The root extracts of Paeonia lactiflora cv. ‘Red Charm’ has been studied by many groups, however, little attention has been paid to its flower petal. Paeonia is the genus in the Paeoniaceae family. ‘Red Charm’ Paeonia is a soft-stemmed herbaceous peony hybrid of P. officinalis and P. lactiflora. We previously showed the flower petal extract of Red Charm might have anti-oxidant and anti-inflammatory activities, however, it was not clear which components might be involved in this activity. Bioinformatics analysis previously indicated these extracts have potential anti-oxidant materials. One of them is identified as paeoniflorin, which is major component in root extract of Red Charm. In this study, we compared paeoniflorin and oxypaeoniflorin using DPPH assays to measure its anti-oxidant activities. Oxypaeoniflorin showed higher levels of radical scavenging activity, similar to ascorbic acid control, whereas paeoniflorin did not. Furthermore, nitric oxide assay showed they have similar anti-inflammatory effects. Taken together, these results suggest oxypaeoniflorin may play a more important role in the anti-oxidant activity of the flower petal and root extracts of Red Charm, compared to paeoniflorin. Further studies may be able to provide a platform to develop potential dual effects therapeutics for oxidant-mediated and inflammation-mediated disease in the near future.

Little attention has been paid to the functional aspect of the flower petal of Paeonia lactiflora, compared to that of its root. To determine the components of flower petal of Paeonia lactiflora, we conducted the Fourier transform ion cyclotron resonance (FT-ICR) MASS spectrophotometric analysis. We detected the 24 different types of ingredients from the 70% ethanol extracts of flower petal of peonia lactiflora cv. ‘Red Charm’. The main compounds were quercetin glucopyranosides, methyl gallate, paonioflolol and kaemperol glucopyranosides. We further tested its functional activity. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the extracts was 87.9-90.4% at 0.1mg/ml. This result showed that these flower extracts have approximately 5-fold stronger antioxidant potential than a previous report with root extracts (Bang et al. 1999). The result of tyrosinase inhibition assay of Paeonia lactflora extract was almost similar to that of arbutin except significantly higher effect in the coral sunset extract at 0.1% concentration. Hyaluronidase inhibition assay showed 76.5% inhibition at 5% concentration of this flower extract, indicating that Peaonia lactiflora flower extracts have the major anti-inflammatory, anti-oxidant and brightening effects. Taken together, these results suggest these three Paeonia lactiflora species extracts might provide the basis to develop a new natural brightening agent.