The anti-migration and anti-invasion effects of Bruceine D in human triple-negative breast cancer MDA-MB-231 cells

The quassinoids bruceines A-M: pharmacology, mechanism of action, synthetic advance, and pharmacokinetics-a review

Bruceines A-L are among the quassinoid representatives found in the medicinal plant Brucea javanica (L.). An overview of their pharmacological activities is still unknown. The given research deals with highlights in their pharmacological result, molecular mechanism of action, synthetic progress, and pharmacokinetics. From previous evidence, bruceine derivatives are potential agents for anticancer treatments, as well as they are appropriate to treat inflammation, diabetes, and parasitic infections, and protect the neurons, kidneys, and lungs. Cytokine inhibitions, oxidative stress responses, and various signaling pathways, such as MAPK (mitogen-activated protein kinase) and NF-κB (nuclear factor-kappa B), have been proposed as the underlying mechanisms of action. Synthetic approaches to synthesize new derivatives with enhancement activities are based on free hydroxyl group modifications. Bruceines seem to be promptly absorbed by both oral and intravenous administrations, but their bioavailability is not high (less than 6%). Pre-clinical and clinical studies to prove their anticancer potential and other activities are urgent. Structural modifications, nano-combinations, and synergistic effects are necessary.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Targeting the key players of phenotypic plasticity in cancer cells by phytochemicals

Plasticity of phenotypic traits refers to an organism's ability to change in response to environmental stimuli. As a result, the response may alter an organism's physiological state, morphology, behavior, and phenotype. Phenotypic plasticity in cancer cells describes the considerable ability of cancer cells to transform phenotypes through non-genetic molecular signaling activities that promote therapy evasion and tumor metastasis via amplifying cancer heterogeneity. As a result of metastable phenotypic state transitions, cancer cells can tolerate chemotherapy or develop transient adaptive resistance. Therefore, new findings have paved the road in identifying factors and agents that inhibit or suppress phenotypic plasticity. It has also investigated novel multitargeted agents that may promise new effective strategies in cancer treatment. Despite the efficiency of conventional chemotherapeutic agents, drug toxicity, development of resistance, and high-cost limit their use in cancer therapy. Recent research has shown that small molecules derived from natural sources are capable of suppressing cancer by focusing on the plasticity of phenotypic responses. This systematic, comprehensive, and critical review analyzes the current state of knowledge regarding the ability of phytocompounds to target phenotypic plasticity at both preclinical and clinical levels. Current challenges/pitfalls, limitations, and future perspectives are also discussed.

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.

The ethyl acetate extract of Vernonia amygdalina leaf ameliorates gemcitabine effect against migration and invasion of PANC-1 cells via down-regulation the VEGF, COX2, and RAS/MEK pathways

Individuals diagnosed with cancer often turn to the use of herbal remedies with the intention of treating and ameliorating the condition, impeding the progression of metastasis, enhancing immune function, mitigating stress, and inducing relaxation. Recently, medicinal plants were combined with conventional chemotherapy to decrease the side effects and increase the effectiveness of chemotherapy. This study showed the effectiveness of gemcitabine (Gem) was significantly increased after being used together with ethyl acetate extract obtained from Vernonia amygdalina (Eav) leaves. The combination doses of Eav and Gem were determined based on cytotoxic activity using the MTT assay method. The anticancer effect of this combination was identified by several parameters including the apoptosis effect, anti-migration, and anti-invasion activities of PANC-1 cells. Furthermore, this effect was explained via protein expression evaluation using immunohistochemical and flow cytometry. The Eav has a better Inhibitory Concentration 50 (IC50) than Gem of 21.19 ± 0.64 µg/mL and 164.78 ± 1.40 µg/mL. The combination of Eav and Gem at IC50 (1:1) has the strongest activity than Eav and Gem alone at 500.00 µg/mL. The anti-cancer effect of this combination showed significantly increased levels of apoptosis, particularly in the early phase of 17.46 ± 0.35 % (p < 0.0001) than Eav and Gem alone of 7.76 ± 0.25 % and 7.06 ± 0.20 %. A similar impact was evaluated in the migration and invasion of PANC-1 cells after the combination treatment. The % relative migration and cell invasion were significantly decreased compared to the control group and Eav or Gem alone by 21.49 ± 0.96 % and 125.25 ± 5.25 cells, respectively (p < 0.0001). This study found that signature molecules of VEGF, COX2, RAS, and MEK were down-regulated after treatment. Our study suggested that the Eav ameliorates the Gem effect against PANC-1 cells through apoptosis, migration, and invasion influence via RAS/MEK pathways.

In vitro anticancer evaluation of Enceleamycin A and its underlying mechanism

It has become more crucial than ever to find novel anticancer compounds due to the rise in cancer mortality and resistance to the present chemotherapeutic drugs. Naphthoquinones are regarded as privileged structures for their ability to inhibit various cancers. The current study examined three novel furo-naphthoquinones (Enceleamycins A-C) previously isolated from Amycolatopsis sp. MCC 0218 for their anticancer potential. Enceleamycin A demonstrated considerable cytotoxicity for triple-negative breast cancer (TNBC) MDA-MB-231 cells with an IC50 value of 1.25 μg mL-1 (3.78 μM). It also showed the ability to inhibit MDA-MB-231 cell migration. Enceleamycin A raises intracellular ROS levels in TNBC cells, ultimately leading to apoptotic cell death, as demonstrated by Annexin V/PI staining. The molecular docking and simulation investigation revealed better binding affinity of Enceleamycin A with AKT2, which plays a vital role in breast cancer's invasiveness and chemo-resistance. Enceleamycin A inhibits the AKT2 enzyme in vitro with an IC50 value of 0.736 μg mL-1 (2.22 μM), further validating the docking study. The in silico physicochemical and pharmacokinetics characteristics of Enceleamycin A demonstrated its drug-likeness. Intriguingly, Enceleamycin A is non-hemolytic in nature. Taken together, Enceleamycin A could be a candidate molecule for treating TNBC cells by targeting the AKT2 signaling pathway.

Natural Nrf2 Inhibitors: A Review of Their Potential for Cancer Treatment

Nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that regulates redox homeostasis, plays a pivotal role in several cellular processes such as cell proliferation and survival, and has been found to be aberrantly activated in many cancers. As one of the key oncogenes, Nrf2 represents an important therapeutic target for cancer treatment. Research has unraveled the main mechanisms underlying the Nrf2 pathway regulation and the role of Nrf2 in promoting tumorigenesis. Many efforts have been made to develop potent Nrf2 inhibitors, and several clinical trials are being conducted on some of these inhibitors. Natural products are well-recognized as a valuable source for development of novel therapeutics for cancer. So far, a number of natural compounds have been identified as Nrf2 inhibitors, such as apigenin, luteolin, and quassinoids compounds including brusatol and brucein D. These Nrf2 inhibitors have been found to mediate an oxidant response and display therapeutic effects in different types of human cancers. In this article, we reviewed the structure and function of the Nrf2/Keap1 system and the development of natural Nrf2 inhibitors with an emphasis on their biological function on cancer. The current status regarding the Nrf2 as a potential therapeutic target for cancer treatment was also summarized. It is hoped that this review will stimulate research on naturally occurring Nrf2 inhibitors as therapeutic candidates for cancer treatment.

Triple Negative Breast Cancer Preclinical Therapeutic Management by a Cationic Ruthenium-Based Nucleolipid Nanosystem

Based on compelling preclinical evidence concerning the progress of our novel ruthenium-based metallotherapeutics, we are focusing research efforts on challenging indications for the treatment of invasive neoplasms such as the triple-negative breast cancer (TNBC). This malignancy mainly afflicts younger women, who are black, or who have a BRCA1 mutation. Because of faster growing and spreading, TNBC differs from other invasive breast cancers having fewer treatment options and worse prognosis, where existing therapies are mostly ineffective, resulting in a large unmet biomedical need. In this context, we benefited from an experimental model of TNBC both in vitro and in vivo to explore the effects of a biocompatible cationic liposomal nanoformulation, named HoThyRu/DOTAP, able to effectively deliver the antiproliferative ruthenium(III) complex AziRu, thus resulting in a prospective candidate drug. As part of the multitargeting mechanisms featuring metal-based therapeutics other than platinum-containing agents, we herein validate the potential of HoThyRu/DOTAP liposomes to act as a multimodal anticancer agent through inhibition of TNBC cell growth and proliferation, as well as migration and invasion. The here-obtained preclinical findings suggest a potential targeting of the complex pathways network controlling invasive and migratory cancer phenotypes. Overall, in the field of alternative chemotherapy to platinum-based drugs, these outcomes suggest prospective brand-new settings for the nanostructured AziRu complex to get promising goals for the treatment of metastatic TNBC.

Compounds from diverse natural origin against triple-negative breast cancer: A comprehensive review

Triple-negative breast cancer (TNBC) is caused due to the lack of estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor 2 (HER2) expression. Triple-negative breast cancer is the most aggressive heterogeneous disease that is capable of producing different clones and mutations. Tumorigenesis in TNBC is caused due to the mutation or overexpression of tumor suppressor genes. It is also associated with mutations in the BRCA gene which is linked to hereditary breast cancer. In addition, PARP proteins and checkpoint proteins also play a crucial function in causing TNBC. Many cell signaling pathways are dysregulated in TNBC. Even though chemotherapy and immunotherapy are good options for TNBC treatment, the response rates are still low in general. Many phytochemicals that are derived from natural compounds have shown very good inhibitions for TNBC. Natural compounds have the great advantage of being less toxic, having lesser side effects, and being easily available. The secondary metabolites such as alkaloids, terpenoids, steroids, and flavonoids in natural products make them promising inhibitors of TNBC. Their compositions also offer vital insights into inhibitory action, which could lead to new cancer-fighting strategies. This review can help in understanding how naturally occurring substances and medicinal herbs decrease specific tumors and pave the way for the development of novel and extremely efficient antitumor therapies.

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.

Bruceine D Identified as a Drug Candidate against Breast Cancer by a Novel Drug Selection Pipeline and Cell Viability Assay

The multi-target effects of natural products allow us to fight complex diseases like cancer on multiple fronts. Unlike docking techniques, network-based approaches such as genome-scale metabolic modelling can capture multi-target effects. However, the incompleteness of natural product target information reduces the prediction accuracy of in silico gene knockout strategies. Here, we present a drug selection workflow based on context-specific genome-scale metabolic models, built from the expression data of cancer cells treated with natural products, to predict cell viability. The workflow comprises four steps: first, in silico single-drug and drug combination predictions; second, the assessment of the effects of natural products on cancer metabolism via the computation of a dissimilarity score between the treated and control models; third, the identification of natural products with similar effects to the approved drugs; and fourth, the identification of drugs with the predicted effects in pathways of interest, such as the androgen and estrogen pathway. Out of the initial 101 natural products, nine candidates were tested in a 2D cell viability assay. Bruceine D, emodin, and scutellarein showed a dose-dependent inhibition of MCF-7 and Hs 578T cell proliferation with IC50 values between 0.7 to 65 μM, depending on the drug and cell line. Bruceine D, extracted from Brucea javanica seeds, showed the highest potency.

In Silico Evaluation of Natural Compounds for an Acidic Extracellular Environment in Human Breast Cancer

The survival rates for breast cancer (BC) have improved in recent years, but resistance, metastasis, and recurrence still remain major therapeutic challenges for BC. The acidic tumor microenvironment (TME) has attracted attention because of its association with tumorigenesis, metastasis, drug resistance, and immune surveillance. In this study, we evaluated natural compounds from traditional herbal medicine used to treat cancer that selectively target genes regulated by extracellular acidosis. We integrated four transcriptomic data including BC prognostic data from The Cancer Genome Atlas database, gene expression profiles of MCF-7 cells treated with 102 natural compounds, patterns of gene profiles by acidic condition, and single-cell RNA-sequencing from BC patient samples. Bruceine D (BD) was predicted as having the highest therapeutic potential, having an information gain (IG) score of 0.24, to regulate reprogrammed genes driven by acidosis affecting the survival of BC patients. BD showed the highest IG on EMT (IG score: 0.11) and invasion (IG score: 0.1) compared to the other phenotypes with the CancerSEA database. BD also demonstrated therapeutic potential by interfering with the tumor cell-TME interactions by reducing the amyloid beta precursor protein and CD44 expression. Therefore, BD is a potential candidate to target the acidic TME induced metastatic process in BC.

Diclofenac impairs the proliferation and glucose metabolism of triple-negative breast cancer cells by targeting the c-Myc pathway

Triple-negative breast cancer (TNBC) cells obtain energy mainly through aerobic glycolysis, and their glycolytic rate is significantly higher compared with that of non-TNBC cells. Glucose transporter 1 (GLUT1) is a transmembrane transporter necessary for the entry of glucose into tumor cells, hexokinase (HK) is a key enzyme in the glycolytic pathway, and both are targets of the transcription factor c-Myc. c-Myc can promote aerobic glycolysis by upregulating GLUT1 expression and enhancing HK activity. c-Myc and GLUT1 are highly expressed in TNBC. The non-steroidal anti-inflammatory drug diclofenac can inhibit glycolysis in melanoma cells and thereby promote apoptosis by downregulating c-Myc and GLUT1. To explore the effect of diclofenac on the energy metabolism of TNBC cells and determine the underlying mechanism, a comparative study in two TNBC cell lines (MDA-MB-231 and HCC1937) and one non-TNBC cell line (MCF-7) was conducted. Cell proliferation was detected by Cell Counting Kit-8 (CCK-8) and flow cytometric assays; GLUT1 and c-Myc expression was measured by western blotting. Diclofenac significantly inhibited cell proliferation, downregulated GLUT1 and c-Myc expression, and decreased HK activity in TNBC cells compared with non-TNBC cells. In conclusion, the studies suggested that diclofenac inhibited cell glycolysis and suppressed TNBC cell growth by decreasing GLUT1 protein expression and HK activity through the c-Myc pathway.

Medicinal Activities and Nanomedicine Delivery Strategies for Brucea javanica Oil and Its Molecular Components

Brucea javanica oil (BJO) is widely used in traditional Chinese medicine to treat various types of cancer and inflammatory diseases. There is significant interest in understanding the medicinal activities of BJO and its molecular components, especially quassinoids, and in exploring how they can be incorporated into nanomedicine delivery strategies for improved application prospects. Herein, we cover the latest progress in developing different classes of drug delivery vehicles, including nanoemulsions, liposomes, nanostructured lipid carriers, and spongosomes, to encapsulate BJO and purified quassinoids. An introduction to the composition and medicinal activities of BJO and its molecular components, including quassinoids and fatty acids, is first provided. Application examples involving each type of drug delivery vehicle are then critically presented. Future opportunities for nanomedicine delivery strategies in the field are also discussed and considered within the context of translational medicine needs and drug development processes.

A brief overview of antitumoral actions of bruceine D

Cancer remains the second leading cause of mortality globally. In combating cancer, conventional chemotherapy and/or radiotherapy are administered as first-line therapy. However, these are usually accompanied with adverse side effects that decrease the quality of patient’s lives. As such, natural bioactive compounds have gained an attraction in the scientific and medical community as evidence of their anticancer properties and attenuation of side effects mounted. In particular, quassinoids have been found to exhibit a plethora of inhibitory activities such as anti-proliferative effects on tumor development and metastasis. Recently, bruceine D, a quassinoid isolated from the shrub Brucea javanica (L.) Merr. (Simaroubaceae), has come under immense investigation on its antineoplastic properties in various human cancers including pancreas, breast, lung, blood, bone, and liver. In this review, we have highlighted the antineoplastic effects of bruceine D and its mode of actions in different tumor models.