α-Conidendrin inhibits the expression of intercellular adhesion molecule-1 induced by tumor necrosis factor-α in human lung adenocarcinoma A549 cells

Correlation between the biological activities and the chemical structures of conidendrin-related compounds: (-)-β-conidendrin inhibits degranulation of RBL-2H3 cells

Conidendrin, a metabolite of lariciresinol (a lignan in dietary plants), has 8 stereoisomers with 3 asymmetric carbon atoms. However, the relationship between the chemical structure and biological activity of these stereoisomers remains unclear. Since strong cytotoxicity against rat basophilic cell line RBL-2H3 cells has been observed in 4 stereoisomers, the degranulation inhibitory effect of the other conidendrin isomers possessing no cytotoxicity was investigated. Significant degranulation inhibitory effect was observed on all 4 stereoisomers especially on (-)-β-conidendrin, suggesting that conidendrin exhibits stereospecific cytotoxic and degranulation inhibitory activities, and (-)-β-conidendrin is the most structurally effective isomer on antidegranulation. Additionally, (-)-β-conidendrin inhibited the antigen-induced increase in intracellular Ca2+ concentration and phosphorylation levels of Syk, PLCγ, and Akt, indicating that (-)-β-conidendrin inhibits Ca2+ influx into cells by downregulating the Syk/PLCγ and PI3K/Akt signaling pathways, thereby suppressing degranulation. Our findings suggest that conidendrin may be useful as an antiallergic functional food ingredient.

The polyphenolic compound, α-conidendrin, exerts anti-colon cancer and anti-angiogenic effects by targeting several signaling molecules

Our previous study indicated that α-conidendrin had considerable anti-proliferative activities against breast cancer cell lines. The present study aimed to evaluate the anti-colon cancer and anti-angiogenic influences of α-conidendrin as well as its molecular mechanisms. The findings of the current study demonstrate that α-conidendrin possesses potent anti-colon cancer and anti-angiogenic effects. α-Conidendrin significantly inhibited the proliferation of colon cancer cells. This polyphenolic compound induced caspase-mediated apoptosis in HT-29 cells by modulating the PTEN/PI3K/Akt/mTOR signaling pathway. α-Conidendrin markedly upregulated the protein expression of PTEN and downregulated the protein expression of p-PI3K, p-AKt, and p-mTOR. The protein expression of caspase-3 and caspase-9 enhanced in colon cancer cells following treatment with α-conidendrin. This study also revealed the anti-angiogenic activities of α-conidendrin in the ex vivo and in vitro models. α-Conidendrin significantly downregulated the mRNA expression of HIF-1α, VEGF, MMP-2, and MMP-9 in endothelial cells. These data highlight that α-conidendrin can act as a novel and promising anti-cancer and anti-angiogenic agent for treatment of colon cancer.

1'-Acetoxychavicol Acetate Selectively Downregulates Tumor Necrosis Factor Receptor-Associated Factor 2 (TRAF2) Expression

1'-Acetoxychavicol acetate (ACA) is a natural compound derived from rhizomes of the Zingiberaceae family that suppresses the nuclear factor κB (NF-κB) signaling pathway; however, the underlying mechanisms remain unclear. Therefore, the present study investigated the molecular mechanisms by which ACA inhibits the NF-κB signaling pathway in human lung adenocarcinoma A549 cells. The results obtained showed ACA decreased tumor necrosis factor (TNF)-α-induced intercellular adhesion molecule-1 (ICAM-1) expression in A549 cells. It also inhibited TNF-α-induced ICAM-1 mRNA expression and ICAM-1 promoter-driven and NF-κB-responsive luciferase reporter activities. Furthermore, the TNF-α-induced degradation of the inhibitor of NF-κB α protein in the NF-κB signaling pathway was suppressed by ACA. Although ACA did not affect TNF receptor 1, TNF receptor-associated death domain, or receptor-interacting protein kinase 1 protein expression, it selectively downregulated TNF receptor-associated factor 2 (TRAF2) protein expression. The proteasome inhibitor MG-132, but not inhibitors of caspases or lysosomal degradation, attenuated ACA-induced reductions in TRAF2 expression. ACA also downregulated TRAF2 protein expression in human fibrosarcoma HT-1080 cells. This is the first study to demonstrate that ACA selectively downregulates TRAF2 protein expression.

Porphyrin derivatives inhibit tumor necrosis factor α-induced gene expression and reduce the expression and increase the cross-linked forms of cellular components of the nuclear factor κB signaling pathway

The transcription factor nuclear factor κB (NF-κB) is activated by proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and Toll-like receptor (TLR) ligands. Screening of NPDepo chemical libraries identified porphyrin derivatives as anti-inflammatory compounds that strongly inhibited the up-regulation of intercellular adhesion molecule-1 (ICAM-1) expression induced by TNF-α, interleukin-1α, the TLR3 ligand, and TLR4 ligand in human umbilical vein endothelial cells. In the present study, the mechanisms of action of porphyrin derivatives were further elucidated using human lung adenocarcinoma A549 cells. Porphyrin derivatives, i.e., dimethyl-2,7,12,18-tetramethyl-3,8-di(1-methoxyethyl)-21H,23H-porphine-13,17-dipropionate (1) and pheophorbide a (2), inhibited TNF-α-induced ICAM-1 expression and decreased the TNF-α-induced transcription of ICAM-1, vascular cell adhesion molecule-1, and E-selectin genes. 1 and 2 reduced the expression of the NF-κB subunit RelA protein for 1 h, which was not rescued by the inhibition of proteasome- and lysosome-dependent protein degradation. In addition, 1 and 2 decreased the expression of multiple components of the TNF receptor 1 complex, and this was accompanied by the appearance of their cross-linked forms. As common components of the NF-κB signaling pathway, 1 and 2 also cross-linked the α, β, and γ subunits of the inhibitor of NF-κB kinase complex and the NF-κB subunits RelA and p50. Cellular protein synthesis was prevented by 2, but not by 1. Therefore, the present results indicate that porphyrin derivative 1 reduced the expression and increased the cross-linked forms of cellular components required for the NF-κB signaling pathway without affecting global protein synthesis.

Alantolactone derivatives inhibit the tumor necrosis factor α-induced nuclear factor κB pathway by a different mechanism from alantolactone

Alantolactone is a eudesmane-type sesquiterpene lactone that exerts various biological effects, including anti-inflammatory activity. In the present study, screening using the RIKEN Natural Products Depository chemical library identified alantolactone derivatives that inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) on human umbilical vein endothelial cells stimulated with proinflammatory cytokines and Toll-like receptor ligands. In human lung adenocarcinoma A549 cells stimulated with tumor necrosis factor-α (TNF-α), six alantolactone derivatives inhibited ICAM-1 expression in a dose-dependent manner and at IC50 values of 13-21 μM, whereas that of alantolactone was 5 μM. Alantolactone possesses an α-methylene-γ-lactone moiety, whereas alantolactone derivatives do not. In the nuclear factor κB (NF-κB) signaling pathway, alantolactone prevented the TNF-α-induced phosphorylation and degradation of the inhibitor of NF-κB α (IκBα) protein, and its downstream signaling pathway. In contrast, alantolactone derivatives neither reduced TNF-α-induced IκBα degradation nor the nuclear translocation of the NF-κB subunit RelA, but inhibited the binding of RelA to the ICAM-1 promoter. The inhibitory activities of alantolactone and alantolactone derivatives were attenuated by glutathione. These results indicate that alantolactone derivatives inhibit the TNF-α-induced NF-κB pathway by a different mechanism from alantolactone.

Exploring the Core Prescription and Underlying Mechanism of Traditional Chinese Medicine in Treating Allergic Rhinitis in Children: A Real- World Study Based on an Illustrious Senior Traditional Chinese Medicine Practitioner

BACKGROUND

Traditional Chinese medicine (TCM) is widely used to treat allergic rhinitis (AR) in China, especially in children. However, due to the complicated composition rules and unclear underlying mechanisms, effective herbal prescriptions' popularization and application are limited.

PURPOSE

This study tried to detect the core prescription of herbs in treating AR in children, reveal its mechanism based on the ingredients' network, and explore the main signaling pathways.

METHODS

We screened medical records of children patients with AR who were treated by TCM in DongZhiMen Hospital from Aug 2009 to Jan 2020 and adopted a descriptive analysis method on herbal characteristics. We used association rules to mine core prescriptions and used network pharmacology to establish the ingredient-target-pathway network through online databases and TCMSP, Genecards, KEGG pathway, Excel, R-Studio, and Cytoscape software.

RESULTS

The analysis of 1,092 clinical visits highlighted that the principle of formulating prescription was as follows: 'pungent and warm herbs were used more frequently while cold-natured herbs were paid equal attention as warm-natured herbs.' The core prescription was formed by FangFeng, BaiZhi, CangErzi, and ChanTui. These herbs covered 130 underlying targets and 141 signaling pathways of AR, which mainly had an effect on signal transduction and immunoregulation.

CONCLUSION

The core prescription based on these real-world clinical records includes FangFeng, BaiZhi, CangErzi, and ChanTui. It principally acts on targets of signal transduction pathways and immune pathways.

Cucurbitacin B Down-Regulates TNF Receptor 1 Expression and Inhibits the TNF-α-Dependent Nuclear Factor κB Signaling Pathway in Human Lung Adenocarcinoma A549 Cells

Pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), induce the expression of intracellular adhesion molecule-1 (ICAM-1) by activating the nuclear factor κB (NF-κB) signaling pathway. In the present study, we found that cucurbitacin B decreased the expression of ICAM-1 in human lung adenocarcinoma A549 cells stimulated with TNF-α or interleukin-1α. We further investigated the mechanisms by which cucurbitacin B down-regulates TNF-α-induced ICAM-1 expression. Cucurbitacin B inhibited the nuclear translocation of the NF-κB subunit RelA and the phosphorylation of IκBα in A549 cells stimulated with TNF-α. Cucurbitacin B selectively down-regulated the expression of TNF receptor 1 (TNF-R1) without affecting three adaptor proteins (i.e., TRADD, RIPK1, and TRAF2). The TNF-α-converting enzyme inhibitor suppressed the down-regulation of TNF-R1 expression by cucurbitacin B. Glutathione, N-acetyl-L-cysteine, and, to a lesser extent, L-cysteine attenuated the inhibitory effects of cucurbitacin B on the TNF-α-induced expression of ICAM-1, suggesting that an α,β-unsaturated carbonyl moiety is essential for anti-inflammatory activity. The present results revealed that cucurbitacin B down-regulated the expression of TNF-R1 at the initial step in the TNF-α-dependent NF-κB signaling pathway.