Cucurbitacin B induces apoptosis of primary effusion lymphoma via disruption of cytoskeletal organization

Potential of cucurbitacin as an anticancer drug

In Chinese medicine, the Cucurbitaceae family contains many compounds known as cucurbitacins, which have been categorized into 12 classes ranging from A to T and more than 200 derivatives. Cucurbitacins are a class of highly oxidized tetracyclic triterpenoids with potent anticancer properties. The eight components of cucurbitacins with the strongest anticancer activity are cucurbitacins B, D, E, I, IIa, L-glucoside, Q, and R. Cucurbitacins have also been reported to suppress JAK-STAT 3, mTOR, VEGFR, Wnt/β-catenin, and MAPK signaling pathways, all of which are crucial for the survival and demise of cancer cells. In this paper, we review the progress in research on cucurbitacin-induced apoptosis, autophagy, cytoskeleton disruption, cell cycle arrest, inhibition of cell proliferation, inhibition of invasion and migration, inhibition of angiogenesis, epigenetic alterations, and synergistic anticancer effects in tumor cells. Recent studies have identified cucurbitacins as promising molecules for therapeutic innovation with broad versatility in immune response. Thus, cucurbitacin is a promising class of anticancer agents that can be used alone or in combination with chemotherapy and radiotherapy for the treatment of many types of cancer.Therefore, based on the research reports in the past five years at home and abroad, we further summarize and review the structural characteristics, chemical and biological activities, and studies of cucurbitacins based on the previous studies to provide a reference for further development and utilization of cucurbitacins.

Cucurbitacin C as an effective anti-cancer agent: unveiling its potential role against cholangiocarcinoma and mechanistic insights

BACKGROUND

Cholangiocarcinoma (CCA) is a malignant epithelial tumor characterized by a dismal prognosis. Given the lack of therapeutic strategies and durable treatment options currently available, identifying innovative treatments for CCA is an urgent unmet clinical need. Cucurbitacin C (CuC) is a distinct variant of the cucurbitacin family, displaying promising anti-cancer activity against various tumor types. The primary objective of our research is to elucidate the promising effects of CuC on CCA.

METHODS

The impact of CuC on CCA cell lines was assessed by cell count kit-8 assay, EdU staining assay, colony formation assay, wound-healing assay, and Transwell assay. Flow cytometric analysis was conducted to explore the function of CuC treatments on cell-cycle distribution and apoptosis in CCA cells. Computational biology and network pharmacology approaches were utilized to predict potential targets of CuC. Furthermore, a tumor xenograft mouse model was established using CCA cells to explore the anti-cancer effects of CuC in vivo.

RESULTS

Our research findings revealed that CuC exerted a suppressive effect on CCA cell progression. Cell viability assays, EdU staining assays, and colony formation assays demonstrated that CuC effectively suppressed viability and proliferation of CCA cells. Wound-healing assays and Transwell assays indicated that CuC effectively inhibits the migratory and invasive capabilities of CCA cells. Flow cytometry analysis elucidated that CuC played its anti-proliferative role in CCA cells by arresting G0/G1 phase and increasing apoptosis. Through bioinformatics and network pharmacology analysis, in conjunction with western blot analysis, we demonstrated CuC mediated the inhibition of CCA cell progression through modulation of JAK2/STAT3 pathway. Additionally, the CCA xenograft tumor model was established, and the results supported the inhibition of CuC treatment against CCA progression in vivo.

CONCLUSION

Our study demonstrates that CuC possesses notable capabilities to suppress cell proliferation, migration, and invasion in CCA. Importantly, the inhibitory effects of CuC on CCA progression are attributed to its modulation of the JAK2/STAT3 signaling pathway. Altogether, our study demonstrated that CuC holds promise as a prospective therapeutic agent for treating CCA.

Network pharmacological analysis and experimental study of cucurbitacin B in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a malignant tumor with a high incidence and poor prognosis. Cucurbitacin B (CuB) is a tetracyclic triterpenoid small-molecule compound extracted from plants, such as Cucurbitaceae and Brassicaceae, which has powerful anticancer effects. However, the effect and mechanism of CuB on OSCC remain unclear. Within the framework of the current study, network pharmacology was used to analyze the relationship between CuB and OSCC. The network pharmacology analysis showed that CuB and OSCC share 134 common targets; among them, PIK3R1, SRC, STAT3, AKT1, and MAPK1 are the key targets. The molecular docking analysis showed that CuB binds five target proteins. The results of the enrichment analysis showed that CuB exerted effects on OSCC through various pathways; of these pathways, PI3K-AKT was the most important pathway. The results of the in vitro cell experiments showed that CuB could inhibit the proliferation and migration of SCC25 and CAL27 cells, block the cell cycle in the G2 phase, induce cell apoptosis, and regulate the protein expression of the PI3K-AKT signaling pathway. The results of the in vivo animal experiments showed that CuB could inhibit 4NQO-induced oral cancer in mice. Therefore, network pharmacology, molecular docking, cell experiments, and animal experiments showed that CuB could play a role in OSCC by regulating multiple targets and pathways.

Modulation of Cytoskeleton, Protein Trafficking, and Signaling Pathways by Metabolites from Cucurbitaceae, Ericaceae, and Rosaceae Plant Families

One promising frontier within the field of Medical Botany is the study of the bioactivity of plant metabolites on human health. Although plant metabolites are metabolic byproducts that commonly regulate ecological interactions and biochemical processes in plant species, such metabolites also elicit profound effects on the cellular processes of human and other mammalian cells. In this regard, due to their potential as therapeutic agents for a variety of human diseases and induction of toxic cellular responses, further research advances are direly needed to fully understand the molecular mechanisms induced by these agents. Herein, we focus our investigation on metabolites from the Cucurbitaceae, Ericaceae, and Rosaceae plant families, for which several plant species are found within the state of Florida in Hillsborough County. Specifically, we compare the molecular mechanisms by which metabolites and/or plant extracts from these plant families modulate the cytoskeleton, protein trafficking, and cell signaling to mediate functional outcomes, as well as a discussion of current gaps in knowledge. Our efforts to lay the molecular groundwork in this broad manner hold promise in supporting future research efforts in pharmacology and drug discovery.

Novel Triterpenoid Alkaloids With Their Potential Cytotoxic Activity From the Roots of Siraitia grosvenorii

Four novel triterpenoid alkaloids, siragrosvenins A–D (1–4), and two new cucurbitane-type triterpenoids, siragrosvenins E–F (5, 6), together with eight known analogs (7−14), were isolated from the roots of Siraitia grosvenorii. Compounds 1−4 possessed a rare cucurbitane-type triterpenoid scaffold, featuring an extra pyrazine unit via the Strecker reaction in the cucurbitane framework. Compound 5 displayed a 6/6/6/5/6/5-fused polycyclic ring system, with an uncommon fused furan and pyran ring in the side chain. All the structures were characterized by extensive spectroscopic analysis, including HRESIMS, NMR, and X-ray crystallographic data. It is worth noting that the DP4⁺ analysis method was applied for the first time to determine the absolute configurations of the trihydroxybutyl moiety in the side chain of compounds 1–4. In vitro cytotoxicity screening found that compounds 4, 8, 9, 13, and 14 exhibited remarkable cytotoxic activities against three cell lines with IC₅₀ values ranging from 1.44 to 9.99 μM. Siragrosvenin D shows remarkable cytotoxic activity on MCF-7 cells. As a result, it inhibited the proliferation of MCF-7 cells and reduced their viability via the induction of G2/M phase arrest and significantly induced apoptosis in MCF-7 cells.

Cucurbitacin B controls M2 macrophage polarization to suppresses metastasis via targeting JAK-2/STAT3 signalling pathway in colorectal cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Cucurbitacin B (CuB), extracted from muskmelon pedicel, is a widely available triterpenoid molecule that exerts influence on various biological activities. Modern pharmacological studies have found that cucurbitacin B has many kinds of pharmacological anti-tumor and anti-metastasis functions.

AIM OF THE STUDY

To explore the mechanism of anti-tumor and anti-metastasis effect of cucurbitacin B.

MATERIALS AND METHODS

The effect of cucurbitacin B on the growth of HCT116 and CT-26 was detected by CCK8; apoptosis was determined by flow cytometry and colony formation; the expression of apoptosis-related protein Bax, Bcl-2 and Cleaved-caspase-3 were examined by western Blot. To explore the underlying mechanism of cucurbitacin B against tumor, the Western blot, Immunofluorescence staining, Microscale Thermophoresis assays were used. Multiple molecular biology experiments were applied to validate the effect of polarization of cucurbitacin B-induced macrophages. The supernatant of Cucurbitacin B-induced macrophages and colon cells were co-cultured in vitro, and then transwell and wound healing assay were employed to the related phenotypes. C57BL/6 and BALB/c murine colon cancer model were also used to study the drug effects in vivo.

RESULTS

Cucurbitacin B distinctly induced the apoptosis of CRC cells. It was observed that cucurbitacin B not only inhibited the phosphorylation of JAK2 and STAT3, but also the translocation from the cytosol to the nucleus. Meanwhile, we observed that cucurbitacin B is bound to STAT3. Further experimentation demonstrated that cucurbitacin B reduced the polarization of M2 macrophage by down-regulating JAK2/STAT3 signaling pathway. Cucurbitacin B-induced M2-like macrophages were found to diminish the migration of CRC cells. In vitro study suggested that cucurbitacin inhibited the CRC cells proliferation via JAK2/STAT3 and suppressed the cell migration by suppressing M2-like macrophages polarization. Consistent with in vitro results, the cucurbitacin B therapy significantly inhibited tumor growth and metastasis in mice. Moreover, in vivo the treatment with cucurbitacin B enhanced anti-tumor immunity by regulating M2-like macrophages and promoted the expression of CD4 and CD8 in tumor microenvironment.

CONCLUSION

Our results proved that cucurbitacin B might be a potential candidate agent for adjuvant therapy in the process of CRC growth and metastasis.