Thymoquinone inhibits proliferation and invasion of human nonsmall-cell lung cancer cells via ERK pathway

Recent research on the physicochemical properties and biological activities of quinones and their practical applications: a comprehensive review

Quinones represent a class of crude organic compounds ubiquitously distributed in nature. Their distinctive quinone-type structure confers upon them unique properties and applications. Quinones demonstrate significant biological activities, including antioxidant, antimicrobial, and antitumor properties. Additionally, they demonstrate noteworthy physicochemical characteristics, including excellent dyeing properties and stability. Given their diverse qualities, quinones hold significant promise for applications in industrial manufacturing, healthcare, and food production, thus garnering considerable attention in recent years. While there is a growing body of research on quinones, the existing literature falls short of providing a comprehensive review encompassing recent advancements in this field along with established knowledge. This paper offers a comprehensive review of research progress for quinones, encompassing structural classification, source synthesis, extraction methods, properties, functions, and specific applications. It serves as a reference and theoretical foundation for the further development and utilization of quinones.

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.

Thymoquinone: An Effective Natural Compound for Kidney Protection

Kidney disease is a common health problem worldwide. Acute or chronic injuries may interfere with kidney functions, eventually resulting in irreversible kidney damage. A number of recent studies have shown that the plant-derived natural products have an extensive potential for renal protection. Thymoquinone (TQ) is an essential compound derived from Nigella Sativa (NS), which is widely applied in the Middle East as a folk medicine. Previous experiments have demonstrated that TQ has a variety of potential pharmacological effects, including anti-oxidant, antibacterial, antitumor, immunomodulatory, and neuroprotective activities. In particular, the prominent renal protective efficacy of TQ has been demonstrated in both in vivo and in vitro experiments. TQ can prevent acute kidney injuries from various xenobiotics through anti-oxidation, anti-inflammatory, and anti-apoptosis effects. In addition, TQ exhibited significant pharmacological effects on renal cell carcinoma, renal fibrosis, and urinary calculi. The essential mechanisms involve scavenging ROS and increasing anti-oxidant activity, decreasing inflammatory mediators, inducing apoptosis, and inhibiting migration and invasion. The purpose of this review is to conclude the pharmacological effects and the potential mechanisms of TQ in renal protection, shedding new light on the exploration of medicinal phyto-protective agents targeting kidneys.

Determination of anti-cancer effects of Nigella sativa seed oil on MCF7 breast and AGS gastric cancer cells

BACKGROUND

This study aimed to investigate the cytotoxic, apoptotic, invasion, metastasis, and heat shock proteins (HSPs) effects of N. sativa oil on breast and gastric cancer cells.

METHODS

We assessed the cytotoxic and apoptotic effects of various concentrations of N. sativa oil (10-50-100-200 µg/mL) on MCF7 breast cancer and AGS, an adenocarcinoma of the gastric cell line, at 24, 48 and 72 h using the MTT test. Additionally, the expression of the Caspase-3, BCL2/Bax, MMP2-9 and HSP60-70 gene was examined using RT-PCR in cell lines treating with N. sativa.

RESULTS

The MTT experiments demonstrate that N. sativa has a time and dose-dependent inhibitory effect on the proliferation of MCF7 and AGS cancer cells. The vitality rates of MCF7 and AGS cells treated with N. sativa were 77.04-67.50% at 24 h, 65.28-39.14% at 48 h, and 48.95-32.31% at 72 h. The doses of 100 and 200 µg/mL were shown to be the most effective on both cancer cells. RT-PCR analysis revealed that N. sativa oil extract increased caspase-3 levels in both cell lines at higher concentrations and suppressed BCL2/Bax levels. Exposure of MCF7 and AGS cell lines to N. sativa caused a significant decrease in the expression of MMP2-9 and HSP60-70 genes over time, particularly at a dosage of 200 µg/mL compared to the control group (p < 0.05).

CONCLUSIONS

Our findings indicate that N. sativa oil has a dose-dependent effect on cytotoxicity and the expression of apoptotic, heat shock proteins, and matrix metalloproteinases genes in breast and gastric cancer.

Therapeutic and Phytochemical Properties of Thymoquinone Derived from Nigella sativa

BACKGROUND

Nigella sativa (N. sativa), commonly known as black seed or black cumin, belongs to the family Ranunculaceae. It contains several phytoconstituents, Thymoquinone (TQ), thymol, thymohydroquinone, carvacrol, and dithymoquinone. TQ is the main phytoconstituent present in N. sativa that is used as an herbal compound, and it is widely used as an antihypertensive, liver tonic, diuretic, digestive, anti-diarrheal, appetite stimulant, analgesic, and antibacterial agent, and in skin disorders.

OBJECTIVE

The study focused on collecting data on the therapeutic or pharmacological activities of TQ present in N. sativa seed.

METHODS

Antidiabetic, anticancer, immunomodulator, analgesic, antimicrobial, anti-inflammatory, hepato-protective, renal protective, and antioxidant properties of TQ have been studied by various scientists.

CONCLUSION

TQ seems to have a variety of consequences on how infected cells behave at the cellular level.

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.

Therapeutic effects of medicinal plants and their constituents on lung cancer, in vitro, in vivo and clinical evidence

The most common type of cancer in the world is lung cancer. Traditional treatments have an important role in cancer therapy. In the present review, the most recent findings on the effects of medicinal plants and their constituents or natural products (NP) in treating lung cancer are discussed. Empirical studies until the end of March 2022 were searched using the appropriate keywords through the databases PubMed, Science Direct and Scopus. The extracts and essential oils tested were all shown to effect lung cancer by several mechanisms including decreased tumour weight and volume, cell viability and modulation of cytokine. Some plant constituents increased expression of apoptotic proteins, the proportion of cells in the G2/M phase and subG0/G1 phase, and Cyt c levels. Also, natural products (NP) activate apoptotic pathways in lung cancer cell including p-JNK, Akt/mTOR, PI3/ AKT\ and Bax, Bcl2, but suppressed AXL phosphorylation. Plant-derived substances altered the cell morphology, reduced cell migration and metastasis, oxidative marker production, p-eIF2α and GRP78, IgG, IgM levels and reduced leukocyte counts, LDH, GGT, 5'NT and carcinoembryonic antigen (CEA). Therefore, medicinal plant extracts and their constituents could have promising therapeutic value for lung cancer, especially if used in combination with ordinary anti-cancer drugs.

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.

Therapeutic Targeting of Regulated Signaling Pathways of Non-Small Cell Lung Carcinoma

Non-small cell lung carcinoma (NSCLC) is the most common cancer globally. Phytochemicals and small molecule inhibitors significantly prevent varying types of cancers, including NSCLC. These therapeutic molecules serve as important sources for new drugs that interfere with cellular proliferation, apoptosis, metastasis, and angiogenesis by regulating signaling pathways. These molecules affect several cellular signaling cascades, including p53, NF-κB, STAT3, RAS, MAPK/ERK, Wnt, and AKT/PI3K, and are thus implicated in the therapeutic management of cancers. This review aims to describe the bioactive compounds and small-molecule inhibitors, their anticancer action, and targeting cellular signaling cascades in NSCLC. We highlighted the therapeutic potential of Epigallocatechin gallate (EGCG), Perifosine, ABT-737, Thymoquinine, Quercetin, Venetoclax, Gefitinib, and Genistein. These compounds are implicated in the therapeutic management of NSCLC. This review further offers deeper mechanistic insights into different signaling pathways that could be targeted for NSCLC therapy by phytochemicals and small-molecule inhibitors.

Molecular mechanisms and signaling pathways of black cumin (Nigella sativa) and its active constituent, thymoquinone: a review

BACKGROUND

Nigella sativa and its main bioactive ingredient, thymoquinone, exhibit various pharmacological activities, including neuroprotective, nephroprotective, cardioprotective, gastroprotective, hepatoprotective, and anti-cancer effects. Many studies have been conducted trying to elucidate the molecular signaling pathways that mediate these diverse pharmacological properties of N. sativa and thymoquinone. Accordingly, the goal of this review is to show the effects of N. sativa and thymoquinone on different cell signaling pathways.

METHODS

The online databases Scopus, PubMed and Web of Science were searched to identify relevant articles using a list of related keywords such as Nigella sativa, black cumin, thymoquinone, black seed, signal transduction, cell signaling, antioxidant, Nrf2, NF-κB, PI3K/AKT, apoptosis, JAK/STAT, AMPK, MAPK, etc. Only articles published in the English language until May 2022 were included in the present review article.

RESULTS

Studies indicate that N. sativa and thymoquinone improve antioxidant enzyme activities, effectively scavenges free radicals, and thus protect cells from oxidative stress. They can also regulate responses to oxidative stress and inflammation via Nrf2 and NF-κB pathways. N. sativa and thymoquinone can inhibit cancer cell proliferation through disruption of the PI3K/AKT pathway by upregulating phosphatase and tensin homolog. Thymoquinone can modulate reactive oxygen species levels in tumor cells, arrest the cell cycle in the G2/M phase as well as affect molecular targets including p53, STAT3 and trigger the mitochondrial apoptosis pathway. Thymoquinone, by adjusting AMPK, can regulate cellular metabolism and energy hemostasis. Finally, N. sativa and thymoquinone can elevate brain GABA content, and thus it may ameliorate epilepsy.

CONCLUSIONS

Taken together, the improvement of antioxidant status and prevention of inflammatory process by modulating the Nrf2 and NF-κB signaling and inhibition of cancer cell proliferation through disruption of the PI3K/AKT pathway appear to be the main mechanisms involved in different pharmacological properties of N. sativa and thymoquinone.

The effect of hydro alcoholic extract of Nigella sativa seeds on inflammatory mediators in C6 glioma cell line

SUBJECT

Nigella sativa (N. sativa) is a highly valued nutritional plant, which has long been used in traditional medicine to treat a variety of human diseases. The multifaceted pharmacological impacts of N. sativa, such as attenuating oxidative stress and inflammation, make it a suitable therapeutic candidate against cardiovascular, hepatic, and neurological disorders as well as cancer. Therefore, the current study aimed to evaluate the effect of the hydroalcoholic extract of N. sativa seeds on several pro-inflammatory cytokines in the C6 glioma cell line and to compare it with the effect of the extract on the normal fibroblast cell line.

METHODS

C6 and fibroblast cell lines were treated with the extract of N. sativa seeds, and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was performed to determine the half-maximal inhibitory concentration (IC50) after 72h of treatment. Real-time polymerase chain reaction (RT-PCR) was carried out to assess the expression levels of interleukin (IL)-6, IL-10, tumor necrosis factor-alpha (TNF-α), and transforming growth factor- β1 (TGF-β1) at the mRNA level in both cell lines after 72h of treatment with non-toxic and IC50 concentrations obtained from C6 cell line.

RESULTS

The IC50 values for the hydroalcoholic extract of N. sativa seeds were 260±20μg/mL in the C6 cell line and 398±27μg/mL in fibroblast cells. The real-time PCR results indicated that the treatment of C6 and fibroblast cells with the extract at the IC50 value of N. sativa in C6 for 72h could increase the mRNA expression levels of IL-10 and reduce the mRNA expression levels of IL-6, TNF-α, and TGF-β1 in C6 and fibroblast cells. The N. sativa extract showed a higher anti-inflammatory effect on C6 cells in comparison with fibroblast cells.

CONCLUSIONS

Regarding the anti-inflammatory effect of Nigella sativa in C6 cell line, it may be considered a promising candidate to fortify antitumor actions in combination with other therapeutic options in the treatment of patients with GBM.

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.

Curcumin, thymoquinone, and 3, 3′-diindolylmethane combinations attenuate lung and liver cancers progression

Cancer can develop due to abnormal cell proliferation in any body’s cells, so there are over a hundred different types of cancer, each with its distinct behavior and response to treatment. Therefore, many studies have been conducted to slow cancer progression and find effective and safe therapies. Nutraceuticals have great attention for their anticancer potential. Therefore, the current study was conducted to investigate the anticancer effects of curcumin (Cur), thymoquinone (TQ), and 3, 3′-diindolylmethane (DIM) combinations on lung (A549) and liver (HepG2) cancer cell lines’ progression. Results showed that triple (Cur + TQ + DIM) and double (Cur + TQ, Cur + DIM, and TQ + DIM) combinations of Cur, TQ, and DIM significantly increased apoptosis with elevation of caspase-3 protein levels. Also, these combinations exhibited significantly decreased cell proliferation, migration, colony formation activities, phosphatidylinositol 3-kinase (PI3K), and protein kinase B (AKT) protein levels with S phase reduction. Triple and double combinations of Cur, TQ, and DIM hindered tumor weight and angiogenesis of A549 and HepG2 implants in the chorioallantoic membrane model. Interestingly, Cur, TQ, and DIM combinations are considered promising for suppressing cancer progression via inhibiting tumor angiogenesis. Further preclinical and clinical investigations are warranted.

Anticancer and Anti-Metastatic Role of Thymoquinone: Regulation of Oncogenic Signaling Cascades by Thymoquinone

Cancer is a life-threatening and multifaceted disease. Pioneering research works in the past three decades have mechanistically disentangled intertwined signaling networks which play contributory roles in carcinogenesis and metastasis. Phenomenal strides have been made in leveraging our scientific knowledge altogether to a new level of maturity. Rapidly accumulating wealth of information has underlined a myriad of transduction cascades which can be pharmaceutically exploited for cancer prevention/inhibition. Natural products serve as a treasure trove and compel interdisciplinary researchers to study the cancer chemopreventive roles of wide-ranging natural products in cell culture and preclinical studies. Experimental research related to thymoquinone has gradually gained momentum because of the extra-ordinary cancer chemopreventive multifunctionalities of thymoquinone. In this mini-review, we provide an overview of different cell signaling cascades reported to be regulated by thymoquinone for cancer chemoprevention. Essentially, thymoquinone efficacy has also been notably studied in animal models, which advocates for a rationale-based transition of thymoquinone from the pre-clinical pipeline to clinical trials.

Thymoquinone Alterations of the Apoptotic Gene Expressions and Cell Cycle Arrest in Genetically Distinct Triple-Negative Breast Cancer Cells

Breast cancer (BC) is the most common cancer in women worldwide, and it is one of the leading causes of cancer death in women. triple-negative breast Cancer (TNBC), a subtype of BC, is typically associated with the highest pathogenic grade and incidence in premenopausal and young African American (AA) women. Chemotherapy, the most common treatment for TNBC today, can lead to acquired resistance and ineffective treatment. Therefore, novel therapeutic approaches are needed to combat medication resistance and ineffectiveness in TNBC patients. Thymoquinone (TQ) is shown to have a cytotoxic effect on human cancer cells in vitro. However, TQ's mode of action and precise mechanism in TNBC disease in vitro have not been adequately investigated. Therefore, TQ's effects on the genetically different MDA-MB-468 and MDA-MB-231 human breast cancer cell lines were assessed. The data obtained show that TQ displayed cytotoxic effects on MDA-MB-468 and MDA-MB-231 cells in a time- and concentration-dependent manner after 24 h, with IC50 values of 25.37 µM and 27.39 µM, respectively. Moreover, MDA-MB-231 and MDA-MB-468 cells in a scratched wound-healing assay displayed poor wound closure, inhibiting invasion and migration via cell cycle blocking after 24 h. TQ arrested the cell cycle phase in MDA-MB-231 and MDA-MB-468 cells. The three cell cycle stages in MDA-MB-468 cells were significantly affected at 15 and 20 µM for G0/G1 and S phases, as well as all TQ concentrations for G2/M phases. In MDA-MB-468 cells, there was a significant decrease in G0/G1 phases with a substantial increase in the S phase and G2/M phases. In contrast, MDA-MB-231 showed a significant effect only during the two cell cycle stages (S and G2/M), at concentrations of 15 and 20 µM for S phases and all TQ values for G2/M phases. The TQ effect on the apoptotic gene profiles indicated that TQ upregulated 15 apoptotic genes in MDA-MB-231 TNBC cells, including caspases, GADD45A, TP53, DFFA, DIABLO, BNIP3, TRAF2/3, and TNFRSF10A. In MDA-MB-468 cells, 16 apoptotic genes were upregulated, including TNFRSF10A, TNF, TNFRSF11B, FADD TNFRSF10B, CASP2, and TRAF2, all of which are important for the apoptotic pathway andsuppress the expression of one anti-apoptotic gene, BIRC5, in MDA-MB-231 cells. Compared to MDA-MB-231 cells, elevated levels of TNF and their receptor proteins may contribute to their increased sensitivity to TQ-induced apoptosis. It was concluded from this study that TQ targets the MDA-MB-231 and MDA-MB-468 cells differently. Additionally, due to the aggressive nature of TNBC and the lack of specific therapies in chemoresistant TNBC, our findings related to the identified apoptotic gene profile may point to TQ as a potential agent for TNBC therapy.

Natural quinones induce ROS-mediated apoptosis and inhibit cell migration in PANC-1 human pancreatic cancer cell line

Pancreatic cancer is one of the most devastating of all malignancies with poor prognosis and high mortality rates worldwide. Thymoquinone, plumbagin and juglone, which are naturally occurring quinones, have been reported for their promising anticancer effect on different cancer cells. However, their mechanism of action and antimetastatic effects are largely unknown against the human pancreatic cancer cell line (PANC-1). In this study, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay revealed a dose-dependent decrease of viability in quinone-treated PANC-1 cells. In addition, the assessment of changes in cells has demonstrated an occurrence of typical apoptotic morphology in treated PANC-1 cells compared with control. Besides this, the apoptosis induction was further quantitatively confirmed through flow cytometry analysis. Furthermore, thymoquinone, plumbagin and juglone were evaluated for their influence on reactive oxygen species (ROS) generation through 2,7-dichlorofluorescein diacetate (DCFDA) staining and they dramatically increased the intracellular ROS level in treated PANC-1 cells, suggesting the critical role of ROS in their apoptosis induction. This study also demonstrated the wound healing potential of these compounds and inhibited PANC-1 cell migration in a time-dependent manner compared with control. This inhibition was correlated with reduced expression of matrix metalloproteinase-9 (MMP-9) in juglone-treated cells detected through gelatin zymography. In conclusion, thymoquinone, plumbagin and juglone significantly inhibited cell growth and induced ROS-mediated apoptosis in PANC-1 cells. In addition, they could be potent antimetastatic agents due to their anti-migratory effect against PANC-1 human pancreatic cancer cells.

Targeting Mutant Kirsten Rat Sarcoma Viral Oncogene Homolog in Non-Small Cell Lung Cancer: Current Difficulties, Integrative Treatments and Future Perspectives

In the past few decades, several gene mutations, including the anaplastic lymphoma kinase, epidermal growth factor receptor, ROS proto-oncogene 1 and rat sarcoma viral oncogene homolog (RAS), have been discovered in non-small cell lung cancer (NSCLC). Kirsten rat sarcoma viral oncogene homolog (KRAS) is the isoform most frequently altered in RAS-mutated NSCLC cases. Due to the structural and biochemical characteristics of the KRAS protein, effective approaches to treating KRAS-mutant NSCLC still remain elusive. Extensive recent research on KRAS-mutant inhibitors has made a breakthrough in identifying the covalent KRASG12C inhibitor as an effective agent for the treatment of NSCLC. This review mainly concentrated on introducing new covalent KRASG12C inhibitors like sotorasib (AMG 510) and adagrasib (MRTX 849); summarizing inhibitors targeting the KRAS-related upstream and downstream effectors in RAF/MEK/ERK pathway and PI3K/AKT/mTOR pathway; exploring the efficacy of immunotherapy and certain emerging immune-related therapeutics such as adoptive cell therapy and cancer vaccines. These inhibitors are being investigated in clinical trials and have exhibited promising effects. On the other hand, naturally extracted compounds, which have exhibited safe and effective properties in treating KRAS-mutant NSCLC through suppressing the MAPK and PI3K/AKT/mTOR signaling pathways, as well as through decreasing PD-L1 expression in preclinical studies, could be expected to enter into clinical studies. Finally, in order to confront the matter of drug resistance, the ongoing clinical trials in combination treatment strategies were summarized herein.

Thymoquinone (TQ) Inhibits Inflammation and Migration of THP-1 Macrophages: Mechanistic Insights into the Prevention of Atherosclerosis Using In-Vitro and In-Silico Analysis

Atherosclerosis is an inflammatory disease mediated by interferon (IFN-γ) in concert with cell adhesion molecules and chemokines. Thymoquinone (TQ), a flavonoid derived from Nigella sativa, is reported to have anti-inflammatory, antioxidant, and cardiovascular protective properties. We evaluated the effects of TQ on the key pathogenic stages of atherosclerosis, including cell viability, inflammatory gene expression, cell migration, and cholesterol efflux, on human THP-1 macrophages in-vitro. Moreover, in-silico analysis was performed to predict the molecular targets and signaling mechanisms. We demonstrated that TQ treatment had no effect on cell viability and decreased the expression of monocyte chemoattractant protein (MCP-1) and intercellular adhesion molecule (ICAM-1) in response to IFN-γ. In addition, we have also demonstrated that the THP-1 cell migration was inhibited by TQ in the absence or presence of MCP-1. Thymoquinone had no effect on cholesterol efflux from monocytes. In-silico analysis also identified several putative targets for TQ that are associated with inflammatory diseases and associated signaling pathways. Collectively, these results suggest that TQ has anti-inflammatory effects and may be a potential nutraceutical candidate for the prevention and treatment of atherosclerosis.

Role of Plant-Derived Active Constituents in Cancer Treatment and Their Mechanisms of Action

Despite significant technological advancements in conventional therapies, cancer remains one of the main causes of death worldwide. Although substantial progress has been made in the control and treatment of cancer, several limitations still exist, and there is scope for further advancements. Several adverse effects are associated with modern chemotherapy that hinder cancer treatment and lead to other critical disorders. Since ancient times, plant-based medicines have been employed in clinical practice and have yielded good results with few side effects. The modern research system and advanced screening techniques for plants’ bioactive constituents have enabled phytochemical discovery for the prevention and treatment of challenging diseases such as cancer. Phytochemicals such as vincristine, vinblastine, paclitaxel, curcumin, colchicine, and lycopene have shown promising anticancer effects. Discovery of more plant-derived bioactive compounds should be encouraged via the exploitation of advanced and innovative research techniques, to prevent and treat advanced-stage cancers without causing significant adverse effects. This review highlights numerous plant-derived bioactive molecules that have shown potential as anticancer agents and their probable mechanisms of action and provides an overview of in vitro, in vivo and clinical trial studies on anticancer phytochemicals.

Bax/Bcl-2 Cascade Is Regulated by the EGFR Pathway: Therapeutic Targeting of Non-Small Cell Lung Cancer

Non-small cell lung carcinoma (NSCLC) comprises 80%-85% of lung cancer cases. EGFR is involved in several cancer developments, including NSCLC. The EGFR pathway regulates the Bax/Bcl-2 cascade in NSCLC. Increasing understanding of the molecular mechanisms of fundamental tumor progression has guided the development of numerous antitumor drugs. The development and improvement of rationally planned inhibitors and agents targeting particular cellular and biological pathways in cancer have been signified as a most important paradigm shift in the strategy to treat and manage lung cancer. Newer approaches and novel chemotherapeutic agents are required to accompany present cancer therapies for improving efficiency. Using natural products as a drug with an effective delivery system may benefit therapeutics. Naturally originated compounds such as phytochemicals provide crucial sources for novel agents/drugs and resources for tumor therapy. Applying the small-molecule inhibitors (SMIs)/phytochemicals has led to potent preclinical discoveries in various human tumor preclinical models, including lung cancer. In this review, we summarize recent information on the molecular mechanisms of the Bax/Bcl-2 cascade and EGFR pathway in NSCLC and target them for therapeutic implications. We further described the therapeutic potential of Bax/Bcl-2/EGFR SMIs, mainly those with more potent and selectivity, including gefitinib, EGCG, ABT-737, thymoquinone, quercetin, and venetoclax. In addition, we explained the targeting EGFR pathway and ongoing in vitro and in vivo and clinical investigations in NSCLC. Exploration of such inhibitors facilitates the future treatment and management of NSCLC.

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.

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.

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.

Piperine for treating breast cancer: A review of molecular mechanisms, combination with anticancer drugs, and nanosystems

Piperine (PIP) is an alkaloid found primarily in Piper longum, and this natural compound has been shown to exert effects on proliferation and survival against various types of cancer. In particular, PIP has potent inhibitory effects on breast cancer (BC), the most prevalent type of cancer in women worldwide. PIP targets numerous signaling pathways associated with the therapy of BC cells through the following mechanisms: (a) induction of arrest of the cell cycle and apoptosis; (b) alteration of the signaling protein expression; (c) reduction in transcription factors; and (d) inhibition of tumor growth. BC cells have the ability to resist conventional drugs, so one of the strategies is the combination of PIP with other phytochemicals such as paclitaxel, thymoquinone, hesperidin, bee venom, tamoxifen, mitoxantrone, piperlongumin, and curcumin. Nanotechnology-based drug encapsulation systems are currently used to enhance the release of PIP. This includes polymer nanoparticles, carbon nanotubes, and liposomes. In the present review, the chemistry and bioavailability of PIP, its molecular targets in BC, and nanotechnological strategies are discussed. Future research directions are also discussed to further understand this promising natural product.

Nigella sativa extract kills pre-malignant and malignant oral squamous cell carcinoma cells

In this study, the potential of Nigella sativa was evaluated in the management of oral cancer through assays designed to mimic conditions expected when chewing the whole seeds or use of a seed extract. For this purpose, a water-based extract of N. sativa seeds was prepared, mimicking the chewing process. This extract demonstrated significant cytotoxic effect on oral cancer and pre-cancerous leukoplakia cells in vitro at a much lower concentration than the predicted oral concentration that could be achieved upon seed chewing. When the active constituent(s) in this water-based N. sativa seed extract, was explored significant quantities of the compound α-hederin was detected but only modest quantities of thymoquinone suggesting that thymoquinone is not fully released into the aqueous medium during the chewing process. While the N. sativa seed extract induced a different effect on the cells than that of pure thymoquinone, α-hederin alone induced a very similar effect on the cells to that of the extract. These results suggest that α-hederin and not thymoquinone, is the major component of the seed that is responsible for the inhibitory effect observed in vitro. Therefore, chewing N. sativa whole seeds or applying a concentrated extract on the oral lesions may be an inexpensive, widely available, and effective option for patients at risk of developing oral cancer who are receiving no other preventive treatment.

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.

Inactivation Effect of Thymoquinone on Alicyclobacillus acidoterrestris Vegetative Cells, Spores, and Biofilms

Alicyclobacillus acidoterrestris (A. acidoterrestris), a spore-forming bacterium, has become a main challenge and concern for the juices and acid beverage industry across the world due to its thermo-acidophilic characteristic. Thymoquinone (TQ) is one of the active components derived from Nigella sativa seeds. The objective of this study was to investigate antibacterial activity and associated molecular mechanism of TQ against A. acidoterrestris vegetative cells, and to evaluate effects of TQ on A. acidoterrestris spores and biofilms formed on polystyrene and stainless steel surfaces. Minimum inhibitory concentrations of TQ against five tested A. acidoterrestris strains ranged from 32 to 64 μg/mL. TQ could destroy bacterial cell morphology and membrane integrity in a concentration-dependent manner. Field-emission scanning electron microscopy observation showed that TQ caused abnormal morphology of spores and thus exerted a killing effect on spores. Moreover, TQ was effective in inactivating and removing A. acidoterrestris mature biofilms. These findings indicated that TQ is promising as a new alternative to control A. acidoterrestris and thereby reduce associated contamination and deterioration in the juice and acid beverage industry.

A narrative review of the migration and invasion features of non-small cell lung cancer cells upon xenobiotic exposure: insights from in vitro studies

Lung cancer (LC) is the leading cause of cancer deaths worldwide, being non-small lung cancer (NSCLC) sub-types the most prevalent. Since most LC cases are only detected during the last stage of the disease the high mortality rate is strongly associated with metastases. For this reason, the migratory and invasive capacity of these cancer cells as well as the mechanisms involved have long been studied to uncover novel strategies to prevent metastases and improve the patients’ prognosis. This narrative review provides an overview of the main in vitro migration and invasion assays employed in NSCLC research. While several methods have been developed, experiments using conventional cell culture models prevailed, specifically the wound-healing and the transwell migration and invasion assays. Moreover, it is provided herewith a summary of the available information concerning chemical contaminants that may promote the migratory/invasive properties of NSCLC cells in vitro, shedding some light on possible LC risk factors. Most of the reported agents with pro-migration/invasion effects derive from cigarette smoking [e.g., Benzo(a)pyrene and cadmium] and air pollution. This review further presents several studies in which different dietary/plant-derived compounds demonstrated to impair migration/invasion processes in NSCLC cells in vitro. These chemicals that have been proposed as anti-migratory consisted mainly of natural bioactive substances, including polyphenols non-flavonoids, flavonoids, bibenzyls, terpenes, alkaloids, and steroids. Some of these compounds may eventually represent novel therapeutic strategies to be considered in the future to prevent metastasis formation in LC, which highlights the need for additional in vitro methodologies that more closely resemble the in vivo tumor microenvironment and cancer cell interactions. These studies along with adequate in vivo models should be further explored as proof of concept for the most promising compounds.

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.

Erianthridin Induces Non-small Cell Lung Cancer Cell Apoptosis through the Suppression of Extracellular Signal-regulated Kinase Activity

Due to the high mortality of lung cancer, natural derivative compounds have been promoted as versatile sources for anticancer drug discovery. Erianthridin, a phenanthrene compound isolated from Dendrobium formosum, exhibits intriguing apoptosis-inducing effects in non-small cell lung cancer cells. Apoptotic nuclei staining assays showed that apoptotic cells with DNA fragmentation and apoptotic bodies were apparent, and an increase in annexin V-FITC-positive cells were found in cells treated with erianthridin. The apoptosis protein markers for cleaved caspase-3 and cleaved poly-ADP-ribose polymerase were significantly upregulated in response to erianthridin. A mechanistic investigation revealed that erianthridin was able to attenuate extracellular signal-regulated kinase activity and thereby mediate apoptosis through the modulation of Bcl-2 family protein levels. U0126, an extracellular signal-regulated kinase inhibitor, augmented the apoptosis-inducing effect of erianthridin; in contrast, overexpression of exogenous extracellular signal-regulated kinase substantially abrogated erianthridin activity. Furthermore, an in vitro 3D tumorigenesis assay showed that erianthridin was able to potentially suppress lung cancer cell proliferation. This study is the first to report a promising cytotoxic effect of erianthridin, which provides preclinical evidence for further research and development of this compound.

Curry versus cancer: Potential of some selected culinary spices against cancer with in vitro, in vivo, and human trials evidences

Spices are dietary agents with immense potential for cancer chemo-prevention. A wide variety of spices are extensively used as food flavoring agents which possess potent antioxidant, anti-inflammatory, and anticancer properties due to the presence of certain bio-active compounds in them. In vitro, in vivo studies and clinical trials of selected spices against various types of cancer are being specified in this review. Effect of certain putative dietary spices namely turmeric, clove, garlic, ginger, fennel, black cumin, cinnamon, pepper, saffron, rosemary, and chilli along with its role in cancer are being discussed. Literature search was conducted through PubMed, Google scholar, Science direct, and Scopus using the keywords "spice," "cancer," "natural medicine," "herbal compound," "bioactive compounds." About 4,000 published articles and 127 research papers were considered to grab the brief knowledge on spices and their anticancer potential on a predefined inclusion and exclusion criteria. PRACTICAL APPLICATION: Historically, spices and herbs are known for its traditional flavor, odor, and medicinal properties. Intensified risk of chronic and pervasive clinical conditions and increased cost of advanced drug treatments have developed a keen interest among researchers to explore the miscellaneous properties of herbal spices. Cancer is one of the deleterious causes of mortality affecting a huge number of populations worldwide. Arrays of cancer treatments including surgery, chemotherapy, and radiation therapy are used to compromise the disease but effective only when the size of the tumor is small. So, an effective treatment need to be developed that produces less side effects and herbal spices are found to be the promising agents. In this review, we illustrate about different in vitro, in vivo, and clinical studies of wide range of culinary spices having antineoplastic potential.

Thymoquinone Inhibits Proliferation and Migration of MDA-MB-231 Triple Negative Breast Cancer Cells by Suppressing Autophagy, Beclin-1 and LC3

BACKGROUND

Triple Negative Breast Cancer (TNBC) is an aggressive and highly heterogeneous subtype of breast cancer associated with poor prognosis. A better understanding of the biology of this complex cancer is needed to develop novel therapeutic strategies for the improvement of patient survival. We have previously demonstrated that Thymoquinone (TQ), the major phenolic compound found in Nigella sativa, induces anti-proliferative and anti-metastatic effects and inhibits in vivo tumor growth in orthotopic TNBC models in mice. Also, we have previously shown that Beclin-1 and LC3 autophagy genes contributes to TNBC cell proliferation, migration and invasion, suggesting that Beclin-1 and LC3 genes provide proto-oncogenic effects in TNBC. However, the role of Beclin-1 and LC3 in mediating TQ-induced anti-tumor effects in TNBC is not known.

OBJECTIVE

To investigate the effects of TQ on the major autophagy mediators, Beclin-1 and LC3 expression, as well as autophagic activity in TNBC cells.

METHODS

Cell proliferation, colony formation, migration and autophagy activity were evaluated using MTS cell viability, colony formation assay, wound healing and acridine orange staining assays, respectively. Western blotting and RT-PCR assays were used to investigate LC3 and Beclin-1 protein and gene expressions, respectively, in MDA-MB-231 TNBC cells in response to TQ treatments.

RESULTS

TQ treatment significantly inhibited cell proliferation, colony formation, migration and autophagic activity of MDA-MB-231 cells and suppressed LC3 and Beclin-1 expressions. Furthermore, TQ treatment led to the inhibition of Integrin-β1, VEGF, MMP-2 and MMP-9 in TNBC cells.

CONCLUSION

TQ inhibits autophagic activity and expression of Beclin-1 and LC3 in TNBC cells and suppresses pathways related to cell migration/invasion and angiogenesis, including Integrin-β1, VEGF, MMP-2 and MMP- 9, suggesting that TQ may be used to control autophagic activity and oncogenic signaling in TNBC.

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.

The effects of Nigella sativa on respiratory, allergic and immunologic disorders, evidence from experimental and clinical studies, a comprehensive and updated review

Nigella sativa (N. sativa) seed had been used traditionally due to several pharmacological effects. The updated experimental and clinical effects of N. sativa and its constituents on respiratory, allergic and immunologic disorders are provided in this comprehensive review article. Various databases including PubMed, Science Direct and Scopus were used. The preventive effects of N. sativa on pulmonary diseases were mainly due to its constituents such as thymoquinone, thymol, carvacrol and alpha-hederin. Extracts and constituents of N. sativa showed the relaxant effect, with possible mechanisms indicating its bronchodilatory effect in obstructive pulmonary diseases. In experimental animal models of different respiratory diseases, the preventive effect of various extracts and constituents of N. sativa was demonstrated by mechanisms such as antioxidant, immunomodulatory and antiinflammatory effects. Bronchodilatory and preventive effects of the plant and its components on asthma, COPD and lung disorders due to exposure to noxious agents as well as on allergic and immunologic disorders were also shown in the clinical studies. Various extracts and constituents of N. sativa showed pharmacological and therapeutic effects on respiratory, allergic and immunologic disorders indicating possible remedy effect of that the plant and its effective substances in treating respiratory, allergic and immunologic diseases.

Thymoquinone-Loaded Soluplus®-Solutol® HS15 Mixed Micelles: Preparation, In Vitro Characterization, and Effect on the SH-SY5Y Cell Migration

Thymoquinone (TQ) is the main active ingredient of Nigella sativa essential oil, with remarkable anti-neoplastic activities with anti-invasive and anti-migratory abilities on a variety of cancer cell lines. However, its poor water solubility, high instability in aqueous solution and pharmacokinetic drawbacks limits its use in therapy. Soluplus^® and Solutol^® HS15 were employed as amphiphilic polymers for developing polymeric micelles (SSM). Chemical and physical characterization studies of micelles are reported, in terms of size, homogeneity, zeta potential, critical micelle concentration (CMC), cloud point, encapsulation efficiency (EE%), load capacity (DL), in vitro release, and stability. This study reports for the first time the anti-migratory activity of TQ and TQ loaded in SSM (TQ-SSM) in the SH-SY5Y human neuroblastoma cell line. The inhibitory effect was assessed by the wound-healing assay and compared with that of the unformulated TQ. The optimal TQ-SSM were provided with small size (56.71 ± 1.41 nm) and spherical shape at ratio of 1:4 (Soluplus:Solutol HS15), thus increasing the solubility of about 10-fold in water. The entrapment efficiency and drug loading were 92.4 ± 1.6% and 4.68 ± 0.12, respectively, and the colloidal dispersion are stable during storage for a period of 40 days. The TQ-SSM were also lyophilized to obtain a more workable product and with increased stability. In vitro release study indicated a prolonged release of TQ. In conclusion, the formulation of TQ into SSM allows a bio-enhancement of TQ anti-migration activity, suggesting that TQ-SSM is a better candidate than unformulated TQ to inhibit human SH-SY5Y neuroblastoma cell migration.

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.

Thymoquinone, an Active Compound of Nigella sativa: Role in Prevention and Treatment of Cancer

Background:

Cancer is the leading cause of death worldwide and the current mode of cancer treatment causes side effects on normal cells and are still the key challenges in its’ treatment. However, natural products or active compounds of medicinal plants have shown to be safe, affordable, and effective in diseases cure.

Methods:

In this context, scientific studies evidence the health-promoting effects of natural products, which work through its anti-oxidant, anti-inflammatory, and anti-cancer activity. Thymoquinone (TM), a predominant active compound of Nigella sativa, has confirmed anti-neoplastic activity through its ability to regulate various genetic pathways. In addition, thymoquinone has established anti-cancerous effects through killing of various cancerous cells,and inhibiting the initiation, migration, invasion, and progression of the cancer. The anti-cancer effects of TM are chiefly mediated via regulating various cell signaling pathways such as VEGF, bcl2/bax ratio, p53, NF-kB, and oncogenes.

Results:

The anti-cancer drugs have limitations in efficacy and also causes adverse side effects on normal cells. The combination of anti-cancer drugs and thymoquinone improves the efficacy of drugs which is evident by decrease resistance to drugs and regulation of various cell signaling pathways. Moreover, combination of anti-cancer drugs as well as thymoquinone shows synergistic effect on killing of cancer cells and cells viability. Thus, TM, in combination with anti-cancer drugs, can be a good strategy in the management of various types of cancer.

Conclusion:

In this review article, we deliver an outline of thymoquinone role in cancer inhibition and prevention of cancer-based on in vivo and in vitro studies. Further studies on thymoquinone based on clinical trials are highly required to explore the benefits of thymoquinone in cancer management.

Metalloproteinases and Their Inhibitors: Potential for the Development of New Therapeutics

The metalloproteinase (MP) family of zinc-dependent proteases, including matrix metalloproteinases (MMPs), a disintegrin and metalloproteases (ADAMs), and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) plays a crucial role in the extracellular matrix (ECM) remodeling and degradation activities. A wide range of substrates of the MP family includes ECM components, chemokines, cell receptors, and growth factors. Metalloproteinases activities are tightly regulated by proteolytic activation and inhibition via their natural inhibitors, tissue inhibitors of metalloproteinases (TIMPs), and the imbalance of the activation and inhibition is responsible in progression or inhibition of several diseases, e.g., cancer, neurological disorders, and cardiovascular diseases. We provide an overview of the structure, function, and the multifaceted role of MMPs, ADAMs, and TIMPs in several diseases via their cellular functions such as proteolysis of other cell signaling factors, degradation and remodeling of the ECM, and other essential protease-independent interactions in the ECM. The significance of MP inhibitors targeting specific MMP or ADAMs with high selectivity is also discussed. Recent advances and techniques used in developing novel MP inhibitors and MP responsive drug delivery tools are also reviewed.

Quinonoids: Therapeutic Potential for Lung Cancer Treatment

Lung cancer is the leading cause of cancer-related deaths worldwide. Owing to its high incidence and mortality, the development and discovery of novel anticancer drugs is of great importance. In recent years, many breakthroughs have been achieved in the search for effective anticancer substances from natural products. Many anticancer drugs used clinically and proven to be effective are derived from natural products. Quinonoids, including naphthoquinones, phenanthrenequinones, benzoquinones, and anthraquinones, constitute a large group of natural bioactive compounds that widely exist in higher and lower plant species. Given that most of these compounds possess anticancer effects, they are applied in many cancer studies, especially in lung cancer research. They can promote apoptosis, induce autophagy, and inhibit proliferation, angiogenesis, and cell invasion and migration. Some drugs can enhance anticancer effects when combined with other drugs. Thus, quinonoids have broad application prospects in the treatment of lung cancer. Here, we summarize the previous studies on the antilung cancer activities of quinonoids together with their underlying mechanisms and analyze the common research targets with different effects so as to provide references for the discovery of quinonoids against lung cancer.

Antiproliferative Effects of Thymoquinone in MCF-7 Breast and HepG2 Liver Cancer Cells: Possible Role of Ceramide and ER Stress

We aimed to investigate the impact of thymoquinone (TQ), on sphingolipid metabolites, ER stress and apoptotic pathways in MCF-7 and HepG2 cancer cells. Antiproliferative effect was exerted in cancer cells via TQ incubation at different doses and durations. Cell viability was measured by MTT assay. Levels of sphingosine-1-phosphate (S1P), C16-C24 sphingomyelins (SM) and C16-C24 ceramides (CER) were determined by LC-MS/MS. Neutral sphingomyelinase (N-SMase) enzyme activity was measured by colorimetric assay and ceramide-1-phosphate (C1P) levels were determined by immunoassay. Nuclear factor kappa-b subunit 1 (NFκB1) and glucose-regulated protein 78-kd (GRP78) gene expressions were evaluated by quantitative PCR analysis, while NF-κB p65, GRP 78 and cleaved caspase-3 protein levels were assesed by immunofluorescence and western blot analysis. Incubation with TQ significantly decreased cell viability, S1P, C1P, NF-κB1 mRNA and NF-κB p65 protein levels in cancer cells compared to controls. A significant increase was observed in N-SMase activity, cellular levels of C16-C24 CERs and cleaved caspase-3 levels in cancer cells treated with TQ. GRP78 mRNA and protein levels also increased in cancer cells treated with TQ. In conclusion, TQ-induced ceramide accumulation and ER stress in conjunction with decreased S1P, C1P and NF-κB mediated cell survival may promote cancer cell death by triggering apoptosis.

Inhibitory effects on melanogenesis by thymoquinone are mediated through the β‑catenin pathway in B16F10 mouse melanoma cells

Thymoquinone (TQ) is a component found in the seeds of Nigella sativa, an annual plant growing on the Mediterranean coast, and is known for its anticancer and anti‑inflammatory effects. However, to date, at least to the best of our knowledge, limited studies are available examining the molecular mechanisms through which TQ inhibits melanogenesis. Accordingly, this study aimed to treat B16F10 mouse melanoma cells with TQ to investigate its apparent effects and its molecular regulatory mechanisms. Treatment of the B16F10 cells with 10, 15 and 20 µM of TQ for 48 h resulted in a dose‑dependent decrease in the expression of microphthalmia‑associated transcription factor (MITF), tyrosinase expression and tyrosinase activity, and these treatments simultaneously led to a decrease in the protein expression and transcription of β‑catenin, a Wnt signaling pathway protein. Pre‑treatment of the cells with the proteasome inhibitor, MG132, to confirm the inhibition of melanogenesis through the β‑catenin pathway by TQ treatment resulted in an increase in the expression of β‑catenin that was initially reduced by TQ, and the expression and activity of MITF and tyrosinase also increased. Pre‑treatment with LiCl, which is known to inactivate glycogen synthase kinase 3β (GSK3β) by inducing the phosphorylation of the Ser‑9 site, resulted in an increased phospho‑GSK3β expression accompanied by β‑catenin that was initially reduced by TQ, and the recovery of the expression and activity of tyrosinase was also confirmed. The transfection of S37A cDNA into B16F10 cells that overexpress β‑catenin resulted in the recovery of β‑catenin expression that was initially reduced by TQ, and this treatment also recovered the expression and activity of tyrosinase. When zebrafish eggs were treated with 1, 2.5 and 5 µM of TQ at 10 h following fertilization, their melanin content decreased in a dose‑dependent manner. On the whole, these findings demonstrated that the inhibition of melanogenesis in B16F10 mouse melanoma cells by TQ treatment resulted from the inhibition of the β‑catenin pathway and confirmed that TQ treatment inhibited melanogenesis in zebrafish.

Thymoquinone suppresses platelet-derived growth factor-BB-induced vascular smooth muscle cell proliferation, migration and neointimal formation

The excessive proliferation and migration of vascular smooth muscle cells (VSMCs) are mainly responsible for vascular occlusion diseases, such as pulmonary arterial hypertension and restenosis. Our previous study demonstrated thymoquinone (TQ) attenuated monocrotaline‐induced pulmonary arterial hypertension. The aim of the present study is to systematically examine inhibitory effects of TQ on platelet‐derived growth factor‐BB (PDGF‐BB)–induced proliferation and migration of VSMCs in vitro and neointimal formation in vivo and elucidate the potential mechanisms. Vascular smooth muscle cells were isolated from the aorta in rats. Cell viability and proliferation were measured in VSMCs using the MTT assay. Cell migration was detected by wound healing assay and Transwell assay. Alpha‐smooth muscle actin (α‐SMA) and Ki‐67‐positive cells were examined by immunofluorescence staining. Reactive oxygen species (ROS) generation and apoptosis were measured by flow cytometry and terminal deoxyribonucleotide transferase–mediated dUTP nick end labelling (TUNEL) staining, respectively. Molecules including the mitochondria‐dependent apoptosis factors, matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), PTEN/AKT and mitogen‐activated protein kinases (MAPKs) were determined by Western blot. Neointimal formation was induced by ligation in male Sprague Dawley rats and evaluated by HE staining. Thymoquinone inhibited PDGF‐BB–induced VSMC proliferation and the increase in α‐SMA and Ki‐67‐positive cells. Thymoquinone also induced apoptosis via mitochondria‐dependent apoptosis pathway and p38MAPK. Thymoquinone blocked VSMC migration by inhibiting MMP2. Finally, TQ reversed neointimal formation induced by ligation in rats. Thus, TQ is a potential candidate for the prevention and treatment of occlusive vascular diseases.

Thymoquinone (2-Isoprpyl-5-methyl-1, 4-benzoquinone) as a chemopreventive/anticancer agent: Chemistry and biological effects

Cancer remains the topmost disorders of the mankind and number of cases is unceasingly growing at unprecedented rates. Although the synthetic anti-cancer compounds still hold the largest market in the modern treatment of cancer, natural agents have always been tried and tested for potential anti-cancer properties. Thymoquinone (TQ), a monoterpene and main ingredient in the essential oil of Nigella sativa L. has got very eminent rankings in the traditional systems of medicine for its anti-cancer pharmacological properties. In this review we summarized the diverse aspects of TQ including its chemistry, biosynthesis, sources and pharmacological properties with a major concern being attributed to its anti-cancer efficacies. The role of TQ in different aspects involved in the pathogenesis of cancer like inflammation, angiogenesis, apoptosis, cell cycle regulation, proliferation, invasion and migration have been described. The mechanism of action of TQ in different cancer types has been briefly accounted. Other safety and toxicological aspects and some combination therapies involving TQ have also been touched. A detailed literature search was carried out using various online search engines like google scholar and pubmed regarding the available research and review accounts on thymoquinone upto may 2019. All the articles reporting significant addition to the activities of thymoquinone were selected. Additional information was acquired from ethno botanical literature focusing on thymoquinone. The compound has been the centre of attention for a long time period and researched regularly in quite considerable numbers for its various physicochemical, medicinal, biological and pharmacological perspectives. Thymoquinone is studied for various chemical and pharmacological activities and demonstrated promising anti-cancer potential. The reviewed reports confirmed the strong anti-cancer efficacy of thymoquinone. Further in-vitro and in-vivo research is strongly warranted regarding the complete exploration of thymoquinone in ethnopharmacological context.

In vitro study of the cytotoxicity of thymoquinone/curcumin fluorescent liposomes

In the present study, thymoquinone-loaded liposomes (Lip (TQ)), curcumin-encapsulated liposome (Lip (CUR)), and thymoquinone/curcumin-encapsulated liposome (Lip (TQ + CUR)) in addition to rhodamine-labeled thymoquinone/curcumin liposome (Lip (TQ + CUR + ROD)) were prepared with encapsulation efficiency exceeding 99%. The aim of the present study was to evaluate the effect of the different prepared formulations either labeled with the fluorescent dye (rhodamine B) or not on A549 lung cancer cells. Cytotoxicity of different formulations was assessed by MTT assay. Proliferation of A549 cells was significantly inhibited by the different formulations in a concentration-dependent manner in 72 h. The Lip (TQ + CUR + ROD) formulation demonstrated the lowest IC₅₀ value. To investigate its mechanism of action on A549 lung cancer cells, the Comet assay (for DNA damage) was done, the measurement of some oxidative stress parameters in addition to performing inverted fluorescence microscopy imaging. The results of the present study demonstrated the increased DNA damage, oxidative stress damage, and cell apoptosis in A549 treated with TQ, CUR, and rhodamine-encapsulated fluorescent liposome formulation as compared to untreated cells. The results obtained from the present study demonstrate the significant role of the TQ/CUR fluorescent liposomes on decreasing the viability of A549 lung cancer cells. Graphical abstract.

Cadmium induces A549 cell migration and invasion by activating ERK

Cadmium (Cd) is an established carcinogen that is involved in the progression of lung cancer. However, the mechanisms underlying this Cd-induced process have yet to be fully elucidated. The present study explored the potential roles of phosphorylated (p)-ERK in the Cd-induced migration and invasion of lung cancer cells. An MTT assay was performed to evaluate cell viability whilst western blot analysis and reverse transcription-quantitative PCR were used to detect the expression of protein and mRNA, respectively. Migration and invasion assays were performed to assess cell migratory and invasive abilities. The results demonstrated that exposure to Cd increased the expression of p-ERK in A549 cells. Cd also enhanced the migration and invasion of A549 cells, which could be blocked via U0126 treatment (an inhibitor of mitogen activated protein kinase). In addition, it was identified that Cd-induced expression of matrix metalloproteinases 2 mRNA was mediated by p-ERK. In conclusion, the present findings indicated that Cd induced A549 cell migration and invasion by activating ERK, and it was hypothesized that p-ERK could serve as a target in the clinical treatment of Cd-induced lung cancer.