Sesquiterpene lactones as inhibitors of IL-8 expression in HeLa cells

The high level of IL-1β in the serum of ACLF patients induces increased IL-8 expression in hUC-MSCs and reduces the efficacy of hUC-MSCs in liver failure

BACKGROUND

Stem cells play a therapeutic role mainly through immunoregulation. However, the immunomodulatory function of stem cells may be affected by inflammation-related factors in patients' serum. Therefore, this study aims to investigate the possible mechanism by which acute-on-chronic liver failure (ACLF) patient serum influences the efficacy of hUC-MSCs.

METHODS

The serum of surviving and dead ACLF patients was collected to culture hUC-MSCs in vitro, and the hUC-MSCs cultured in the serum of ACLF patients were used to treat acute liver failure (ALF) rats. The therapeutic effect on the rats was evaluated by a survival curve, the transaminase level and liver histopathology. The expression of cytokines in hUC-MSCs was detected by Q-PCR and ELISA.

RESULTS

Serum pretreatment reduced the therapeutic effect of hUC-MSCs on ALF, especially pretreatment in the serum from dead ACLF patients. After hUC-MSCs were cultured in the serum of surviving or dead ACLF patients, the most differentially expressed factor was IL-8. Interfering with the expression of IL-8 in hUC-MSCs can improve the therapeutic effect of hUC-MSCs on ALF. The high level of IL-1β in the serum of dead ACLF patients causes the increased expression of IL-8 in hUC-MSCs through the activation of the NF-κB signaling pathway. Meanwhile, we found that the neutralizing IL-1β in serum from dead ACLF patients can improve the therapeutic effect of hUC-MSCs on ALF.

CONCLUSION

The high level of IL-1β in ACLF serum can promote the expression of IL-8 in hUC-MSCs through the NF-κB signaling pathway, thus reducing the effect of hUC-MSCs on ALF.

Nardoguaianone L Isolated from Nardostachys jatamansi Improved the Effect of Gemcitabine Chemotherapy via Regulating AGE Signaling Pathway in SW1990 Cells

Pancreatic cancer is the seventh leading cause of cancer-related death worldwide and is known as “the king of cancers”. Currently, gemcitabine (GEM) as the clinical drug of choice for chemotherapy of advanced pancreatic cancer has poor drug sensitivity and ineffective chemotherapy. Nardoguaianone L (G-6) is a novel guaiane-type sesquiterpenoid isolated from Nardostachys jatamansi DC., and it exhibits anti-tumor activity. Based on the newly discovered G-6 with anti-pancreatic cancer activity in our laboratory, this paper aimed to evaluate the potential value of the combination of G-6 and GEM in SW1990 cells, including cell viability, cell apoptosis, colony assay and tandem mass tags (TMT) marker-based proteomic technology. These results showed that G-6 combined with GEM significantly inhibited cell viability, and the effect was more obvious than that with single drug. In addition, the use of TMT marker-based proteomic technology demonstrated that the AGE-RAGE signaling pathway was activated after medication-combination. Furthermore, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) assays were used to validate the proteomic results. Finally, apoptosis was detected by flow cytometry. In conclusion, G-6 combined with GEM induced an increase in ROS level and a decrease in MMP in SW1990 cells through the AGE-RAGE signaling pathway, ultimately leading to apoptosis. G-6 improved the effect of GEM chemotherapy and may be used as a potential combination therapy for pancreatic cancer.

Ainslides A-F, Six Sesquiterpenoids Isolated from Ainsliaea pertyoides and Their NLRP3-Inflammasome Inhibitory Activity

Six new sesquiterpenoids, named as ainslides A-F (1-6), including one carotene-type sesquiterpene (1), one eudesmane (2), four guaianolides (3-6), together with eight known sesquiterpenoids (7-14), were purified from the whole plants of Ainsliaea pertyoides. The structures of these sesquiterpenoids were characterized based on spectroscopic methods including 1D and 2D NMR, HR-ESI-MS, UV, and IR spectra, together with ECD calculations and X-ray diffraction experiments. The anti-inflammatory activity of all the isolated compounds was screened and compounds 3 and 7-13 exhibited NLRP3-inflammasome inhibitory activity with IC₅₀ values of 1.80-4.33 μM.

The Effect of Different Ester Chain Modifications of Two Guaianolides for Inhibition of Colorectal Cancer Cell Growth

Several sesquiterpene lactones (STLs) have been tested as lead drugs in cancer clinical trials. Salograviolide-A (Sal-A) and salograviolide-B (Sal-B) are two STLs that have been isolated from Centaurea ainetensis, an indigenous medicinal plant of the Middle Eastern region. The parent compounds Sal-A and Sal-B were modified and successfully prepared into eight novel guaianolide-type STLs (compounds 1-8) bearing ester groups of different geometries. Sal-A, Sal-B, and compounds 1-8 were tested against a human colorectal cancer cell line model with differing p53 status; HCT116 with wild-type p53 and HCT116 p53^-/- null for p53, and the normal-like human colon mucosa cells with wild-type p53, NCM460. IC₅₀ values indicated that derivatization of Sal-A and Sal-B resulted in potentiation of HCT116 cell growth inhibition by 97% and 66%, respectively. The effects of the different molecules on cancer cell growth were independent of p53 status. Interestingly, the derivatization of Sal-A and Sal-B molecules enhanced their anti-growth properties versus 5-Fluorouracil (5-FU), which is the drug of choice in colorectal cancer. Structure-activity analysis revealed that the enhanced molecule potencies were mainly attributed to the position and number of the hydroxy groups, the lipophilicity, and the superiority of ester groups over hydroxy substituents in terms of their branching and chain lengths. The favorable cytotoxicity and selectivity of the potent molecules, to cancer cells versus their normal counterparts, pointed them out as promising leads for anti-cancer drug design.

New guaiane-type sesquiterpenoid dimers from Artemisia atrovirens and their antihepatoma activity

Leading by cytotoxicity against HepG2 cells, bioactivity-guided fractionation of the EtOAc fraction from Artemisia atrovirens led to the isolation of 18 new guaianolide dimers, artematrolides A–R and lavandiolides A, B, C, H, and J. Eight compounds (1, 4, 10, 12, 13, and 19–21) were unambiguously confirmed by the single-crystal X-ray diffraction analyses, and the others were elucidated based on IR, UV, HRESIMS, 1D and 2D NMR experiments, and comparison of the experimental and calculated ECD data. Structurally, all of them were [4 + 2] Diels–Alder adducts of two monomeric guaianolides. The isolates were evaluated for their cytotoxicity against three human hepatoma cell lines, and 19 compounds demonstrated cytotoxicity against HepG2, SMMC-7721, and Huh7 cell lines. Especially, compounds 1, 12, 14, and 15 exhibited cytotoxicity with IC₅₀ values of 4.4, 3.8, 7.6, and 6.7 μmol/L (HepG2), 9.6, 4.6, 6.6, and 6.0 μmol/L (SMMC-7721), and 7.6, 4.5, 6.9, and 5.6 μmol/L (Huh7), respectively. Notably, compound 12 showed the most promising activity against three human hepatoma cell lines and dose-dependently inhibited cell migration and invasion, induced G2/M cell cycle arrest and cell apoptosis in HepG2 cells, down-regulated the expression of BCL-2 and PARP-1, and activated PARP-1 to up-regulate the expression of cleaved-PARP-1.

Triterpenoids from Ainsliaea latifolia and Their Cyclooxyenase-2 (COX-2) Inhibitory Activities

Eight new triterpenoids were isolated from Ainsliaea latifolia. The structures of these compounds were elucidated by interpretation of spectroscopic data, including HRESIMS and NMR data. Compounds 4-6 are identified as rare trinorcucurbitane or tetranorcucurbitane triterpenoids. The absolute configurations of compounds 1 and 2 were confirmed by Snatzke's method. All compounds were evaluated for their inhibition against cyclooxyenase-2 (COX-2), in which compound 4 showed significant inhibitory effect against COX-2 with IC₅₀ value of 3.98 ± 0.32 μM, comparable to that of positive control NS-398 (IC₅₀ 4.14 ± 0.28 μM).

Study on synthesis and bioactivity of biotinylated emodin

A novel compound biotinylated emodin was synthesized by a two-step acyl chloride method which connects the biotin to emodin with esterification reaction. The product was characterized with ultraviolet-visible spectrophotometry, fourier transform infrared and high-performance liquid chromatography tandem mass spectrometry techniques. Its antibacterial activity against Staphylococcus aureus CMCC 26003 was investigated, and the emodin- and biotinylated emodin-caused antibacterial mechanism was proposed. It was shown that the product was isolated and activity of emodin was remained. These results indicated that our study provides a kind of chemosynthesis method under mild conditions and a strong molecular tool for investigating the emodin-binding protein.

Terpenoids from Ainsliaea latifolia and their cytotoxic activities

Two new compounds including one new sesquiterpenoid and one new monoterpenoid, together with 10 known compounds were isolated from the whole plants of Ainsliaea latifolia. The structures of these compounds were elucidated by analysis of spectroscopic data. All compounds were evaluated for their cytotoxic activities.

A systematic investigation of the fragmentation pattern of two furanoheliangolide C-8 stereoisomers using electrospray ionization mass spectrometry

RATIONALE

Budlein A is a sesquiterpene lactone (STL) with some reported biological activities. Pre-clinical studies to identify in vivo metabolites often employ hyphenated techniques such as liquid chromatography/tandem mass spectrometry (LC/MS/MS). It is also possible to use the fragmentation pattern obtained by Collision-Induced Dissociation (CID) and Higher Energy Collision-Induced Dissociation (HCD) to distinguish between the stereoisomers budlein A and centratherin.

METHODS

The experiments were carried out in the positive mode using four different spectrometers with an electrospray ionization (ESI) source: (a) Waters ACQUITY(®) TQD triple quadrupole mass spectrometer (QqQ), (b) AB Sciex API 4000 QTrap(®) (QqQ), (c) Bruker Daltonics micrOTOF™-Q II (time-of-flight, QTOF), and (d) Thermo Scientific LTQ Orbitrap XL hybrid FTMS (Fourier transform mass spectrometer). Computational chemistry studies helped to identify the protonation sites. The B3LYP/6-31G(d) model furnished the equilibrium geometries and energies.

RESULTS

The stereochemistry (α- or β-orientation) of the centratherin and budlein A side-chain esters influences the fragmentation pattern recorded on QqQ, QTOF, and Orbitrap-HCD. On QqQ, centratherin releases the side chain, to generate the m/z 275 fragment ion, whereas budlein A gives the m/z 83 fragment ion. On QTOF and Orbitrap-HCD, only budlein A affords the m/z 293 and 83 fragment ions, respectively.

CONCLUSIONS

The data suggest that proton migration governs the fragmentation pathways under α- or β-orientation. The difference in the QqQ, QTOF, and Orbitrap-HCD spectral profiles of each isomer can help to distinguish between centratherin and budlein A using MS/MS, which becomes an alternative to nuclear magnetic resonance (NMR) analysis.

Cytokines in terms of QSAR. Review, evaluation and comparative studies

Cytokines represent a class of chemical factors that act as mediators in the complex biological response of inflammation, potentially implicated in various diseases. Therefore, selective inhibition or antagonism of cytokines is a target of anti-inflammatory drug design. The QSAR (Quantitative Structure-Activity Relationships) analysis presented here attempts to identify the structural features and physicochemical properties that are significant for cytokine antagonists or inhibitors and in particular of i) interleukin-5 (IL-5), ii) interleukin-6 (IL-6) and iii) of the chemotactic cytokine (chemokine) interleukin-8 (IL-8). Firstly, a historical aspect of the limited published QSARs is discussed and then a 2D-QSAR analysis was carried out for 26 data sets of compounds using the C-QSAR program of Biobyte. In six cases hydrophobicity appeared to be important. Steric factors in the form of overall molar refractivity (CMR), molar refractivity of the substituent (MR), molar volume (MgVol), Taft's Es constant and the sterimol parameters B1 and B5 have a significant impact on biological activity in most of the derived equations whereas electronic parameters as σp, σm or Σσ appeared in five cases.

Bicyclic Cyclohexenones as Inhibitors of NF-κB Signaling

A series of structurally simplified cryptocaryone analogues were synthesized by a facile Pd-catalyzed acetoxylation of alkyne-tethered cyclohexadienones and evaluated as inhibitors of NF-κB signaling. Compounds 10 and 11 were found to possess low micromolar inhibitory properties towards induced NF-κB activity by blocking p50/p65 nuclear protein through a covalent inhibition mechanism. Both compounds were able to inhibit NF-κB-induced IL-8 expression and exhibited antiproliferative activity against two model cancer cell lines. These analogues constitute a promising new scaffold for the development of novel NF-κB inhibitors and anticancer agents.

Self-organizing maps of molecular descriptors for sesquiterpene lactones and their application to the chemotaxonomy of the Asteraceae family

The Asteraceae, one of the largest families among angiosperms, is chemically characterised by the production of sesquiterpene lactones (SLs). A total of 1,111 SLs, which were extracted from 658 species, 161 genera, 63 subtribes and 15 tribes of Asteraceae, were represented and registered in two dimensions in the SISTEMATX, an in-house software system, and were associated with their botanical sources. The respective 11 block of descriptors: Constitutional, Functional groups, BCUT, Atom-centred, 2D autocorrelations, Topological, Geometrical, RDF, 3D-MoRSE, GETAWAY and WHIM were used as input data to separate the botanical occurrences through self-organising maps. Maps that were generated with each descriptor divided the Asteraceae tribes, with total index values between 66.7% and 83.6%. The analysis of the results shows evident similarities among the Heliantheae, Helenieae and Eupatorieae tribes as well as between the Anthemideae and Inuleae tribes. Those observations are in agreement with systematic classifications that were proposed by Bremer, which use mainly morphological and molecular data, therefore chemical markers partially corroborate with these classifications. The results demonstrate that the atom-centred and RDF descriptors can be used as a tool for taxonomic classification in low hierarchical levels, such as tribes. Descriptors obtained through fragments or by the two-dimensional representation of the SL structures were sufficient to obtain significant results, and better results were not achieved by using descriptors derived from three-dimensional representations of SLs. Such models based on physico-chemical properties can project new design SLs, similar structures from literature or even unreported structures in two-dimensional chemical space. Therefore, the generated SOMs can predict the most probable tribe where a biologically active molecule can be found according Bremer classification.

Novel depsides as potential anti-inflammatory agents with potent inhibitory activity against Escherichia coli-induced interleukin-8 production

Sixteen novel depsides were synthesized for the first time. Their chemical structures were clearly determined by (1)H NMR, ESI mass spectra, and elemental analyses. All the compounds were assayed for antibacterial activities against three Gram-positive bacterial strains (Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538, and Streptococcus faecalis ATCC 9790) and three Gram-negative bacterial strains (Escherichia coli ATCC 35218, Pseudomonas aeruginosa ATCC 13525, and Enterobacter cloacae ATCC 13047) by the MTT method. Compound 2-(2-methoxy-2-oxoethyl)phenyl 5-bromonicotinate (5) exhibited significant antibacterial activities against E. coli ATCC 35218 with an MIC of 0.78 microg/mL, which was superior to the positive control kanamycin B. In addition, compound 5 showed potent inhibitory activity against E. coli-induced interleukin-8 production.

Semisynthetic derivatives of sesquiterpene lactones by palladium-catalyzed arylation of the alpha-methylene-gamma-lactone substructure

The palladium-catalyzed arylation of different alpha-methylene-gamma-lactone-containing sesquiterpene lactones was shown to produce E-olefin coupling products selectively in moderate to excellent yields. Biological evaluation of these semisynthetic sesquiterpene lactone derivatives in HeLa cells showed interesting antiproliferative profiles and provided initial structure-activity data.

Ainsliatrimers A and B, the first two guaianolide trimers from Ainsliaea fulvioides

Ainsliatrimers A (1) and B (2), the first two guaianolide-type sesquiterpene lactone trimers, together with one new structurally related sesquiterpene dimer ainsliadimer B (3), were isolated from the aerial part of Ainsliaea fulvioides. Their structures were elucidated by spectroscopic techniques, including X-ray crystal diffraction. Both 1 and 2 showed potent cytotoxicites against LOVO and CEM cell lines.

3-Hydr-oxy-3a,6,8c-trimethyl-perhydro-oxireno[2',3':7,8]naphtho[1,2-b]furan-7(2H)-one

The title compound, C₁₅H₂₂O₄, consists of two trans-fused six-membered rings and a trans-fused five-membered γ-lactone. The ep­oxy and hydroxyl groups are α-oriented. The cyclo­hexane rings adopt half-chair and chair conformations and the lactone ring is in an envelope conformation. The mol­ecular structure is stabilized by one O—H⋯O and three C—H⋯O intra­molecular hydrogen bonds.

Microarray analysis reveals influence of the sesquiterpene lactone parthenolide on gene transcription profiles in human epithelial cells

Sesquiterpene lactones are known for their anti-inflammatory activity which has been proven in various assays on DNA, mRNA and protein level. Here we report on the change in the gene expression profile in TNF-alpha stimulated human 293 cells after treatment with parthenolide using a cDNA microarray analysis. Twenty-one of 7028 genes were found to be up- and 18 down-regulated. They encode for chemoattractants, immune system proteins, glycoproteins, metabolism, serine proteinases, and transcription factors. Confirmatory analyses were carried out using quantitative real-time RT-PCR (TaqMan). Additional studies with selected genes revealed the concentration-dependent influence of parthenolide on the expression of these genes.

Chamazulene carboxylic acid and matricin: a natural profen and its natural prodrug, identified through similarity to synthetic drug substances

Chamazulene carboxylic acid (1) is a natural profen with anti-inflammatory activity and a degradation product of proazulenic sesquiterpene lactones, e.g., matricin. Both 1 and proazulenes occur in chamomile (Matricaria recutita), yarrow (Achillea millefolium), and a few other Asteraceae species. It was isolated in improved yields, characterized physicochemically, and found to be an inhibitor of cyclooxygenase-2, but not of cyclooxygenase-1. It had anti-inflammatory activity in several animal models with local and systemic application. When human volunteers were given matricin orally, plasma levels of 1 were found to be in the micromolar range. Matricin was converted to 1 in artificial gastric fluid, but not in artificial intestinal fluid. Matricin and the yarrow proazulenes are proposed to be anti-inflammatory through conversion to 1. Intriguingly, the biological activity of the natural compound 1 was found because of its similarity to fully synthetic drug substances. This is the reverse process of the common lead function of natural compounds in drug discovery.