interleukin-8 and esculetin

Pulmonary fibrosis is a disease in which lung tissues become fibrous and thereby causes severe respiratory disturbances. Various stimuli induce infiltration of macrophages to the respiratory tract, secreting inflammatory cytokines, which subsequently leads to the development of pulmonary fibrosis. Aesculetin, a major component of the sancho tree and chicory, is known to biologically have antioxidant and anti-inflammatory effects. Human alveolar epithelial A549 cells were cultured for 24 h in conditioned media of THP-1 monocyte-derived macrophages (mCM) with 1-20 μM aesculetin. Micromolar aesculetin attenuated the cytotoxicity of mCM containing inflammatory tumor necrosis factor-α (TNF)-α and interleukin (IL)-8 as major cytokines. Aesculetin inhibited alveolar epithelial induction of the mesenchymal markers in mCM-exposed/IL-8-loaded A549 cells (≈47-51% inhibition), while epithelial markers were induced in aesculetin-treated cells subject to mCM/IL-8 (≈1.5-2.3-fold induction). Aesculetin added to mCM-stimulated A549 cells abrogated the collagen production and alveolar epithelial CXC-chemokine receptor 2 (CXCR2) induction. The production of matrix metalloproteinase (MMP) proteins in mCM-loaded A549 cells was reduced by aesculetin (≈52% reduction), in parallel with its increase in tissue inhibitor of metalloproteinases (TIMP) proteins (≈1.8-fold increase). In addition, aesculetin enhanced epithelial induction of tight junction proteins in mCM-/IL-8-exposed cells (≈2.3-2.5-fold induction). The inhalation of polyhexamethylene guanidine (PHMG) in mice accompanied neutrophil predominance in bronchoalveolar lavage fluid (BALF) and macrophage infiltration in alveoli, which was inhibited by orally administrating aesculetin to mice. Treating aesculetin to mice alleviated PHMG-induced IL-8-mediated subepithelial fibrosis and airway barrier disruption. Taken together, aesculetin may antagonize pulmonary fibrosis and alveolar epithelial barrier disruption stimulated by the infiltration of monocyte-derived macrophages, which is typical of PHMG toxicity, involving interaction of IL-8 and CXCR2. Aesculetin maybe a promising agent counteracting macrophage-mediated inflammation-associated pulmonary disorders.

Topics: A549 Cells; Alveolar Epithelial Cells; Animals; Epithelial-Mesenchymal Transition; Fibrosis; Humans; Interleukin-8; Macrophages; Male; Mice, Inbred BALB C; Pulmonary Alveoli; Pulmonary Fibrosis; Signal Transduction; THP-1 Cells; Umbelliferones

Allergic rhinitis (AR) is a type of respiratory disease closely associated with chronic inflammation. Esculetin is a natural coumarin derivative and has been reported to possess anti-allergic and anti-inflammatory effects. However, the roles of esculetin in AR have not been studied. In this study, we aimed to examine the effect of esculetin on AR using an in vitro model. The human nasal epithelial cells (HNEpC) were stimulated by histamine for 24 hours with or without the pretreatment of esculetin. The mRNA levels and production of inflammatory cytokines including IL-6 and IL-8, as well as mucin 5AC (MUC5AC) were measured using qRT-PCR and ELISA, respectively. The results showed that esculetin suppressed histamine-induced expression and secretion of IL-6, IL-8, and MUC5AC in HNEpCs. Furthermore, we examined the effect of esculetin on NF-κB pathway by detecting the expression levels of NF-κB p65, p-p65 and IκBα using western blot analysis. Esculetin treatment suppressed the histamine-induced p-p65 expression and p-IκBα degradation. Inhibiting NF-κB pathway suppressed histamine-induced production of IL-6, IL-8, and MUC5AC in HNEpCs. These findings suggested that esculetin suppressed histamine-induced production of inflammatory cytokines and mucin in HNEpCs, which were partly mediated by the inhibition of NF-κB pathway.

Topics: Cell Line; Cytokines; Epithelial Cells; Gene Expression Regulation; Histamine; Humans; Inflammation; Interleukin-6; Interleukin-8; Mucin 5AC; NF-kappa B; Nose; Umbelliferones

The aim of the research was to investigate the anti-inflammatory mechanism of Pulsatillae Decoction (PD), the levels of interleukin (IL)-6, IL-8, E-selectin, and thromboxane B(2) (TXB(2)) secreted by cultured rat intestinal microvascular endothelial cells (RIMECs) were determined after treatment with its active ingredients, namely anemoside B4, anemonin, berberine, jatrorrhizine, palmatine, aesculin, and esculetin. RIMECs were challenged with 1 microg/mL lipopolysaccharide (LPS) for 3 h, and then treated with each of the seven ingredients at three concentrations (1, 5 and 10 microg/mL) for 24 h. The results revealed that anemonin, aesculin and esculetin inhibited the production of IL-6, aesculin and esculetin inhibited the secretion of IL-8, anemoside B4, berberine and jatrorrhizine downregulated E-selectin expression, anemonin, berberine, jatrorrhizine and palmatine decreased the content of TXB(2). All these changes were significant. Taken together, the data suggest that all seven active ingredients of PD can effectively reduce inflammatory response, thus relieving intestinal dysfunction via multiple pathways.

Topics: Animals; Berberine; Berberine Alkaloids; Cells, Cultured; Drugs, Chinese Herbal; E-Selectin; Endothelium, Vascular; Esculin; Furans; Interleukin-6; Interleukin-8; Intestinal Mucosa; Lipopolysaccharides; Rats; Thromboxane B2; Umbelliferones