Cucurbitacin B synergistically enhances the apoptosis-inducing effect of arsenic trioxide by inhibiting STAT3 phosphorylation in lymphoma Ramos cells

Recent Advances in the Application of Cucurbitacins as Anticancer Agents

Cucurbitacins are tetracyclic triterpenoid secondary metabolites, widely distributed in the Cucurbitaceae family. These bitter-tasting compounds act primarily as defense mechanisms against external injuries, and thus against herbivores, and furthermore, they have also found use in folk medicine in the treatment of various diseases. Many studies have acknowledged significant biological activities of cucurbitacins, such as antioxidant and anti-inflammatory activities, antimicrobial properties, or antitumor potential. Overall, cucurbitacins have the ability to inhibit cell proliferation and induce apoptosis in various cancer cell lines. Both in vitro and in vivo studies were performed to evaluate the anticancer activity of varied cucurbitacins. Cucurbitacins offer a promising avenue for future cancer treatment strategies, and their diverse mechanisms of action make them attractive candidates for further investigation. The aim of the present study is to shed light on the chemical diversity of this group of compounds by providing the sources of origin of selected compounds and their chemical structure, as well as insight into their anticancer potential. In addition, within this paper molecular targets for cucurbitacins and signalling pathways important for cancer cell proliferation and/or survival that are affected by the described class of compounds have been presented.

Development and Validation of a New Analytical HPLC-PDA Method for Simultaneous Determination of Cucurbitacins B and D from the Roots of Trichosanthes kirilowii

Trichosanthes kirilowii, one of the herbal formulas named SH003, has been used for treatment in traditional medicine. This paper aimed to analyze the marker compounds from the roots of T. kirilowii and evaluate a validation method for cucurbitacins B and D using high-performance liquid chromatography-photodiode array detector (HPLC-PDA). Two marker compounds were identified as cucurbitacin B (1) and cucurbitacin D (2) from the roots of T. kirilowii by spectroscopic analyses. Cucurbitacins B and D peaks were well separated and were detected at 15.4 min and 12.4 min, respectively, by a UV detector at 230 nm with the linearity (R2 > 0.999) range between 5 and 250 μg/mL, limit of detections (LODs) were 1.87 μg/mL and 1.30 μg/mL, respectively, while limit of quantifications (LOQs) were 5.66 μg/mL and 3.93 μg/mL, respectively. The established method offered good precision with overall intra- and inter-day variations of 0.34–1.26 and 0.26–1.35%, respectively, for % relative standard deviation (RSD, acceptance limit %RSD <3%). The cucurbitacins B and D recoveries ranged from 99.2 to 101.7% and 98.6 to 102.0%, respectively. These results suggest that cucurbitacins B and D could be a valuable candidate for marker compounds of the extract from T. kirilowii, and the proposed method was shown applicability for quality control of SH003.

The Ethanolic Extract of Trichosanthes Kirilowii Root Exerts anti-Cancer Effects in Human Non-Small Cell Lung Cancer Cells Resistant to EGFR TKI

The aim of this study was to investigate whether the ethanol extract of the Trichosanthes kirilowii root (ETK), traditionally used to treat lung diseases, exhibits anticancer activity in epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-resistant non-small cell lung cancer (NSCLC) cells. ETK treatment suppressed the growth of EGFR TKI-resistant NSCLC cells, including H1299, H1975, PC9/ER (erlotinib-resistant PC9) and PC9/GR (gefitinib-resistant PC9) cells, in a concentration- and time-dependent manner. Dose-dependent decline in anchorage-dependent and -independent colony formation was also detected following ETK treatment. We demonstrate that the growth-inhibitory effect of ETK was related to apoptosis induction, based on flow cytometry results showing ETK-induced increase in the percentage of cells with sub-G1 DNA and the population of annexin V-positive cells. Consistently, ETK induced chromatin condensation and cleavage of poly(ADP-ribose) polymerase (PARP). As a molecular mechanism, the phosphorylation level of signal transducer and activator of transcription 3 (STAT3) and Src was decreased by ETK. ETK-induced apoptosis was partially reversed by transfection of constitutively activated STAT3, indicating that STAT3 inactivation mediated ETK-induced apoptosis in EGFR TKI-resistant NSCLC cells. Our results provide basic evidence supporting the role of ETK as a novel therapeutic in EGFR TKI-resistant NSCLC.

Cucumber-Derived Nanovesicles Containing Cucurbitacin B for Non-Small Cell Lung Cancer Therapy

Purpose

In recent years, a variety of nanoparticles with excellent anticancer and delivery properties have emerged for cancer therapy. However, potential toxicity, high production cost and complex preparation procedures have been obstacles to their use in biomedicine. Here, we obtained cucumber-derived nanovesicles (CDNVs) at high yield and low cost by simple juicing and ultracentrifugation. The anticancer effects of CDNVs were evaluated in vitro and in vivo.

Methods

Transmission electron microscope, nanoparticle tracking analysis and laser particle size analysis were used to characterize the morphology, diameter and zeta potential of CDNVs, respectively. The anticancer effects of CDNVs in vitro were evaluated by MTT and apoptosis assays. The mechanism was further explored by measuring the protein levels of signal transducer and activator of transcription 3 pathway, reactive oxygen species, cell cycle distribution and caspase activity. In-vivo anticancer efficacy was evaluated by measuring tumor volume and weight of mice in three different treatment groups (CDNVs, cucurbitacin B and PBS).

Results

CDNVs inhibited proliferation of human non-small cell lung cancer cells by suppressing signal transducer and activator of transcription 3 activation, generating reactive oxygen species, promoting cell cycle arrest, and activating the caspase pathway. These CDNVs exhibited strong anticancer effects both in vitro and in vivo, and reduced the rate of tumor growth without obvious toxicity to mouse visceral organs. Compared with an equivalent dose of cucurbitacin B, CDNVs exerted stronger anticancer effects in vitro and in vivo.

Conclusion

These results demonstrate that CDNVs suppress tumor growth. This study addresses the development of cancer therapeutic drugs using plant-derived nanovesicles that are cost-efficient, simple to produce in high yields, and provide an alternative approach to drug isolation that may help advance sustainability of medicinal plants.

Diet-derived small molecules (nutraceuticals) inhibit cellular proliferation by interfering with key oncogenic pathways: an overview of experimental evidence in cancer chemoprevention

Discouraging statistics of cancer disease has projected an increase in the global cancer burden from 19.3 to 28.4 million incidences annually within the next two decades. Currently, there has been a revival of interest in nutraceuticals with evidence of pharmacological properties against human diseases including cancer. Diet is an integral part of lifestyle, and it has been proposed that an estimated one-third of human cancers can be prevented through appropriate lifestyle modification including dietary habits; hence, it is considered significant to explore the pharmacological benefits of these agents, which are easily accessible and have higher safety index. Accordingly, an impressive embodiment of evidence supports the concept that the dietary factors are critical modulators to prevent, retard, block, or reverse carcinogenesis. Such an action reflects the ability of these molecules to interfere with multitude of pathways to subdue and neutralize several oncogenic factors and thereby keep a restraint on neoplastic transformations. This review provides a series of experimental evidence based on the current literature to highlight the translational potential of nutraceuticals for the prevention of the disease through consumption of enriched diets and its efficacious management by means of novel interventions. Specifically, this review provides the current understanding of the chemopreventive pharmacology of nutraceuticals such as cucurbitacins, morin, fisetin, curcumin, luteolin and garcinol toward their potential as anticancer agents.

Network pharmacology-based and clinically relevant prediction of active ingredients and potential targets of Chinese herbs on stage IV lung adenocarcinoma patients

AIM

This study is designed to ascertain the relative molecular targets of effective Chinese herbs in treating stage IV lung adenocarcinoma based on clinical data and network pharmacology. In addition, we showed that Chinese Herbal Medicine (CHM) treatment was associated with survival benefit for patients with stage IV lung adenocarcinoma and identified 18 herbs beneficial to survival through correlation analysis.

BACKGROUND

Increasing evidence has shown that CHM has efficient therapeutic effects for advanced lung adenocarcinoma, while active ingredients and potential targets remain unclear.

METHODS

Kaplan-Meier method and Cox regression analysis were used to evaluate the survival benefit of CHM treatment, and correlation analysis was applied to identify the most effective components in the formulas. A network pharmacological approach was used to decipher the potential therapeutic mechanisms of CHM.

RESULTS

CHM treatment was an independent protective factor. The hazard ratio (HR) was 0.487 (95% CI 0.293-0.807; P = 0.005). Patients in the CHM group had a longer median survival time (31 months) compared with the non-CHM group (19 months; P < 0.001). 18 out of the total 241 herbs were significantly correlated with favorable survival outcomes (P < 0.05), likely representing the most effective components in these formulas. Bioinformatics analysis suggested that the 18 herbs realize anti-lung-adenocarcinoma activity mainly through (1) inhibiting the activity of some growth factors' receptors, such as HGFR, EGFR, and IGFR. (2) Suppressing angiogenesis not only through VEGFR and PDGFR, but also through the function of neurotransmitters such as dopamine and serotonin. (3) Inhibiting the Ras signaling pathway directly through Ras as well as through ALK and FNTA/FNTB.

CONCLUSIONS

We performed a network pharmacological method to decipher the underlying mechanisms, which provides a good foundation for herbal research based on clinical data.

Cucurbitacin mediated regulation of deregulated oncogenic signaling cascades and non-coding RNAs in different cancers: Spotlight on JAK/STAT, Wnt/β-catenin, mTOR, TRAIL-mediated pathways

Research over decades has enabled us in developing a better understanding of the multifaceted and heterogeneous nature of cancer. High-throughput technologies have helped the researchers in unraveling of the underlying mechanisms which centrally regulate cancer onset, metastasis and drug resistance. Our rapidly expanding knowledge about signal transduction cascade has added another layer of complexity to already complicated nature of cancer. Deregulation of cell signaling pathways played a linchpin role in carcinogenesis and metastasis. Cucurbitacins have gained tremendous attention because of their remarkable pharmacological properties and considerable ability to mechanistically modulate myriad of cell signaling pathways in different cancers. In this review, we have attempted to provide a mechanistic and comprehensive analysis of regulation of oncogenic pathways by cucurbitacins in different cancers. We have partitioned this review into separate sections for exclusive analysis of each signaling pathway and critical assessment of the knowledge gaps. In this review, we will summarize most recent and landmark developments related to regulation of Wnt/β-catenin, JAK/STAT, mTOR, VEGFR, EGFR and Hippo pathway by cucurbitacins. Moreover, we will also address how cucurbitacins regulate DNA damage repair pathway and TRAIL-driven signaling in various cancers. However, there are still outstanding questions related to regulation of SHH/GLI, TGF/SMAD and Notch-driven pathway by cucurbitacins in different cancers. Future studies must converge on the analysis of full-fledge potential of cucurbitacins by in-depth analysis of these pathways and how these pathways can be therapeutically targeted by cucurbitacins.

Cucurbitacin B and cisplatin induce the cell death pathways in MB49 mouse bladder cancer model

IMPACT STATEMENT

Alternative agents that will increase the effectiveness of cisplatin, which are widely used in the advanced stage and metastatic bladder cancer, are being investigated. In previous studies, Cucurbitacin B (CuB), which is a natural compound from the Cucurbitaceae family has been shown to inhibit the proliferation of tumor cells and create synergistic effects with cisplatin. In this study, we investigated the synergistic effect of CuB with cisplatin for the first time in bladder cancer in vitro and in vivo models. Our findings showed that CuB treatment with cisplatin reduced cell proliferation, and reduced tumor development through activating apoptosis and autophagy via PI3K/AKT/mTOR signaling pathway. Our results showed that CuB may be a new agent that can support conventional treatment in bladder cancer. Our study is important in terms of enlightening new pathways and developing new treatment methods in the treatment of bladder cancer.

In Vitro and In Vivo Antitumor Activity of Cucurbitacin C, a Novel Natural Product From Cucumber

Cucurbitacin C (CuC), a novel analogue of triterpenoids cucurbitacins, confers a bitter taste in cucumber. Genes and signaling pathways responsive for biosynthesis of CuC have been identified in the recent years. In the present study, we explored the anti-cancer effects of CuC against human cancers in vitro and in vivo. CuC inhibited proliferation and clonogenic potential of multiple cancer cells in a dose-dependent manner. Low-dose CuC treatment induced cell cycle arrest at G1 or G2/M stage in different cancer lines, whereas high-dose treatment of CuC caused apoptosis in cancer cells. PI3K-Akt signaling pathway was found to be one of the major pathways involved in CuC-induced cell growth arrest and apoptosis by RNA-Seq and Western blotting. Mechanistic dissection further confirmed that CuC effectively inhibited the Akt signaling by inhibition of Akt phosphorylation at Ser473. In vivo CuC treatment (0.1 mg/kg body weight) effectively inhibited growth of cancer cell-derived xenograft tumors in athymic nude mice and caused significant apoptosis. Our findings for the first time demonstrated the potential therapeutic significance of CuC against human cancers.

Novel activators and small-molecule inhibitors of STAT3 in cancer

Excessive activation of signal transducer and activator of transcription 3 (STAT3) signaling is observed in a subset of many cancers, making activated STAT3 a highly promising potential therapeutic target supported by multiple preclinical and clinical studies. However, early-phase clinical trials have produced mixed results with STAT3-targeted cancer therapies, revealing substantial complexity to targeting aberrant STAT3 signaling. This review discusses the diverse mechanisms of oncogenic activation of STAT3, and the small molecule inhibitors of STAT3 in cancer treatment.

Cucurbitacin B Inhibits the Hippo-YAP Signaling Pathway and Exerts Anticancer Activity in Colorectal Cancer Cells

BACKGROUND Colorectal carcinoma (CRC) is one of the most frequently diagnosed malignancies. Cucurbitacin B (CuB) is a natural compound isolated from herbs and shows anticancer activity in several cancers. MATERIAL AND METHODS Here, we analyzed the effects of different CuB concentrations on the proliferative and invasive behaviors of CRC cells using MTT, clonogenic assay, Transwell invasion, and wound healing assays. Flow cytometry was performed to measure the apoptotic effects of CuB on CRC cells. Western blot and real-time PCR were used to investigate the expression of apoptosis and Hippo-YAP signaling pathway proteins. RESULTS CuB inhibited the proliferation and invasion of CRC cells while promoting apoptosis. In addition, the Western blot and real-time PCR results indicated that CuB suppressed YAP expression and its downstream target genes Cyr 61 and c-Myc in CRC cells. To assess the underlying mechanism, we investigated the upstream regulating factor LATS1, and the results revealed that CuB upregulated LATS1 expression in CRC cells. CONCLUSIONS In conclusion, our findings uncovered a novel therapeutic mechanism of CuB and suggest that there is therapeutic potential and feasibility in developing novel YAP inhibitors for cancer treatment.

Trichosanthis Fructus: botany, traditional uses, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Trichosanthis Fructus (ripe fruits of Trichosanthes kirilowii Maxim. and Trichosanthes rosthornii Harms) is an essential traditional Chinese medicine to treat thoracic obstruction, angina, cardiac failure, myocardial infarction, pulmonary heart disease, some cerebral ischaemic diseases, etc. The present report reviews the advancements in research on the botany, traditional uses, phytochemistry and pharmacology of Trichosanthis Fructus. Finally, perspectives on future research and its possible directions are discussed.

AIM OF THE STUDY

This review provides up-to-date information about the botany, traditional uses, phytochemistry, pharmacology, toxicity and quality control of Trichosanthis Fructus and discusses the perspectives on future research and possible directions of this traditional Chinese Medicine and its origin plants.

MATERIALS AND METHODS

The information on Trichosanthes kirilowii Maxim. and Trichosanthes rosthornii Harms was collected from published scientific materials, including books; monographs on medicinal plants; pharmacopoeia and electronic databases such as SCI finder, PubMed, Web of Science, ACS, Science Direct, Wiley, Springer, Taylor, CNKI and Google Scholar.

RESULTS

Approximately 162 compounds, including terpenoids, phytosterols, flavonoids, nitrogenous compounds and lignans, have been isolated and identified from Trichosanthes kirilowii Maxim. and Trichosanthes rosthornii Harms. Numerous studies have shown that the extracts and compounds isolated from these two plants exhibit pharmacological activities, including protection against myocardial ischaemia, calcium antagonist, endothelial cell protection, anti-hypoxic, anti-platelet aggregation, expectorant, anti-inflammatory, cytotoxic and antioxidant.

CONCLUSIONS

Trichosanthis Fructus is an essential traditional Chinese medicine with pharmacological activities that mainly affect the cardiovascular system. This review summarises its botany, traditional uses, phytochemistry and pharmacology. Future research is needed to clarify the different uses of the seeds, pericarps and fruits. Quality control of investigations of the fruits should be improved, and the potential uses of the flesh, leaves and twigs should be further explored.

Trichosanthes kirilowii lectin alleviates diabetic nephropathy by inhibiting the LOX1/NF-κB/caspase-9 signaling pathway

Trichosanthes kirilowii lectin (TKL) has been reported to exert hypoglycemic effects in alloxan-induced diabetic mice. However, there is no evidence showing that it helps to prevent diabetic nephropathy (DN). We used a high glucose (HG)-induced HK-2 cell model and a streptozocin (STZ)-induced Wistar rat model to investigate the effects of TKL on DN, as well as the mechanisms for those effects. Our results showed that TKL significantly increased the viability of HG-treated HK-2 cells and inhibited cell apoptosis. In vivo experiments demonstrated that TKL attenuated STZ-induced histopathological damage and the inflammatory response in rat kidney tissues. Pre-treatment of HK-2 cells or STZ-treated rats with polyinosinic acid (Poly IC), an inhibitor of lectin-like oxLDL receptor 1 (LOX1), blocked the protective effect of TKL against HG- or STZ-induced damage to kidney tissue, indicating that TKL might exert its effect via LOX1-mediated endocytosis. Additional results suggested that TKL inhibits the phosphorylation of IκB kinase β (IKKβ) and the nuclear factor-κB (NF-κB) inhibitor protein (IκBα), and thereby reduces the nuclear translocation of NF-κB (p65). ChIP assay data indicated that TKL markedly inhibits the binding of p65 to the CASP9 gene in HG-treated HK-2 cells, subsequently suppressing transcription of the CASP9 gene. In the dual-luciferase reporter assay, TKL significantly inhibited luciferase activity in cells co-transfected with p65 and a wild-type capase-9 construct instead of mutated caspase-9 constructs.

Taken together, our results show that TKL helps to protect against DN by inhibiting the LOX1/NF-κB/caspase-9 signaling pathway, suggesting TKL as a promising agent for treating DN.

Targeting oncogenic transcription factors by polyphenols: A novel approach for cancer therapy

Inflammation is one of the major causative factor of cancer and chronic inflammation is involved in all the major steps of cancer initiation, progression metastasis and drug resistance. The molecular mechanism of inflammation driven cancer is the complex interplay between oncogenic and tumor suppressive transcription factors which include FOXM1, NF-kB, STAT3, Wnt/β- Catenin, HIF-1α, NRF2, androgen and estrogen receptors. Several products derived from natural sources modulate the expression and activity of multiple transcription factors in various tumor models as evident from studies conducted in cell lines, pre-clinical models and clinical samples. Further combination of these natural products along with currently approved cancer therapies added an additional advantage and they considered as promising targets for prevention and treatment of inflammation and cancer. In this review we discuss the application of multi-targeting natural products by analyzing the literature and future directions for their plausible applications in drug discovery.

Inhibition of STAT3/VEGF/CDK2 axis signaling is critically involved in the antiangiogenic and apoptotic effects of arsenic herbal mixture PROS in non-small lung cancer cells

Despite the antitumor effects of asrsenic trioxide (As2O3), tetraarsenic hexoxide (As4O6 or PR) and tetraarsenic tetrasulfide (As4S4) in several cancers, their adverse poisoning, toxicity and resistance are still hot issues for effective cancer therapy. Here, antitumor mechanism of arsenic herbal mixture PROS including PR and OS (Oldenlandia diffusa and Salvia miltiorrhiza extract) was elucidated in non-small cell lung cancer cells (NSCLCs), since PR alone showed resistant cytotoxicity in NSCLCs compared to other cancers. PROS exerted significant cytotoxicity, induced sub-G1 phase and S phase arrest, increased apoptotic bodies, and attenuated the expression of pro-PARP, Bcl-2, Cyclin E, Cyclin A, CDK2, E2F1, p-Src, p-STAT3, p-ERK, p-AKT, COX-2 and SOCS-1 in A549 and H460 cells along with disrupted binding of STAT3 with CDK2 or VEGF. Notably, PROS inhibited VEGF induced proliferation, migration and tube formation in HUVECs and suppressed angiogenesis in chorioallantoic membrane (CAM) assay via reduced phosphorylation of VEGFR2, Src and STAT3. Consistently, PROS reduced the growth of H460 cells implanted in BALB/c athymic nude mice via inhibition of STAT3, and VEGF and activation of caspase 3. Overall, these findings suggest that PROS exerts antiangiogenic and apoptotic effects via inhibition of STAT3/ VEGF/ CDK2 axis signaling as a potent anticancer agent for lung cancer treatment.