Cytotoxic sesquiterpenoids against hepatic stellate cell line LX2 from Artemisia lavandulaefolia

Eudesmane-type sesquiterpenoids from the aerial parts of Artemisia lavandulaefolia and their anti-pancreatic cancer activities

Five undescribed eudesmane sesquiterpenoids, artemilavanins A-E, and one undescribed rearranged eudesmane sesquiterpenoid, artemilavanin F, were isolated from the 95% ethanol extract of the aerial parts of Artemisia lavandulaefolia DC., along with ten known compounds. The structures and configurations of undescribed compounds were mainly elucidated by spectroscopic analyses and single-crystal X-ray diffraction analysis. Among all isolated compounds, artemilavanin F exhibited inhibitory activity on PANC-1 pancreatic cancer cells with IC50 of 9.69 ± 2.39 μM. Artemilavanin F inhibited PANC-1 cell proliferation by induction of G2/M cell cycle arrest and apoptosis mediated by downregulation of cyclin-dependent kinases and accumulation of reactive oxygen species. Moreover, artemilavanin F inhibited the colony formation, cell migration and sphere formation of PANC-1 cells, indicating the suppression of stem-cell-like phenotype of PANC-1 cells. Further results confirmed that the expression of cancer stem cell markers such as Bmi1, CD44, CD133 were inhibited by artemilavanin F. Downregulation of epithelial-mesenchymal transition (EMT) markers such as N-cadherin and Oct-4 indicated the potential of artemilavanin F in prevention of metastasis.

Artemongolins A-K, undescribed germacrane-guaiane sesquiterpenoid dimers from Artemisia mongolica and their antihepatoma activities

Artemongolins A-K (1-11), which are undescribed sesquiterpenoid dimers, were obtained from Artemisia mongolica and characterized through comprehensive spectral data, including HRESIMS, IR, 1D and 2D NMR, and ECD calculations. The absolute configurations of compounds 1, 4, and 7 were undoubtedly determined by a single-crystal X-ray crystallography. Artemongolins A-K (1-11) featured a rare 5/7/5/5/5/10 hexacyclic system composed of a germacrene and a guaianolide by a fused 2-oxaspiro[4,4]nonane-1-one ring system. Antihepatoma evaluation against three human hepatoma cell lines demonstrated that the most active compounds 5 and 6 displayed inhibitory activity with IC50 values of 88.6 and 57.0 (HepG2), 59.1 and 26.4 (Huh7), and 67.5 and 32.5 (SK-Hep-1) µM, respectively.

Combined Amphiphilic Silybin Meglumine Nanosuspension Effective Against Hepatic Fibrosis in Mice Model

Introduction

Silybin (SLB) as an effective hepatoprotective phytomedicine has been limited by its hydrophobicity, poor bioavailability and accumulation at lesion sites. Additionally, present drug loading methods are impeded by their low drug loading capacity, potential hazard of materials and poor therapeutic effects. Consequently, there is a pressing need to devise an innovative approach for preparing nanosuspensions loaded with both SLB and Silybin Meglumine salt (SLB-M), as well as to investigate the therapeutic effects of SLB nanosuspensions against hepatic fibrosis.

Methods

The SLB nanosuspension (NS-SLB) was prepared and further modified with a hyaluronic acid-cholesterol conjugate (NS-SLB-HC) to improve the CD44 targeting proficiency of NS-SLB. To validate the accumulation of CD44 and ensure minimal cytotoxicity, cellular uptake and cytotoxicity assessments were carried out for the nanosuspensions. Western blotting was employed to evaluate the anti-hepatic fibrosis efficacy in LX-2 cells by inhibiting the secretion of collagen I. Hepatic fibrosis mouse models were used to further confirm the effectiveness of NS-SLB and NS-SLB-HC against hepatic fibrosis in vivo.

Results

Uniform nanosuspensions were prepared through self-assembly, achieving high drug loading rates of 89.44% and 60.67%, respectively. Both SLB nanosuspensions showed minimal cytotoxicity in cellular environments and mitigated hepatic fibrosis in vitro. NS-SLB-HC was demonstrated to target activated hepatic stellate cells by receptor-ligand interaction between HA and CD44. They can reverse hepatic fibrosis in vivo by downregulating TGF-β and inhibiting the secretion of α-SMA and collagen I.

Conclusion

Designed as a medical excipient analogue, SLB-M was aimed to establish an innovative nanosuspension preparation method, characterized by high drug loading capacity and a notable impact against hepatic fibrosis.

Artemiprinolides A-M, thirteen undescribed sesquiterpenoid dimers from Artemisia princeps and their antihepatoma activity

Bioassay-guided investigation of the active fraction of Artemisia princeps led to 13 undescribed sesquiterpenoid dimers, artemiprinolides A-M (1-13), together with 11 known ones (14-24). Their structures were elucidated by comprehensive spectroscopic data and absolute configurations were assigned based on single crystal X-ray diffraction data and ECD calculations. Structurally, all compounds were postulated to be derived from the Diels-Alder cycloaddition. The isolated dimers except 11 and 15 were assayed for their cytotoxicity against HepG2, Huh7, and SK-Hep-1 cell lines, of which four compounds (3, 13, 17, 18) exhibited obvious cytotoxicity with IC₅₀ values ranging from 8.8 to 20.1 μM. Interestingly, the most active compounds 1 and 16 manifested significant cytotoxicity on the three tested hepatoma cell lines with IC₅₀ values of 5.4, 4.1 (HepG2), 7.7, 5.6 (Huh7), and 11.8, 15.7 μM (SK-Hep-1), respectively, which were better than sorafenib. Compound 1 dose-dependently inhibited cell migration and invasion, and significantly induced the HepG2 cell arrest in G2/M phase by downregulating cdc2 and pcdc2 and upregulating cyclinB1; and induced apoptosis by downregulating Bcl-2 expression and upregulating Bax level. The molecular docking study implied that the carbonyl at the C-12' of 1 had a strong binding affinity with PRKACA.

Discovery of Novel Sesquiterpene Lactone Derivatives as Potent PKM2 Activators for the Treatment of Ulcerative Colitis

The pyruvate kinase M2 (PKM2) can significantly affect the differentiation of Th17 and Treg cells; thus, it is considered a promising target for UC therapy. Herein, five series of costunolide (Cos) derivatives are designed, synthesized, and biologically evaluated. Among them, D5 exhibits excellent immunomodulatory activity against T-cell proliferation and potent PKM2 activating activity. Meanwhile, it has been confirmed that D5 can also covalently interact with Cys424 of PKM2. The molecular docking and molecular dynamic (MD) studies indicate that difluorocyclopropyl derivative of D5 improves the protein-ligand interaction by interacting with Arg399 electrostatically. Furthermore, D5 significantly dampens the differentiation of Th17 but not Treg cells to recover the Th17/Treg balance, which is attributed to the suppression of PKM2-mediated glycolysis. Oral administration of D5 ameliorates the symptoms of dextran sulfate sodium (DSS)- and 2,4,6-trinitro-benzenesulfonic acid (TNBS)-induced colitis in mouse model. Collectively, D5 has the potential to be developed as a novel anti-UC candidate.

Artemleucolides A-L, eudesmane-type sesquiterpenoids from Artemisia leucophylla and their antihepatoma cytotoxicity

Twelve undescribed and 13 known eudesmane-type sesquiterpenoids were obtained from Artemisia leucophylla, and structurally elucidated based on comprehensive analyses of spectral data, including HRESIMS, IR, 1D and 2D NMR, and ECD calculation. The absolute configuration of compound 1 was determined by a single X-ray single crystal diffraction. Chemically, compounds 1-5 featured unprecedented 1,2-seco-1-nor-eudesmane-type skeleton with a cis-fused 6/5 bicyclic system. Antihepatoma evaluation against three human hepatoma cell lines (HepG2, Huh7, and SK-Hep-1) for all compounds demonstrated that compound 7 displayed the most active cytotoxicity with IC₅₀ values of 35.1, 35.0, and 32.7 μΜ.

Artemongolides A-F, undescribed sesquiterpenoid dimers from Artemisia mongolica and their antihepatic fibrosis activities

Artemongolides A-E (1-5), an unusual class of diseco-guaianolides featuring a rare fused 7-methylbicyclo[2.2.1]-2-ene-7-heptanol ring system, and artemongolide F (6), the first example of [4 + 2] Diels-Alder type adducts presumably incorporating a chain farnesane sesquiterpene and a guaianolide diene, were isolated from the whole plant of Artemisia mongolica. Their structures were elucidated based on the spectroscopic analyses of UV, IR, MS, and 1D and 2D NMR spectra. The absolute configurations of artemongolides A (1) and F (6) were determined by single-crystal X-ray crystallography, and those of artemongolides B-E (2-5) were established by ECD calculations. Cytotoxicity evaluation suggested that compound 1 exhibited activity against HSC-LX2 cells with an IC₅₀ value of 165.0 μM, equivalent to that of the positive control silybin (IC₅₀, 146.4 μM). Preliminary mechanism studies revealed that compound 1 could inhibit the deposition of human collagen type I (Col I), human hyaluronic acid (HA), and human laminin (HL) with IC₅₀ values of 123.8, 160.4, and 139.20 μM.

Insecticidal Activity of a Component, (-)-4-Terpineol, Isolated from the Essential Oil of Artemisia lavandulaefolia DC. against Plutella xylostella (L.)

Plutella xylostella (L.) is one of the most serious pests of cruciferous vegetables. Our previous work demonstrated that the essential oil of Artemisia lavandulaefolia DC. exhibits promising insecticidal activities against P. xylostella. This study further characterizes the key components that are responsible for the insecticidal effect. In total, 47 compounds (96.52% of the total compounds) were identified from the total oil using GC-MS, and the major compounds were eucalyptol (21.57%), D(+)-camphor (17.33%), (-)-4-terpineol (9.96%) and caryophyllene oxide (10.96%). Among them, (-)-4-terpineol showed significantly larvicidal and fumigant activities against P. xylostella. The LD₅₀ of (-)-4-terpineol was 43.15 mg/mL at 12 h and 31.22 mg/mL at 24 h for 3rd instar larvae, and the LC₅₀ for adults was 8.34 mg/mL at 12 h and 7.35 mg/mL at 24 h. In addition, the adults treated with (-)-4-terpineol showed varying degrees of inhibitory activity toward glutathione S-transferase, catalase, acetylcholinesterase and Na⁺/K⁺-ATPase at different post-treatment intervals and concentrations. The results indicate that (-)-4-terpineol has promising insecticidal activities against P. xylostella, and it has good inhibitory effects on the four enzymes of P. xylostella adults.

Guaianolides from Artemisia codonocephala suppress interleukine-1β secretion in macrophages

Sesquiterpene lactones supply a variety of scaffolds for the development of anti-inflammatory drugs. In this study, eight undescribed guaianolides, i.e., lavandolides A‒H, were isolated from the whole plants of Artemisia codonocephala, together with five known analogues. Their planar structures and relative configurations were elucidated by spectroscopic measurements, and their absolute configurations were determined by electronic circulardichroism spectra and single crystal X-ray diffraction experiments. The nitric oxide inhibitory effect of all the isolates was assessed on lipopolysaccharide stimulated THP-1 macrophages. Lavandolide D showed a potent inhibitory effect on NO production, with IC₅₀ values of 3.31 ± 0.74 μM. Furthermore, lavandolide D inhibited NOD-, LRR- and pyrin domain-containing protein 3 inflammasome-mediated interleukin-1β production through activating autophagy.

Biomimetic Synthesis of Lavandiolides H, I, and K and Artematrolide F via Diels-Alder Reaction

The biomimetic synthesis of guaianolide dimers lavandiolides H, I, and K and artematrolide F containing a spirolactone moiety has been accomplished for the first time from naturally abundant arglabin in four to six steps with an overall yield up to 60%, and a series of natural product-like guaianolide dimers, trimer, and tetramer were also successfully synthesized. Notably, the trimeric compound exhibited antihepatoma cytotoxicity more potent than that of sorafenib with IC₅₀ values of 6.2 μM (HepG2), 6.8 μM (Huh7), and 7.2 μM (SK-HEP-1).

Artemicapillasins A-N, cytotoxic coumaric acid analogues against hepatic stellate cell LX2 from Artemisia capillaris (Yin-Chen)

Under the guidance of bioassay against HSC-LX2, the EtOH extract and the EtOAc fraction of Artemisia capillaris (Yin-Chen) exhibited cytotoxic activity against HSC-LX2 with inhibitory ratios of 39.7% and 68.7% at the concentration of 400.0 μg/mL. Bioassay-guided investigation of Fr. D (the active fraction) yielded 14 new coumaric acid analogues, artemicapillasins A-N (1-14). The structures of the isolates were elucidated by spectroscopic analyses involving UV, IR, MS, 1D and 2D NMR spectra and ECD calculations. Cytotoxic activity against HSC-LX2 cells of these isolates was performed to reveal that 12 compounds demonstrated cytotoxicity with inhibitory ratios more than 50% at 400 μM. The most active artemicapillasin B (2) gave an IC₅₀ value of 24.5 μM, which was about 7 times more toxic than the positive drug silybin (IC₅₀, 162.3 μM). Importantly, artemicapillasin B (2) showed significant inhibition on the deposition of human collagen type I (Col I), human laminin (HL) and human hyaluronic acid (HA) with IC₅₀ values of 11.0, 14.4 and 13.8 μM, which was about 7, 11 and 5 times more active than silybin. Artemicapillasin B (2) as an interesting antihepatic fibrosis candidate is worth in-depth study.

Synthesis and anti-fibrotic effects of santamarin derivatives as cytotoxic agents against hepatic stellate cell line LX2

Liver fibrosis is a final result of extensive deposition of extracellular matrix (ECM) and starts with the activation and proliferation of hepatic stellate cells (HSCs). Our previous study showed that eudesmane sesquiterpenoid santamarin had cytotoxicity against hepatic stellate cell line LX2 (HSC-LX2) with IC₅₀ values of 16.5 ± 0.7 μM. To explore the structure-activity relationships, twenty-six derivatives were synthesized by modifying the hydroxyl group, double-bond and unsaturated lactone. Cytotoxicity evaluation suggested that eight derivatives (6, 9, 13, 17, 20 and 25-27) increased activity against HSC-LX2. Especially, derivatives 17, 20 and 25 displayed obvious cytotoxicity with IC₅₀ values of 6.4 ± 0.4, 4.6 ± 0.1, and 3.5 ± 0.1 μM, which were 3 to 5-fold higher than santamarin. Preliminary mechanisms study revealed that the active compound 20 exhibited more than 8-fold and 6-fold enhancement of inhibitory effect on the deposition of human hyaluronic acid (HA) and human laminin (HL) with IC₅₀ values of 7.6 ± 0.6 and 3.3 ± 1.2 μM.

Trimeric and dimeric sesquiterpenoids from Artemisia atrovirens and their cytotoxicities

Two sesquiterpenoid trimers and two sesquiterpenoid dimers possessing unprecedented scaffolds with a methylene-bridged connection were identified from Artemisia atrovirens. Compound 3 showed obvious cytotoxicity against HepG2 and Huh7 cell lines.

Sesquiterpene lactone dimers from Artemisia lavandulifolia inhibit interleukin-1β production in macrophages through activating autophagy

Twelve new sesquiterpene lactone dimers, lavandiolides A-L (1-12), were isolated from the whole plants of Artemisia lavandulifolia. Among them, compounds 1-6 are 1,3-linked Diels-Alder adducts between two guaianolide monomers, and 7-12 are 2,4-linked sesquiterpene lactone dimers. Their structures were elucidated by comprehensive analysis of HRESIMS, 1D and 2D NMR spectra. Their absolute configurations were determined by ECD spectra and single-crystal X-ray diffraction analyses with Cu Kα radiation. The nitric oxide (NO) inhibitory effect of all the isolates was assessed on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Compounds 1, 3, 7 and 9 showed potent inhibitory effects on NO production, with IC₅₀ values of 0.61 ± 0.15, 1.64 ± 0.04, 1.89 ± 0.16, and 1.40 ± 0.23 μM, respectively. Furthermore, compound 1 inhibited NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome-mediated interleukin-1β (IL-1β) production through activating autophagy.