Inhibitory effect of fermented Arctium lappa fruit extract on the IgE-mediated allergic response in RBL-2H3 cells

Abstract

Arctium lappa fruit has been used in traditional medicine, and it is known to exert beneficial effects, such as antioxidant, anti-inflammatory and anticancer effects. However, the effects of the Arctium lappa fruit on the allergic response remain unknown. In this study, we evaluated the anti-allergic effects of Arctium lappa fruit extract (AFE) and its fermented form (F-AFE) using immunoglobulin E (IgE)-activated RBL‑2H3 cells. To investigate the anti-allergic effects of AFE or F-AFE, we examined the release of β-hexosaminidase, a key biomarker of degranulation during an allergic reaction, and the production of pro-inflammatory mediators, such as tumor necrosis factor-α (TNF-α) and prostaglandin E2 (PGE2) in the cells treated with or without the above-mentioned extracts. AFE weakly inhibited the release of β-hexosaminidase, whereas F-AFE significantly suppressed the release of β-hexosaminidase in a dose-dependent manner. Consistently, F-AFE suppressed the production of TNF-α and PGE2 in a dose-dependent manner. F-AFE exerted an inhibitory effect on the production of β-hexosaminidase, TNF-α and PGE2 with an IC50 value of 30.73, 46.96 and 36.27 µg/ml, respectively. Furthermore, F-AFE inhibited the phosphorylation of Lyn, Fyn and Syk, which are involved in the FcεRI signaling pathway, that of phosphoinositide phospholipase C (PLC)γ1/2 and protein kinase C (PKC)δ, which are associated with the degranulation process, as well as that of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase 1/2 (JNK), p38 and Akt, which are associated with cytokine expression. In the late phase, F-AFE partially suppressed the phosphorylation of cytosolic phospholipase A2 (cPLA2), but not the expression of cyclooxygenase (COX)-2. To compare and identify the major components of the two extracts, we used high-performance liquid chromatography. The levels of arctigenin, one of the major compounds, were elevated 6-fold in F-AFE compared with AFE, whereas the levels of arctiin, an arctigenin glycoside, were decreased in F-AFE by approximately 57.40%. These results suggest that arctigenin plays an important role in the anti-allergic effects of F-AFE. Taken together, F-AFE containing anti-allergic phytochemicals, including arctigenin, inhibited the activation of the FcεRI receptor induced by the antigen‑IgE complex. Such effects may provide further information for the development of a phytomedicine for allergic diseases.

Inhibitory Effects of Viscum coloratum Extract on IgE/Antigen-Activated Mast Cells and Mast Cell-Derived Inflammatory Mediator-Activated Chondrocytes

“…The biosynthesis of inflammatory mediators is associated with activation of FcεRI and arachidonate cascades [ 3 ]. Actually, both formation of inflammatory mediators and activation of FcεRI and arachidonate cascades are reduced by drug candidates in IgE/Ag-activated mast cells [ 14 , 15 , 16 , 21 , 22 ]. In the arachidonate cascade (DNP-HSA stimulation for 4 h), VEE significantly blocked the expression of COX-2 and the phosphorylation of 5-lipoxygenase (5-LO); however, it did not block the phosphorylation of cPLA 2 ( Figure 3 A).…”

“…VAE and VEE were prepared according to a modification of a process previously reported [ 16 ]. Viscum coloratum (1 kg) was boiled in distilled water or 70% ethanol (10 L) for approximately 3 h at 115 °C.…”

“…Cell viability was determined following a previous method [ 16 ]. IgE-sensitized RBL-2H3 cells were preincubated with VEE (0–200 μg/mL) in MEM-α containing 1% FBS for 1 h. The cells were then simultaneously mixed with 0.1 μg/mL DNP-HSA and 10 μL EZ-Cytox reagent and further incubated for 4 h. Cell viability was determined at 450 nm using a microplate reader.…”

“…Therefore, the beneficial effects of mistletoe are related to bioactive compounds including phenolic compounds and flavonoids [ 9 , 10 , 11 , 12 , 13 ]. Actually, phenolic compounds and flavonoids are known to be associated with anti-allergic activity in IgE/Ag-activated mast cells [ 14 , 15 , 16 ]. Therefore, ethanol extract of Viscum coloratum (VEE) may have anti-osteoarthritic properties and can potentially be used as a new herbal medicine for anti-osteoarthritic therapy.…”

Therapeutic Value of Arctium Lappa Linn. – A Review

“…The butanol fraction of AL showed potential antiallergic and anti-inflammatory effects by decreasing β-hexosaminidase release in mast cells and the secretion of IL-4 and IL-5 in Con A-induced T cells [66]. The release of β-hexosaminidase and the production of pro-inflammatory mediators, such as TNF-α and prostaglandin E2 in the cells treated with or without the AL fruit extract showed positive results [67]. Ethanol extract (90%) of AL (ALE, 100 µg/mL) inhibited the degranulation rate by 52.9%, determined by the level of β-hexosaminidase.…”