Molecular targeting of Akt by thymoquinone promotes G(1) arrest through translation inhibition of cyclin D1 and induces apoptosis in breast cancer cells

Harnessing natural inhibitors of protein synthesis for cancer therapy: A comprehensive review

Cancer treatment remains a formidable challenge in modern medicine, necessitating a nuanced understanding of its molecular underpinnings and the identification of novel therapeutic modalities. Among the intricate web of cellular pathways implicated in oncogenesis, protein synthesis has emerged as a fundamental process warranting meticulous investigation. This review elucidates the multifaceted role of protein synthesis pathways in tumor initiation and progression, highlighting the potential of targeting key nodes within these pathways as viable therapeutic strategies. Natural products have long served as a source of bioactive compounds with therapeutic potential owing to their structural diversity and evolutionary honing. Within this framework, we provide a thorough examination of natural inhibitors of protein synthesis as promising candidates for cancer therapy, drawing upon recent advancements and mechanistic insights. By synthesizing current evidence and elucidating key challenges and opportunities, this review aims to galvanize further research into the development of natural product-based anticancer therapeutics, thereby advancing the clinical armamentarium against malignancies.

Novel strategy for activating gene expression through triplex DNA formation targeting epigenetically suppressed genes

Triplex DNA formation is a useful genomic targeting tool that is expected to have a wide range of applications, including the antigene method; however, there are fundamental limitations in its forming sequence. We recently extended the triplex DNA-forming sequence to methylated DNA sequences containing 5mCG base pairs by developing guanidino-dN, which is capable of recognizing a 5mCG base pair with high affinity. We herein investigated the effect of triplex DNA formation using TFOs with guanidino-dN on methylated DNA sequences at the promoter of the RASSF1A gene, whose expression is epigenetically suppressed by DNA methylation in MCF-7 cells, on gene expression. Interestingly, triplex DNA formation increased the expression of the RASSF1A gene at the transcript and protein levels. Furthermore, RASSF1A-activated MCF-7 cells exhibited cell growth suppressing activity. Changes in the expression of various genes associated with the promotion of apoptosis and breast cancer survival accompanied the activation of RASSF1A in cells exhibited antiproliferative activity. These results suggest the potential of increases in gene expression through triplex DNA formation as a new genomic targeting tool.

The anti-neoplastic impact of thymoquinone from Nigella sativa on small cell lung cancer: In vitro and in vivo investigations

PURPOSE

Malignant and aggressive, small cell lung cancer (SCLC) constitutes about 15% of all diagnosed lung cancer cases. With primary therapeutic options such as chemotherapy accompanied by debilitating side effects, interest has been soaring in the therapeutic competencies of herbs. The pharmacological driving force behind the beneficial properties of Nigella sativa is the quinone, thymoquinone (TQ). The anti-cancer effects of TQ on different cancers have been extensively studied. Nonetheless, only one paper in the entire National Center for Biotechnology Information (NCBI) database describes its effects on SCLC. A more detailed investigation is required.

METHODS

The current study examined the impact of TQ in vitro on five SCLC cell lines and in vivo in a nude mouse xenograft model. The following in vitro effects of TQ on SCLC were evaluated: (a) cell viability; (b) apoptosis; (c) cell cycle arrest; (d) intracellular reactive oxygen species (ROS) levels, and (e) protein expression in concomitant signaling pathways. For the in vivo effects of TQ on SCLC, (a) tumor volume was measured, and (b) selected protein expression in selected concomitant signaling pathways was determined by Western blotting.

RESULT

In general, TQ reduced cell viability, induced apoptosis and cell cycle arrest, depleted ROS, and altered protein expression in associated signaling pathways. Furthermore, TQ exhibited a tumor-suppressive effect in an H446 SCLC xenograft model.

CONCLUSION

The cytotoxic impact of TQ arising from anti-cancer mechanisms was elucidated. The positive results obtained in this study warrant further investigation.

Antimicrobial, Antioxidant and Cytotoxic Effects of Essential Oil, Fatty Acids and Bioactive Compounds of Beta vulgaris var. crassa (Fodder Beet)

Beta vulgaris var. crassa is undoubtedly a very important plant that is not used enough in the world. In this study, it was aimed to determine the cytotoxic activities of the components (essential oils, fatty acids, total phenol and flavonoid) found in the leaf parts of Beta vulgaris var. crassa against PC-3, MCF-7 and HeLa cancer cell lines. In addition, the effectiveness of these ingredients against bacteria and fungi that can cause serious health problems in humans was tested. In experiments, three tumor cell lines were exposed to various plant extract concentrations (31.25, 62.5, 125, 250, 500 and 1000 µg/mL) for 72 h. It was found that plant extracts showed high (SI: 2.14 > 2) cytotoxicity to PC-3 cells, moderate (SI: 1.62 < 2) to HeLa cells, and low (SI: 0.93 < 2) cytotoxicity to MCF-7 cells. Also, different plant extract concentrations were found to cause an inhibition rate of 16.3-22.3% in Staphylococcus aureus, 16.8-23.5% in Streptococcus pyogenes and 12-16.2% in Cutibacterium acnes. Similarly, inhibition rates were determined between 9.5-20.7% for Candida albicans, 3.5-7.7% for Candida auris, and 5.5-15.1% for Candida glabrata. The results showed that the plant extract exhibited a concentration-dependent cytotoxic and antimicrobial effect against both cancer cell lines and microbial pathogens.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-024-01269-8.

Monoterpenoids: An upcoming class of therapeutic agents for modulating cancer metastasis

Monoterpenoids, a sub-class of terpenoids, are secondary metabolites frequently extracted from the essential oils of aromatic plants. Their antitumor properties including antiproliferative, apoptotic, antiangiogenic, and antimetastatic effects along with other biological activities have been the subject of extensive study due to their diverse characteristics. In recent years, numerous investigations have been conducted to understand its potential anticancer impacts, specifically focusing on antiproliferative and apoptotic mechanisms. Metastasis, a malignancy hallmark, can exert either protective or destructive influences on tumor cells. Despite this, the potential antimetastatic and antiangiogenic attributes of monoterpenoids need further exploration. This review focuses on specific monoterpenoids, examining their effects on metastasis and relevant signaling pathways. The monoterpenoids exhibit a high level of complexity as natural products that regulate metastatic proteins through various signaling pathways, including phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin, mitogen-activated protein kinase/extracellular signal-regulated kinase/jun N-terminal kinase, nuclear factor kappa B, vascular endothelial growth factor, and epithelial mesenchymal transition process. Additionally, this review delves into the biosynthesis and classification of monoterpenoids, their potential antitumor impacts on cell lines, the plant sources of monoterpenoids, and the current status of limited clinical trials investigating their efficacy against cancer. Moreover, monoterpenoids depict promising potential in preventing cancer metastasis, however, inadequate clinical trials limit their drug usage. State-of-the-art techniques and technologies are being employed to overcome the challenges of utilizing monoterpenoids as an anticancer agent.

Thymoquinone: A Promising Therapeutic Agent for the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and is responsible for approximately one million deaths each year. The current standard of care is surgical resection of the lesion and chemotherapy with 5-fluorouracil (5-FU). However, of concern is the increasing incidence in an increasingly younger patient population and the ability of CRC cells to develop resistance to 5-FU. In this review, we discuss the effects of thymoquinone (TQ), one of the main bioactive components of Nigella sativa seeds, on CRC, with a particular focus on the use of TQ in combination therapy with other chemotherapeutic agents. TQ exhibits anti-CRC activity by inducing a proapoptotic effect and inhibiting proliferation, primarily through its effect on the regulation of signaling pathways crucial for tumor progression and oxidative stress. TQ can be used synergistically with chemotherapeutic agents to enhance their anticancer effects and to influence the expression of signaling pathways and other genes important in cancer development. These data appear to be most relevant for co-treatment with 5-FU. We believe that TQ is a suitable candidate for consideration in the chemoprevention and adjuvant therapy for CRC, but further studies, including clinical trials, are needed to confirm its safety and efficacy in the treatment of cancer.

Potential anticancer properties and mechanisms of thymoquinone in colorectal cancer

Colorectal neoplasms are one of the deadliest diseases among all cancers worldwide. Thymoquinone (TQ) is a natural compound of Nigella sativa that has been used in traditional medicine against a variety of acute/chronic diseases such as asthma, bronchitis, rheumatism, headache, back pain, anorexia, amenorrhea, paralysis, inflammation, mental disability, eczema, obesity, infections, depression, dysentery, hypertension, gastrointestinal, cardiovascular, hepatic, and renal disorders. This review aims to present a detailed report on the studies conducted on the anti-cancer properties of TQ against colorectal cancer, both in vitro and in vivo. TQ stands as a promising natural therapeutic agent that can enhance the efficacy of existing cancer treatments while minimizing the associated adverse effects. The combination of TQ with other anti-neoplastic agents promoted the efficacy of existing cancer treatments. Further research is needed to acquire a more comprehensive understanding of its exact molecular targets and pathways and maximize its clinical usefulness. These investigations may potentially aid in the development of novel techniques to combat drug resistance and surmount the obstacles presented by chemotherapy and radiotherapy.

Thymoquinone, a Novel Multi-Strike Inhibitor of Pro-Tumorigenic Breast Cancer (BC) Markers: CALR, NLRP3 Pathway and sPD-L1 in PBMCs of HR+ and TNBC Patients

Breast cancer (BC) is not only a mass of malignant cells but also a systemic inflammatory disease. BC pro-tumorigenic inflammation has been shown to promote immune evasion and provoke BC progression. The NOD-like receptor (NLR) family pyrin domain-containing protein 3 (NLRP3) inflammasome is activated when pattern recognition receptors (PRRs) sense danger signals such as calreticulin (CALR) from damaged/dying cells, leading to the secretion of interleukin-1β (IL-1β). CALR is a novel BC biological marker, and its high levels are associated with advanced tumors. NLRP3 expression is strongly correlated with an elevated proliferative index Ki67, BC progression, metastasis, and recurrence in patients with hormone receptor-positive (HR+) and triple-negative BC (TNBC). Tumor-associated macrophages (TAMs) secrete high levels of IL-1β promoting endocrine resistance in HR+ BC. Recently, an immunosuppressive soluble form of programmed death ligand 1 (sPD-L1) has been identified as a novel prognostic biomarker in triple-negative breast cancer (TNBC) patients. Interestingly, IL-1β induces sPD-L1 release. BC Patients with elevated IL-1β and sPD-L1 levels show significantly short progression-free survival. For the first time, this study aims to investigate the inhibitory impact of thymoquinone (TQ) on CALR, the NLRP3 pathway and sPD-L1 in HR+ and TNBC. Blood samples were collected from 45 patients with BC. The effect of differing TQ concentrations for different durations on the expression of CALR, NLRP3 complex components and IL-1β as well as the protein levels of sPD-L1 and IL-1β were investigated in the peripheral blood mononuclear cells (PBMCs) and TAMs of TNBC and HR+ BC patients, respectively. The findings showed that TQ significantly downregulated the expression of CALR, NLRP3 components and IL-1β together with the protein levels of secreted IL-1β and sPD-L1. The current findings demonstrated novel immunomodulatory effects of TQ, highlighting its potential role not only as an excellent adjuvant but also as a possible immunotherapeutic agent in HR+ and TNBC patients.

Coencapsulation of Gemcitabine and Thymoquinone in Citrem-Phosphatidylcholine Hexosome Nanocarriers Improves In Vitro Cellular Uptake in Breast Cancer Cells

Lyotropic liquid crystalline nanoassemblies (LLCNs) are internally self-assembled (ISA)-somes formed by amphiphilic molecules in a mixture comprising a lipid, stabilizer, and/or surfactant and aqueous media/dispersant. LLCNs are unique nanoassemblies with versatile applications in a wide range of biomedical functions. However, they comprise a nanosystem that is yet to be fully explored for targeted systemic treatment of breast cancer. In this study, LLCNs proposed for gemcitabine and thymoquinone (Gem-TQ) co-delivery were prepared from soy phosphatidylcholine (SPC), phytantriol (PHYT), or glycerol monostearate (MYVR) in optimized ratios containing a component of citric and fatty acid ester-based emulsifier (Grinsted citrem) or a triblock copolymer, Pluronic F127 (F127). Hydrodynamic particle sizes determined were below 400 nm (ranged between 96 and 365 nm), and the series of nanoformulations displayed negative surface charge. Nonlamellar phases identified by small-angle X-ray scattering (SAXS) profiles comprise the hexagonal, cubic, and micellar phases. In addition, high entrapment efficiency that accounted for 98.3 ± 0.1% of Gem and 99.5 ± 0.1% of TQ encapsulated was demonstrated by the coloaded nanocarrier system, SPC/citrem/Gem-TQ hexosomes. Low cytotoxicity of SPC-citrem hexosomes was demonstrated in MCF10A cells consistent with hemo- and biocompatibility observed in zebrafish (Danio rerio) embryos for up to 96 h postfertilization (hpf). SPC/citrem/Gem-TQ hexosomes demonstrated IC50 of 24.7 ± 4.2 μM in MCF7 breast cancer cells following a 24 h treatment period with the moderately synergistic interaction between Gem and TQ retained (CI = 0.84). Taken together, biocompatible SPC/citrem/Gem-TQ hexosomes can be further developed as a multifunctional therapeutic nanodelivery approach, plausible for targeting breast cancer cells by incorporation of targeting ligands.

Serum/glucose starvation strikingly reduces heterogeneous nuclear ribonucleoprotein A1 protein and its target, cyclin D1

Our investigation to explore cellular alterations related to undernutrition in cancer cells revealed that the protein level of heterogenous nuclear ribonucleoprotein A1 (hnRNP A1) is drastically decreased by serum/glucose starvation. Its loss was reversible, serum/glucose starvation-specific and universal throughout cell types and species. The hnRNP A1 mRNA level and hnRNP A1 mRNA/protein stability were not altered under this condition. CCND1 mRNA, which we newly identified as the binding target of hnRNP A1, was decreased by serum/glucose starvation. Under similar conditions, CCND1 protein was reduced in vitro and in vivo, whereas hnRNP A1 mRNA level and CCND1 mRNA level revealed no correlation in most clinical samples. Functional analyses revealed that CCND1 mRNA stability is certainly dependent on hnRNP A1 protein level and that RNA recognition motif-1 (RRM1) in hnRNP A1 plays a central role in maintaining CCND1 mRNA stability and subsequent protein expression. The injection of RRM1-deleted hnRNP A1-expressing cancer cells in the mouse xenograft model did not form any tumours, and that of hnRNP A1-expressing cancer cells retained CCND1 expression at the lesion adjacent to necrosis with a slight increase in tumour volume. Furthermore, RRM1 deletion caused growth suppression with the induction of apoptosis and autophagy, whereas CCND1 restoration completely recovered it. Our results indicate that serum/glucose starvation triggers entire hnRNP A1 protein loss, and its loss may play a role in CCND1 mRNA destabilization and CCND1-mediated cellular event inhibition, i.e. growth promotion, apoptosis induction and autophagosome formation.

Exploring the Potent Anticancer Activity of Essential Oils and Their Bioactive Compounds: Mechanisms and Prospects for Future Cancer Therapy

Cancer is one of the leading causes of death worldwide, affecting millions of people each year. Fortunately, the last decades have been marked by considerable advances in the field of cancer therapy. Researchers have discovered many natural substances, some of which are isolated from plants that have promising anti-tumor activity. Among these, essential oils (EOs) and their constituents have been widely studied and shown potent anticancer activities, both in vitro and in vivo. However, despite the promising results, the precise mechanisms of action of EOs and their bioactive compounds are still poorly understood. Further research is needed to better understand these mechanisms, as well as their effectiveness and safety in use. Furthermore, the use of EOs as anticancer drugs is complex, as it requires absolute pharmacodynamic specificity and selectivity, as well as an appropriate formulation for effective administration. In this study, we present a synthesis of recent work on the mechanisms of anticancer action of EOs and their bioactive compounds, examining the results of various in vitro and in vivo studies. We also review future research prospects in this exciting field, as well as potential implications for the development of new cancer drugs.

Antioxidant, antiproliferative, and apoptotic activity of thymoquinone against benzo(a)pyrene-induced experimental lung cancer

Several studies have suggested that increased consumption of phytochemicals is a comparatively easy and practical strategy to significantly decrease the incidence of cancer. In the present study, we have reported the protective effect of a natural compound, thymoquinone (TQ) against benzo(a)pyrene (B(a)P)-induced lung carcinogenesis in Swiss albino mice. B(a)P (50 mg/kg body weight) was administered twice weekly for four successive weeks and left until 20 weeks to induce lung cancer in mice. TQ (20 mg/kg body weight) was given orally as a pretreatment and posttreatment drug to determine its chemopreventive and therapeutic effects. B(a)P-induced lung cancer-bearing animals displayed cachexia-like symptoms along with an abnormal increase in lung weight and the activities of marker enzymes adenosine deaminase, aryl hydrocarbon hydroxylase, gamma-glutamyl transpeptidase, 5'-nucleotidase and lactate dehydrogenase; tumor marker carcinoembryonic antigen levels. Furthermore, B(a)P-induced animals showed elevated levels of lipid peroxides with subsequent depletion in the antioxidant status and histological aberrations. These anomalies were accompanied by increased expressions of proliferating cell nuclear antigen and cyclin D1 in the lung sections derived from B(a)P-induced animals. On TQ treatment, all the above alterations were returned to near normalcy. Furthermore, TQ administration in B(a)P-induced animals downregulated phosphatidylinositol 3-kinase/protein kinase B signaling pathway and induced apoptosis as evidenced by a decrease in cytochrome c, proapoptotic Bax, caspase-3, and p53 with a parallel increase in antiapoptotic Bcl-2. Our present results demonstrate the potential effectiveness of TQ as an antioxidant, antiproliferative, and apoptotic agent against B(a)P-induced experimental lung tumorigenesis.

Anticancer Effects of Thymoquinone through the Antioxidant Activity, Upregulation of Nrf2, and Downregulation of PD-L1 in Triple-Negative Breast Cancer Cells

The variety of therapies available for treating and preventing triple-negative breast cancer (TNBC) is constrained by the absence of progesterone receptors, estrogen receptors, and human epidermal growth factor receptor 2. Nrf2 (nuclear factor-erythroid 2-related factor), and PD-L1 (program cell death ligand 1), a downstream signaling target, have a strong correlation to oxidative stress and inflammation, major factors in the development and progression of TNBC. In this study, the genetically distinct MDA-MB-231 and MDA-MB-468 TNBC cells were treated with the natural component thymoquinone (TQ). The results show that TQ exhibits considerable antioxidant activity and decreases the generation of H₂O₂, at the same time increasing catalase (CAT) activity, superoxide dismutase (SOD) enzyme, and glutathione (GSH). Additionally, the results show that TQ treatment increased the levels of the different genes involved in the oxidative stress-antioxidant defense system PRNP, NQO1, and GCLM in both cell lines with significant large-fold change in MDA-MB-468 cells (+157.65 vs. +1.7, +48.87 vs. +2.63 and +4.78 vs. +2.17), respectively. Nrf2 mRNA and protein expression were also significantly increased in TQ-treated TNBC cells despite being higher in MDA-MB-468 cells (6.67 vs. 4.06). Meanwhile, TQ administration increased mRNA levels while decreasing PD-L1 protein expression in both cell lines. In conclusion, TQ modifies the expression of multiple oxidative-stress-antioxidant system genes, ROS, antioxidant enzymes, Nrf2, and PD-L1 protein, pointing to the therapeutic potential and chemopreventive utilization of TQ in TNBC.

The efficacy of applying some plants and herbs in cancer therapy for humans and animals – a comperhensive review

Cancer is a challenging ailment and represents the main reason for death worldwide for humans and animals. Although great developments have hindered cancer progression, several adverse effects are associated with modern chemotherapy. Natural remedies, such as the usage of medicinal plant or their products in cancer treatment, may decrease prejudicial side properties. Recently, the modern research scheme and innovative screening practices for herbs or plants have enabled phytochemical discovery for the prevention and treatment of cancer. This criticism highlights herbs such as acacia, basil, black seeds, cedar, castus, ficus, garlic, ginger, indigo, onion, pomegranate, quince, and thyme, promising anticancer effects. The present review also revealed the mode of action of each herb as anticancer effects at level in vitro and in vivo studies. The item also totalizes the vital mechanisms and signaling molecules involved in preventing cancer diseases. This will fill the investigate gap in the exploration of using natural molecules and encourage researchers in clinical trials of anticancer agents from herbs for humans and animals.

Anticancer properties of medicinal plants and their bioactive compounds against breast cancer: a review on recent investigations

Breast cancer (BC) is one of the most common and recurring diseases and the second leading cause of death in women. Despite prevention, diagnostics, and therapeutic options such as radiation therapy and chemotherapy, the number of occurrences increases every year. Therefore, novel therapeutic drugs targeting specifically different checkpoints should be developed against breast cancer. Among drugs that can be developed to treat breast cancer, natural products, such as plant-derived compounds, showed significant anti-breast cancer properties. These substances belong to different chemical classes such as flavonoids, terpenoids, phenolic acids, and alkaloids. They exert their in vitro and in vivo cytotoxic activities against breast cancer cell lines via different mechanisms, including the inhibition of extrinsic and intrinsic apoptotic pathways, the arrest of the cell cycle, and the activation of autophagy. Moreover, they also exhibit anti-angiogenesis and antimetastatic action. Moreover, chemoprevention effects of these bioactive compounds were signaled only for certain drugs. Therefore, the aim of this review is to highlight the pharmacological actions of medicinal plants and their bioactive compounds on breast cancer. Moreover, the role of these substances in breast cancer chemoprevention was also discussed.

Natural Small Molecules in Breast Cancer Treatment: Understandings from a Therapeutic Viewpoint

Breast cancer (BrCa) is the most common malignancy in women and the second most significant cause of death from cancer. BrCa is one of the most challenging malignancies to treat, and it accounts for a large percentage of cancer-related deaths. The number of cases requiring more effective BrCa therapy has increased dramatically. Scientists are looking for more productive agents, such as organic combinations, for BrCa prevention and treatment because most chemotherapeutic agents are linked to cancer metastasis, the resistance of the drugs, and side effects. Natural compounds produced by living organisms promote apoptosis and inhibit metastasis, slowing the spread of cancer. As a result, these compounds may delay the spread of BrCa, enhancing survival rates and reducing the number of deaths caused by BrCa. Several natural compounds inhibit BrCa production while lowering cancer cell proliferation and triggering cell death. Natural compounds, in addition to therapeutic approaches, are efficient and potential agents for treating BrCa. This review highlights the natural compounds demonstrated in various studies to have anticancer properties in BrCa cells. Future research into biological anti-BrCa agents may pave the way for a new era in BrCa treatment, with natural anti-BrCa drugs playing a key role in improving BrCa patient survival rates.

Natural Products for Cancer Therapy: A Review of Their Mechanism of Actions and Toxicity in the Past Decade

The ethnopharmacological information gathered over many centuries and the presence of diverse metabolites have made the medicinal plants as the prime source of drugs. Despite the positive attributes of natural products, there are many questions pertaining to their mechanism of actions and molecular targets that impede their development as therapeutic agents. One of the major challenges in cancer research is the toxicity exerted by investigational agents towards the host. An understanding of their molecular targets, underlying mechanisms can reveal their anticancer efficacy, help in optimal therapeutic dose selection, to mitigate their side effects and toxicity towards the host. The purpose of this review is to collate details on natural products that are recently been investigated extensively in the past decade for their anticancer potential. Besides, critical analysis of their molecular targets and underlying mechanisms on multiple cancer cell lines, an in-depth probe of their toxicological screening on rodent models is outlined as well to observe the prevalence of their toxicity towards host. This review can provide valuable insights for researchers in developing methods, strategies during preclinical and clinical evaluation of anticancer candidates.

Genesis and Mechanism of Some Cancer Types and an Overview on the Role of Diet and Nutrition in Cancer Prevention

Cancer is a major disease with a high mortality rate worldwide. In many countries, cancer is considered to be the second most common cause of death after cardiovascular disease. The clinical management of cancer continues to be a challenge as conventional treatments, such as chemotherapy and radiation therapy, have limitations due to their toxicity profiles. Unhealthy lifestyle and poor dietary habits are the key risk factors for cancer; having a healthy diet and lifestyle may minimize the risk. Epidemiological studies have shown that a high fruit and vegetable intake in our regular diet can effectively reduce the risk of developing certain types of cancers due to the high contents of antioxidants and phytochemicals. In vitro and in vivo studies have shown that phytochemicals exert significant anticancer effects due to their free radical scavenging capacity potential. There has been extensive research on the protective effects of phytochemicals in different types of cancers. This review attempts to give an overview of the etiology of different types of cancers and assesses the role of phytonutrients in the prevention of cancers, which makes the present review distinct from the others available.

Potential anticancer properties and mechanisms of thymoquinone in osteosarcoma and bone metastasis

Despite great advances, therapeutic approaches of osteosarcoma, the most prevalent class of preliminary pediatric bone tumors, as well as bone-related malignancies, continue to demonstrate insufficient adequacy. In recent years, a growing trend toward applying natural bioactive compounds, particularly phytochemicals, as novel agents for cancer treatment has been observed. Bioactive phytochemicals exert their anticancer features through two main ways: they induce cytotoxic effects against cancerous cells without having any detrimental impact on normal cell macromolecules such as DNA and enzymes, while at the same time combating the oncogenic signaling axis activated in tumor cells. Thymoquinone (TQ), the most abundant bioactive compound of Nigella sativa, has received considerable attention in cancer treatment owing to its distinctive properties, including apoptosis induction, cell cycle arrest, angiogenesis and metastasis inhibition, and reactive oxygen species (ROS) generation, along with inducing immune system responses and reducing side effects of traditional chemotherapeutic drugs. The present review is focused on the characteristics and mechanisms by which TQ exerts its cytotoxic effects on bone malignancies.

Therapeutic Potential of Certain Terpenoids as Anticancer Agents: A Scoping Review

Cancer is a life-threatening disease and is considered to be among the leading causes of death worldwide. Chemoresistance, severe toxicity, relapse and metastasis are the major obstacles in cancer therapy. Therefore, introducing new therapeutic agents for cancer remains a priority to increase the range of effective treatments. Terpenoids, a large group of secondary metabolites, are derived from plant sources and are composed of several isoprene units. The high diversity of terpenoids has drawn attention to their potential anticancer and pharmacological activities. Some terpenoids exhibit an anticancer effect by triggering various stages of cancer progression, for example, suppressing the early stage of tumorigenesis via induction of cell cycle arrest, inhibiting cancer cell differentiation and activating apoptosis. At the late stage of cancer development, certain terpenoids are able to inhibit angiogenesis and metastasis via modulation of different intracellular signaling pathways. Significant progress in the identification of the mechanism of action and signaling pathways through which terpenoids exert their anticancer effects has been highlighted. Hence, in this review, the anticancer activities of twenty-five terpenoids are discussed in detail. In addition, this review provides insights on the current clinical trials and future directions towards the development of certain terpenoids as potential anticancer agents.

Novel PARP inhibitor DDPF-20 induces DNA damage and inhibits angiogenesis through the PI3K/Akt/VEGF pathway

BACKGROUND

Poly (ADP-ribose) polymerase (PARP) plays a key role in DNA damage repair. A novel compound (E)-N'-(2,3-dibromo-4,5-dihydroxyphenyl)-N-(phenylcarbamothioyl)formimidamide (DDPF-20) with excellent PARP inhibitory activity was synthesized.

OBJECTIVE

In this study, we aimed to clarify the mechanism of the novel PARP inhibitor DDPF-20 against lung cancer by inducing DNA damage and inhibiting angiogenesis.

METHOD

The cytotoxic effect of DDPF-20 on A549 cell line was determined with an MTT assay. Cell cycle and apoptosis was determined by flow cytometer. The γH2AX foci was detected by immunofluorescence. Capillary-like tube formation assay and chick chorioallantoic membrane (CAM) assay was used to detect angiogenesis inhibitory effect of DDPF-20. The expressions of related proteins were detected by western blot. The anticancer activity of DDPF-20 in vivo was also detected.

RESULTS

With an IC50 value of 52.42 ± 15.13 nM, DDPF-20 inhibited the proliferation, induced G2/M cycle arrest and induced apoptosis of human lung cancer A549 cells. Further research showed that DDPF-20 induced DNA double-strand breaks (DSBs). Interestingly, DDPF-20 inhibited the tube formation of HUVEC cells, as well as inhibited the neovascularization of CAM, proving the angiogenesis inhibitory ability of DDPF-20. Mechanism studies proved that DDPF-20 inhibited the PI3K/Akt/VEGF signaling pathway. In an in vivo study, DDPF-20 inhibited tumor growth of an A549 xenograft. Analysis of the molecular mechanism underlying this effect revealed that the PI3K/Akt/VEGF pathway was involved in DDPF-20-induced cell death and inhibited angiogenesis in vivo.

CONCLUSION

This study suggested that the novel PARP inhibitor DDPF-20 may have therapeutic potential in treating lung cancer.

PI3K-AKT Pathway Modulation by Thymoquinone Limits Tumor Growth and Glycolytic Metabolism in Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of death in men and the fourth in women worldwide and is characterized by deranged cellular energetics. Thymoquinone, an active component from Nigella sativa, has been extensively studied against cancer, however, its role in affecting deregulated cancer metabolism is largely unknown. Further, the phosphoinositide 3-kinase (PI3K) pathway is one of the most activated pathways in cancer and its activation is central to most deregulated metabolic pathways for supporting the anabolic needs of growing cancer cells. Herein, we provide evidence that thymoquinone inhibits glycolytic metabolism (Warburg effect) in colorectal cancer cell lines. Further, we show that such an abrogation of deranged cell metabolism was due, at least in part, to the inhibition of the rate-limiting glycolytic enzyme, Hexokinase 2 (HK2), via modulating the PI3/AKT axis. While overexpression of HK2 showed that it is essential for fueling glycolytic metabolism as well as sustaining tumorigenicity, its pharmacologic and/or genetic inhibition led to a reduction in the observed effects. The results decipher HK2 mediated inhibitory effects of thymoquinone in modulating its glycolytic metabolism and antitumor effects. In conclusion, we provide evidence of metabolic perturbation by thymoquinone in CRC cells, highlighting its potential to be used/repurposed as an antimetabolite drug, though the latter needs further validation utilizing other suitable cell and/or preclinical animal models.

Promoting Apoptosis, a Promising Way to Treat Breast Cancer With Natural Products: A Comprehensive Review

Breast cancer is one of the top-ranked malignant carcinomas associated with morbidity and mortality in women worldwide. Chemotherapy is one of the main approaches to breast cancer treatment. Breast cancer initially responds to traditional first- and second-line drugs (aromatase inhibitor, tamoxifen, and carboplatin), but eventually acquires resistance, and certain patients relapse within 5 years. Chemotherapeutic drugs also have obvious toxic effects. In recent years, natural products have been widely used in breast cancer research because of their low side effects, low toxicity, and good efficacy based on their multitarget therapy. Apoptosis, a programmed cell death, occurs as a normal and controlled process that promotes cell growth and death. Inducing apoptosis is an important strategy to control excessive breast cancer cell proliferation. Accumulating evidence has revealed that natural products become increasingly important in breast cancer treatment by suppressing cell apoptosis. In this study, we reviewed current studies on natural product–induced breast cancer cell apoptosis and summarized the proapoptosis mechanisms including mitochondrial, FasL/Fas, PI3K/AKT, reactive oxygen species, and mitogen-activated protein kinase–mediated pathway. We hope that our review can provide direction in the search for candidate drugs derived from natural products to treat breast cancer by promoting cell apoptosis.

Thymoquinone: A Review of Pharmacological Importance, Oxidative Stress, COVID-19, and Radiotherapy

Widely consumed worldwide, Nigella sativa (NS) is a medicinal herb commonly used in various alternative medicine systems such as Unani and Tibb, Ayurveda, and Siddha. Recommended for regular use in Tibb-e-Nabwi (Prophetic Medicine), NS is considered one of the most notable forms of healing medicine in Islamic literature. Thymoquinone (TQ), the main component of the essential oil of NS, has been reported to have many properties such as antioxidant, anti-inflammatory, antiviral, and antineoplastic. Its chemical structure indicates antiviral potential against many viruses, including the hepatitis C virus, human immunodeficiency virus, and other coronavirus diseases. Interestingly, molecular docking studies have demonstrated that TQ can potentially inhibit the development of the coronavirus disease 2019 (COVID-19) by binding to the receptor site on the transmembrane serine proteinase 2 (the activator enzyme that attaches the virus to the cell). In addition, TQ has been shown to be effective against cancer cells due to its inhibitory effect by binding to the different regions of MDM2, according to the proposed molecular docking study. Detailed in this review is the origin of TQ, its significance in alternative medicine, pharmacological value, potential as a cancer anti-proliferative agent, use against the coronavirus disease 2019 (COVID-19), and treatment of other diseases.

Curcumin and Thymoquinone Combination Attenuates Breast Cancer Cell Lines' Progression

Breast cancer is the most harmful malignancy in women worldwide. Therefore, in the current study, we investigated the combinatory effect of natural bioactive compounds, including curcumin (Cur) and thymoquinone (TQ), on MCF7 and MDA-MB-231 breast cancer cell lines’ progression. We investigated the Fa values and combination index of Cur and TQ in this context. Moreover, cytotoxicity percentages, annexin-V, proliferation, colony formation, and migration assays were used along with cell cycle analysis. In addition, caspase-3, phosphatidylinositol 3-kinase (PI3K), and protein kinase B (AKT) protein levels were determined by ELISA assessment. The results showed that Cur, TQ, and Cur + TQ induced apoptosis with cell cycle arrest and decreased cell proliferation, colony formation, and migration activities. Cur + TQ combination significantly increased caspase-3 and decreased PI3K and AKT protein levels. These results suggest the promising anticancer benefit of the Cur and TQ combination against breast cancer.

Insights into the Protective Effects of Thymoquinone against Toxicities Induced by Chemotherapeutic Agents

The drugs used to treat cancer not only kill fast-growing cancer cells, but also kill or slow the growth of healthy cells, causing systemic toxicities that lead to altered functioning of normal cells. Most chemotherapeutic agents have serious toxicities associated with their use, necessitating extreme caution and attention. There is a growing interest in herbal remedies because of their pharmacological activities, minimal side effects, and low cost. Thymoquinone, a major component of the volatile oil of Nigella sativa Linn, also known as black cumin or black seeds, is commonly used in Middle Eastern countries as a condiment. It is also utilized for medicinal purposes and possesses antidiabetic, anti-cancer, anti-inflammatory, hepatoprotective, anti-microbial, immunomodulatory, and antioxidant properties. This review attempts to compile the published literature demonstrating thymoquinone's protective effect against chemotherapeutic drug-induced toxicities.

Therapeutic Potential of Thymoquinone in Triple-Negative Breast Cancer Prevention and Progression through the Modulation of the Tumor Microenvironment

To date, the tumor microenvironment (TME) has gained considerable attention in various areas of cancer research due to its role in driving a loss of immune surveillance and enabling rapid advanced tumor development and progression. The TME plays an integral role in driving advanced aggressive breast cancers, including triple-negative breast cancer (TNBC), a pivotal mediator for tumor cells to communicate with the surrounding cells via lymphatic and circulatory systems. Furthermore, the TME plays a significant role in all steps and stages of carcinogenesis by promoting and stimulating uncontrolled cell proliferation and protecting tumor cells from the immune system. Various cellular components of the TME work together to drive cancer processes, some of which include tumor-associated adipocytes, fibroblasts, macrophages, and neutrophils which sustain perpetual amplification and release of pro-inflammatory molecules such as cytokines. Thymoquinone (TQ), a natural chemical component from black cumin seed, is widely used traditionally and now in clinical trials for the treatment/prevention of multiple types of cancer, showing a potential to mitigate components of TME at various stages by various pathways. In this review, we focus on the role of TME in TNBC cancer progression and the effect of TQ on the TME, emphasizing their anticipated role in the prevention and treatment of TNBC. It was concluded from this review that the multiple components of the TME serve as a critical part of TNBC tumor promotion and stimulation of uncontrolled cell proliferation. Meanwhile, TQ could be a crucial compound in the prevention and progression of TNBC therapy through the modulation of the TME.

Phyto-Phospholipid Conjugated Scorpion Venom Nanovesicles as Promising Carrier That Improves Efficacy of Thymoquinone against Adenocarcinoma Human Alveolar Basal Epithelial Cells

Lung cancer is a dangerous type of cancer in men and the third leading cause of cancer-related death in women, behind breast and colorectal cancers. Thymoquinone (THQ), a main compound in black seed essential oils, has a variety of beneficial effects, including antiproliferative, anti-inflammatory, and antioxidant properties. On the other hand, scorpion venom peptides (SV) induce apoptosis in the cancer cells, making it a promising anticancer agent. THQ, SV, and Phospholipon® 90H (PL) were incorporated in a nano-based delivery platform to assess THQ's cellular uptake and antiproliferative efficacy against a lung cancer cell line derived from human alveolar epithelial cells (A549). Several nanovesicles were prepared and optimized using factorial experimental design. The optimized phytosome formulation contained 79.0 mg of PL and 170.0 mg of SV, with vesicle size and zeta potential of 209.9 nm and 21.1 mV, respectively. The IC50 values revealed that A549 cells were significantly more sensitive to the THQ formula than the plain formula and THQ. Cell cycle analysis revealed that THQ formula treatment resulted in significant cell cycle arrest at the S phase, increasing cell population in this phase by 22.1%. Furthermore, the THQ formula greatly increased cell apoptosis (25.17%) when compared to the untreated control (1.76%), plain formula (11.96%), or THQ alone (13.18%). The results also indicated that treatment with THQ formula significantly increased caspase-3, Bax, Bcl-2, and p53 mRNA expression compared to plain formula and THQ. In terms of the inflammatory markers, THQ formula significantly reduced the activity of TNF-α and NF-κB in comparison with the plain formula and THQ only. Overall, the findings from the study proved that a phytosome formulation of THQ could be a promising therapeutic approach for the treatment of lung adenocarcinoma.

Medicinal plants used by patients to fight cancer in northwestern Algeria

Cancer is among the deadliest diseases in the world, especially in developed countries where modern treatments are not available to everyone. In North Africa, and especially in Algeria, few herbal treatments against cancer have been documented despite the richness of flora in these countries. This research aim to documents the medicinal plants used by patient to fight cancer in the northwest of Algeria. Data were collected through ethnobotanical surveys engaging 211 cancer patients in hospitals (departments of medical oncology) in two of the largest provinces in northwest Algeria (Tiaret and Tlemcen). The data were organized into usage reports (UR), while the Informant Consensus Factor (ICF) was calculated to evaluate agreement among informants. The patients investigated were mainly women, of middle age (41-50 years) and illiterate. In total, 53 medicinal plants used against several types of cancer have been identified. These plants are dominated by Lamiaceae, Apiaceae and Rosaceae. The leaves and powder of plants are most often used in traditional preparations often mixed with honey. The plants most often cited in the survey were Aristolochia longa, Aquilaria malaccensis, Ephedra alata subsp. alenda, while the most often treated cancer were breast, cervical, colorectal and stomach. 23 plants are not known as a treatment against cancers in North Africa, while 25 plants already known as treatment for cancer were cited here to treat specific new types of this disease.

Co-delivery of doxorubicin and conferone by novel pH-responsive β-cyclodextrin grafted micelles triggers apoptosis of metastatic human breast cancer cells

Adjuvant-aided combination chemotherapy is one of the most effective ways of cancer treatment by overcoming the multidrug resistance (MDR) and reducing the side-effects of anticancer drugs. In this study, Conferone (Conf) was used as an adjuvant in combination with Doxorubicin (Dox) for inducing apoptosis to MDA-MB-231 cells. Herein, the novel biodegradable amphiphilic β-cyclodextrin grafted poly maleate-co-PLGA was synthesized by thiol-ene addition and ring-opening process. Micelles obtained from the novel copolymer showed exceptional properties such as small size of around 34.5 nm, CMC of 0.1 μg/mL, and cell internalization of around 100% at 30 min. These novel engineered micelles were used for combination delivery of doxorubicin-conferone with high encapsulation efficiency of near 100% for both drugs. Our results show that combination delivery of Dox and Conf to MDA-MB-231 cells had synergistic effects (CI < 1). According to cell cycle and Annexin-V apoptosis analysis, Dox-Conf loaded micelle significantly induce tumor cell apoptosis (more than 98% of cells population showed apoptosis at IC50 = 0.259 μg/mL). RT-PCR and western-blot tests show that Dox-Conf loaded βCD-g-PMA-co-PLGA micelle induced apoptosis via intrinsic pathway. Therefore, the unique design of multi-functional pH-sensitive micelles open a new perspective for the development of nanomedicine for combination chemo-adjuvant therapy against malignant cancer.

Thymoquinone upregulates miR-125a-5p, attenuates STAT3 activation, and potentiates doxorubicin antitumor activity in murine solid Ehrlich carcinoma

In breast cancer, there has been evidence of atypical activation of signal transduction and activators of transcription 3 (STAT3). Thymoquinone (TQ) exerts its anti-neoplastic effect through diverse mechanisms, including STAT3 inhibition. The tumor suppressor, microRNA-125a-5p was reported to be downregulated in various breast cancer cells. Therefore, we investigated the influence of TQ and/or doxorubicin on microRNA-125a-5p and its correlation with STAT3 activation as well as tumor growth in mice bearing solid Ehrlich tumors. We found that TQ markedly suppressed inducible and constitutive phosphorylation of STAT3 in tumor tissue without affecting STAT5. Moreover, it attenuated tumor growth, downregulated STAT3 downstream target proteins, and increased the apoptotic activities of caspase-3 and -9. Interestingly, TQ-elicited synergism of doxorubicin anti-neoplastic activity was coupled with upregulation of tumoral microRNA-125a-5p. Taken together, the current findings raise the potential of TQ as a promising chemomodulatory adjuvant to augment mammary carcinoma sensitivity to doxorubicin.

Concurrent Reactive Oxygen Species Generation and Aneuploidy Induction Contribute to Thymoquinone Anticancer Activity

Thymoquinone (TQ) is the main biologically active constituent of Nigella sativa. Many studies have confirmed its anticancer actions. Herein, we investigated the different anticancer activities of, and considered resistance mechanisms to, TQ. MTT and clonogenic data showed TQ’s ability to suppress breast MDA-MB-468 and T-47D proliferation at lower concentrations compared to other cancer and non-transformed cell lines tested (GI₅₀ values ≤ 1.5 µM). Flow-cytometric analyses revealed that TQ consistently induced MDA-MB-468 and T-47D cell-cycle perturbation, specifically inducing pre-G1 populations. In comparison, less sensitive breast MCF-7 and colon HCT-116 cells exhibited only transient increases in pre-G1 events. Annexin V/PI staining confirmed apoptosis induction in MDA-MB-468 and HCT-116 cells, which was continuous in the former and transient in the latter. Experiments revealed the role of reactive oxygen species (ROS) generation and aneuploidy induction in MDA-MB-468 cells within the first 24 h of treatment. The ROS-scavenger NAD(P)H dehydrogenase (quinone 1) (NQO1; DT-diaphorase) and glutathione (GSH) were implicated in resistance to TQ. Indeed, western blot analyses showed that NQO1 is expressed in all cell lines in this study, except those most sensitive to TQ-MDA-MB-468 and T-47D. Moreover, TQ treatment increased NQO1 expression in HCT-116 in a concentration-dependent fashion. Measurement of GSH activity in MDA-MB-468 and HCT-116 cells found that GSH is similarly active in both cell lines. Furthermore, GSH depletion rendered these cells more sensitive to TQ’s antiproliferative actions. Therefore, to bypass putative inactivation of the TQ semiquinone metabolite, the benzylamine analogue was designed and synthesised following modification of TQ’s carbon-3 atom. However, the structural modification negatively impacted potency against MDA-MB-468 cells. In conclusion, we disclose the following: (i) The anticancer activity of TQ may be a consequence of ROS generation and aneuploidy; (ii) Early GSH depletion could substantially enhance TQ’s anticancer activity; (iii) Benzylamine substitution at TQ’s carbon-3 failed to enhance anticancer activity.

LPS/TLR4 pathways in breast cancer: insights into cell signalling

BACKGROUND

Cancer cells are usually recognized as foreign particles by the immune cells. Mounting evidences suggest important link between toll like receptors (TLRs) and carcinogenesis. This review article focused on the role of TLRs, especially TLR4 in breast cancer. <p> Methods: Research data on TLRs and cancer was explored in PubMed, Scopus, Google Scholar, and reviewed. Although some pioneer works are referenced, papers published in last ten years were mostly cited. <p> Results: TLRs are widely investigated pattern recognition receptors (PRR), and TLR4 is the most studied TLRs, implicated with occurrence of several types of cancers including breast cancer. TLR4 activation occurs via the binding of its ligand lipopolysaccharide (LPS), a component of the outer membrane of gram negative bacteria. Upon LPS binding, TLR4 dimerizes and recruits downstream signalling and/or adapter molecules leading to gene expression related to cancer cell proliferation, survival, invasion, and metastasis. Although LPS/TLR4 signalling seems a single signal transduction pathway, the TLR4 activation results in the activation of multiple diverse intracellular networks with huge cellular responses in both immune and cancer cells. The role of TLR4 in growth, invasion and metastasis of breast cancer is attracting huge attention in oncology research. Several clinical and preclinical studies utilize both TLR4 agonists and antagonists as treatment option for cancer therapy either as monotherapy or adjuvants for vaccine development. <p> Conclusion: This review narrates the role of LPS/TLR4 signalling in breast cancer development and future prospective for targeting LPS/TLR4 axis in the treatment of breast cancer.

Epigenetics of Triple-negative breast cancer via natural compounds

Triple-negative breast cancer (TNBC) is a highly resistant, lethal, and metastatic sub-division of breast carcinoma, characterized by the deficiency of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). In women, TNBC shows a higher aggressive behavior with poor patient prognosis and a higher recurrence rate during reproductive age. TNBC is defined by the presence of epithelial-to-mesenchymal-transition (EMT), which shows a significant role in cancer progression. At the epigenetic level, TNBC is characterized by epigenetic signatures, such as DNA methylation, histone remodeling, and a host of miRNA, MiR-193, LncRNA, HIF-2α, eEF2K, LIN9/NEK2, IMP3, LISCH7/TGF-β1, GD3s and KLK12 mediated regulation. These modifications either are silenced or activate the necessary genes that are prevalent in TNBC. The review is based on epigenetic mediated mechanistic changes in TNBC. Furthermore, Thymoquinone (TQ), Regorafenib, Fangjihuangqi decoction, Saikosaponin A, and Huaier, etc., are potent antitumor natural compounds extensively reported in the literature. Further, the review emphasizes the role of these natural compounds in TNBC and their possible epigenetic targets, which can be utilized as a potential therapeutic strategy in treatment of TNBC.

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.

Therapeutic perspectives of the black cumin component thymoquinone: A review

The dietary phytochemical thymoquinone (TQ), belonging to the family of quinones, mainly obtained from the black and angular seeds of Nigella sativa, is one of the promising monoterpenoid hydrocarbons, which has been receiving massive attention for its therapeutic potential and pharmacological properties. It plays an important role as a chemopreventive and therapeutic agent in the treatment of various diseases and illnesses. The aim of this review is to present a summary of the most recent literature pertaining to the use of TQ for the prevention and treatment of various diseases along with possible mechanisms of action, and the potential use of this natural product as a complementary or alternative medicine. Research findings indicated that TQ exhibits numerous pharmacological activities including antioxidant, anti-inflammatory, cardioprotective, hepatoprotective, antidiabetic, neuroprotective, and anticancer, among others. Conclusions of this review on the therapeutic aspects of TQ highlight the medicinal and folk values of this compound against various diseases and ailments. In short, TQ could be a novel drug in clinical trials, as we hope.

Thymoquinone anticancer activity is enhanced when combined with royal jelly in human breast cancer

BACKGROUND

Breast cancer is the most common cause of the majority of cancer-related deaths in women, among which triple-negative breast cancer is the most aggressive type of breast cancer diagnosed with limited treatment options. Thymoquinone (TQ), the main bioactive constituent of Nigella sativa, has been extensively studied as a potent anticancer molecule against various types of cancers. Honeybee products such as the royal jelly (RJ), the nutritive secretion fed to honeybee queens, exhibit a variety of biological activities besides its anticancer effect. However, the anticancer activity of the combination of TQ and RJ against breast cancer is still unknown.

AIM

To investigate cytotoxicity of RJ in FHs 74 Int cells and the anticancer effects of TQ, RJ, and their combinations in the MDA-MB-231 cell line.

METHODS

Cells were treated with TQ, RJ, and their combinations for 24 h. Using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, we determined the half-maximal inhibitory concentration of TQ. Trypan blue and 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were then performed to assess the cell viability in response to different treatment conditions. Cell death and cycle regulation were investigated using propidium iodide deoxyribonucleic acid staining followed by flow cytometry in response to a single dose of TQ, RJ, and their combination. Immunostaining for cleaved caspase 3 and Ki67 expression was used to determine apoptosis induction and changes in cell proliferation.

RESULTS

TQ alone inhibited cell viability in a dose-dependent manner at concentrations below and above the half-maximal inhibitory concentration. RJ exhibited relatively nontoxic effects against MDA-MB-231 cells and FHs 74 Int small intestinal cells at concentrations below 5 µg/mL. High doses of RJ (200 µg/mL) had greater toxicity against MDA-MB-231 cells. Interestingly, the inhibition of cell viability was most pronounced in response to 15 µmol/L TQ and 5 µg/mL RJ. A dose of 15 µmol/L TQ caused a significant increase in the PreG1 population, while a more pronounced effect on cell viability inhibition and PreG1 increase was observed in response to TQ and RJ combinations. TQ was the main inducer of caspase 3-dependent apoptosis when applied alone and in combination with RJ. In contrast, no significant regulation of Ki67 expression was observed, indicating that the decrease in cell viability was due to apoptosis induction rather than to inhibition of cell proliferation.

CONCLUSION

This study is the first to report enhanced anticancer effects of TQ and RJ combination against MDA-MB-231 breast cancer cells, which could confer an advantage for cancer therapy.

Recent Findings on Thymoquinone and Its Applications as a Nanocarrier for the Treatment of Cancer and Rheumatoid Arthritis

Cancer causes a considerable amount of mortality in the world, while arthritis is an immunological dysregulation with multifactorial pathogenesis including genetic and environmental defects. Both conditions have inflammation as a part of their pathogenesis. Resistance to anticancer and disease-modifying antirheumatic drugs (DMARDs) happens frequently through the generation of energy-dependent transporters, which lead to the expulsion of cellular drug contents. Thymoquinone (TQ) is a bioactive molecule with anticancer as well as anti-inflammatory activities via the downregulation of several chemokines and cytokines. Nevertheless, the pharmacological importance and therapeutic feasibility of thymoquinone are underutilized due to intrinsic pharmacokinetics, including short half-life, inadequate biological stability, poor aqueous solubility, and low bioavailability. Owing to these pharmacokinetic limitations of TQ, nanoformulations have gained remarkable attention in recent years. Therefore, this compilation intends to critically analyze recent advancements in rheumatoid arthritis and cancer delivery of TQ. This literature search revealed that nanocarriers exhibit potential results in achieving targetability, maximizing drug internalization, as well as enhancing the anti-inflammatory and anticancer efficacy of TQ. Additionally, TQ-NPs (thymoquinone nanoparticles) as a therapeutic payload modulated autophagy as well as enhanced the potential of other drugs when given in combination. Moreover, nanoformulations improved pharmacokinetics, drug deposition, using EPR (enhanced permeability and retention) and receptor-mediated delivery, and enhanced anti-inflammatory and anticancer properties. TQ's potential to reduce metal toxicity, its clinical trials and patents have also been discussed.

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.

Senescent Colon and Breast Cancer Cells Induced by Doxorubicin Exhibit Enhanced Sensitivity to Curcumin, Caffeine, and Thymoquinone

Cellular senescence is a process of physiological growth arrest that can be induced by intrinsic or extrinsic stress signals. Some cancer therapies are associated with senescence of cancer cells with a typical cell cycle arrest. Doxorubicin (Dox) induces senescence by a p53-dependent pathway and telomere dysfunction of numerous cancers. However, cellular senescence induces suppression in proliferation activity, and these cells will remain metabolically active and play an important role in tumor relapse and development of drug resistance. In the current study, we investigated the apoptotic effect of curcumin (Cur), caffeine (Caff), and thymoquinone (TQ) on senescent colon cancer HCT116 and breast cancer MCF7 cell lines treated with Dox. Results showed typical senescence markers including decreased bromodeoxyuridine incorporation, increased accumulation of senescence-associated β-galactosidase (SA-β-gal), cell cycle arrest, and upregulation of p53, P-p53, and p21 proteins. Annexin-V analysis by flow cytometry revealed 2- to 6-fold increases in annexin-V–positive cells in Dox-treated MCF7 and HCT116 cells by Cur (15 µM), Caff (10 mM), and TQ (50 µM; P < .001). In comparison between proliferative and senescent of either HCT116 or MCF7 cells, Caff at 15 mM and TQ at 25 µM induced significant increases in apoptosis of Dox-treated cells compared with proliferative cells (P < .001). Data revealed that Cur, Caff, and TQ potentially induced apoptosis of both proliferative and senescent HCT116 and MCF7 cells. In vivo and clinical trials are of great importance to validate this result.

Thymoquinone: A Tie-Breaker in SARS-CoV2-Infected Cancer Patients?

Since the beginning of the SARS-CoV-2(severe acute respiratory syndrome-coronavirus-2) pandemic, arace to develop a vaccine has been initiated, considering the massive and rather significant economic and healthcare hits that this virus has caused. The pathophysiology occurring following COVID-19(coronavirus disease-2019) infection has givenhints regarding the supportive and symptomatic treatments to establish for patients, as no specific anti-SARS-CoV-2 is available yet. Patient symptoms vary greatly and range from mild symptoms to severe fatal complications. Supportive treatments include antipyretics, antiviral therapies, different combinations of broad-spectrum antibiotics, hydroxychloroquine and plasma transfusion. Unfortunately, cancer patients are at higher risk of viral infection and more likely to develop serious complications due to their immunocompromised state, the fact that they are already administering multiple medications, as well as combined comorbidity compared to the general population. It may seem impossible to find a drug that possesses both potent antiviral and anticancer effects specifically against COVID-19 infection and its complications and the existing malignancy, respectively. Thymoquinone (TQ) is the most pharmacologically active ingredient in Nigella sativa seeds (black seeds); it is reported to have anticancer, anti-inflammatory and antioxidant effects in various settings. In this review, we will discuss the multiple effects of TQ specifically against COVID-19, its beneficial effects against COVID-19 pathophysiology and multiple-organ complications, its use as an adjuvant for supportive COVID-19 therapy and cancer therapy, and finally, its anticancer effects.

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.

Novel pH-sensitive and biodegradable micelles for the combined delivery of doxorubicin and conferone to induce apoptosis in MDA-MB-231 breast cancer cell line

pH-sensitive micelles are desirable for co-drug delivery in cancer chemotherapy. Herein, a novel, very pH-sensitive and biodegradable citric acid grafted poly maleate-block-poly lactic-co-glycolic acid was synthesized and assembled as micelles via ultrasonication. The engineered homogeneous nanomicelles were used for the first time for doxorubicin and conferone combination chemotherapy in the MDA-MB-231 breast cancer cell line. The physicochemical properties of the micelles were investigated via 13CNMR, 1HNMR, FTIR, CHNS, DSC, SEM, and DLS-zeta analysis, and the in vitro degradation of the synthetic copolymer was investigated to confirm its biodegradability. The critical micelle concentration (CMC) value of the micelles was determined using pyrene as a probe and a spectrofluorometer. The drug release process was studied in acidic and neutral pH. The anti-tumoral properties of the dual drug-loaded micelles were investigated via MTT assay, cell cycle, and apoptosis experiments. The apoptosis was confirmed by Annexin-V, qRT-PCR and western blotting. The particle size (51.9 nm), zeta potential (-6.57 mV) and CMC (1.793 μg mL-1) of the co-drug loaded micelles were in the acceptable range for electrostatic stability. The uptake of the co-drug loaded micelles in the MDA-MB-231 cell line and spheroids was 97% and 36.1%, respectively. The cell cycle and apoptosis tests revealed that the cells treated with the co-drug-loaded micelles showed the highest amount of apoptosis (95.35%) in comparison to the single drug-loaded micelles and free drugs. Reverse transcription PCR (RT-PCR) showed that the expression levels of the proapoptotic genes were significantly up-regulated in the presence of the co-drug loaded micelles versus the single-drug loaded micelles and free drugs. Western blotting revealed that the co-drug-loaded micelles promoted apoptosis via the caspase-dependent pathway. Our findings confirmed that the pH-responsive biodegradable micelles containing doxorubicin and conferone are novel and effective for combination chemotherapy and offer a promising strategy for future in vivo studies.

Targeting kinases with thymoquinone: a molecular approach to cancer therapeutics

Kinases are enzymes that are important for cellular functions, but their overexpression has strong connections with carcinogenesis, rendering them important targets for anticancer drugs. Thymoquinone (TQ) is a natural compound with proven anticancer activities, at least in preclinical studies. TQ can target several kinases, including phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK), Janus kinase/signal transducers and activators of transcription (JAK/STAT), polo-like kinase 1 (PLK1), and tyrosine kinase in different cancer cells and animal models. Inhibiting the activity of kinases or suppressing their expression might be among the mechanisms of TQ anticancer activity. In this review, we discuss the role of TQ in kinase regulation in different cancer models.

Role of natural compounds in preventing and treating breast cancer

Breast cancer (BrCa) is the most commonly diagnosed cancer and the second leading cause of cancer-related death in women. Alarming increases in the cases quests for more effective treatment of BrCa. As most chemotherapeutic drugs are associated with drug resistance, cancer relapse, and side effects, scientists are turning to agents with more efficacy, such as natural compounds for treatment and prevention of BrCa. Selected natural compounds, substances derived from living organisms, promote apoptosis and inhibit metastasis, preventing cancer growth. As a result, these compounds have the potential to suppress BrCa progression, thus increasing patient survival rates and decreasing the number of BrCa-related deaths. In this review, we summarize natural compounds that have displayed, anti-cancer effects on BrCa cells in various studies. These natural compounds inhibit the development of BrCa, suppress the growth of cancer cells, and promote cell death. We conclude that natural compounds are efficient, effective and promising agents for treating BrCa other than therapeutic methods.

Reverse Screening Bioinformatics Approach to Identify Potential Anti Breast Cancer Targets Using Thymoquinone from Neutraceuticals Black Cumin Oil

BACKGROUND

Functional foods, neutraceuticals and natural antioxidants have established their potential roles in the protection of human health and diseases. Thymoquinone (TQ), the main bioactive component of Nigella sativa seeds (black cumin seeds), a plant derived neutraceutical was used by ancient Egyptians because of their ability to cure a variety of health conditions and used as a dietary food supplement. Owing to its multi targeting nature, TQ interferes with a wide range of tumorigenic processes and counteracts carcinogenesis, malignant growth, invasion, migration, and angiogenesis. Additionally, TQ can specifically sensitize tumor cells towards conventional cancer treatments (e.g., radiotherapy, chemotherapy, and immunotherapy) and simultaneously minimize therapy-associated toxic effects in normal cells besides being cost effective and safe. TQ was found to play a protective role when given along with chemotherapeutic agents to normal cells.

METHODS

In the present study, reverse in silico docking approach was used to search for potential molecular targets for cancer therapy. Various metastatic and apoptotic targets were docked with the target ligand. TQ was also tested for its anticancer activities for its ability to cause cell death, arrest cell cycle and ability to inhibit PARP gene expression.

RESULTS

In silico docking studies showed that TQ effectively docked metastatic targets MMPs and other apoptotic and cell proliferation targets EGFR. They were able to bring about cell death mediated by apoptosis, cell cycle arrest in the late apoptotic stage and induce DNA damage too. TQ effectively down regulated PARP gene expression which can lead to enhanced cancer cell death.

CONCLUSION

Thymoquinone a neutraceutical can be employed as a new therapeutic agent to target triple negative breast cancer which is otherwise difficult to treat as there are no receptors on them. Can be employed along with standard chemotherapeutic drugs to treat breast cancer as a combinatorial therapy.

A multiple endpoint approach reveals potential in vitro anticancer properties of thymoquinone in human renal carcinoma cells

Thymoquinone (TQ) is a monoterpene isolated from the oil of Nigella sativa seeds. The aim of this work was to evaluate the cytotoxic effects induced by TQ and its impact on the migration and invasion potential of 786-O human renal cancer cells. These cells were exposed to TQ (1-100 μM) for 24 and 48 h and cell viability assessed using the Crystal Violet and MTS assays. TQ treatment clearly decreased cell viability in a concentration- and time-dependent manner. TQ exposure moderately increased intracellular ROS levels and co-incubation with reduced glutathione markedly increased cell viability. Moreover, the effect of TQ in the cell cycle distribution was evaluated using flow cytometry, and an increase in the sub-G1 population was observed, especially at 30 μM, along with an increase in the % of apoptotic cells. TQ did not show genotoxic effects at a non-cytotoxic concentration (1.0 μM). At this concentration level, TQ significantly decreased the collective migration of 786-O cells, whereas it had no effect in chemotactic migration. TQ also decreased the invasiveness potential of 786-O cells, as evaluated by the transwell invasion assay. Overall, these results suggest that TQ presents an anticancer potential in the context of renal cancer, warranting further investigation.

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.