The combination of thymoquinone and paclitaxel shows anti-tumor activity through the interplay with apoptosis network in triple-negative breast cancer

Integrative Geriatric Oncology: A Review of Current Practices

PURPOSE OF REVIEW

This article aims to offer a comprehensive review of optimal integrative medicine practices for geriatric oncology patients. Given the aging population and the global rise in cancer incidence, it is crucial to identify evidence-based modalities and employ an integrated approach to enhance cancer outcomes and quality of life in older adults.

RECENT FINDINGS

It has been predicted that 20.5% (6.9 million) of new cancer cases in 2050 will occur in adults over 80 years old.1 The increasing focus on lifestyle factors in healthy aging has shed light on various overlooked areas of significance. Notably, anti-inflammatory diets and the promotion of a healthy gut microbiome have demonstrated significant impacts on overall health outcomes, bolstering the body's innate capacity to combat disease. This review delves into further evidence and extrapolation concerning integrative approaches and their influence on cancer outcomes and older adults quality of life. The complexity and unique nature of cancer in older adults requires a wide range of support from medical providers. Incorporating various integrative techniques as part of cancer treatment and side effect support can improve health outcomes and patient's quality of life. Familiarity with the lifestyle interventions and other topics explored in this review equips healthcare providers to offer tailored and holistic care to geriatric patients navigating cancer.

Computational and in vitro analyses on synergistic effects of paclitaxel and thymoquinone in suppressing invasive breast cancer cells

BACKGROUND

In the present experiment, we evaluated the impact of thymoquinone (TQ) and paclitaxel (PTX) treatment on MDA-MB-231 cell line growth inhibition via controlling apoptosis/autophagy.

MATERIALS AND RESULTS

MDA-MB-231cells were exposed to PTX (0, 25, 50, 75, and 100 nM), TQ (0, 25, 50, 75, and 100 µM), and combinations for 48 h. After the MTT assessment, dose-response curves and IC50 values were calculated, and the combination synergism was evaluated using the Compusyn software. Following the treatment with PTX, TQ, and combinations at IC50 doses, the expression of apoptosis and autophagy genes was assessed in cells. The GraphPad Prism program was used to analyze the data, and Tukey's test at p < 0.05 was then run. PTX, TQ, and their combinations inhibited MDA-MB-231cell proliferation and viability dose-dependently. TQ reduced the effective concentration (IC50) of PTX in co-treatment groups. PTX and TQ showed antagonistic effects when cell proliferation declined above 70%. Antagonistic effects shifted into additive and synergistic effects upon increasing PTX concentration, indicated by diminished cell proliferation below 70%. PTX-TQ co-treatment significantly enhanced P53 and BAX expression while reducing Bcl-2 expression. Also, their combination increased Beclin-1, ATG-5, and ATG-7 expression in treated cells.

CONCLUSION

Effective concentrations of TQ and PTX had synergic effects and inhibited breast cancer cells via prompting apoptosis and autophagy in vitro.

Drug repurposing: A novel strategy to target cancer stem cells and therapeutic resistance

Chemotherapy is an effortless and frequently used approach in cancer therapy. However, in most cases, it can only prolong life expectancy and does not guarantee a complete cure. Furthermore, chemotherapy is associated with severe adverse effects, one of the major complications of effective cancer therapy. In addition, newly published research outputs show that cancer stem cells are involved in cancer disease progression, drug resistance, metastasis, and recurrence and that they are functional in the trans-differentiation capacity of cancer stem cells to cancer cells in response to treatments. Novel strategies are therefore required for better management of cancer therapy. The prime approach would be to synthesize and develop novel drugs that need extensive resources, time, and endurance to be brought into therapeutic use. The subsequent approach would be to screen the anti-cancer activity of available non-cancerous drugs. This concept of repurposing non-cancer drugs as an alternative to current cancer therapy has become popular in recent years because using existing anticancer drugs has several adverse effects. Micronutrients have also been investigated for cancer therapy due to their significant anti-cancer effects with negligible or no side effects and availability in food sources. In this paper, we discuss an ideal hypothesis for screening available non-cancerous drugs with anticancer activity, with a focus on cancer stem cells and their clinical application for cancer treatment. Further, drug repurposing and the combination of micronutrients that can target both cancers and cancer stem cells may result in a better therapeutic approach leading to maximum tumor growth control.

Anticancer activity of thymoquinone against breast cancer cells: Mechanisms of action and delivery approaches

The rising incidence of breast cancer has been a significant source of concern in the medical community. Regarding the adverse effects and consequences of current treatments, cancers' health, and socio-economical aspects have become more complicated, leaving research aimed at improved or new treatments on top priority. Medicinal herbs contain multitarget compounds that can control cancer development and advancement. Owing to Nigella Sativa's elements, it can treat many disorders. Thymoquinone (TQ) is a natural chemical derived from the black seeds of Nigella sativa Linn proved to have anti-cancer and anti-inflammatory properties. TQ interferes in a broad spectrum of tumorigenic procedures and inhibits carcinogenesis, malignant development, invasion, migration, and angiogenesis owing to its multitargeting ability. It effectively facilitates miR-34a up-regulation, regulates the p53-dependent pathway, and suppresses Rac1 expression. TQ promotes apoptosis and controls the expression of pro- and anti-apoptotic genes. It has also been shown to diminish the phosphorylation of NF-B and IKK and decrease the metastasis and ERK1/2 and PI3K activity. We discuss TQ's cytotoxic effects for breast cancer treatment with a deep look at the relevant stimulatory or inhibitory signaling pathways. This review discusses the various forms of polymeric and non-polymeric nanocarriers (NC) and the encapsulation of TQ for increasing oral bioavailability and enhanced in vitro and in vivo efficacy of TQ-combined treatment with different chemotherapeutic agents against various breast cancer cell lines. This study can be useful to a broad scientific community, comprising pharmaceutical and biological scientists, as well as clinical investigators.

TQ-Ox, a novel synthetic derivative of thymoquinone on ovarian cancer cells in vitro

There are many studies in the literature on thymoquinone (TQ)-related cancer cells and models, and there is no relevant study investigating the efficacy of the oxime derivative of TQ (TQ-Ox). This study synthesized TQ-Ox and examined its cytotoxic, genotoxic and apoptotic properties in ovarian cancer cells. The structure TQ-Ox was confirmed with NMR. The cytotoxicity by luminometric ATP, intracellular reactive oxygen species (iROS) by fluorometric, intracellular calcium (iCa2+) by fluorometric, mitochondrial membrane potential (MMP) by flow cytometry, glutathione (GSH) levels with GSH/GSSG-Glo assay, DNA damage by comet assay, and apoptosis by acridine orange/ethidium bromide dye were determined. Concentrations of TQ-Ox were statistically increased cytotoxicity, DNA damage, apoptosis, iROS, and iCa2+ in a concentration-dependent manner (p < 0.001). Besides, MMP and GSH levels also decreased statistically significantly (p < 0.001) with increasing concentrations. TQ-Ox would be an effective treatment option by increasing cytotoxicity, genotoxicity, and apoptosis in ovarian carcinoma.

Targeting Triple-Negative Breast Cancer by the Phytopolyphenol Carnosol: ROS-Dependent Mechanisms

Triple-negative breast cancer (TNBC), which lacks the expression of the three hormone receptors (i.e., estrogen receptor, progesterone receptor, and human epidermal growth factor receptor), is characterized by a high proliferative index, high invasiveness, poor prognosis, early relapse, and a tendency to be present in advanced stages. These characteristics rank TNBC among the most aggressive and lethal forms of breast cancer. The lack of the three receptors renders conventional hormonal therapy ineffective against TNBC. Moreover, there are no clinically approved therapies that specifically target TNBC, and the currently used chemotherapeutic agents, such as cisplatin, taxanes, and other platinum compounds, have a limited clinical effect and develop chemoresistance over time. Phytochemicals have shown efficacy against several types of cancer, including TNBC, by targeting several pathways involved in cancer development and progression. In this review, we focus on one phytochemical carnosol, a natural polyphenolic terpenoid with strong anti-TNBC effects and its ROS-dependent molecular mechanisms of action. We discuss how carnosol targets key pathways and proteins regulating the cell cycle, growth, epigenetic regulators, invasion, and metastasis of TNBC. This review identifies carnosol as a potential novel targeting protein degradation molecule.

Therapeutic implications and clinical manifestations of thymoquinone

Thymoquinone (TQ), a natural phytochemical predominantly found in Nigella sativa, has been investigated for its numerous health benefits. TQ showed anti-cancer, anti-oxidant, and anti-inflammatory properties, validated in various disease models. The anti-cancer potential of TQ is goverened by anti-proliferation, cell cycle arrest, apoptosis induction, ROS production, anti-metastasis and anti-angiogenesis, inhibition of cell migration and invasion action. Additionally, TQ exhibited antitumor activity via the modulation of multiple pathways and molecular targets, including Akt, ERK1/2, STAT3, and NF-κB. The present review highlighted the anticancer potential of TQ . We summarize the anti-cancer, anti-oxidant, and anti-inflammatory properties of TQ, focusing on its molecular targets and its promising action in cancer therapy. We further described the molecular mechanisms by which TQ prevents signaling pathways that mediate cancer progression, invasion, and metastasis.

Opportunities and challenges for co-delivery nanomedicines based on combination of phytochemicals with chemotherapeutic drugs in cancer treatment

The therapeutic limitations such as insufficient efficacy, drug resistance, metastasis, and undesirable side effects are frequently caused by the long duration monotherapy based on chemotherapeutic drugs. multiple combinational anticancer strategies such as nucleic acids combined with chemotherapeutic agents, chemotherapeutic combinations, chemotherapy and tumor immunotherapy combinations have been embraced, holding great promise to counter these limitations, while still taking including some potential risks. Nowadays, an increasing number of research has manifested the anticancer effects of phytochemicals mediated by modulating cancer cellular events directly as well as the tumor microenvironment. Specifically, these natural compounds exhibited suppression of cancer cell proliferation, apoptosis, migration and invasion of cancer cells, P-glycoprotein inhibition, decreasing vascularization and activation of tumor immunosuppression. Due to the low toxicity and multiple modulation pathways of these phytochemicals, the combination of chemotherapeutic agents with natural compounds acts as a novel approach to cancer therapy to increase the efficiency of cancer treatments as well as reduce the adverse consequences. In order to achieve the maximized combination advantages of small-molecule chemotherapeutic drugs and natural compounds, a variety of functional nano-scaled drug delivery systems, such as liposomes, host-guest supramolecules, supramolecules, dendrimers, micelles and inorganic systems have been developed for dual/multiple drug co-delivery. These co-delivery nanomedicines can improve pharmacokinetic behavior, tumor accumulation capacity, and achieve tumor site-targeting delivery. In that way, the improved antitumor effects through multiple-target therapy and reduced side effects by decreasing dose can be implemented. Here, we present the synergistic anticancer outcomes and the related mechanisms of the combination of phytochemicals with small-molecule anticancer drugs. We also focus on illustrating the design concept, and action mechanisms of nanosystems with co-delivery of drugs to synergistically improve anticancer efficacy. In addition, the challenges and prospects of how these insights can be translated into clinical benefits are discussed.

Functional regulations between genetic alteration-driven genes and drug target genes acting as prognostic biomarkers in breast cancer

Differences in genetic molecular features including mutation, copy number alterations and DNA methylation, can explain interindividual variability in response to anti-cancer drugs in cancer patients. However, identifying genetic alteration-driven genes and characterizing their functional mechanisms in different cancer types are still major challenges for cancer studies. Here, we systematically identified functional regulations between genetic alteration-driven genes and drug target genes and their potential prognostic roles in breast cancer. We identified two mutation and copy number-driven gene pairs (PARP1-ACSL1 and PARP1-SRD5A3), three DNA methylation-driven gene pairs (PRLR-CDKN1C, PRLR-PODXL2 and PRLR-SRD5A3), six gene pairs between mutation-driven genes and drug target genes (SLC19A1-SLC47A2, SLC19A1-SRD5A3, AKR1C3-SLC19A1, ABCB1-SRD5A3, NR3C2-SRD5A3 and AKR1C3-SRD5A3), and four copy number-driven gene pairs (ADIPOR2-SRD5A3, CASP12-SRD5A3, SLC39A11-SRD5A3 and GALNT2-SRD5A3) that all served as prognostic biomarkers of breast cancer. In particular, RARP1 was found to be upregulated by simultaneous copy number amplification and gene mutation. Copy number deletion and downregulated expression of ACSL1 and upregulation of SRD5A3 both were observed in breast cancers. Moreover, copy number deletion of ACSL1 was associated with increased resistance to PARP inhibitors. PARP1-ACSL1 pair significantly correlated with poor overall survival in breast cancer owing to the suppression of the MAPK, mTOR and NF-kB signaling pathways, which induces apoptosis, autophagy and prevents inflammatory processes. Loss of SRD5A3 expression was also associated with increased sensitivity to PARP inhibitors. The PARP1-SRD5A3 pair significantly correlated with poor overall survival in breast cancer through regulating androgen receptors to induce cell proliferation. These results demonstrate that genetic alteration-driven gene pairs might serve as potential biomarkers for the prognosis of breast cancer and facilitate the identification of combination therapeutic targets for breast cancers.

Combinatorial effect of thymoquinone with chemo agents for tumor therapy

BACKGROUND

Most chemotherapeutics used in cancer therapies exhibit considerable side effects to the patients. Thus, developing new chemo agents to treat cancer patients with minimal toxic and side effects is urgently needed. Recently, the combination of different chemotherapeutics has become a promising strategy to treat malignancies. Thymoquinone (TQ) is a primary bioactive compound derived from the folk medicinal plant Nigella sativa, which has been found an antitumor, chemopreventive and chemopotentiating agent against human neoplastic diseases.

PURPOSE

We briefly summarize the current research of the biomolecular mechanisms of TQ and evaluate the existing literature on TQ adjuvant therapies against various cancers.

METHOD

The data in this review were gathered by several search engines including, Google Scholar, PubMed and ScienceDirect. We highlighted and classified the outcomes of both in vitro and in vivo experiments of TQ adjuvant therapies against human cancers and their chemopreventive activities on vital organs.

RESULTS

Several studies have shown that TQ synergistically potentiated the antitumor activity of numerous chemo agents against human neoplastic disease, including lung, breast, liver, colorectal, skin, prostate, stomach, bone and blood cancers. TQ also acted as a chemopreventive agent and reduced the toxicity of many chemo agents to vital organs, such as the heart, liver, kidneys and lungs.

CONCLUSION

In summary, we highly recommend an advanced evaluation of TQ adjuvant therapies at the level of preclinical and clinical trials, which could lead to a novel combinatorial therapy for cancer treatment with low or tolerable adverse effects on patients.

Triangulating the pharmacological properties of thymoquinone in regulating reactive oxygen species, inflammation, and cancer: Therapeutic applications and mechanistic pathways

Cancer is a heterogeneous disease with high morbidity and mortality rate involving changes in redox balance and deregulation of redox signalling. For decades, studies have involved developing an effective cancer treatment to combat treatment resistance. As natural products such as thymoquinone have numerous health benefits, studies are also focusing on using them as a viable method for cancer treatment, as they have minimal toxic effects compared with standard cancer treatments. Thymoquinone studies have shown numerous mechanisms of action, such as regulation of reactive species interfering with DNA structure, modulating various potential targets and their signalling pathways as well as immunomodulatory effects in vitro and in vivo. Thymoquinone's anti-cancer effect is mainly due to the induction of apoptotic mechanisms, such as activation of caspases, downregulation of precancerous genes, inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), anti-tumour cell proliferation, ROS regulation, hypoxia and anti-metastasis. Insight into thymoquinone's potential as an alternative treatment for chemoprevention and inflammation can be accomplished via compiling these studies, to provide a better understanding on how and why it works, as well as its interactions with common chemotherapeutic treatments.

Therapeutic potential of thymoquinone in combination therapy against cancer and cancer stem cells

The long-term success of standard anticancer monotherapeutic strategies has been hampered by intolerable side effects, resistance to treatment and cancer relapse. These monotherapeutic strategies shrink the tumor bulk but do not effectively eliminate the population of self-renewing cancer stem cells (CSCs) that are normally present within the tumor. These surviving CSCs develop mechanisms of resistance to treatment and refuel the tumor, thus causing cancer relapse. To ensure durable tumor control, research has moved away from adopting the monotreatment paradigm towards developing and using combination therapy. Combining different therapeutic modalities has demonstrated significant therapeutic outcomes by strengthening the anti-tumor potential of monotreatment against cancer and cancer stem cells, mitigating their toxic adverse effects, and ultimately overcoming resistance. Recently, there has been growing interest in combining natural products from different sources or with clinically used chemotherapeutics to further improve treatment efficacy and tolerability. Thymoquinone (TQ), the main bioactive constituent of Nigella sativa, has gained great attention in combination therapy research after demonstrating its low toxicity to normal cells and remarkable anticancer efficacy in extensive preclinical studies in addition to its ability to target chemoresistant CSCs. Here, we provide an overview of the therapeutic responses resulting from combining TQ with conventional therapeutic agents such as alkylating agents, antimetabolites and antimicrotubules as well as with topoisomerase inhibitors and non-coding RNA. We also review data on anticancer effects of TQ when combined with ionizing radiation and several natural products such as vitamin D3, melatonin and other compounds derived from Chinese medicinal plants. The focus of this review is on two outcomes of TQ combination therapy, namely eradicating CSCs and treating various types of cancers. In conclusion, the ability of TQ to potentiate the anticancer activity of many chemotherapeutic agents and sensitize cancer cells to radiotherapy makes it a promising molecule that could be used in combination therapy to overcome resistance to standard chemotherapeutic agents and reduce their associated toxicities.

Synergistic Role of Thymoquinone on Anticancer Activity of 5-fluorouracil in Triple-Negative Breast Cancer Cells

BACKGROUND

Triple-negative breast cancer (TNBC) is considered the most deadly subtype of breast cancer because of heterogeneity, fewer treatment options, and resistance to chemotherapy.

OBJECTIVE

We investigated the combined therapy of 5-Fluorouracil (5-FU) and thymoquinone (TQ) against TNBC cell lines BT-549 and MDA-MB-231 in this study to find out efficient chemotherapeutic options.

METHODS

We tested 5-FU and TQ alone and in combination (5-FU + TQ) to observe the cellular growth, cell cycle, and apoptosis status of BT-549 and MDA-MB-231 cells. Also, we have measured the mRNA level expression of genes related to the cell cycle and apoptosis.

RESULTS

Experimental results suggest that both 5-FU and TQ are effective in controlling cell growth, cell cycle, and inducing apoptosis, but their combination is much more effective. 5-FU was found more effective in controlling cell growth, while TQ was found more effective in inducing apoptosis, but in both cases, their combination was most effective. TQ was found to be more effective in increasing and BAX/BCL-2 ratio), while 5-FU was more effective in inhibiting thymidylate synthase. They had shown significant increasing effects on caspases and P53 and decreasing effects on CDK-2, where their combination was found most effective.

CONCLUSIONS

Thus, TQ and 5-FU probably showed a synergistic effect on both of cell cycle and apoptosis of tested TNBC cell lines. Our study reveals that TQ can synergise 5-FU action and increase its anticancer efficiency against TNBC cells, which might be a good choice in drug development for TNBC treatment.

Biological Role of AKT and Regulation of AKT Signaling Pathway by Thymoquinone: Perspectives in Cancer Therapeutics

BACKGROUND

AKT/PKB is an important enzyme with numerous biological functions, and its overexpression is related to carcinogenesis. AKT stimulates different signaling pathways that are downstream of activated tyrosine kinases and phosphatidylinositol 3-kinase, hence functions as an important target for anti-cancer drugs.

OBJECTIVE

In this review article, we have interpreted the role of AKT signaling pathway in cancer and the natural inhibitory effect of Thymoquinone (TQ) in AKT and its possible mechanisms.

METHOD

We have collected the updated information and data on AKT, its role in cancer and the inhibitory effect of TQ in AKT signaling pathway from Google Scholar, PubMed, Web of Science, Elsevier, Scopus, and many more.

RESULTS

Many drugs are already developed, which can target AKT, but very few among them have passed clinical trials. TQ is a natural compound, mainly found in black cumin, which has been found to have potential anti-cancer activities. TQ targets numerous signaling pathways, including AKT, in different cancers. In fact, many studies revealed that AKT is one of the major targets of TQ. The preclinical success of TQ suggests its clinical studies on cancer.

CONCLUSION

This review article summarizes the role of AKT in carcinogenesis, its potent inhibitors in clinical trials, and how TQ acts as an inhibitor of AKT and TQ's future as a cancer therapeutic drug.

Black Cumin (Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety

Mounting evidence support the potential benefits of functional foods or nutraceuticals for human health and diseases. Black cumin (Nigella sativa L.), a highly valued nutraceutical herb with a wide array of health benefits, has attracted growing interest from health-conscious individuals, the scientific community, and pharmaceutical industries. The pleiotropic pharmacological effects of black cumin, and its main bioactive component thymoquinone (TQ), have been manifested by their ability to attenuate oxidative stress and inflammation, and to promote immunity, cell survival, and energy metabolism, which underlie diverse health benefits, including protection against metabolic, cardiovascular, digestive, hepatic, renal, respiratory, reproductive, and neurological disorders, cancer, and so on. Furthermore, black cumin acts as an antidote, mitigating various toxicities and drug-induced side effects. Despite significant advances in pharmacological benefits, this miracle herb and its active components are still far from their clinical application. This review begins with highlighting the research trends in black cumin and revisiting phytochemical profiles. Subsequently, pharmacological attributes and health benefits of black cumin and TQ are critically reviewed. We overview molecular pharmacology to gain insight into the underlying mechanism of health benefits. Issues related to pharmacokinetic herb-drug interactions, drug delivery, and safety are also addressed. Identifying knowledge gaps, our current effort will direct future research to advance potential applications of black cumin and TQ in health and diseases.

Paclitaxel-Based Chemotherapy Targeting Cancer Stem Cells from Mono- to Combination Therapy

Paclitaxel (PTX) is a chemotherapeutical agent commonly used to treat several kinds of cancer. PTX is known as a microtubule-targeting agent with a primary molecular mechanism that disrupts the dynamics of microtubules and induces mitotic arrest and cell death. Simultaneously, other mechanisms have been evaluated in many studies. Since the anticancer activity of PTX was discovered, it has been used to treat many cancer patients and has become one of the most extensively used anticancer drugs. Regrettably, the resistance of cancer to PTX is considered an extensive obstacle in clinical applications and is one of the major causes of death correlated with treatment failure. Therefore, the combination of PTX with other drugs could lead to efficient therapeutic strategies. Here, we summarize the mechanisms of PTX, and the current studies focusing on PTX and review promising combinations.

Thymoquinone Is a Multitarget Single Epidrug That Inhibits the UHRF1 Protein Complex

Silencing of tumor suppressor genes (TSGs) through epigenetic mechanisms, mainly via abnormal promoter DNA methylation, is considered a main mechanism of tumorigenesis. The abnormal DNA methylation profiles are transmitted from the cancer mother cell to the daughter cells through the involvement of a macromolecular complex in which the ubiquitin-like containing plant homeodomain (PHD), and an interesting new gene (RING) finger domains 1 (UHRF1), play the role of conductor. Indeed, UHRF1 interacts with epigenetic writers, such as DNA methyltransferase 1 (DNMT1), histone methyltransferase G9a, erasers like histone deacetylase 1 (HDAC1), and functions as a hub protein. Thus, targeting UHRF1 and/or its partners is a promising strategy for epigenetic cancer therapy. The natural compound thymoquinone (TQ) exhibits anticancer activities by targeting several cellular signaling pathways, including those involving UHRF1. In this review, we highlight TQ as a potential multitarget single epidrug that functions by targeting the UHRF1/DNMT1/HDAC1/G9a complex. We also speculate on the possibility that TQ might specifically target UHRF1, with subsequent regulatory effects on other partners.

Thymoquinone, as a Novel Therapeutic Candidate of Cancers

To date, natural products are widely used as pharmaceutical agents for many human diseases and cancers. One of the most popular natural products that have been studied for anticancer properties is thymoquinone (TQ). As a bioactive compound of Nigella sativa, TQ has shown anticancer activities through the inhibition of cell proliferation, migration, and invasion. The anticancer efficacy of TQ is being investigated in several human cancers such as pancreatic cancer, breast cancer, colon cancer, hepatic cancer, cervical cancer, and leukemia. Even though TQ induces apoptosis by regulating the expression of pro- apoptotic and anti-apoptotic genes in many cancers, the TQ effect mechanism on such cancers is not yet fully understood. Therefore, the present review has highlighted the TQ effect mechanisms on several signaling pathways and expression of tumor suppressor genes (TSG). Data from relevant published experimental articles on TQ from 2015 to June 2020 were selected by using Google Scholar and PubMed search engines. The present study investigated the effectiveness of TQ alone or in combination with other anticancer therapeutic agents, such as tyrosine kinase inhibitors on cancers, as a future anticancer therapy nominee by using nanotechnology.

Nutritional Value and Preventive Role of Nigella sativa L. and Its Main Component Thymoquinone in Cancer: An Evidenced-Based Review of Preclinical and Clinical Studies

In recent times, scientific attention has been paid to different foods and their bioactive components for the ability to inhibit the onset and progress of different types of cancer. Nigella sativa extract, powder and seed oil and its main components, thymoquinone and α-hederin, have showed potent anticancer and chemosensitizing effects against various types of cancer, such as liver, colon, breast, renal, cervical, lung, ovarian, pancreatic, prostate and skin tumors, through the modulation of various molecular signaling pathways. Herein, the purpose of this review was to highlight the anticancer activity of Nigella sativa and it constitutes, focusing on different in vitro, in vivo and clinical studies and projects, in order to underline their antiproliferative, proapoptotic, cytotoxic and antimetastatic effects. Particular attention has been also given to the synergistic effect of Nigella sativa and it constitutes with chemotherapeutic drugs, and to the synthesized analogs of thymoquinone that seem to enhance the chemo-sensitizing potential. This review could be a useful step towards new research on N. sativa and cancer, to include this plant in the dietary treatments in support to conventional therapies, for the best achievement of therapeutic goals.

Nigella sativa and Cancer: A Review Focusing on Breast Cancer, Inhibition of Metastasis and Enhancement of Natural Killer Cell Cytotoxicity

BACKGROUND

In the last decade, there have been accumulating data that the use of medicinal plants could bring additional benefits to the supportive treatment of various diseases. Nigella sativa (N. sativa, family Ranunculaceae) is one of these plants that has attracted considerable interest. The extracts and seeds of N. sativa and its active component thymoquinone have been studied extensively and the results suggest that N. sativa might carry some therapeutic potential for many diseases, including cancer.

METHODS

The selection criteria for references were applied through Pubmed with "N. sativa and cancer", "N. sativa and breast cancer", "N. sativa and metastasis", "N. sativa and cytotoxicity of natural killer cells". The pathway analysis was performed using the PANTHER tool by using five randomly selected N. sativa affected genes (Cyclin D1, P53, p21 protein (Cdc42/Rac) activated kinase 1 (PAK1), B-cell lymphoma 2 (Bcl-2) and vascular endothelial growth factor (VEGF)) in order to elucidate further potentially affected signaling pathways.

RESULTS

The aim of this review was to summarize studies regarding the effects of N. sativa in cancer generally, with a focus on breast cancer, its anti-metastatic effects, and how N. sativa modulates the cytotoxicity of Natural Killer cells that play a crucial role in tumor surveillance.

CONCLUSION

In summary, the data suggest that N. sativa might be used for its anti-cancer and antimetastatic properties and as an immune system activator against cancer.

Chemopreventive and Anticancer Effects of Thymoquinone: Cellular and Molecular Targets

Thymoquinone (TQ) is a bioactive component derived from the seeds of Nigella sativa that are commonly as black cumin. Evidences indicate that the medicinal properties of TQ have been recognized for more than 2000 years. TQ has been shown to possess potent chemopreventive properties that include anti-inflammatory and anti-neoplastic activities. Recent studies have unraveled the multiple mechanisms through which TQ exerts its chemopreventive and anticancer activity in different cancer cells in a contextual manner. The present review aims to provide a brief compendium on the molecular mechanisms through which TQ inhibits signaling pathways underlying cancer genesis, progression, and metastasis.

Medicinal Herbs Used in Traditional Management of Breast Cancer: Mechanisms of Action

Background: Breast cancer is one of the principal causes of death among women and there is a pressing need to develop novel and effective anti-cancer agents. Natural plant products have shown promising results as anti-cancer agents. Their effectiveness is reported as decreased toxicity in usage, along with safety and less recurrent resistances compared with hormonal targeting anti-cancer agents. Methods: A literature search was conducted for all English-language literature published prior to June 2020. The search was conducted using electronic databases, including PubMed, Embase, Web of Science, and Cochrane Library. The search strategy included keywords such as breast cancer, herbs, anti-cancer biologically active components, clinical research, chemotherapy drugs amongst others. Results: The literature provides documented evidence of the chemo-preventative and chemotherapeutic properties of Ginseng, garlic (Allium sativum), Black cohosh (Actaea racemose), Tumeric (Curcuma longa), Camellia sinenis (green tea), Echinacea, Arctium (burdock), Flaxseed (Linum usitatissimum) and Black Cumin (Nigella sativa). Conclusions: The nine herbs displayed anti-cancer properties and their outcomes and mechanisms of action include inhibition of cell proliferation, angiogenesis and apoptosis as well as modulation of key intracellular pathways. However, more clinical trials and cohort human studies should be conducted to provide key evidence of their medical benefits.

Thymoquinone-chemotherapeutic combinations: new regimen to combat cancer and cancer stem cells

Cancer is a worldwide disease that causes millions of cases of mortality and morbidity. The major problem associated with the cancer is its resistance to conventional therapy and a high relapse rate. The use of chemotherapy to treat cancer began at the start of the twentieth century with attempts to control cancer. In time advance, many cancer chemotherapeutic agents have been developed for cancer treatment with different mechanisms of action including the alkylating agents, antimetabolites, antimicrotubule, topoisomerase inhibitors, and cytotoxic antibiotics, all of which have toxic effects toward normal cells in the body. Here, we reviewed chemotherapeutics' anticancer role potentiation and safety by thymoquinone (TQ) alone or in combination with the most common therapeutic drugs. Our search was done through PubMed, Science Direct, Springer Link, Taylor & Francis Online, Wiley Online Library, Nature publication group, SAGE Journals, and Web of Science databases. We recognized that TQ-chemotherapeutics combination increased chemo-modulation to the anticancer effect of different chemotherapeutics and protected the normal body cells from the toxic injuries that are induced by chemotherapeutics based on its antioxidant power. Moreover, the current study investigates the possible combinatory effect of TQ and chemotherapeutics to control cancer stem cells through molecular docking targeting of wingless/integrated (Wnt) and Hedgehog (Hh). We found that TQ modulates the Wnt and Hh pathways, by binding with tankyrase-2 and smoothened 7TM receptor, respectively, more efficiently than most chemotherapeutics drugs, while methotrexate showed high-binding affinity compared with TQ. Therefore, we encourage researchers to investigate the chemo-modulatory potential and protective effects of TQ in combination with chemotherapeutics for either cancer or cancer stem cell treatment.

Thymoquinone Enhances Paclitaxel Anti-Breast Cancer Activity via Inhibiting Tumor-Associated Stem Cells Despite Apparent Mathematical Antagonism

Thymoquinone (TQ) has shown substantial evidence for its anticancer effects. Using human breast cancer cells, we evaluated the chemomodulatory effect of TQ on paclitaxel (PTX). TQ showed weak cytotoxic properties against MCF-7 and T47D breast cancer cells with IC₅₀ values of 64.93 ± 14 µM and 165 ± 2 µM, respectively. Combining TQ with PTX showed apparent antagonism, increasing the IC₅₀ values of PTX from 0.2 ± 0.07 µM to 0.7 ± 0.01 µM and from 0.1 ± 0.01 µM to 0.15 ± 0.02 µM in MCF-7 and T47D cells, respectively. Combination index analysis showed antagonism in both cell lines with CI values of 4.6 and 1.6, respectively. However, resistance fractions to PTX within MCF-7 and T47D cells (42.3 ± 1.4% and 41.9 ± 1.1%, respectively) were completely depleted by combination with TQ. TQ minimally affected the cell cycle, with moderate accumulation of cells in the S-phase. However, a significant increase in Pre-G phase cells was observed due to PTX alone and PTX combination with TQ. To dissect this increase in the Pre-G phase, apoptosis, necrosis, and autophagy were assessed by flowcytometry. TQ significantly increased the percent of apoptotic/necrotic cell death in T47D cells after combination with paclitaxel. On the other hand, TQ significantly induced autophagy in MCF-7 cells. Furthermore, TQ was found to significantly decrease breast cancer-associated stem cell clone (CD44+/CD24-cell) in both MCF-7 and T47D cells. This was mirrored by the downregulation of TWIST-1 gene and overexpression of SNAIL-1 and SNAIL-2 genes. TQ therefore possesses potential chemomodulatory effects to PTX when studied in breast cancer cells via enhancing PTX induced cell death including autophagy. In addition, TQ depletes breast cancer-associated stem cells and sensitizes breast cancer cells to PTX killing effects.

Co-encapsulation of docetaxel and thymoquinone in mPEG-DSPE-vitamin E TPGS-lipid nanocapsules for breast cancer therapy: Formulation optimization and implications on cellular and in vivo toxicity

Rationally designed combination nano-therapy approaches have emerged as a promising strategy for resistant breast cancer treatment. This research reports the combination of Docetaxel (DTX) and Thymoquinone (THQ) co-encapsulated within long circulating sub-100 nm mPEG-DSPE-Vitamin E TPGS-Lipid nanocapsules (DxTq-LNCs). DxTq-LNCs with sufficient drug loading exhibited controlled drug release, enhanced protein binding resistance (confirming its long circulation in physiological environment and suitability for iv application) and retained the antioxidant effects of THQ. DxTq-LNCs were further subjected to cytotoxicity analysis against human breast cancer cells (MCF-7 & MDA-MB-231). The presence of multidrug resistance (MDR) reversal agents; Vitamin E TPGS and THQ, along with the nanoencapsulation, re-sensitized the resistant triple negative breast cancer (TNBC) cells to the anticancer effects of DTX. Greater inhibition of cell migration indicated improved anti-metastatic effects. Drastic changes in cellular morphology indicated by nuclear fragmentation (the hall marks of apoptosis), were observed upon DxTq-LNCs treatment to the breast cancer cells. In vivo toxicity studies indicated no substantial blood biochemical and histological changes with near normal appearance of kidney and liver tissue sections upon DxTq-LNCs treatment in contrast to free drug that showed parenchymal degeneration, areas of interstitial haemorrhage, glomerular atrophy and other histological changes, indicating hepato- and nephro-protective potential of DxTq-LNCs. Furthermore, enhanced antitumor efficacy was observed with DxTq-LNCs treatment to mice bearing ehrlich ascites carcinoma. Thus, nanocapsules presents a simple yet effective approach for successful combination chemotherapy with reduced unwanted toxicity.

Epigenetic role of thymoquinone: impact on cellular mechanism and cancer therapeutics

Thymoquinone is a natural product known for its anticancer activity. Preclinical studies indicated numerous mechanisms of action by which thymoquinone exerts its effects on cancer cells. Recent evidence has indicated that thymoquinone can modulate epigenetic machinery, like modifying histone acetylation and deacetylation, DNA methylation and demethylation, which are among the major epigenetic changes that can contribute to carcinogenesis. Moreover, thymoquinone can alter the genetic expression of various noncoding RNAs, such as miRNA and lncRNA, which are the key parts of cellular epigenetics. This review focuses on cellular epigenetic systems, epigenetic changes responsible for cancer and the counteraction of thymoquinone to target epigenetic challenges, which might be among the mechanisms of the thymoquinone effect in cancer cells.

Co-encapsulation of thymoquinone with docetaxel enhances the encapsulation efficiency into PEGylated liposomes and the chemosensitivity of MCF7 breast cancer cells to docetaxel

Combinatorial therapeutic strategies to eradicate tumors can be superior to a single therapeutic modality. Docetaxel (DT) has been approved for the treatment of local or metastasized breast cancer alone or in combination with other chemotherapeutic agents. Thymoquinone (TQ) originated from the seeds of Nigella Sativa plant has been reported to possess in vitro and in vivo antitumor activity against variety of tumors. In the current study, we have investigated the synergistic anticancer efficacy of a novel combination of DT and TQ on MCF7 breast cancer cell line using MTT cell viability assay. Moreover, this study describes for the first time the co-encapsulation of DT and TQ into PEGylated liposomes. The results showed that the combination of DT and TQ resulted in significant synergistic cytotoxicity compared to DT and TQ alone. Moreover, DT and TQ have been successfully co-encapsulated into PEGylated liposomes with higher encapsulation efficiency compared to DT and TQ alone. In conclusion, DT and TQ combination poses a synergistic effect and may aid in decreasing the required doses of DT. Also, the co-encapsulation of DT and TQ into PEGylated liposomes can provide a promising DT and TQ delivery system into cancer cells.

Nigella sativa L. (Black Cumin): A Promising Natural Remedy for Wide Range of Illnesses

The seed of Nigella sativa (N. sativa) has been used in different civilization around the world for centuries to treat various animal and human ailments. So far, numerous studies demonstrated the seed of Nigella sativa and its main active constituent, thymoquinone, to be medicinally very effective against various illnesses including different chronic illness: neurological and mental illness, cardiovascular disorders, cancer, diabetes, inflammatory conditions, and infertility as well as various infectious diseases due to bacterial, fungal, parasitic, and viral infections. In spite of limited studies conducted so far, the promising efficacy of N. sativa against HIV/AIDS can be explored as an alternative option for the treatment of this pandemic disease after substantiating its full therapeutic efficacy. Moreover, the strong antioxidant property of this valued seed has recently gained increasing attention with regard to its potential role as dietary supplement with minimal side effects. Besides, when combined with different conventional chemotherapeutic agents, it synergizes their effects resulting in reducing the dosage of concomitantly used drugs with optimized efficacy and least and/or no toxicity. A number of pharmaceutical and biological properties have been ascribed to seeds of N. sativa. The present review focuses on the profile of high-value components along with traditional medicinal and biological principles of N. sativa seed and its oil so as to explore functional food and nutraceutical potential of this valued herb.

Preclinical Pharmacokinetics of Triptolide: A Potential Antitumor Drug

Background:

Triptolide, a bioactive component in Tripterygium wilfordii extracts, possess strong antiproliferative activity on all 60-National Cancer Institute (NCI) cancer cell lines. However, the widespread use of triptolide in the clinical practice is greatly limited for its multi-organ toxicity and narrow therapeutic window. All the toxic characteristics of triptolide are associated with the pharmacokinetics especially its distribution and accumulation in the target organ.

Methods:

The literature review was done using PubMed search, SciFinder and Google Scholar databases with specific keywords such as triptolide, pharmacokinetics, drug-drug interaction, transporters, metabolism, modification to collect the related full-length articles and abstracts from 2000 to 2018.

Results:

Oral triptolide is rapidly and highly absorbed. Grapefruit juice affects oral absorption, increasing the area under the concentration-time curve (AUC) by 153 % and the maximum concentration (Cmax) by 141 %. The AUC and the Cmax are not dose proportional. Triptolide distributes into the liver, heart, spleen, lung and kidney. Biotransformation of triptolide in rats includes hydroxylation, sulfate, glucuronide, N-acetylcysteine (NAC) and Glutathione (GSH) conjugation and combinations of these pathways. Less than 4 % of triptolide was recovered from the feces, bile and urine within 24 h. After repeating dosage, triptolide was eliminated quickly without accumulation in vivo. As a substrate of P-glycoprotein (P-gp) and CYP3A4, triptolide could have clinically significant pharmacokinetic interactions with those proteins substrates/inhibitors.

Conclusion:

The findings of this review confirm the importance of pharmacokinetic character for understanding the pharmacology and toxicology of triptolide.

Synergistic Effects of Plant Derivatives and Conventional Chemotherapeutic Agents: An Update on the Cancer Perspective

Synergy is a process in which some substances cooperate to reach a combined effect that is greater than the sum of their separate effects. It can be considered a natural "straight" strategy which has evolved by nature to obtain more efficacy at low cost. In this regard, synergistic effects may be observed in the interaction between herbal products and conventional drugs or biochemical compounds. It is important to identify and exploit these interactions since any improvement brought by such kind of process can be advantageously used to treat human disorders. Even in a complex disease such as cancer, positive synergistic plant-drug interactions should be investigated to achieve the best outcomes, including providing a greater benefit to patients or avoiding adverse side effects. This review analyzes and summarizes the current knowledge on the synergistic effects of plant-drug interactions with a focus on anticancer strategies.

Combating breast cancer using combination therapy with 3 phytochemicals: Piperine, sulforaphane, and thymoquinone

Despite the significant advances in screening methods for early diagnosis, breast cancer remains a global threat and continues to be the leading cancer diagnosed in women, requiring effective therapy. Currently, combination therapy has become the hallmark of breast cancer treatment due to the high incidence of tumor recurrence and disease progression after monotherapeutic treatments, including surgery, radiotherapy, endocrine therapy, and chemotherapy. Over the past decades, there has been considerable interest in studying the anticancer effect of bioactive phytochemicals from medicinal plants combined with these conventional therapies. The rationale for this type of therapy is to use combinations of drugs that work by different mechanisms, thereby decreasing the likelihood that cancer cells will develop resistance, and also reduce the therapeutic dose and toxicity of single treatments. Three agents have received great attention with regard to their anticancer properties: 1) piperine, a dietary phytochemical isolated from black pepper (Piper nigrum L.) and long pepper (Piper longum L.); 2) sulforaphane, an isothiocyanate mainly derived from cruciferous vegetables; and 3) thymoquinone, the active compound from black seed (Nigella sativa L.). This review focused on the combined effect of these 3 compounds on conventional cancer therapy with the objective of observing enhanced efficacy compared with single treatments. This review also highlights the importance of the nanoformulation of such bioactive phytochemicals that could enhance their bioavailability by providing an efficient targeted delivery system with a reduced systemic dose while resulting in a more efficient dosing at the target site.

Mechanistic evaluation of phytochemicals in breast cancer remedy: current understanding and future perspectives

Breast cancer is one of the most commonly diagnosed cancers around the globe and accounts for a large proportion of fatalities in women. Despite the advancement in therapeutic and diagnostic procedures, breast cancer still represents a major challenge. Current anti-breast cancer approaches include surgical removal, radiotherapy, hormonal therapy and the use of various chemotherapeutic drugs. However, drug resistance, associated serious adverse effects, metastasis and recurrence complications still need to be resolved which demand safe and alternative strategies. In this scenario, phytochemicals have recently gained huge attention due to their safety profile and cost-effectiveness. These phytochemicals modulate various genes, gene products and signalling pathways, thereby inhibiting breast cancer cell proliferation, invasion, angiogenesis and metastasis and inducing apoptosis. Moreover, they also target breast cancer stem cells and overcome drug resistance problems in breast carcinomas. Phytochemicals as adjuvants with chemotherapeutic drugs have greatly enhanced their therapeutic efficacy. This review focuses on the recently recognized molecular mechanisms underlying breast cancer chemoprevention with the use of phytochemicals such as curcumin, resveratrol, silibinin, genistein, epigallocatechin gallate, secoisolariciresinol, thymoquinone, kaempferol, quercetin, parthenolide, sulforaphane, ginsenosides, naringenin, isoliquiritigenin, luteolin, benzyl isothiocyanate, α-mangostin, 3,3'-diindolylmethane, pterostilbene, vinca alkaloids and apigenin.

Loading of doxorubicin and thymoquinone with F2 gel nanofibers improves the antitumor activity and ameliorates doxorubicin-associated nephrotoxicity

AIMS

This study aimed to elucidate the benefits of nanoformulation of doxorubicin (DOX) and thymoquinone (TQ) loaded with nanofibers of poly-N-acetyl glucosamine (pGlcNAc), which is known as F2 gel, over their conventional free forms. Moreover, evaluate the role of TQ in improving chemotherapeutic effect and ameliorating nephrotoxicity of DOX.

MAIN METHODS

The drugs were loaded into F2 gel followed by measurement of physicochemical characterization. Next, MCF-7 and HEPG2 cells were treated with the prepared formulations and assessed for apoptosis alongside with cellular proliferation. Furthermore, we experimentally induced Heps liver carcinoma in mice and at the end of the treatment, mice were sacrificed and serum samples were used to assess nephrotoxicity markers; blood urea nitrogen (BUN) and creatinine. Additionally, renal tissue was used for determination of oxidative markers and antioxidant enzymes; whereas, tumor tissue was utilized to measure nuclear factor kappa B (NF-κB) and caspase 3.

KEY FINDINGS

Nanoformulation showed dramatic increase in apoptosis, caspase 3, and antioxidant enzymes; in contrast to, dramatic fall in cell viability, tumor volume, oxidative and nephrotoxicity markers, and NF-κB compared to corresponding free therapies. Combined therapy was superior in conserving the measured parameters compared to other treated groups.

SIGNIFICANCE

F2 gel loaded with DOX and TQ revealed enhanced antitumor activity with minimal toxicity. Moreover, using TQ as an adjuvant with DOX could augment its cytotoxicity and ameliorate nephrotoxicity.

β-elemene enhances anticancer bone neoplasms efficacy of paclitaxel through regulation of GPR124 in bone neoplasms cells

The purpose of the present study was to investigate the anticancer effects of β-elemene and paclitaxel for bone neoplasms. MTT assay, reverse transcription-quantitative polymerase chain reaction, western blotting, flow cytometry and immunostaining were used to analyze the combined effects of β-elemene and paclitaxel both in vitro and in vivo. The results demonstrated that combined treatment of β-elemene and paclitaxel (β-elemene-paclitaxel) significantly inhibited growth and aggressiveness of U-2OS cells compared with either β-elemene or paclitaxel treatment alone. It was demonstrated that β-elemene promoted paclitaxel-induced apoptosis of U-2OS cells. Anti-apoptosis B-cell lymphoma (Bcl)-2 and Bcl-w genes were downregulated and pro-apoptotic Bcl-2-associated agonist of cell death and caspase-3 genes were upregulated in U-2OS cells following treatment with β-elemene-paclitaxel. Treatment of β-elemene-paclitaxel arrested the cell cycle and decreased cyclin-dependent kinase, cyclin-B1, P21 and P27 expression levels and decreased resistant genes alterations of ATP binding cassette subfamily B member 1, LDL receptor related protein and TS in U-2OS cells. Results demonstrated that β-elemene-paclitaxel decreased G-protein coupled receptor 124 (GPR124), vascular endothelial growth factor receptor, matrix metallopeptidase (MMP)-3, MMP-9 expression levels and increased endostatin, TIMP metallopeptidase inhibitor (TIMP)-1, TIMP-2 expression in U-2OS cells. In vivo assay demonstrated that β-elemene-paclitaxel treatment inhibited tumor growth of BALB/c-nu/nu nude mice and prolonged survival rate of tumor-bearing mice. Immunostaining demonstrated that β-elemene-paclitaxel treatment increased apoptotic bodies, GPR124 and increased endostatin, TIMP-1 and TIMP-2 expression in tumor tissues. In conclusion, these results suggest that the combined treatment of β-elemene-paclitaxel is more effective at inhibiting bone neoplasm growth than β-elemene or paclitaxel single treatment GPR124.

Thymoquinone: A novel strategy to combat cancer: A review

The higher consumption of fruit, herbs, spices, and vegetables is well known and practical strategy to cure human cancers owing to their presence of bioactive compounds. Among these, Nigella sativa is a promising source of bioactive compounds including thymoquinone, monoterpenes, p-cymene and α-piene etc. Thymoquinone has been found effective to inhibit the different cancer stages such as proliferation, migration and invasion. It also acts as anticancer agent against different human cancers such as breast, pancreatic, prostate, blood, oral, bone, head and neck, cervical, liver and lung. It significantly mediated miR-34a up-regulation, enhanced the levels of miR-34a through p53, and down controlled Rac1 expression. Thymoquinone induces apoptosis, regulates the levels of pro- and anti- apoptotic genes. It also has been known to lower the phosphorylation of NF-κB and IKKα/β and reduces the metastasis as well as also lowered the ERK1/2 and PI3K activities. Thymoquinone inhibits the metastasis through activation of JNK and p38. The present review article highlights the anticancer perspectives of thymoquinone in human by various pathways and use of this compound as diet based therapy has proven new pharmacological agent against several types of cancers.

Paclitaxel inhibits breast cancer metastasis via suppression of Aurora kinase-mediated cofilin-1 activity

The main problem in breast cancer treatment is the recurrence of tumor growth and metastases. Previous studies have suggested that Paclitaxel is widely used to treat various cancers. The present study analyzed the potential signaling pathway of Paclitaxel-inhibited breast cancer metastasis. It was demonstrated that Paclitaxel treatment significantly inhibited growth of breast cancer cell lines including MCF-7 and SKBR3 cells. Results demonstrated that Paclitaxel significantly inhibited breast cancer cell migration and invasion. Results additionally demonstrated that Paclitaxel treatment suppressed Aurora kinase and cofilin-1 activity in breast cancer cells. The potential mechanism indicated that activation of Aurora kinase activity stimulated cofilin-1 activity, which canceled Paclitaxel-inhibited growth and aggressiveness of breast cancer cells. An in vivo assay revealed that Paclitaxel treatment significantly inhibited breast cancer growth. Immunohistochemistry demonstrated that Paclitaxel treatment increased apoptosis of tumor cells in tumor tissue. Notably, Aurora kinase and cofilin-1 activity were downregulated by Paclitaxel in tumor tissues. In conclusion, these results indicated that Paclitaxel inhibited breast cancer cell growth and metastasis via suppression of Aurora kinase-mediated cofilin-1 activity, suggesting Paclitaxel may be an efficient anticancer agent for the treatment of this disease.

Therapeutic Potential of Thymoquinone in Glioblastoma Treatment: Targeting Major Gliomagenesis Signaling Pathways

Glioblastoma multiforme (GBM) is one of the most devastating brain tumors with median survival of one year and presents unique challenges to therapy because of its aggressive behavior. Current treatment strategy involves surgery, radiotherapy, immunotherapy, and adjuvant chemotherapy even though optimal management requires a multidisciplinary approach and knowledge of potential complications from both the disease and its treatment. Thymoquinone (TQ), the main bioactive component of Nigella sativa L., has exhibited anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteract carcinogenesis, malignant growth, invasion, migration, and angiogenesis. TQ can specifically sensitize tumor cells towards conventional cancer treatments and minimize therapy-associated toxic effects in normal cells. Its potential to enter brain via nasal pathway due to volatile nature of TQ adds another advantage in overcoming blood-brain barrier. In this review, we summarized the potential role of TQ in different signaling pathways in GBM that have undergone treatment with standard therapeutic modalities or with TQ. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical level to delineate its implied utility as novel therapeutics to combat the challenges for the treatment of GBM.

Anti-cancer properties and mechanisms of action of thymoquinone, the major active ingredient of Nigella sativa

Over the past two decades, studies have documented the wide-range anti-cancer effects of Nigella sativa, known as black seed or black cumin. Thymoquinone (TQ), its major active ingredient, has also been extensively studied and reported to possess potent anti-cancer properties. Herein, we provide a comprehensive review of the findings related to the anti-cancer activity of TQ. The review focuses on analyzing experimental studies performed using different in vitro and in vivo models to identify the anti-proliferative, pro-apoptotic, anti-oxidant, cytotoxic, anti-metastatic, and NK-dependent cytotoxic effects exerted by TQ. In addition, we pinpoint the molecular mechanisms underlying these effects and the signal transduction pathways implicated by TQ. Our analysis show that p53, NF-κB, PPARγ, STAT3, MAPK, and PI3K/AKT signaling pathways are among the most significant pathways through which TQ mediates its anti-cancer activity. Experimental findings and recent advances in the field highlight TQ as an effective therapeutic agent for the suppression of tumor development, growth and metastasis for a wide range of tumors.

Anticancer Effect of a Novel Octahydropyrazino[2,1-a:5,4-a']diisoquinoline Derivative and Its Synergistic Action with Nigella sativa in Human Gastric Cancer Cells

Many studies have shown that naturally occurring compounds may support prevention and treatment of various diseases, including cancer. Pharmacological investigations revealed a wide spectrum of Nigella sativa biological activities. Combining natural compounds together with synthetic drugs may increase the anticancer activity and limit severe side effects of such a treatment and may be an alternative to monotherapy. The aim of the study was to evaluate the cytotoxic and proapoptotic effects of a novel octahydropyrazino[2,1-a:5,4-a']diisoquinoline derivative and its effect in combination with Nigella sativa seed oil or extract in human gastric cancer cells (AGS). Etoposide was used as a reference. Our studies proved that combination strategy based on novel octahydropyrazino[2,1-a:5,4-a']diisoquinoline derivative (OM-90) with Nigella sativa seed oil or extract represents the strongest efficacy in AGS cancer cells as compared to monotherapy and combined treatment with Nigella sativa seed oil or extract together with etoposide. Such a combination also leads to the activation of mitochondrial pathway, which plays a significant role in molecular mechanism of induction of apoptosis by these compounds.

Modulation of diverse oncogenic transcription factors by thymoquinone, an essential oil compound isolated from the seeds of Nigella sativa Linn

Thymoquinone (TQ), isolated almost fifty years ago, is the main bioactive constituent of black seed essential oil extracted from the seed of Nigella sativa. TQ has been shown to have promising effects against a variety of inflammatory diseases and cancer. Cancer development is a multistep process where normal cells acquire qualities that enable the cells to proliferate continuously and migrate to distant sites in the human body. Drugs that interfere with this process are considered potential anti-cancer therapeutics, which may ultimately result in their clinical usage. TQ is once such compound which has been reported to modulate several major signaling pathways and key oncogenic molecules that play a prominent role in cancer initiation, progression, invasion, metastasis, and angiogenesis. Various studies have reported that TQ can enhance the anti-cancer potential when co-administered with several chemotherapeutic agents while reducing their toxic side effects. In addition, TQ has been shown to inhibit the growth of breast, prostate, pancreatic, colon, lung, and hematological malignancies in different mouse models of cancer. This review focuses on TQ's chemical and pharmacological properties, its diverse molecular targets and also provides clear evidence on its promising potential under preclinical and clinical settings.

Dietary Natural Products for Prevention and Treatment of Breast Cancer

Breast cancer is the most common cancer among females worldwide. Several epidemiological studies suggested the inverse correlation between the intake of vegetables and fruits and the incidence of breast cancer. Substantial experimental studies indicated that many dietary natural products could affect the development and progression of breast cancer, such as soy, pomegranate, mangosteen, citrus fruits, apple, grape, mango, cruciferous vegetables, ginger, garlic, black cumin, edible macro-fungi, and cereals. Their anti-breast cancer effects involve various mechanisms of action, such as downregulating ER-α expression and activity, inhibiting proliferation, migration, metastasis and angiogenesis of breast tumor cells, inducing apoptosis and cell cycle arrest, and sensitizing breast tumor cells to radiotherapy and chemotherapy. This review summarizes the potential role of dietary natural products and their major bioactive components in prevention and treatment of breast cancer, and special attention was paid to the mechanisms of action.

Thymoquinone as a Potential Adjuvant Therapy for Cancer Treatment: Evidence from Preclinical Studies

Thymoquinone (TQ), the main bioactive component of Nigella sativa, has been found to exhibit anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteracts carcinogenesis, malignant growth, invasion, migration, and angiogenesis. Moreover, TQ can specifically sensitize tumor cells toward conventional cancer treatments (e.g., radiotherapy, chemotherapy, and immunotherapy) and simultaneously minimize therapy-associated toxic effects in normal cells. In this review, we summarized the adjuvant potential of TQ as observed in various in vitro and in vivo animal models and discussed the pharmacological properties of TQ to rationalize its supplementary role in potentiating the efficacy of standard therapeutic modalities namely surgery, radiotherapy, chemotherapy, and immunotherapy. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical levels to delineate its implied utility as a novel complementary adjuvant therapy for cancer treatment.

Thymoquinone, as an anticancer molecule: from basic research to clinical investigation

Thymoquinone is an anticancer phytochemical commonly found in black cumin. In this review, we discuss the potential of thymoquinone as anticancer molecule, its mechanism of action and future usage in clinical applications. Thymoquinone exhibits anticancer activity via numerous mechanisms of action, specifically by showing selective antioxidant and oxidant activity, interfering with DNA structure, affecting carcinogenic signaling molecules/pathways and immunomodulation. In vitro activity of thymoquinone has been further implicated in animal models of cancer; however, no clinical application has been proven yet. This is the optimum time to focus on clinical trials for developing thymoquinone as a future drug in cancer therapeutics.