Anticancer effects of brusatol in nasopharyngeal carcinoma through suppression of the Akt/mTOR signaling pathway

5-fluorouracil and Rumex obtusifolius extract combination trigger A549 cancer cell apoptosis: uncovering PI3K/Akt inhibition by in vitro and in silico approaches

The continuous increase in cancer rates, failure of conventional chemotherapies to control the disease, and excessive toxicity of chemotherapies clearly demand alternative approaches. Natural products contain many constituents that can act on various bodily targets to induce pharmacodynamic responses. This study aimed to explore the combined anticancer effects of Rumex obtusifolius (RO) extract and the chemotherapeutic agent 5-fluorouracil (5-FU) on specific molecular targets involved in cancer progression. By focusing on the PI3K/Akt signaling pathway and its related components, such as cytokines, growth factors (TNFa, VEGFa), and enzymes (Arginase, NOS, COX-2, MMP-2), this research sought to elucidate the molecular mechanisms underlying the anticancer effects of RO extract, both independently and in combination with 5-FU, in non-small lung adenocarcinoma A549 cells. The study also investigated the potential interactions of compounds identified by HPLC/MS/MS of RO on PI3K/Akt in the active site pocket through an in silico analysis. The ultimate goal was to identify potent therapeutic combinations that effectively inhibit, prevent or delay cancer development with minimal side effects. The results revealed that the combined treatment of 5-FU and RO demonstrated a significant reduction in TNFa levels, comparable to the effect observed with RO alone. RO modulated the PI3K/Akt pathway, influencing the phosphorylated and total amounts of these proteins during the combined treatment. Notably, COX-2, a key player in inflammatory processes, substantially decreased with the combination treatment. Caspase-3 activity, indicative of apoptosis, increased by 1.8 times in the combined treatment compared to separate treatments. In addition, the in silico analyses explored the binding affinities and interactions of RO's major phytochemicals with intracellular targets, revealing a high affinity for PI3K and Akt. These findings suggest that the combined treatment induces apoptosis in A549 cells by regulating the PI3K/Akt pathway.

A bibliometric analysis of the application of the PI3K-AKT-mTOR signaling pathway in cancer

PI3K-AKT-mTOR plays as important role in the growth, metabolism, proliferation, and migration of cancer cells, and in apoptosis, autophagy, inflammation, and angiogenesis in cancer. In this study, the aim was to comprehensively review the current research landscape regarding the PI3K-AKT-mTOR pathway in cancer, using bibliometrics to analyze research hotspots, and provide ideas for future research directions. Literature published on the topic between January 2006 and May 2023 was retrieved from the Web of Science core database, and key information and a visualization map were analyzed using CiteSpace and VOSviewer. A total of 5800 articles from 95 countries/regions were collected, including from China and the USA. The number of publications on the topic increased year on year. The major research institution was the University of Texas MD Anderson Cancer Center. Oncotarget and Clinical Cancer Research were the most prevalent journals in the field. Of 26,621 authors, R Kurzrock published the most articles, and J Engelman was cited most frequently. "A549 cell," "first line treatment," "first in human phase I," and "inhibitor" were the keywords of emerging research hotspots. Inhibitors of the PI3K-AKT-mTOR pathway and their use in clinical therapeutic strategies for cancer were the main topics in the field, and future research should also focus on PI3K-AKT-mTOR pathway inhibitors. This study is the first to comprehensively summarize trends and development s in research into the PI3K-AKT-mTOR pathway in cancer. The information that was obtained clarified recent research frontiers and directions, providing references for scholars of cancer management.

A review of Brucea javanica: metabolites, pharmacology and clinical application

This review examines advances in the metabolites, pharmacological research, and therapeutic applications of the medicinal fruit of Brucea javanica (L.) Merr. Brucea javanica (BJ) is derived from the fruit of the Brucea javanica (L.) Merr. There are nearly 200 metabolites present in BJ, and due to the diversity of its metabolites, BJ has a wide range of pharmacological effects. The traditional pharmacological effects of BJ include anti-dysentery, anti-malaria, etc. The research investigating the contemporary pharmacological impacts of BJ mainly focuses on its anti-tumor properties. In the article, the strong monomeric metabolites among these pharmacological effects were preliminarily screened. Regarding the pharmacological mechanism of action, current research has initially explored BJ's pharmacological agent and molecular signaling pathways. However, a comprehensive system has yet to be established. BJ preparations have been utilized in clinical settings and have demonstrated effectiveness. Nevertheless, clinical research is primarily limited to observational studies, and there is a need for higher-quality research evidence to support its clinical application. There are still many difficulties and obstacles in studying BJ. However, it is indisputable that BJ is a botanical drugs with significant potential for application, and it is expected to have broader global usage.

Prediction of network pharmacology, molecular docking-based strategy, and vitro assays to determine potential pharmacological mechanism of Dioscoreae bulbiferae and Bruceae fructus against laryngocarcinoma

BACKGROUND

Based on network pharmacology, molecular docking, and vitro assays, investigate the probable pharmacological mechanism of Dioscoreae bulbiferae and Bruceae fructus in the treatment of laryngocarcinoma.

METHODS

The active components and targets of Dioscoreae bulbiferae and Bruceae fructus were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform database. Targets linked with laryngocarcinoma were gathered from the GeneCards, DisGeNET, and DrugBank databases. The String database was utilized to build a protein-protein interaction network of common medication and illness targets, after which the core targets were filtered out. The Metascape database served for gene ontology enrichment and Kyoto encyclopedia of genes and genomes pathway analysis of common targets. AutoDock then performed molecular docking between the essential component and the vital target. To investigate the biological effects of diosbulbin B, we assessed the viability of laryngocarcinoma cells after diosbulbin B therapy using the Mahalanobis Taguchi system technique. Following that, we looked at how diosbulbin B affected colony formation after 14 days of culture of treated cells. Flow cytometry was utilized to detect apoptosis in order to examine the influence of diosbulbin B on laryngocarcinoma cell apoptosis.

RESULTS

According to a study of the literature, the fundamental components of Dioscoreae bulbiferae and Bruceae fructus in the treatment of laryngocarcinoma include brusatol and diosbulbin B, which may operate on core targets such as cyclin D1, Cyclin Dependent Kinase Inhibitor 1A, and E2F Transcription Factor 1. The significant pathways discovered using Kyoto encyclopedia of genes and genomes enrichment analysis were the phosphoinositide 3-kinase-protein kinase B signaling route, the tumor necrosis factor signaling pathway, and so on. These pathways primarily influence the development and prognosis of laryngeal cancer by controlling cell growth, cell proliferation, angiogenesis, tumorigenesis, and metastasis. The molecular docking studies revealed that the affinity between the heart and crucial targets was robust. The results of vitro assays indicate that diosbulbin B suppressed Hep-2 cell activity in a concentration-dependent manner. Besides, diosbulbin B has powerful antiproliferative properties in Hep-2 cells. Flow cytometry results showed that diosbulbin B promoted laryngocarcinoma cell apoptosis in a concentration-dependent manner.

CONCLUSION

The article delivered a preliminary discussion of the probable mechanism of Dioscoreae bulbiferae and Bruceae fructus in the treatment of laryngocarcinoma, which can serve as a theoretical basis and evidence for subsequent experimental investigation.

Brusatol enhances MEF2A expression to inhibit RCC progression through the Wnt signalling pathway in renal cell carcinoma

Renal cell carcinoma (RCC) is the most aggressive subtype of kidney tumour with a poor prognosis and an increasing incidence rate worldwide. Brusatol, an essential active ingredient derived from Brucea javanica, exhibits potent antitumour properties. Our study aims to explore a novel treatment strategy for RCC patients. We predicted 37 molecular targets of brusatol based on the structure of brusatol, and MEF2A (Myocyte Enhancer Factor 2A) was selected as our object through bioinformatic analyses. We employed various experimental techniques, including RT-PCR, western blot, CCK8, colony formation, immunofluorescence, wound healing, flow cytometry, Transwell assays and xenograft mouse models, to investigate the impact of MEF2A on RCC. MEF2A expression was found to be reduced in patients with RCC, indicating a close correlation with MEF2A deubiquitylation. Additionally, the protective effects of brusatol on MEF2A were observed. The overexpression of MEF2A inhibits RCC cell proliferation, invasion and migration. In xenograft mice, MEF2A overexpression in RCC cells led to reduced tumour size compared to the control group. The underlying mechanism involves the inhibition of RCC cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT) through the modulation of Wnt/β-catenin signalling. Altogether, we found that MEF2A overexpression inhibits RCC progression by Wnt/β-catenin signalling, providing novel insight into diagnosis, treatment and prognosis for RCC patients.

Predictors of gastrointestinal complaints in patients on metformin therapy

Although being very effective in the treatment of diabetes and a few other conditions, metformin (MTF) cannot be tolerated by many patients due to gastrointestinal (GI) complaints. A number of risk factors for intolerance were identified, but many are still controversial or uninvestigated. The aim of this study was to further investigate possible risk factors for the occurrence of GI complaints in patients on MTF therapy. A cross-sectional design was used for this multicentric study on adult patients visiting 50 community pharmacies in Montenegro. The patients were surveyed by semi-structured questionnaire after a service of a pharmacist was delivered, and their drugs dispensed. Uni- and multi-variate regression methods were used for processing the data. In total 330 patients participated in the study. A higher body mass index (OR = 1.113, p = 0.003), living at a higher altitude (OR = 1.725, p = 0.000), anaemia (OR = 4.221, p = 0.008), and intestinal infection in the last 3 months (OR = 2.801, p = 0.006) increased the risk of GI complaints in patients on MTF therapy, while the use of statins was protective (OR = 0.204, p = 0.016). Each case of MTF intolerance should be carefully investigated for risk and protective factors, which could be potentially eliminated or augmented, respectively, and MTF withdrawal avoided.

Brusatol induces ferroptosis in oesophageal squamous cell carcinoma by repressing GSH synthesis and increasing the labile iron pool via inhibition of the NRF2 pathway

Brusatol (Bru), a bioactive compound found in Brucea sumatrana, exerts antitumour effects on several malignancies. However, the role and molecular mechanism of Bru in squamous cell carcinoma of the oesophagus (ESCC) remain unclear. Here, we found that Bru decreased the survival of ESCC cells. Subsequently, the ferroptosis inhibitors, deferoxamine and liproxstatin-1, rescued Bru-induced cell death, indicating that ferroptosis plays a major role in Bru-induced cell death. Furthermore, Bru promoted lipid peroxidation, glutathione (GSH) depletion, and ferrous iron overload in vitro. Consistent with these in vitro results, Bru significantly inhibited tumour growth in KYSE150 xenograft nude mice by triggering ferroptosis. Mechanistically, nuclear factor E2-related factor 2 (NRF2) inactivation via increased ubiquitin-proteasome degradation was found to be a vital determinant of ferroptosis induced by Bru. Notably, Bru significantly decreases GSH synthesis, iron storage, and efflux by downregulating the expression of NRF2 target genes (glutamate-cysteine ligase catalytic subunit (GCLC), solute carrier family 7 member 11 (SLC7A11), ferritin heavy chain 1 (FTH1), and solute carrier family 40 member 1 (SLC40A1)), resulting in the accumulation of lethal lipid-based reactive oxygen species (ROS) and intracellular enrichment of chelated iron. Taken together, our findings indicate that ferroptosis is a novel mechanism underlying Bru-induced antitumour activity and will hopefully provide a valuable compound for ESCC treatment.

Comprehensive scientometrics and visualization study profiles lymphoma metabolism and identifies its significant research signatures

Background

There is a wealth of poorly utilized unstructured data on lymphoma metabolism, and scientometrics and visualization study could serve as a robust tool to address this issue. Hence, it was implemented.

Methods

After strict quality control, numerous data regarding the lymphoma metabolism were mined, quantified, cleaned, fused, and visualized from documents (n = 2925) limited from 2013 to 2022 using R packages, VOSviewer, and GraphPad Prism.

Results

The linear fitting analysis generated functions predicting the annual publication number (y = 31.685x - 63628, R² = 0.93614, Prediction in 2027: 598) and citation number (y = 1363.7x - 2746019, R² = 0.94956, Prediction in 2027: 18201). In the last decade, the most academically performing author, journal, country, and affiliation were Meignan Michel (n = 35), European Journal of Nuclear Medicine and Molecular Imaging (n = 1653), USA (n = 3114), and University of Pennsylvania (n = 86), respectively. The hierarchical clustering based on unsupervised learning further divided research signatures into five clusters, including the basic study cluster (Cluster 1, Total Link Strength [TLS] = 1670, Total Occurrence [TO] = 832) and clinical study cluster (Cluster 3, TLS = 3496, TO = 1328). The timeline distribution indicated that radiomics and artificial intelligence (Cluster 4, Average Publication Year = 2019.39 ± 0.21) is a relatively new research cluster, and more endeavors deserve. Research signature burst and linear regression analysis further confirmed the findings above and revealed additional important results, such as tumor microenvironment (a = 0.6848, R² = 0.5194, p = 0.019) and immunotherapy (a = 1.036, R² = 0.6687, p = 0.004). More interestingly, by performing a "Walktrap" algorithm, the community map indicated that the "apoptosis, metabolism, chemotherapy" (Centrality = 12, Density = 6), "lymphoma, pet/ct, prognosis" (Centrality = 11, Density = 1), and "genotoxicity, mutagenicity" (Centrality = 9, Density = 4) are crucial but still under-explored, illustrating the potentiality of these research signatures in the field of the lymphoma metabolism.

Conclusion

This study comprehensively mines valuable information and offers significant predictions about lymphoma metabolism for its clinical and experimental practice.

Identification of the Brucea javanica Constituent Brusatol as a EGFR-Tyrosine Kinase Inhibitor in a Cell-Free Assay

Inhibitors of the tyrosine kinase (TK) activity of the epidermal growth factor receptor (EGFR) are routinely used in cancer therapy. However, there is a need to discover a new TK inhibitor. This study evaluated extracts from Brucea javanica and its components for their potential as novel EGFR-TK inhibitors. The cytotoxic effect of a g aqueous extract and its fractions was assessed by MTT assays with A549 lung cancer cells. The two fractions with the highest cytotoxicity were analyzed by LC/MS and 1H NMR. Brusatol was identified as the main constituent of these fractions, and its cytotoxic and pro-apoptotic activities were confirmed in A549 cells. To elucidate the inhibitory activity of brusatol against EGFR-TK, a specific ADP-GloTM kinase assay was used. In this assay, the IC50 value for EGFR-TK inhibition was 333.1 nM. Molecular dynamic simulations and docking experiments were performed to identify the binding pocket of brusatol to be located in the intracellular TK-domain of EGFR. This study demonstrates that brusatol inhibits EGFR-TK and therefore harbors a potential as a new therapeutic drug for the therapy of EGFR-depending cancers.

A scientometrics and visualization analysis of oxidative stress modulator Nrf2 in cancer profiles its characteristics and reveals its association with immune response

Background

Nrf2, an essential and fascinating transcription factor, enjoys a dual property in the occurrence and development of inflammation and cancer. For over two decades, numerous studies regarding Nrf2 in cancer have been reported, whereas there is still a lack of a scientometrics and visualization analysis of Nrf2 in cancer. Hence, a scientometric study regarding the oxidative stress modulator Nrf2 was implemented.

Methods

After the quality screening, we defined 7168 relevant studies from 2000 to 2021. CiteSpace, VOSviewer, R software, and GraphPad Prism were used for the following scientometric study and visualization analysis, including field profiles, research hotspots, and future predictions.

Results

The total number of publications and citations are 1058 and 54,690, respectively. After polynomial fitting curve analysis, two prediction functions of the annual publication number (y = 3.3909x² - 13585x + 1 E+07) and citation number (185.45x² - 743669x + 7 E+08) were generated. After scientometric analysis, we found that Biochemistry Molecular Biology correlates with Nrf2 in cancer highly, and Free Radical Biology and Medicine is a good choice for submitting Nrf2-related manuscripts. The current research hotspots of Nrf2 in cancer mainly focus on cancer therapy and its cellular and molecular mechanisms. "antioxidant response element (87.5)", "gene expression (43.98)", "antioxidant responsive element (21.14)", "chemoprevention (20.05)", "carcinogenesis (19.2)", "cancer chemoprevention (18.45)", "free radical (17.15)", "response element (14.17)", and "chemopreventive agent (14.04)" are important for cancer therapy study. In addition, "glutathione-S-transferase (47)", "keap1 (15.39)", and "heme oxygenase 1 gene (24.35)" are important for inflammation and cell fate study. More interestingly, by performing an "InfoMap" algorithm, the thematic map showed that the "immune response" is essential to oxidative stress modulator Nrf2 but not well developed, indicating it deserves further exploration.

Conclusion

This study revealed field profiles, research hotspots, and future directions of oxidative stress modulator Nrf2 in inflammation and cancer research, and our findings will offer a vigorous roadmap for further studies in this field.

Brusatol: A potential sensitizing agent for cancer therapy from Brucea javanica

Cancer is currently the most important problem endangering human health. As antitumor drugs have always been the most common methods for treating cancers, searching for new antitumor agents is of great significance. Brusatol, a quassinoid from the seeds of Brucea javanica, exhibits a potent tumor-suppressing effect with improved disease outcome. Studies have shown that brusatol not only shows potential tumor inhibition through multiple pharmacological effects, such as promoting apoptosis and inhibiting metastasis but also exhibits significant synergistic antitumor effects in combination with chemotherapeutic agents and overcoming chemical resistance in a wide range of cancer types. In this paper, the antitumor effects and mechanisms of brusatol were reviewed to provide evidence that brusatol has the exact antitumor efficacy of chemotherapeutic agents and show the potential of brusatol to be developed as a promising antitumor drug.

Brusatol suppresses the tumor growth and metastasis of colorectal cancer via upregulating ARRDC4 expression through modulating PI3K/YAP1/TAZ Pathway

BACKGROUND

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers with high metastasis and lethality. Arrestin domain-containing 4 (ARRDC4) is involved in inhibiting cancer glycolytic phenotypes. Brusatol (BR), extracted from Bruceae Fructus, exerts good anti-cancer effects against a number of cancers.

PURPOSE

In the present study, we aimed to explore the efficacy of BR on inhibiting CRC metastasis and elucidate the underlying mechanisms involving the upregulation of the ARRDC4 expression.

METHODS

Cell viability, colony formation, wound healing and transwell assay were used to detect the anti-proliferative and anti-metastatic effects of BR against CRC in vitro. Microarray analysis was performed to find out differential genes in CRC cells after treatment with BR. Analysis of the CRC patients tumor samples and GEPIA database were first conducted to identify the expression of ARRDC4 on CRC. Stable overexpression and knockdown of ARRDC4 CRC cells were established by lentiviral transfection. The role of ARRDC4 in mediating the anti-metastatic effects of BR on CRC was measured using qRT-PCR, western blotting, immunohistochemical and immunofluorescence analysis. Orthotopic xenograft and pulmonary metastasis mouse models of CRC were established to determine the anti-cancer and anti-metastatic effects of ARRDC4 and BR.

RESULTS

BR markedly suppressed the cell proliferation, migration, invasion and inhibited tumor growth and tumor metastasis. Microarray analysis demonstrated that BR treatment markedly increased the gene expression of ARRDC4 in CRC cells. ARRDC4 was significantly repressed in CRC in the clinical samples and GEPIA analysis. ARRDC4 overexpression plus BR produced better inhibitory effects on CRC metastasis than BR treatment alone, while ARRDC4 knockdown could partially eliminate the inhibitory effects of BR against CRC metastasis. BR exerted anti-metastatic effects against CRC via upregulating ARRDC4 and inhibiting epithelial-mesenchymal transition (EMT) processing through modulating PI3K/Hippo pathway.

CONCLUSION

This study reported for the first time that BR is a potent ARRDC4 agonist, and is worthy of further development into a new therapeutic strategy for CRC.

Role of caspase-3-cleaved/activated PAK2 in brusatol-triggered apoptosis of human lung cancer A549 cells

Brusatol, a major quassinoid extract of Bruceae fructus, is an important bioactive component with antineoplastic capacity. Several beneficial pharmacological and biological properties of brusatol have been uncovered to date, including anti-inflammatory, anticolitis, antimalarial, and anticancer activities. To confer anticancer benefits, brusatol is reported to effectively inhibit the Nrf2-mediated antioxidant response and trigger apoptotic signaling. In this study, we investigated the regulatory mechanisms underlying apoptotic processes in brusatol-treated A549 cells in detail. Our experiments showed that brusatol induces cell death through intracellular ROS-triggered mitochondria-dependent apoptotic events and does not involve necrosis. Mechanistically, p21-activated protein kinase 2 (PAK2) was cleaved by caspase-3 to generate an activated p34 fragment involved in brusatol-induced apoptosis of A549 cells. Notably, PAK2 knockdown led to downregulation of caspase-3-mediated PAK2 activity, in turn, effectively attenuating brusatol-induced apoptosis, highlighting a crucial role of caspase-3-activated PAK2 in this process. Moreover, knockdown of PAK2 resulted in significant inhibition of c-Jun N-terminal kinase (JNK) activity in brusatol-treated A549 cells, clearly suggesting that JNK serves as a downstream substrate of caspase-3-cleaved/activated PAK2 in the apoptotic cascade. SP600125, a specific JNK inhibitor, significantly suppressed brusatol-induced JNK activity but only partially prevented apoptosis, implying that JNK serves as only one of a number of substrates for PAK2 in the brusatol-triggered apoptotic cascade. Based on the collective results, we propose a signaling cascade model for brusatol-induced apoptosis in human A549 cells involving ROS, caspases, PAK2, and JNK.

Brusatol suppresses the growth of intrahepatic cholangiocarcinoma by PI3K/Akt pathway

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is a malignancy with a hidden onset, high metastasis recurrence rate, and poor prognosis. Research on effective drugs for ICC is important for improving the prognosis of patients in the clinic. Brusatol is a quassinoid extracted from the seeds of Brucea sumatrana and has been shown to have the potential to inhibit tumor metastasis and proliferation. There has been no scientific research on the therapeutic effect of brusatol on ICC. Our study offers a novel strategy for the therapy of ICC.

PURPOSE

Explore effects of brusatol treatment on ICC and clarify the possible mechanism.

STUDY DESIGN

Various cell functional experiments and basic experimental techniques were applied to ICC cell lines to explore the influences of brusatol on ICC cells; this conclusion was further verified in animal models.

METHODS

The anti-cancer effects of the drug on the cell, protein, and RNA level were verified by cell functional experiments, WB blotting and transcriptome sequencing experiments, respectively. Finally, the experimental results were verified using subcutaneous tumor experiments in nude mice.

RESULTS

The consequences exhibited that the levels of epithelial markers of ICC cells increased after brusatol treatment, and the levels of interstitial indicators decreased, suppressing the epithelial-mesenchymal transition (EMT) process. Brusatol inhibited proliferation, induced apoptosis, and suppressed the migration and invasion abilities of Hucc-T1 and RBE oncocytes via activating PI3K/Akt pathway. It also suppressed the growth of Hucc-T1 xenografts in nude mice.

CONCLUSION

Brusatol inhibits the proliferation and EMT process in ICC oncocytes by the PI3K/Akt pathway and promotes apoptosis in oncocytes.

Potential cancer treatment effects of brusatol or eriodictyol combined with 5-fluorouracil (5-FU) in colorectal cancer cell

Colorectal cancer is among the most frequently diagnosed cancers in patients today. In the treatment of this disease, combination or multicomponent therapy has been identified as a potential method to improve patient response and delay side effects. The aim of this study was to determine the effects on cell viability of commercial Bru and Erio used together with the anticancer drug 5-FU in the human colorectal cancer (CRC) cell line (HT-29 cell line) for the first time, as far as can be determined from available literature at this time. Additionally, the research seeks to study any potential effects on apoptosis. For this purpose, the effects of independent and combined treatments of the aforementioned agents on cell viability were investigated through the MTT experiment. Apoptotic effects were determined by Annexin V/PI and real-time PCR methods. In addition, a cell cycle analysis was used to determine the distribution of cells in the cycle. Data from experiments for 48 h showed that Bru, alone or in combination with 5-FU, is capable of causing an increase in the percentage of apoptotic cells in HT-29 cells compared to those of Erio alone or in combination with 5-FU. A significant increase in the level of bax and caspase-3 apoptotic genes was also detected in combinations of IC₅₀ concentrations of Bru and 5-FU. These findings suggest that unlike Erio, Bru alone or in combination with 5-FU may be useful for increasing the effects of 5-FU used in the treatment of CRC and to provide data on alternative treatment approaches.

Recent syntheses and biological profiling of quassinoids

Quassinoid natural products have gained considerable recognition for their diverse biological properties and their synthetically challenging, highly oxygenated polycyclic structures. Herein, we discuss strategies and tactics in the total synthesis of quassinoids that have been evolving over the past 15 years. Additionally, recent structure-activity relationships and potential biological mechanisms of actions are briefly summarized.

Brusatol Inhibits Proliferation and Metastasis of Colorectal Cancer by Targeting and Reversing the RhoA/ROCK1 Pathway

Brusatol (BRU) is an important compound extracted from Brucea javanica oil, whose pharmacological effects are able to induce a series of biological effects, including inhibition of tumor cell growth, anti-inflammatory, antiviral, and antitumor. Currently, there are so few studies about the brusatol effects on colorectal cancer that its anticancer mechanism has not been clearly defined. In this study, we made an in-depth investigation into the brusatol effect towards the proliferation and metastasis of colon cancer and the possible mechanism. The inhibitory effect of BRU on the proliferation of colorectal cancer cells was unveiled via CCK-8 method and colony formation assay, while the inhibitory effect of BRU on migration and invasion of colorectal cancer cells was revealed by scratch assay and transwell assay. In addition, Western blot results also revealed that BRU inhibited not only the expressions of RhoA and ROCK1 but also the protein expressions of EMT-related markers e-cadherin, N-cadherin, Vimentin, MMP2, and MMP9 in colon cancer cells. Through the xenotransplantation model, our in vivo experiment further verified the antitumor effect of BRU on colon cancer cells in vitro, and the results were consistent with the protein expression trend. In conclusion, BRU may inhibit the proliferation and metastasis of colorectal cancer by influencing EMT through RhoA/ROCK1 pathway.

Brusatol inhibits the growth of renal cell carcinoma by regulating the PTEN/PI3K/AKT pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Brucea javanica (L.) Merr. is a medicinal herb used in China for the prevention and treatment of diseases such as cancer and malaria. Brusatol was isolated from the seeds of Brucea javanica (L.) Merr, brusatol has a wide range of pharmacological effects, including anti-inflammation and anti-cancer effects.

AIM OF THE STUDY

Renal cell carcinoma is one of the most common urinary system tumours and seriously threatens the lives of patients. We aimed to study the mechanism by which brusatol regulates the growth of renal cancer cells through the PTEN/PI3K/AKT signalling pathway.

MATERIALS AND METHODS

We chose the A498, ACHN, and OSRC-2 cell lines as experimental models. After intervention with brusatol, CCK-8 experiments and plate cloning experiments were used to detect the cell proliferation ability; flow cytometry was used to detect the cell apoptosis rate; scratch and transwell invasion assays were used to detect the cell migration and invasion ability; qRT-PCR and Western blotting was used to detect PTEN, p-PI3K/PI3K, p-AKT/AKT, Bax, Bcl2, E-cadherin, N-cadherin, and vimentin relative expression. Then, we knocked down the PTEN gene in the three cell lines and again tested the proliferation, apoptosis, migration, and invasion capabilities of each group of cells.

RESULTS

Brusatol significantly inhibited the proliferation, migration and invasion and increased the rate of apoptosis of the A498, ACHN, and OSRC-2 cell lines, and brusatol significantly increased the expression of PTEN mRNA and protein, and inhibited the expression of p-PI3K and p-AKT. Moreover, knockdown of PTEN significantly reduced the inhibitory effect of brusatol on the growth of renal cancer cells.

CONCLUSION

Our research results show that brusatol has an effective inhibitory effect on the growth of A498, ACHN, and OSRC-2 renal cancer cell lines, and this effect is likely to be produced by regulating the PTEN/PI3K/AKT signalling pathway.

Major Constituents From Brucea javanica and Their Pharmacological Actions

Brucea javanica (Ya-dan-zi in Chinese) is a well-known Chinese herbal medicine, which is traditionally used in Chinese medicine for the treatment of intestinal inflammation, diarrhea, malaria, and cancer. The formulation of the oil (Brucea javanica oil) has been widely used to treat various types of cancer. It has also been found that B. javanica is rich in chemical constituents, including quassinoids, triterpenes, alkaloids and flavonoids. Pharmacological studies have revealed that chemical compounds derived from B. javanica exhibit multiple bioactivities, such as anti-cancer, anti-bacterial, anti-diabetic, and others. This review provides a comprehensive summary on the pharmacological properties of the main chemical constituents presented in B. javanica and their underlying molecular mechanisms. Moreover, the review will also provide scientific references for further research and development of B. javanica and its chemical constituents into novel pharmaceutical products for disease management.

Cancer Chemopreventive Role of Dietary Terpenoids by Modulating Keap1-Nrf2-ARE Signaling System—A Comprehensive Update

ROS, RNS, and carcinogenic metabolites generate excessive oxidative stress, which changes the basal cellular status and leads to epigenetic modification, genomic instability, and initiation of cancer. Epigenetic modification may inhibit tumor-suppressor genes and activate oncogenes, enabling cells to have cancer promoting properties. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that in humans is encoded by the NFE2L2 gene, and is activated in response to cellular stress. It can regulate redox homoeostasis by expressing several cytoprotective enzymes, including NADPH quinine oxidoreductase, heme oxygenase-1, UDP-glucuronosyltransferase, glutathione peroxidase, glutathione-S-transferase, etc. There is accumulating evidence supporting the idea that dietary nutraceuticals derived from commonly used fruits, vegetables, and spices have the ability to produce cancer chemopreventive activity by inducing Nrf2-mediated detoxifying enzymes. In this review, we discuss the importance of these nutraceuticals in cancer chemoprevention and summarize the role of dietary terpenoids in this respect. This approach was taken to accumulate the mechanistic function of these terpenoids to develop a comprehensive understanding of their direct and indirect roles in modulating the Keap1-Nrf2-ARE signaling system.

Brusatol Inhibits Tumor Growth and Increases the Efficacy of Cabergoline against Pituitary Adenomas

Cabergoline (CAB) is the first choice for treatment of prolactinoma and the most common subtype of pituitary adenoma. However, drug resistance and lack of effectiveness in other pituitary tumor types remain clinical challenges to this treatment. Brusatol (BT) is known to inhibit cell growth and promote apoptosis in a variety of cancer cells. In our present studies, we investigate the effects of BT on pituitary tumor cell proliferation in vitro and in vivo. BT treatment resulted in an increase in Annexin V-expressing cells and promoted the expression of apoptosis-related proteins in rat and human pituitary tumor cells. Investigation of the mechanism underlying this effect revealed that BT increased the production of reactive oxygen species (ROS) and inhibited the phosphorylation of 4EBP1 and S6K1. Furthermore, treatment with a combination of BT and CAB resulted in greater antitumor effects than either treatment alone in nude mice and pituitary tumor cells. Collectively, our results suggest that the BT-induced ROS accumulation and inhibition of mTORC1 signaling pathway leads to inhibition of tumor growth. Combined use of CAB and BT may increase the clinical effectiveness of treatment for human pituitary adenomas.

Brucea javanica: A review on anticancer of its pharmacological properties and clinical researches

BACKGROUND

The dried fruits of Brucea javanica (L.) Merr (BJ) is being widely investigated, both in lab and in clinic, to explore its potential anticancer activity and molecular mechanism involved.

PURPOSE

We appraised the available literature and suggested the future research directions to improve the medicinal value of BJ.

METHOD

In this review, we have summarized the scientific findings from experimental and clinical studies regarding the anticancer activity and mechanisms.

RESULTS

Numerous studies have reported that BJ exerts anticancer effect on various types of cancer lines through inhibiting cell proliferation, inducing apoptosis, inhibiting migration/invasion, inducing autophagy and restraining angiogenesis. Brucea javanica triggers the generation of reactive oxygen species (ROS), release of cytochrome C, activation of mitochondrial apoptosis pathway and regulation of a series of signal pathways and proteins related to cancer. The molecular mechanism involved are inhibiting the PI3K/Akt/mTOR, NF-κB and Nrf2-Notch1 pathways; up or down modulating the levels of p53, p62, p21, Bax, and Bcl-2 respectively, and inhibiting the expression of matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). Brucea javanica's efficacy in treating cancer patients either as a main or supportive treatment is also discussed in this review.

CONCLUSION

This review will serve as a comprehensive resource of BJ's potential as anticancer agent and its molecular pathways. The analysis of the literature suggests that BJ can serve as a potential candidate for the treatment of cancer.

Effect of Chinese Herbal Medicine Therapy on Overall and Cancer Related Mortality in Patients With Advanced Nasopharyngeal Carcinoma in Taiwan

Nasopharyngeal carcinoma (NPC) is a head and neck cancer involving epithelial squamous-cell carcinoma of the nasopharynx that mainly occurs in individuals from East and Southeast Asia. We investigated whether Chinese herbal medicine (CHM) as a complementary therapy offers benefits to these patients. We retrospectively evaluated the Taiwan Cancer Registry (Long Form) database for patients with advanced NPC, using or not using CHM, between 2007–2013. Cox proportional-hazard model and Kaplan‒Meier survival analyses were applied for patient survival. CHM-users showed a lower overall and cancer-related mortality risk than non-users. For advanced NPC patients, the overall mortality risk was 0.799-fold for CHM-users, after controlling for age, gender, and Charlson comorbidity index (CCI) score (Cancer stages 3 + 4: adjusted hazard ratio [aHR]: 0.799, 95% confidence interval [CI]: 0.676–0.943, p = 0.008). CHM-users also showed a lower cancer-related mortality risk than non-users (aHR: 0.71, 95% CI: 0.53–0.96, p = 0.0273). Association rule analysis showed that CHM pairs were Ban-Zhi-Lian (BZL; Scutellaria barbata D.Don) and For single herbs, Bai-Hua-She-She-Cao (Herba Hedyotis Diffusae; Scleromitrion diffusum (Willd.) R.J.Wang (syn. Hedyotis diffusa Willd.) and Mai-Men-Dong (MMD; Ophiopogon japonicus (Thunb.) Ker Gawl.), and Gan-Lu-Yin (GLY) and BHSSC. Network analysis revealed that BHSSC was the core CHM, and BZL, GLY, and Xin-Yi-Qing-Fei-Tang (XYQFT) were important CHMs in cluster 1. In cluster 2, ShengDH, MMD, Xuan-Shen (XS; Scrophularia ningpoensis Hensl.), and Gua-Lou-Gen (GLG; Trichosanthes kirilowii Maxim.) were important CHMs. Thus, as a complementary therapy, CHM, and particularly the 8 CHMs identified, are important for the treatment of advanced NPC patients.

Apoptotic activities of brusatol in human non-small cell lung cancer cells: Involvement of ROS-mediated mitochondrial-dependent pathway and inhibition of Nrf2-mediated antioxidant response

Brusatol occurs as a characteristic bioactive principle of Brucea javanica (L.) Merr., a traditional medicinal herb frequently employed to tackle cancer in China. This work endeavored to unravel the potential anti-cancer activity and action mechanism of brusatol against non-small cell lung cancer (NSCLC) cell lines. The findings indicated that brusatol remarkably inhibited the growth of wild-type NSCLC cell lines (A549 and H1650) and epidermal growth factor receptor-mutant cell lines (PC9 and HCC827) in a dose- and time-related fashion, and profoundly inhibited the clonogenic capability and migratory capacity of PC9 cells. Treatment with brusatol resulted in significant apoptosis in PC9 cells, as evidenced by Hoechst 33342 staining and flow cytometric analysis. The apoptotic effect was closely related to induction of G0-G1 cell cycle arrest, stimulation of reactive oxygen species (ROS) and malondialdehyde, decrease of glutathione levels and disruption of mitochondrial membrane potential. Furthermore, pretreatment with N-acetylcysteine, a typical ROS scavenger, markedly ameliorated the brusatol-induced inhibition of PC9 cells. Western blotting assay indicated that brusatol pronouncedly suppressed the expression levels of mitochondrial apoptotic pathway-associated proteins Bcl-2 and Bcl-xl, accentuated the expression of Bax and Bak, and upregulated the protein expression of XIAP, cleaved caspase-3/pro caspase-3, cleaved caspase-8/pro caspase-8, and cleaved PARP/total PARP. In addition, brusatol significantly suppressed the expression of Nrf2 and HO-1, and abrogated tBHQ-induced Nrf2 activation. Combinational administration of brusatol with four chemotherapeutic agents exhibited marked synergetic effect on PC9 cells. Together, the inhibition of PC9 cells proliferation by brusatol might be intimately associated with the modulation of ROS-mediated mitochondrial-dependent pathway and inhibition of Nrf2-mediated antioxidant response. This novel insight might provide further evidence to buttress the antineoplastic efficacy of B. javanica, and support a role for brusatol as a promising anti-cancer candidate or adjuvant to current chemotherapeutic medication in the therapy of EGFR-mutant NSCLC.