Chemical investigation and anti-inflammatory activities of the aerial part of Filipendula palmata

Ethnopharmacological relevance: Filipendula palmata Maxim. as an ethnic herb is commonly used by Oroqen minority people in the treatment of rheumatism in China and as a wild vegetable is eaten by Russian in the Far East area. However, so far, the chemical constituents and bioactivity of this edible herb are still unclear, especially the anti-inflammatory constituents and action have not been elucidated despite the traditional folk use. Aim of study: The current study was conducted to investigate the main chemical components of the aerial part of F. palmata and evaluate the anti-inflammatory and antioxidant and cytotoxic activities of the extract and the isolated constituents. Materials and methods: Various chromatographic techniques including silica gel, ODS, HPLC were used to isolate the components and several spectroscopic methods such as UV, IR, MS and NMR were adopted to characterize the structures of the compounds. The inhibitory action of the extract and components on the production of nitric oxide stimulated by LPS in RAW264.7 cells was applied to evaluate the anti-inflammatory activity and the MTT method was used to investigate the cytotoxicity. In addition, the antioxidant capacity of F. palmata was measured in three in vitro assays including DPPH and hydroxyl radicals scavenging and FRAP experiments. Results: The bioactivity research demonstrated that the EtOAc fraction and n-BuOH fraction of this ethnic herb possessed potent anti-inflammation activity in RAW264.7 macrophages and antioxidant activity in three in vitro assays. The chemical study on the EtOAc fraction led to a new dihydrophenanthrene derivative, filipendutin A (1), together with 9 known compounds from the herb, in which compound 4 could significantly inhibit the production of nitric oxide in RAW264.7 cells, while compounds 1 and 9 exhibited obvious cytotoxicity in cells. Conclusions: These results demonstrated that F. palmata had significant anti-inflammatory and antioxidant activities and could be used in the treatment of inflammatory diseases. Meanwhile, the cytotoxic activity of EtOAc fraction and its components also indicated the potential application in antitumor which remained the further study in the future.