Antitumor agents, 162. Cell-based assays for identifying novel DNA topoisomerase inhibitors: studies on the constituents of Fatsia japonica

Three new triterpenoids from the fruit of Eleutherococcus senticosus (Rupr.) Harms

A phytochemical investigation on the 70% EtOH extract of the fruit of Acanthpanax senticosus resulted in the isolation of three new triterpenoids, Falcatane C (1), Acasentrioid F (2), Acasentrioid G (3) together with twenty-seven known ones (4-30). Structural elucidation of all the compounds was performed by spectral methods such as 1D or 2D (1H-1H COSY, HSQC, and HMBC), NMR spectroscopy, and high-resolution mass spectrometry. Moreover, all compounds were evaluated for their effects on H2O2-induced neurotoxicity in human neuroblastoma SH-SY5Ycells. Compounds 13 and 15 showed significant neuroprotective impact at a specific concentration, and compounds 1, 3, 5, 9, 11, 13-15, 17, 20-21, 23-25, 27, 29-30 showed moderate neuroprotective effect. The current study suggests that triterpenes in Eleutherococcus senticosus (Rupr.) Harms may play an essential role in the neuroprotective properties.

Fatsia japonica extract exerts antioxidant and anti-neuroinflammatory effects on neuronal cells and a zebrafish model

ETHNOPHARMACOLOGICAL RELEVANCE

Fatsia japonica is a traditional medicine used to treat various diseases, including inflammation-related disorders. However, its antineuroinflammatory and neuroprotective effects remain unclear.

AIM OF THE STUDY

We aimed to evaluate the anti-neuroinflammatory and neuroprotective effects of F. japonica extract to identify the underlying mechanisms.

MATERIALS AND METHODS

The components of F. japonica extract were profiled using ultra-high-performance liquid chromatography-mass spectrometry. The effects of F. japonica extract were investigated in BV2 microglia and HT22 hippocampal cells. Furthermore, in vivo effects of F. japonica extract were assessed using zebrafish models treated with H2O2 and LPS to evaluate the effects of in vivo.

RESULTS

We identified 27 compounds in the F. japonica extract. F. japonica extract demonstrated anti-inflammatory properties by suppressing LPS-induced inflammatory responses in both BV2 cells and zebrafish, along with inhibiting the activation of the nuclear factor (NF)-κB (p65) pathway. The protective effects of this extract were also observed on glutamate-treated HT22 cells and in H2O2-induced zebrafish. Furthermore, F. japonica extract upregulated nuclear factor E2-related (Nrf) 2/heme oxygenase (HO)-1 expression in BV2 and HT22 cells.

CONCLUSIONS

F. japonica extract exerted anti-neuroinflammatory and neuroprotective effects through Nrf2/HO-1 and the NF-κB pathway.

The complete chloroplast genome sequence of Fatsia japonica (Apiales: Araliaceae) and the phylogenetic analysis

In this study, we have sequenced the complete chloroplast genome of Fatsia japonica, a well-known ornamental and potential medicinal plant. The complete chloroplast genome of F. japonica is 155 613 bp in length with 62.09% AT content, has a typical quadripartite structure with large (LSC 86 487 bp) and small (SSC 17 866 bp) single-copy regions separated by a pair of inverted repeats (IRs 25 929 bp) and contains 114 unique genes with 18 genes duplicated in the IR making a total of 132 genes. The phylogenetic analysis indicated the position of F. japonica in Apiales and has the potential to facilitate a better understanding of the intergeneric relationships in the family.

Pharmacokinetics study of asperosaponin VI and its metabolites cauloside A, HN saponin F and hederagenin

This experiment's with aim was to study the pharmacokinetics of asperosaponin VI and its three metabolites (cauloside A, HN saponin F and hederagenin) via a sensitive high performance liquid chromatography connected with electrospray ionization triple quadrupole mass spectrum (HPLC-ESI-MS/MS). Chromatographic separation was achieved on a reverse phase C18 column with a gradient mobile phase of CH3CN-water with 0.1 % HCOOH at a flow rate of 0.3 mL/min. Sample analysis was simultaneously performed with a multiple reaction monitoring mode using target determination ions at m/z 927.5 → 603.4 for asperosaponin VI, m/z 811.1 → 603.4 for cauloside A, m/z 649.4 → 603.4 for HN saponin F, m/z 71.4 → 393.3 for hederagenin and m/z 307.0 → 161.1 for warfarin as the internal standard. The calibration curve was linear at the range of 0.25-500 ng/mL, and the lower limit of quantification was 0.25 ng/mL for each compound. While the precisely intra-assay and inter-assay variabilities were <9.5 and 7.8 %, respectively; accuracy was determined at the concentrations of 5, 25, 100 ng/mL for all the analytes with the relative standard deviation (%) no more than 15.0 %. Consequently, the validated method could be successfully and precisely applied to the pharmacokinetic study of asperosaponin VI and its metabolites. As a result, the pharmacokinetic parameters of cauloside A, HN saponin F and hederagenin such as T max were obtained at 9.33 ± 2.49, 7.33 ± 0.47 and 12.33 ± 2.36 h, respectively.

Anti-Inflammatory Effects and Mechanisms of Fatsia polycarpa Hayata and Its Constituents

Fatsia polycarpa, a plant endemic to Taiwan, is an herbal medicine known for treating several inflammation-related diseases, but its biological function needs scientific support. Thus, the anti-inflammatory effects and mechanisms of the methanolic crude extract (MCE) of F. polycarpa and its feature constituents, that is, brassicasterol (a phytosterol), triterpenoids 3α-hydroxyolean-11,13(18)-dien-28-oic acid (HODA), 3α-hydroxyolean-11-en-28,13β-olide (HOEO), fatsicarpain D, and fatsicarpain F, were investigated. MCE and HOEO, but not brassicasterol, dose-dependently inhibited lipopolysaccharide- (LPS-)induced expression of inducible nitric oxide synthase and cyclooxygenase-2 in RAW 264.7 macrophage line, whereas HODA, fatsicarpain D and fatsicarpain F were toxic to RAW cells. Additionally, MCE and HOEO suppressed LPS-induced production of nitric oxide, prostaglandin E₂, and interleukin-1β and interfered with LPS-promoted activation of the inhibitor kappa B kinase (IKK)/nuclear factor-κB (NF-κB) pathway, and that of the mitogen-activated protein kinases (MAPKs) extracellular signal regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. In animal tests, MCE and HOEO effectively ameliorated 12-O-tetradecanoylphorobol-13 acetate- (TPA-)induced ear edema of mice. Thus, MCE of F. polycarpa exhibited an obvious anti-inflammatory activity in vivo and in vitro that likely involved the inhibition of the IKK/NF-κB pathway and the MAPKs, which may be attributed by triterpenoids such as HOEO.

Oleanane-type triterpenoids from the leaves and twigs of Fatsia polycarpa

Seven new oleanane-type triterpenoids (1-7), named fatsicarpains A-G, and the known compounds 3α-hydroxyolean-11,13(18)-dien-28-oic acid (8) and 3α-hydroxyolean-11-en-28,13β-olide (9) were isolated from the leaves and twigs of Fatsia polycarpa on the basis of bioassay-guided fractionation. The structures of compounds 1-7 were elucidated through spectroscopic analyses and single-crystal X-ray crystallography of 1, 8, and 9. Cytotoxicity against HepG2 2.2.15 and AGS cells and antihepatitis B virus (HBV) and antibacterial activities of 1-9 were also evaluated in vitro.

Antimicrobial triterpenoid glycosides from Cephalaria scoparia

Five new oleanane-type triterpenoid glycosides (1-5), named scoposides A-E, along with one known bisdesmosidic triterpene glycoside, were isolated from the aerial parts of Cephalaria scoparia. Three prosapogenins (2a-4a) were also obtained after alkaline hydrolysis of the bisdesmosidic compounds 2-4. The structures of compounds 1-5 were determined by spectroscopic (1D and 2D NMR, HRESIMS) and chemical methods. The antimicrobial effects of compounds 1-5 were evaluated against a small panel of Gram-positive and Gram-negative bacteria.

Triterpene glycosides from the underground parts of Caulophyllum thalictroides

A total of 22 triterpene glycosides, including 10 new compounds (1-10), were isolated from the underground parts of Caulophyllum thalictroides. The structures of the new glycosides were determined on the basis of extensive spectroscopic analyses, including two-dimensional (2D) NMR data, and of hydrolytic cleavage followed by chromatographic or spectroscopic analyses. All 22 compounds were evaluated for cytotoxicity against HL-60 human leukemia cells. The triterpene monodesmosides based on oleanolic acid (1 and 11-16) showed cytotoxic activity against HL-60 cells with IC(50) values that ranged from 3.4 to 15.9 microg/mL.

Inhibition of DNA topoisomerase II catalytic activity by the antiviral agents 7-chloro-1,3-dihydroxyacridone and 1,3,7-trihydroxyacridone

Previously we reported that the antiproliferative and antiviral actions of 7-chloro-1,3 dihydroxyacridone (compound 1) and its derivatives may be mediated through the inhibition of mammalian DNA topoisomerase II. In the present work, we have extended our investigation into the mechanism of topoisomerase II inhibition by these agents. Both compound 1 and its 7-OH derivative, compound 2, inhibited topoisomerase II catalytic activity in vitro, yet neither agent affected the activity of topoisomerase I. DNA unwinding assays indicated that compound 1 and compound 2 bound to DNA, although no correlation was found between DNA unwinding and topoisomerase II catalytic inhibition. Neither agent enhanced topoisomerase II-mediated DNA cleavage in vitro; however, both compound 1 and compound 2 antagonized breaks induced by etoposide and amsacrine. Experiments indicate that interference with etoposide-stimulated breaks results from inhibition of topoisomerase II * DNA binding by compound 1. These findings suggest that compound 1 and its derivatives may represent a novel structural class of topoisomerase II catalytic inhibitors.

Antitumor agents. 163. Three-dimensional quantitative structure-activity relationship study of 4'-O-demethylepipodophyllotoxin analogs using the modified CoMFA/q2-GRS approach

Analogs of 4'O-demethylepipodophyllotoxin are considered as potential anticancer agents. We have applied comparative molecular field analysis (CoMFA) and a novel CoMFA/q2-GRS technique recently developed in our group to identify the essential structural requirements for increasing the ability of these compounds to form cellular protein-DNA complex. In addition, a new method to incorporate different types of probe atoms as part of q2-GRS routine has been developed. The best final model with 101 compounds using a combination of four different sets of probe atoms and charges [C (sp3, +1), C (sp3, 0), H (+1), and O (sp3, -1)] yielded a q 2 of 0.584 and the standard error of prediction of 0.660 at 5 principal components. The steric and electrostatic contour plots of the final model were compared with the DNA phosphate backbone environment of the DNA-4'O-demethylepipodophylltoxin analog complex, which was generated using the X-ray structure of the DNA-nogalamycin complex. The comparison reveals that the CoMFA steric and electrostatic fields are compatible with stereochemical properties of the DNA backbone. The results obtained from this study shall guide our future synthetic efforts.