In vitro assessment of the anti-inflammatory and skin-moisturizing effects of Filipendula palmata (Pall.) Maxim. On human keratinocytes and identification of its bioactive phytochemicals.

ETHNOPHARMACOLOGICAL RELEVANCE: The meadowsweet family (genus Filipendula) includes about 30 species, which have been traditionally used in folk medicine to treat various inflammatory diseases. Particularily, F. palmata (Pall.) Maxim. (Siberian meadowsweet) were traditionally and widely used as an ethnic herb in the Oroqen application. AIM OF THE STUDY: Limited studies have been documented on most species, except for two main species, F. ulmaria (L.) Maxim. and F. vulgaris Moench. Thus, this study aimed to investigate the anti-inflammatory and skin-moisturizing effects of 70% ethanolic extract (FPE) of F. palmata on human epidermal keratinocytes. MATERIALS AND METHODS: HaCaT keratinocytes were treated with FPE under different conditions. Quantitative real time-PCR, enzyme-linked immunosorbent assay, western blotting methods were used to evaluate the effect and molecular mechanism of the cells treated with FPE. The bioactive compounds in FPE, which are responsible for biological activities, was explored using mass spectrometric analysis. RESULTS: FPE did not show a cytotoxic effect on the cells at concentrations below 200 µg/mL. FPE significantly suppressed the intracellular reactive oxygen species and mitochondrial superoxide of inflamed HaCaT cells induced by tumor necrosis factor-α and interferon-γ (T + I) and inflammatory chemokine genes and proteins, such as CC chemokine ligands (CCL5, CCL17, and CCL27) and CXC chemokine ligand (CXCL8). These anti-inflammatory activities of FPE were mediated by the downregulation of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways. In normal HaCaT cells, FPE significantly promoted the production of hyaluronic acid (HA) via the downregulation of hyaluronidase (HYAL1 and HYAL2) and upregulation of hyaluronic acid synthase (HAS1, HAS2, and HAS3) genes, and these effects seemed to be associated with the PI3K/Akt/NF-κB signaling. Ultraperformance liquid chromatography-tandem mass spectrometry indicated that FPE contains four flavonoids, including (+)-catechin, miquelianin, scutellarin, and quercitrin, as its major phytochemicals. Finally, we demonstrated that miquelianin and quercitrin contribute partially to the anti-inflammatory and HA-producing activity of FPE without cytotoxic effects on HaCaT cells. CONCLUSIONS: Our findings suggest that topical applications of FPE can be utilized as an alternative therapy for treating skin inflammation. Additionally, our findings serve as a reference in applying FPE as a functional ingredient to treat inflammatory skin diseases and promote skin health.

In vitro and in vivo assessment of meadowsweet (Filipendula ulmaria) as anti-inflammatory agent.

ETHNOPHARMACOLOGICAL RELEVANCE: Meadowsweet (Filipendula ulmaria (L.) Maxim, Rosaceae) has been traditionally used in most European countries for the treatment of inflammatory diseases due to its antipyretic, analgesic, astringent, and anti-rheumatic properties. However, there is little scientific evidence on F. ulmaria anti-inflammatory effects regarding its impact on cyclooxygenases enzymatic activity and in vivo assessment of anti-inflammatory potential. This study aims to reveal the anti-inflammatory activity of methanolic extracts from the aerial parts (FUA) and roots (FUR) of F. ulmaria, both in in vitro and in vivo conditions. MATERIALS AND METHODS: The characteristic phenolic compounds in F. ulmaria extracts were monitored via high performance thin layer chromatography (HPTLC). The in vitro anti-inflammatory activity of F. ulmaria extracts was evaluated using cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzyme assays, and an assay for determining COX-2 gene expression. The in vivo anti-inflammatory effect of F. ulmaria extracts was determined in two doses (100 and 200 mg/kg b.w.) with hot plate test and carrageenan-induced paw edema test in rats. Inflammation was also evaluated by histopathological and immunohistochemical analysis. RESULTS: FUA extract showed the presence of rutoside, spiraeoside, and isoquercitrin. Both F. ulmaria extracts at a concentration of 50µg/mL were able to inhibit COX-1 and -2 enzyme activities, whereby FUA extract (62.84% and 46.43% inhibition, respectively) was double as effective as the root extract (32.11% and 20.20%, respectively). Extracts hardly inhibited the level of COX-2 gene expression in THP-1 cells at a concentration of 25µg/mL (10.19% inhibition by FUA and 8.54% by FUR). In the hot plate test, both extracts in two doses (100 and 200mg/kg b.w.), exhibited an increase in latency time when compared with the control group (p<0.05). In the carrageenan-induced acute inflammation test, FUA at doses of 100 and 200mg/kg b.w., and FUR at 200mg/kg, were able to significantly reduce the mean maximal swelling of rat paw until 6h of treatment. Indomethacin, FUA, and FUR extracts significantly decreased inflammation score and this effect was more pronounced after 24h, compared to the control group (p<0.05). CONCLUSIONS: The observed results of in vitro and, for the first time, in vivo anti-inflammatory activity of meadowsweet extracts, provide support of the traditional use of this plant in the treatment of different inflammatory conditions. Further investigation of the anti-inflammatory compounds could reveal the mechanism of anti-inflammatory action of these extracts.