Jietacins, azoxy natural products, as novel NF-κB inhibitors: Discovery, synthesis, biological activity, and mode of action

Design, Synthesis, Nematicidal, and Fungicidal Activities of Novel Azo and Azoxy Compounds

Bursaphelenchus xylophilus (B. xylophilus) and Meloidogyne are parasitic nematodes that have caused severe ecological and economic damage in pinewood and crops, respectively. Jietacins (jietacin A and B) were found to have excellent biological activity against B. xylophilus. Based on our tremendous demand for chemicals against B. xylophilus, a novel scaffold based on the azo and azoxy groups was designed, and a series of compounds were synthesized. In the bioassay, Ia, IIa, IIc, IId, and IVa exhibited higher activity against B. xylophilus in vitro than avermectin (LC50 = 2.43 μg·mL-1) with LC50 values of 1.37, 1.12, 0.889, 1.56, and 1.10 μg·mL-1, respectively. Meanwhile, Ib, Ic, IIc, and IVa showed good inhibition effects against Meloidogyne in vivo at the concentrations of 80 and 40 μg·mL-1 with inhibition rates of 89.0% and 81.6%, 95.6% and 75.7%, 96.3% and 41.2%, and 86.8% and 78.7%, respectively. In fungicidal activity in vitro, IIb and IVa exhibited excellent effect against Botryosphaeria dothidea with the inhibition of 82.59% and 85.32% at the concentration of 10 μg·mL-1, while the inhibition of Ia was 83.16% against Rhizoctonia solani at the concentration of 12.5 μg·mL-1. Referring to the biological activity against B. xylophilus, a 3D-QASR model was built in which the electron-donating group and small group at the 4-phenylhydrazine were favorable for the activity. In general, the novel azoxy compounds, especially IIc possess great potential for application in the prevention of B. xylophilus.

CD30 stimulation induces multinucleation and chromosomal instability in HTLV-1-infected cell lines

A recent report indicated involvement of CD30 in progression of human leukemia virus type 1 (HTLV-1) infection, but the exact roles of CD30 in this process remain unclear. This study was conducted to determine the role of CD30 by stimulating CD30 expressed on HTLV-1-infected cell lines with CD30 ligand and observing its effects. CD30 stimulation increased multinucleated cells and inhibited proliferation of HTLV-1-infected cells. This inhibition was recovered by interruption of CD30 stimulation. Chromatin bridges found in multinucleated cells suggested DNA damage. CD30 stimulation triggered DNA double-strand breaks (DSBs) and chromosomal imbalances. CD30 stimulation induced reactive oxygen species (ROS), which induced DSBs. Generation of ROS and multinucleated cells by CD30 was dependent on phosphoinositide 3-kinase. RNA sequencing showed that CD30 stimulation produced significant changes in gene expression profiles, including upregulation of programmed death ligand 1 (PD-L1). Tax, which has also been shown to induce multinucleation and chromosomal instability, failed to induce CD30. These results suggest that induction of CD30, independent of Tax, triggers morphological abnormalities, chromosomal instability, and alteration of gene expression in HTLV-1-infected cells.

Jietacin Derivative Inhibits TNF-α-Mediated Inflammatory Cytokines Production via Suppression of the NF-κB Pathway in Synovial Cells

Synovial inflammation plays a central role in joint destruction and pain in osteoarthritis (OA). The NF-κB pathway plays an important role in the inflammatory process and is activated in OA. A previous study reported that a jietacin derivative (JD), (Z)-2-(8-oxodec-9-yn-1-yl)-1-vinyldiazene 1-oxide, suppressed the nuclear translocation of NF-κB in a range of cancer cell lines. However, the effect of JD in synovial cells and the exact mechanism of JD as an NF-κB inhibitor remain to be determined. We investigated the effect of JD on TNF-α-induced inflammatory reaction in a synovial cell line, SW982 and human primary synovial fibroblasts (hPSFs). Additionally, we examined phosphorylated levels of p65 and p38 and expression of importin α3 and β1 using Western blotting. RNA-Seq analysis revealed that JD suppressed TNF-α-induced differential expression: among 204 genes significantly differentially expressed between vehicle and TNF-α-stimulated SW982 (183 upregulated and 21 downregulated) (FC ≥ 2, Q < 0.05), expression of 130 upregulated genes, including inflammatory cytokines (IL1A, IL1B, IL6, IL8) and chemokines (CCL2, CCL3, CCL5, CCL20, CXCL9, 10, 11), was decreased by JD treatment and that of 14 downregulated genes was increased. KEGG pathway analysis showed that DEGs were increased in the cytokine−cytokine receptor interaction, TNF signaling pathway, NF-κB signaling pathway, and rheumatoid arthritis. JD inhibited IL1B, IL6 and IL8 mRNA expression and IL-6 and IL-8 protein production in both SW982 and hPSFs. JD also suppressed p65 phosphorylation in both SW982 and hPSFs. In contrast, JD did not alter p38 phosphorylation. JD may inhibit TNF-α-mediated inflammatory cytokine production via suppression of p65 phosphorylation in both SW982 and hPSFs. Our results suggest that JD may have therapeutic potential for OA due to its anti-inflammatory action through selective suppression of the NF-κB pathway on synovial cells.

Synthetic and biosynthetic routes to nitrogen-nitrogen bonds

The nitrogen-nitrogen bond is a core feature of diverse functional groups like hydrazines, nitrosamines, diazos, and pyrazoles. Such functional groups are found in >300 known natural products. Such N-N bond-containing functional groups are also found in significant percentage of clinical drugs. Therefore, there is wide interest in synthetic and enzymatic methods to form nitrogen-nitrogen bonds. In this review, we summarize synthetic and biosynthetic approaches to diverse nitrogen-nitrogen-bond-containing functional groups, with a focus on biosynthetic pathways and enzymes.

Anti-Oxidant and Anticancerous Effect of Fomitopsis officinalis (Vill. ex Fr. Bond. et Sing) Mushroom on Hepatocellular Carcinoma Cells In Vitro through NF-kB Pathway

BACKGROUND

Fomitopsis officinalis (Vill. ex Fr. Bond. et Sing) is a medicinal mushroom, commonly called 'Agarikon', traditionally used to treat cough and asthma in the Mongolian population.

OBJECTIVE

The objective of this study was to examine the significance of biological activity of F. officinalis, and evaluate the antioxidant and anticancer activity of six fractions of F. officinalis residues (Fo1-powder form dissolved in ethanol, Fo2-petroleum ether residue, Fo3-chloroformic, Fo4-ethylacetate, Fo5-buthanolic, and Fo6-water-ethanolic) against hepatocellular carcinoma cells.

METHODS

We performed in vitro studies of cell proliferation and viability assay, annexin V-FITC/Propidium Iodide assay, and NF-kB signaling pathway by immunoblot analysis.

RESULTS

Our findings revealed that all six fractions/extracts have antioxidant activity, and somehow, they exert anticancerous effects against cancer cells. In cancerous cell lines (HepG2 and LO2), Fo3 chloroformic extract promoted the cancer cell apoptosis, cell viability, activated G2/M-phase cell cycle, and selectively induced NF-kB proteins, revealing itself as a novel antitumor extract.

CONCLUSION

This study reports that Fo3-chloroformic extract is rich in antitumor activity; it was previously not investigated in cancer. To study the impact of F. officinalis among natural products to treat/prevent oxidative stress disorders or cancers, further examinations are needed. However, this study assessed only one extract, Fo3-chloroformic, which has a significant impact on cancer cell lines.

Differentiation of Hodgkin lymphoma cells by reactive oxygen species and regulation by heme oxygenase-1 through HIF-1α

We previously indicated that Hodgkin lymphoma (HL) cells contain a small side population (SP) that differentiate into a large major population (MP) with giant Hodgkin and Reed‐Sternberg (H and RS)‐like cells. However, its molecular mechanisms are not fully understood. In this study, we found that intracellular reactive oxygen species (ROS) are low in the SP compared to the MP. Hydrogen peroxide induces large H‐ and RS‐like cells in HL cell lines, but induces cell death in unrelated lymphoid cell lines. Microarray analyses revealed the enrichment of upregulated genes under hypoxic conditions in the SP compared to the MP, and we verified that the SP cells are hypoxic. Hypoxia inducible factor (HIF)‐1α was preferentially expressed in the SP. CoCl₂, a HIF‐1α stabilizer, blunted the effect of hydrogen peroxide. Heme oxygenase‐1 (HO‐1), a scavenger of ROS, was triggered by HIF‐1α. The effect of hydrogen peroxide was inhibited by HO‐1 induction, whereas it was promoted by HO‐1 knockdown. HO‐1 inhibition by zinc protoporphyrin promoted the differentiation and increased ROS. These results stress the unique roles of ROS in the differentiation of HL cells. Immature HL cells are inhibited from differentiation by a reduction of ROS through the induction of HO‐1 via HIF‐1α. The breakdown of this might cause the accumulation of intracellular ROS, resulting in the promotion of HL cell differentiation.

Azodyrecins A-C: Azoxides from a Soil-Derived Streptomyces Species

Azoxy compounds belong to a small group of natural products sharing a common functional group with the general structure RN = N⁺(O^-)R. Three new azoxides, azodyrecins A-C (1-3), were isolated from a soil-derived Streptomyces sp. strain P8-A2. The cis-alkenyl unit in 1-3 was found to readily isomerize to the trans-congeners (4-6). The structures of the new compounds were determined by detailed spectroscopic (1D/2D NMR) and HRMS data analysis. Azodyrecins belong to a new class of natural azoxy compounds and are proposed to derive from l-alanine and alkylamines. The absolute configurations of 1-6 were defined by comparison of ECD spectra. While no antimicrobial effects were observed for 1 against Staphylococcus aureus, Vibrio anguillarum, or Candida albicans, azodyrecin B (2) exhibited cytotoxicity against the human leukemia cell line HL-60 with an IC₅₀ value of 2.2 μM.

Targeted treatment of alcoholic liver disease based on inflammatory signalling pathways

Targeted therapy is an emerging treatment strategy for alcoholic liver disease (ALD). Inflammation plays an important role in the occurrence and development of ALD, and is a key choice for its targeted treatment, and anti-inflammatory treatment has been considered beneficial for liver disease. Surprisingly, immune checkpoint inhibitors have become important therapeutic agents for hepatocellular carcinoma (HCC). Moreover, studies have shown that the combination of inflammatory molecule inhibitors and immune checkpoint inhibitors can exert better effects than either alone in mouse models of HCC. This review discusses the mechanism of hepatic ethanol metabolism and the conditions under which inflammation occurs. In addition, we focus on the potential molecular targets in inflammatory signalling pathways and summarize the potential targeted inhibitors and immune checkpoint inhibitors, providing a theoretical basis for the targeted treatment of ALD and the development of new combination therapy strategies for HCC.

Chemistry and Biology of Natural Azoxy Compounds

Azoxy compounds belong to a small yet intriguing group of natural products sharing a common functional group with the general structure RN═N⁺(O^-)R. Their intriguing chemical structures, diverse biological activities, and important industrial applications have received attention from researchers in natural product chemistry, total synthesis, and biosynthesis. This review presents current updates about the structural diversity of natural azoxy compounds isolated from different organisms and highlights the enzymes and biological logic involved in their construction. We assume that the identification of key enzymes will provide efficient tools in biocatalysis to generate new azoxy compounds, while genome mining may result in novel natural azoxy compounds of medical and industrial interest.

Huoxuezhitong capsule ameliorates MIA-induced osteoarthritis of rats through suppressing PI3K/ Akt/ NF-κB pathway

Huoxuezhitong capsule (HXZT, activating blood circulation and relieving pain capsule), has been applied for osteoarthritis since 1974. It consists of Angelica sinensis (Oliv.) Diels, Panax notoginseng (Burkill) F. H. Chen ex C. H., Boswellia sacra, Borneol, Eupolyphaga sinensis Walker, Pyritum. However, the direct effects of HXZT on osteoarthritis and the underlying mechanisms were poorly understood. In this study, we aimed to explore the analgesia effect of HXZT on MIA-induced osteoarthritis rat and the underlying mechanisms. The analgesia and anti-inflammatory effect of HXZT on osteoarthritis in vivo were tested by the arthritis model rats induced by monosodium iodoacetate (MIA).. Mechanistic studies confirmed that HXZT could inhibit the activation of NF-κB and down-regulate the mRNA expression of related inflammatory factors in LPS-induced RAW264.7 and ATDC5 cells. Furtherly, in LPS-induced RAW264.7 cells, HXZT could suppress NF-κB via inhibiting PI3K/Akt pathway. Taken together, HXZT capsule could ameliorate MIA-induced osteoarthritis of rats through suppressing PI3K/ Akt/ NF-κB pathway.