Deoxyelephantopin, a germacrane-type sesquiterpene lactone from Elephantopus scaber, induces mitochondrial apoptosis of hepatocarcinoma cells by targeting Hsp90α in vitro and in vivo

Hsp90α and cell death in cancers: a review

Heat shock protein 90α (Hsp90α), an important molecular chaperone, plays a crucial role in regulating the activity of various intracellular signaling pathways and maintaining the stability of various signaling transduction proteins. In cancer, the expression level of Hsp90α is often significantly upregulated and is recognized as one of the key factors in cancer cell survival and proliferation. Cell death can help achieve numerous purposes, such as preventing aging, removing damaged or infected cells, facilitating embryonic development and tissue repair, and modulating immune response. The expression of Hsp90α is closely associated with specific modes of cell death including apoptosis, necrotic apoptosis, and autophagy-dependent cell death, etc. This review discusses the new results on the relationship between expression of Hsp90α and cell death in cancer. Hsp90α is frequently overexpressed in cancer and promotes cancer cell growth, survival, and resistance to treatment by regulating cell death, rendering it a promising target for cancer therapy.

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.

ESL attenuates BLM-induced IPF in mice: Dual mediation of the TLR4/NF-κB and TGF-β1/PI3K/Akt/FOXO3a pathways

BACKGROUNDS

Idiopathic pulmonary fibrosis (IPF) is a persistent and advanced pulmonary ailment. The roles of innate immunity and adaptive immunity are pivotal in the evolution of IPF. An ill-adjusted interaction between epithelial cells and immune cells is responsible for initiating the epithelial-mesenchymal transition (EMT) process and sustaining chronic inflammation, thereby fostering fibrosis progression. The intricacy of IPF pathogenesis has hindered the availability of efficacious agents. Elephantopus scaber Linn. (ESL) is a canonical Chinese medicine with significant immunoregulatory effects, and its aqueous extract has been proven to attenuate IPF symptoms in bleomycin (BLM)-induced mice. However, the underlying mechanism through which ESL relieves IPF remains unclear.

AIM

To validate whether ESL reverses IPF by mediating the immune response and EMT.

METHODS

Ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and UPLC were used to identify the components and determine the concentrations of the specific compounds in the ESL. Network pharmacology and molecular docking were applied to predict the potential mechanism underlying the anti-IPF effect of ESL. BLM-induced IPF mice were used to validate the anti-IPF effect of ESL, and lung tissue was collected to test putative pathways involved in inflammation and EMT via immunohistochemistry (ICH), real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting.

RESULTS

Sixty-one compounds were identified, and thirteen main ingredients were quantified in the ESL. In silico experiments predicted that the IPF-mediated reversal of adverse effects by ESL would be related to interruption of the Toll-like receptor 4 (TLR4)/nuclear factor-k-gene binding (NF-ĸB) inflammatory pathway and the transforming growth factor-beta l (TGF-β1)/phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/forkhead box O3 (FOXO3a) fibrosis pathway. In vivo experiments showed that ESL alleviates BLM-induced lung inflammation and fibrosis by reducing neutrophil aggregation and fibroblast foci, similar to the effects of the positive control drug pirfenidone (PFD). ESL markedly inhibited the transcription of TNF-α, IL-1β, and IL-6, which are downstream genes of the NF-κB signaling pathway. Furthermore, the protein levels of TLR4 and p-NF-κB were correspondingly inhibited in response to ESL treatment. Additionally, ESL reverses BLM-induced changes in the expression of EMT-related biological characteristic indicators (collagen I [COLIA1], E-cadherin, and alpha smooth muscle actin [α-SMA]) at the messenger ribonucleic acid (mRNA) level and markedly inhibits the expression of EMT-related upstream proteins (TGF-β1, p-PI3K, p-Akt, and p-FOXO3a).

CONCLUSION

Our research suggested that ESL attenuates BLM-induced IPF through mediating the EMT process via the TGF-β1/PI3K/Akt/FOXO3a signaling pathway and inhibiting inflammation through the TLR4/NF-κB signaling pathway, highlighting that ESL can serve as an immunoregulator for relieving the abnormal immune response and reversing the EMT in IPF.

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.

Recent advances of novel targeted drug delivery systems based on natural medicine monomers against hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most prevalent type of liver cancer, is often diagnosed at an advanced stage. Surgical interventions are often ineffective, leading HCC patients to rely on systemic chemotherapy. Unfortunately, commonly used chemotherapeutic drugs have limited efficacy and can adversely affect vital organs, causing significant physical and psychological distress for patients. Natural medicine monomers (NMMs) have shown promising efficacy and safety profiles in HCC treatment, garnering attention from researchers. In recent years, the development of novel targeted drug delivery systems (TDDS) combining NMMs with nanocarriers has emerged. These TDDS aim to concentrate drugs effectively in HCC cells by manipulating the characteristics of nanomedicines, leveraging receptor and ligand interactions, and utilizing endogenous stimulatory responses to promote specific nanomedicines distribution. This comprehensive review presents recent research on TDDS for HCC treatment using NMMs from three perspectives: passive TDDS, active TDDS, and stimuli-responsive drug delivery systems (SDDS). It consolidates the current state of research on TDDS for HCC treatment with NMMs and highlights the potential of these innovative approaches in improving treatment outcomes. Moreover, the review also identifies research gaps in the related fields to provide references for future targeted therapy research in HCC.

Structurally diverse terpenoids from Elephantopus scaber L. and their acetylcholinesterase inhibitory activities

Three undescribed compounds elephantopuscabers A-C, along with one previously reported compound spirowallichiione, were isolated from Elephantopus scaber L. Their structures were determined via extensive NMR spectroscopic analysis, quantum chemical calculations, and single-crystal X-ray diffraction crystallography. A plausible biosynthetic pathway for spirowallichiione was proposed. All the isolated compounds were tested for their acetylcholinesterase inhibitory activities. Among them, elephantopuscaber B and C displayed promising inhibitory activities against AChE, and the binding sites were predicted by molecular docking.