Tomenphantadenine, an unprecedented germacranolide-adenine hybrid heterodimer from the medicinal plant Elephantopus tomentosus L

Anti-liver tumor ingredient exploration and validation of Elephantopus tomentosus Linn. by combining in silico and in vitro experiments

Elephantopus tomentosus (ET) Linn. was reported to be an anti-tumor plant. However, the chemical composition of ET and its anti-tumor compounds and potential mechanisms still unclear. In this paper, UPLC-Q-TOF-MS/MS was firstly used to identified the ingredients in ET and UPLC was used to determine the main compounds of ET. Network pharmacology was applied to predict the potential mechanisms of anti-liver cancer. Anti-tumor nuclear activate compounds and targets of ET were obtained and the anti-liver cancer effect was validated on HepG2. Finally, Molecule docking, RT-qPCR, and western blotting were used for verification of the relationship between nuclear activate compounds and nuclear targets and the potential anti-cancer mechanisms. The result showed that 42 compounds were identified in ET, which consisted of sesquiterpene lactones, flavonoids, and phenylpropanoid compounds. Scabertopin (ST), chlorogenic acid, Isochlorogenic acid B, Isochlorogenic acid A and Isochlorogenic acid C were identified as main compounds and were determined as 0.426%, 0.457%, 0.159%, 0.701%, and 0.103% respectively. 24 compounds showed high pharmacokinetics and good drug-likeness. 520 overlapping targets of the ET compounds and liver cancer were collected. The targets were used for KEGG and GO analysis. GO enrichment analysis suggested that the targets of 24 active compound closed related to promote apoptosis, inhibit proliferation, and regulate oxidative levels. KEGG enrichment analysis suggested that pathway in cancer was enriched most and p38 MAPK/p53 signaling pathway, which closely related to promoting apoptosis and inhibiting proliferation. Compounds-targets analysis based on the parameter of Betweenness, Closeness, Information, Eigenvector, Degree, and component content indicated that ST was the nucleus anti-tumor active compound of ET. HepG2 was first used to validated the anti-tumor effect of ST and the result showed that ST significantly inhibited HepG2 proliferation with a low IC50 less than 5 μM. Nucleus active compound targets, including TP53, CASP3, BCL2, EGFR, TNF-a, IL-1β, and IL-6 were enriched based on degree value of PPI analysis. Molecule docking suggested that ST showed a good combination to TGFBR1 with the combination energy less than - 5 kcal/mol. RT-qPCR result also suggested that ST significantly medicated the mRNA expression level of TP53, CASP3, BCL2, EGFR, TNF-a, IL-1β, and IL-6. Protein expression of p-p38/p38 and p-p53/p53 notable increased by ST treatment. In conclude, combining with UPLC-Q-TOF-MS/MS qualitative analysis, UPLC quantitative analysis, network pharmacology analysis, molecule docking, and in vitro experiments on HepG2, we suggest that ST is an anti-tumor ingredient of ET, which may target to TGFBR1 and promote apoptosis and inhibited proliferation of HepG2 by activating p38 MAPK/p53 signaling pathway. ST can be regarded as a quality marker of ET.

The specialized sesquiterpenoids produced by the genus Elephantopus L.: Chemistry, biological activities and structure-activity relationship exploration

The genus Elephantopus L. is a valuable resource rich in sesquiterpenoids with structural diversity and various bioactivities, showing great potential for applications in medicinal field and biological industry. Up to now, over 129 sesquiterpenoids have been isolated and identified from this plant genus, including 114 germacrane-type, 7 guaianolide-type, 5 eudesmane-type, 1 elemanolide-type, and 2 bis-sesquiterpenoids. These sesquiterpenoids were reported to show a diverse range of pharmacological properties, including cytotoxic, anti-tumor, anti-inflammatory, antimicrobial, and antiprotozoal. Consequently, some of them were identified as active scaffolds in the design and development of drugs. Considering that there is currently no overview available that covers the sesquiterpenoids and their biological activities in the Elephantopus genus, this article aims to comprehensively review the chemical structures, biosynthetic pathways, pharmacological properties, and structure-activity relationship of sesquiterpenoids found in the Elephantopus genus, which will establish a theoretical framework that can guide further research and exploration of sesquiterpenoids from Elephantopus plants as promising therapeutic agents.

A highly oxidized germacranolide from elephantopus tomentosus inhibits the growth of hepatocellular carcinoma cells by targeting EGFR in vitro and in vivo

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, with high mortality and poor prognosis. WBDC-1 is a novel highly oxidized germacranolide from the Elephantopus tomentosus in our previous work, which has excellent anti-HCC activity, but the detailed mechanism is still unclear. In this study, we found that WBDC-1 was able to inhibit the proliferation and colony formation of Hep3B and HepG2 cells, as well as the cell migration ability and EMT. In addition, WBDC-1 showed no obvious toxicity to normal liver epithelial cells L-02. The potential targets of WBDC-1 were predicted by network pharmacology, and the following verified experiments showed that WBDC-1 exerted anti-HCC effect by targeting EGFR. Mechanismly, subsequent biological analysis showed that WBDC-1 can inhibit EGFR and its downstream RAS/RAF/MEK/ERK and PI3K/AKT signaling pathways. Overexpression of EGFR reversed the anticancer properties of WBDC-1. Consistent with in vitro experiments, WBDC-1 was able to inhibit tumor growth and was non-toxic in xenograft tumor models. In summary, this study revealed a potential tumor suppressive mechanism of WBDC-1 and provided a novel strategy for HCC treatment. It also laid a foundation for further research on the anti-tumor effect of highly oxidized germacranolides.

New caffeoyl derivatives with potent DPPH radical scavenging activity from Elephantopus tomentosus

Eight new caffeoyl derivatives, elephantomentosides A-H (1 - 8), together with ten known ones (9 - 18), were isolated from the whole plant of Elephantopos tomentosus L. Their structures were elucidated using detailed spectroscopic analysis. Structurally, compounds 1 - 8 are composed of β-D-glucopyranose, and almost all of the substituent positions are at the C-1' and C-4' of glucopyranose. The anti-inflammatory and antioxidant activities of all isolated compounds were evaluated in vitro. Compounds 9-10, 13-15, and 17-18 exhibited significant DPPH scavenging capacity with IC50 values in the range of 10.01-25.07 μM, in comparison with Vc (IC50, 17.98 μM).

HSQC-based small molecule accurate recognition technology discovery of diverse cytotoxic sesquiterpenoids from Elephantopus tomentosus L. and structural revision of molephantins A and B

Elephantopus tomentosus L. is a perennial herb taxonomically belonging to the family Asteraceae, which has been used as a folk medicine for the treatment of hepatobiliary diseases. Sesquiterpenoids from this plant have broad biological activities, including anti-tumor, anti-inflammatory, and antibacterial effects. In this study, fifteen structurally diverse sesquiterpenoids comprised 11 germacrane-type and 4 eudesmane-type sesquiterpenoids were prioritized to isolated from Elephantopus tomentosus L. based on the HSQC-based Small Molecule Accurate Recognition Technology (SMART) strategy. Among them, ten sesquiterpenoids were previously unreported, and their structures were elucidated by spectroscopic data, computational methods, single-crystal X-ray diffraction crystallographic data or electronic circular dichroism calculations. In addition, the structures of two known sesquiterpenoids, molephantin A and B, which were reported to possess E-geometry for the Δ¹⁽¹⁰⁾ double bond, were revised by reanalyzing their spectroscopic and X-ray crystallographic data. Some sesquiterpenoids exhibited significant cytotoxic activities against Hep3B and HepG2 cell lines.

Highly Oxidized Germacranolides from Elephantopus tomentosus and the Configurational Revision of Some Previously Reported Analogues

Highly oxidized germacranolides are mainly found in the genus Elephantopus, contain a characteristic ten-membered molecular core that is highly flexible, and exhibit potential cytotoxic properties. However, their configurations were assigned ambiguously in previous reports due to spectroscopic observation of macrocyclic systems. Herein, 17 highly oxidized germacranolides, including 12 new germacranolides (1-12), were isolated from Elephantopus tomentosus. Their structures were characterized by spectroscopic data analysis combined with X-ray crystallography and ECD calculations, and it was possible to propose configurational revisions of five previously reported analogues (13-17). Cytotoxic activities for 1-17 against two hepatocellular carcinoma cell lines (HepG2 and Hep3B) were tested, and compounds 1-10 and 13-16 generated IC₅₀ values of 2.2-9.8 μM. Furthermore, the observed cytotoxic activity of 1 was determined as being mediated by inducing the apoptosis of HepG2 and Hep3B cells via mitochondrial dysfunction.

Cytotoxic Germacrane-Type Sesquiterpene Lactones from the Whole Plant of Carpesium lipskyi

Ten new sesquiterpene lactones, carlipsines A-J (1-10), and 12 known analogues (11-22) were isolated from the whole plant of Carpesium lipskyi. Their structures were elucidated by using 1D and 2D NMR and HRESIMS analyses, and their absolute configurations were confirmed by X-ray diffraction studies. All compounds were identified as germacranolides with diverse substructural features. Compounds 1-4 are 2,5-hemiacetal-linked germacranolides. Compounds 5 and 6 possess a 1,2-epoxy moiety. Compounds 7 and 8 represent unusual 1,5-hemiacetal-linked germacranolides. Compounds 9 and 10 contain a tetrahydrofuran unit with the oxygen atom bridging C-1 and C-8. Compounds 6, 7, 8, 19, 20, 21, and 22 showed cytotoxicity against HL-60 and A-549 cell lines with IC₅₀ values ranging from 2.8 to 10.3 μM.

Anti-inflammatory constituents from Perilla frutescens on lipopolysaccharide-stimulated RAW264.7 cells

Perilla frutescens (L.) Britt. (Lamiaceae) is a traditionally medicinal herb in East Asian countries to treat various diseases. In present study, the low-polarity constituents of the aerial parts of P. frutescens were investigated and their anti-inflammatory effect on lipopolysaccharide (LPS)-stimulated RAW264.7 cells were assayed. Three new furanoid monoterpenoids, named as frutescenones A - C (1-3), together with thirteen known compounds (4-16) were isolated and identified on the basis of extensive spectroscopic analysis and a single-crystal X-ray diffraction study. Among these components, 1 is an unusual monoterpenoid with 2,3'-bifuran skeleton, and 3 is a rare perillaketone-adenine hybrid heterodimer, while the revised NMR arrangements of 4 were reported at the first time. Furthermore, monoterpenoid 4 and alkaloid 15 showed remarkably inhibitory effect on the production of inflammatory mediator (NO) and pro-inflammatory cytokines (TNF-α and/or IL-6) in LPS-stimulated RAW264.7 cells.