 μg/ml) among the subfractions of the ethanol extract (EE). N-transferuloyltyramine isolated from the CF showed strong NO inhibitory activity, presenting with an MIC of 31.36 μg/ml. The EE, CF, and feruloyltyramine shown to have NO inhibition activity were assayed for the activity of PIP synthesis. The EE and CF showed relatively high PIP values of 38.8% and 24.21% at 100 μg/ml, respectively. The PIP value for 20 μg/ml feruloyltyramine showed a 36% increase compared with the non-treated control, whereas that treated with 20 μg/ml ascorbic acid as a positive control showed a 13% increase. The results suggest that the proper stem extract of boxthorn stem could be efficiently used to produce good cosmetic effects.