The biochemical and morphological alterations following administration of melatonin, retinoic acid and Nigella sativa in mammary carcinoma: an animal model

Herbal Honey Preparations of Curcuma Xanthorriza and Black Cumin Protect against Carcinogenesis through Antioxidant and Immunomodulatory Activities in Sprague Dawley (SD) Rats Induced with Dimethylbenz(a)anthracene

BACKGROUND

Traditionally, Curcuma xanthorriza (CX), black cumin seed (BC), and honey have been used by the Indonesian people as medicinal ingredients to treat various health symptoms. CX extracts and BC have been proven in the laboratory as chemopreventive agents, antioxidants, and immunomodulators. In this study, we developed CX extract, BC oil, and honey into herbal honey preparations (CXBCH) and hypothesized that the preparations show chemopreventive activity. The purpose of the study was to determine the CXBCH potential as chemopreventive, antioxidant, and immunomodulatory.

METHOD

In this experimental laboratory research, antioxidant, immunomodulatory, and cytotoxic activities were tested on human mammary cancer cell lines (T47D cells) while the chemopreventive activity of the CXBCH preparations on Sprague Dawley (SD) rats induced with dimethylbenzene(a)anthracene (DMBA).

RESULTS

CXBCH preparations demonstrated immunomodulatory, antioxidant, and cytotoxic activities in T47D, Hela, and HTB-183 cells and in DMBA-induced SD rats, as the preparations inhibited tumor nodule formation, increased the number of CD4, CD8 and CD4CD25 cells, and glutathione-S-transferase (GST) activity, and decreased serum NO levels.

CONCLUSIONS

CXBCH preparations display chemopreventive, antioxidant, and immunomodulatory properties.

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.

Modulation of the immune system by melatonin; implications for cancer therapy

Immune system interactions within the tumour have a key role in the resistance or sensitization of cancer cells to anti-cancer agents. On the other hand, activation of the immune system in normal tissues following chemotherapy or radiotherapy is associated with acute and late effects such as inflammation and fibrosis. Some immune responses can reduce the efficiency of anti-cancer therapy and also promote normal tissue toxicity. Modulation of immune responses can boost the efficiency of anti-tumour therapy and alleviate normal tissue toxicity. Melatonin is a natural body agent that has shown promising results for modulating tumour response to therapy and also alleviating normal tissue toxicity. This review tries to focus on the immunomodulatory actions of melatonin in both tumour and normal tissues. We will explain how anti-cancer drugs may cause toxicity for normal tissues and how tumours can adapt themselves to ionizing radiation and anti-cancer drugs. Then, cellular and molecular mechanisms of immunoregulatory effects of melatonin alone or combined with other anti-cancer agents will be discussed.

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.

Molecular and cellular mechanisms of melatonin in breast cancer

Breast cancer is considered as one of the most important health problems due to its poor prognosis and high rate of mortality and new diagnosed cases. Annually, a great number of deaths are reported in men and women; this means that despite all the improvements in cancer diagnosis and treatment, still, an intense need for more effective approaches exists. Melatonin is a multivalent compound which has a hand in several cellular and molecular processes and therefore, is an appropriate candidate for treatment of many diseases like cancer. Currently, considerable properties of this agent have oriented the research towards investigating its effects specifically in breast cancer. In this review, we gathered a bunch of evidence in order to give a new sight for breast cancer treatment utilizing melatonin. We expect that in coming years, melatonin will become one of the most common therapeutic drugs with lesser side-effects than other chemotherapeutic drugs.

N-(benzylidene)-2-((2-hydroxynaphthalen-1-yl)diazenyl)benzohydrazides (1-2) (NCHDH and NTHDH) attenuate DMBA-induced breast cancer via Nrf2/NF-κB/apoptosis signaling

The present study investigated the effect of the N-(benzylidene)-2-((2-hydroxynaphthalen-1-yl)diazenyl)benzohydrazides (1-2) (NCHDH and NTHDH) against breast cancer using in vitro and in vivo approaches. The NCHDH and NTHDH significantly inhibited the growth of the MCF-7 cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The NCHDH and NTHDH treatment significantly inhibited the tumor size, tumor weight, and tumor volume, while it enhanced the survival and tumor free survival rate following 7,12-Dimethylbenz[a]anthracene (DMBA)-induced breast cancer. The NCHDH and NTHDH markedly attenuated the oxidative stress markers and induced the antioxidant level. The enzyme-linked immunosorbent assay (ELISA) showed significant reduction in the inflammatory cytokines production compared with the DMBA control. The NCHDH and NTHDH treatment significantly improved the histological features using hematoxylin and eosin (H and E) staining, Masson's trichrome, PAS (periodic acid Schiff), and Toluidine blue staining compared with the DMBA-induced group. The NCHDH and NTHDH treatment improved the hematological and serological parameters following DMBA-induced breast tumor compared with DMBA-induced group. Furthermore, the NCHDH and NTHDH treatment significantly enhanced the antioxidants signaling proteins such as nuclear factor erythroid 2-related factor 2 (Nrf2) and Heme oxygenase 1 (HO-1). The NCHDH and NTHDH enhanced the inhibitor of NF-κB (IκB) level, while it attenuated the NF-κB level. Similarly, the NCHDH and NTHDH showed marked increase in the apoptosis proteins such as Caspase-3, Caspase-9, and Bcl-2 Associated X-protein (Bax), while it inhibited the B-cell lymphoma 2 (Bcl-2) expression. In conclusion, the NCHDH and NTHDH significantly improved the DMBA-induced breast cancer via attenuating oxidative stress and inflammatory cytokines.

In vivo, in vitro and in silico anticancer investigation of fullerene C60 on DMBA induced breast cancer in rats

AIMS

The aim of the study was to determine the protective and therapeutic effect of fullerene C₆₀ nanoparticle on DMBA-induced breast cancer in rats.

MAIN METHODS

In vitro cell viability was determined by the WST-1 test. In vivo analysis was performed in female Wistar Albino rats. The expression of caspase-3, Bcl-2, Nrf-2, NF-κB, TNF-α, COX-2, p53, IL-6, IL-1α ve p38α (MAPK) proteins were assessed by western blotting. Furthermore, malondialdehyde (MDA), glutathione (GSH), catalase activity (CAT), total protein levels and DNA damage were investigated. In addition, tissues were evaluated by histopathologically. In in silico analysis, the binding affinities of the fullerene C₆₀ nanoparticle to transcription factors such as caspase-3, Bcl-2, Nrf-2, NF-κB, TNF-α, COX-2, VEGF and Akt were demonstrated by molecular docking.

KEY FINDINGS

Treatment of MCF-7 cells at various concentrations of fullerene C₆₀ (0.1 to 100 mg/ml) inhibited cell viability in a dose dependent manner. Fullerene C₆₀ treated rats exhibited considerable increase in the level of caspase-3 while decrease in the level of pro-survival protein Bcl-2. Bcl-2, NF-κB, TNF-α, COX-2, IL-6, IL-1α and p38α (MAPK) protein expression levels and malondialdehyde (MDA) levels were decreased in the C₆₀ + DMBA groups compared to the DMBA group. It was observed that caspase-3, Nrf-2 and p53 protein expression levels, glutathione (GSH) level, catalase activities (CAT) and total protein levels increased significantly which was further confirmed through the resulting DNA fragmentation.

SIGNIFICANCE

In silico assays, fullerene C₆₀ has been observed to have similar affinity to some crystal ligands, especially against cancer.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Anti-Estrogenic and Anti-Cell Proliferative Effect of Allyl Isothiocyanate in Chemoprevention of Chemically Induced Mammary Carcinogenesis in Rats

The anti-estrogenic and anti-cell proliferative effect of allyl isothiocyanate (AITC) was carried out by analyzing the status of sex hormones and its receptors and cell proliferative markers in chemically induced mammary carcinogenesis in rats. Mammary tumor was induced by a single dose of DMBA (25 mg/rat) and MNU (50 mg/kg bw) injected subcutaneously near mammary gland. RT-PCR, western blotting and immunohistochemical analysis of mammary tissues show an upregulation of ER-α, PR, aromatase, PCNA, cyclin D1 and AgNORs staining and down regulation of p53 expression as well as plasma estradiol, prolactin and testosterone levels increased in DMBA and MNU-induced tumor bearing rats. Oral administration of AITC at a dose of 20 mg/kg bw restored the levels of sex hormones and its receptors, aromatase, cell proliferative markers and AgNORs staining near to normal levels. Molecular docking studies also supported these findings. The results suggest that anti-estrogenic and anti-proliferative effect of AITC prevent the development of DMBA and MNU-induced mammary carcinogenesis in rat.

Night Shift Work Increases the Risks of Multiple Primary Cancers in Women: A Systematic Review and Meta-analysis of 61 Articles

A growing number of studies have examined associations between night shift work and the risks of common cancers among women, with varying conclusions. We did a meta-analysis to identify whether long-term night shift work increased the risks of common cancers in women. We enrolled 61 articles involving 114,628 cases and 3,909,152 participants from Europe, North America, Asia, and Australia. Risk estimates were performed with a random-effect model or a fixed-effect model. Subgroup analyses and meta-regression analyses about breast cancer were conducted to explore possible sources of heterogeneity. In addition, we carried out a dose-response analysis to quantitatively estimate the accumulative effect of night shift work on the risk of breast cancer. A positive relationship was revealed between long-term night shift work and the risks of breast [OR = 1.316; 95% confidence interval (CI), 1.196-1.448], digestive system (OR = 1.177; 95% CI, 1.065-1.301), and skin cancer (OR = 1.408; 95% CI, 1.024-1.934). For every 5 years of night shift work, the risk of breast cancer in women was increased by 3.3% (OR = 1.033; 95% CI, 1.012-1.056). Concerning the group of nurses, long-term night shift work presented potential carcinogenic effect in breast cancer (OR = 1.577; 95% CI, 1.235-2.014), digestive system cancer (OR = 1.350; 95% CI, 1.030-1.770), and lung cancer (OR = 1.280; 95% CI, 1.070-1.531). This systematic review confirmed the positive association between night shift work and the risks of several common cancers in women. We identified that cancer risk of women increased with accumulating years of night shift work, which might help establish and implement effective measures to protect female night shifters. Cancer Epidemiol Biomarkers Prev; 27(1); 25-40. ©2018 AACR.

RNA-Seq transcriptome analysis shows anti-tumor actions of melatonin in a breast cancer xenograft model

Melatonin is a pleiotropic anti-cancer molecule that controls cancer growth by multiple mechanisms. RNA-Seq can potentially evaluate therapeutic response and its use in xenograft tumor models can differentiate the changes that occur specifically in tumor cells or in the tumor microenvironment (TME). Melatonin actions were evaluated in a xenograft model of triple-negative breast cancer. Balb/c nude mice bearing MDA-MB-231 tumors were treated with melatonin or vehicle. RNA-Seq was performed on the Illumina HiSeq. 2500 and data were mapped against human and mouse genomes separately to differentiate species-specific expression. Differentially expressed (DE) genes were identified and Weighted Gene Co-expression Network Analysis (WGCNA) was used to detect clusters of highly co-expressed genes. Melatonin treatment reduced tumor growth (p < 0.01). 57 DE genes were identified in murine cells, which represented the TME, and were mainly involved in immune response. The WGCNA detected co-expressed genes in tumor cells and TME, which were related to the immune system among other biological processes. The upregulation of two genes (Tnfaip8l2 and Il1f6) by melatonin was validated in the TME, these genes play important roles in the immune system. Taken together, the transcriptomic data suggests that melatonin anti-tumor actions occur through modulation of TME in this xenograft tumor model.

Shiftwork Association with Cardiovascular Diseases and Cancers Among Healthcare Workers: A Literature Review

The round-the-clock demands of healthcare services, coupled with the shortage of healthcare providers in many parts of the world, have made shiftwork widespread among healthcare workers. Understanding how to mitigate unfavourable effects of shiftwork on well-being is essential to improve health promotion, to prevent disease prevention, and to increase quality of life. This comprehensive review aims to present evidence linking shiftwork with cardiovascular diseases and cancers among healthcare workers. Several studies have demonstrated evidence indicating the relationship between long-term exposure to shiftwork tempo and a higher risk of cardiovascular diseases. Health workers are increasingly witnesing unfavourable effects of shiftwork on their health state. Shiftwork disturbs circadian rhythm and cardiopulmonary processes, leading to adverse health outcomes. Increasing prevalence of shiftwork in healthcare industries due to population expansion and public health threat of cancers call for investigation towards a better understanding of the underlying mechanism of shiftwork-induced diseases. The shift work period has been considered in different studies using various criteria, resulting in inconsistent definition of measurement criteria leading to misclassification of the study population. There is a need for a more considerable and holistic effort towards standardization of shiftwork definition and conduct an assessment to establish a more conveniently appliacable framework for intervention strategies.

Melatonin: An Anti-Tumor Agent in Hormone-Dependent Cancers

Melatonin (N-acetyl-5-methoxytryptamine) is a hormone synthesized and secreted by the pineal gland mainly during the night, since light exposure suppresses its production. Initially, an implication of this indoleamine in malignant disease was described in endocrine-responsive breast cancer. Data from several clinical trials and multiple experimental studies performed both in vivo and in vitro have documented that the pineal hormone inhibits endocrine-dependent mammary tumors by interfering with the estrogen signaling-mediated transcription, therefore behaving as a selective estrogen receptor modulator (SERM). Additionally, melatonin regulates the production of estradiol through the control of the enzymes involved in its synthesis, acting as a selective estrogen enzyme modulator (SEEM). Many more mechanisms have been proposed during the past few years, including signaling triggered after activation of the membrane melatonin receptors MT-1 and MT-2, or else intracellular actions targeting molecules such as calmodulin, or binding intranuclear receptors. Similar results have been obtained in prostate (regulation of enzymes involved in androgen synthesis and modulation of androgen receptor levels and activity) and ovary cancer. Thus, tumor metabolism, gene expression, or epigenetic modifications are modulated, cell growth is impaired and angiogenesis and metastasis are inhibited. In the last decade, many more reports have demonstrated that melatonin is a promising adjuvant molecule with many potential beneficial consequences when included in chemotherapy or radiotherapy protocols designed to treat endocrine-responsive tumors. Therefore, in this state-of-the-art review, we aim to compile the knowledge about the oncostatic actions of the indoleamine in hormone-dependent tumors, and the latest findings concerning melatonin actions when administered in combination with radio- or chemotherapy in breast, prostate, and ovary cancers. As melatonin has no toxicity, it may be well deserve to be considered as an endogenously generated agent helpful in cancer prevention and treatment.

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

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

Review on the Potential Therapeutic Roles of Nigella sativa in the Treatment of Patients with Cancer: Involvement of Apoptosis: - Black cumin and cancer

Nigella sativa (N. sativa, family Ranunculaceae) is a medicinal plant that has been widely used for centuries throughout the world as a natural remedy. A wide range of chemical compounds found in N. sativa expresses its vast therapeutic effects. Thymoquinone (TQ) is the main component (up to 50%) in the essential oil of N. sativa. Also, pinene (up to 15%), p-cymene (40%), thymohydroquinone (THQ), thymol (THY), and dithymoquinone (DTQ) are other pharmacologically active compounds of its oil. Other terpenoid compounds, such as carvacrol, carvone, 4-terpineol, limonenes, and citronellol, are also found in small quantities in its oil. The main pharmacological characteristics of this plant are immune system stimulatory, anti-inflammatory, hypotensive, hepatoprotective, antioxidant, anti-cancer, hypoglycemic, anti-tussive, milk production, uricosuric, choleretic, anti-fertility, and spasmolytic properties. In this regard, we have searched the scientific databases PubMed, Web of Science, and Google Scholar with keywords of N. sativa, anti-cancer, apoptotic effect, antitumor, antioxidant, and malignancy over the period from 2000 to 2017. The effectiveness of N. sativa against cancer in the blood system, kidneys, lungs, prostate, liver, and breast and on many malignant cell lines has been shown in many studies, but the molecular mechanisms behind that anti-cancer role are still not clearly understood. From among the many effects of N. sativa, including its anti-proliferative effect, cell cycle arrest, apoptosis induction, ROS generation, anti-metastasis/anti-angiogenesis effects, Akt pathway control, modulation of multiple molecular targets, including p53, p73, STAT-3, PTEN, and PPAR-γ, and activation of caspases, the main suggestive anti-cancer mechanisms of N. sativa are its free radical scavenger activity and the preservation of various anti-oxidant enzyme activities, such as glutathione peroxidase, catalase, and glutathione-S-transferase. In this review, we highlight the molecular mechanisms of apoptosis and the anti-cancer effects of N. sativa, with a focus on its molecular targets in apoptosis pathways.

Melatonin and IL-25 modulate apoptosis and angiogenesis mediators in metastatic (CF-41) and non-metastatic (CMT-U229) canine mammary tumour cells

BACKGROUND

Melatonin has oncostatic actions and IL-25 is active in inflammatory processes that induce apoptosis in tumor cells AIM: The aim of this study was to evaluate melatonin and IL-25 in metastatic (CF-41) and non-metastatic (CMT-U229) canine mammary tumor cells cultured as monolayers and tridimensional structures.

MATERIALS AND METHODS

The cells were treated with melatonin, IL-25 and IL-17B silencing gene and performed cell viability, gene and protein expression of caspase-3 and VEGFA (Vascular endothelial growth factor A) and an apoptosis membrane protein array.

RESULTS

Treatment with 1 mM of melatonin reduced cell viability of both tumor cell lines, all treatments alone and combined significantly increased caspase-3 cleaved and proteins involved in the apoptotic pathway and reduced pro-angiogenic VEGFA, confirming the effectiveness of these potential promising treatments.

CONCLUSION

This is the first study evaluating the potential use of these strategies in CF-41 and CMT-U229 cell lines and together encourages subsequent in vitro and in vivo studies for further exploration of clinical applications.

Ulva lactuca polysaccharides prevent Wistar rat breast carcinogenesis through the augmentation of apoptosis, enhancement of antioxidant defense system, and suppression of inflammation

BACKGROUND

Recently, several research studies have been focused on the isolation and function of the polysaccharides derived from different algal species, which revealed multiple biological activities such as antioxidant and antitumor activities. This study assesses the possible breast cancer chemopreventive properties of common seaweeds, sea lettuce, Ulva lactuca (ulvan) polysaccharides using in vitro bioassays on human breast cancer cell line (MCF-7) and an in vivo animal model of breast carcinogenesis.

METHODS

Cytotoxic effect of ulvan polysaccharides on MCF-7 was tested in vitro. For an in vivo investigation, a single dose of 25 mg/kg body weight 7,12-dimethylbenz[a]anthracene (DMBA) and ulvan polysaccharides (50 mg/kg body weight every other day) for 10 weeks were administered orally to the Wistar rats.

RESULTS

Deleterious histopathological alterations in breast tissues including papillary cyst adenoma and hyperplasia of ductal epithelial lining with intraluminal necrotic materials and calcifications were observed in the DMBA-administered group. These lesions were prevented in the DMBA-administered group treated with ulvan polysaccharides. The immunohistochemical sections depicted that the treatment of DMBA-administered rats with ulvan polysaccharides markedly increased the lowered pro-apoptotic protein, p53, and decreased the elevated anti-apoptotic marker, bcl2, expression in the breast tissue. The elevated lipid peroxidation and the suppressed antioxidant enzyme activities in DMBA-administered control were significantly prevented by the treatment with ulvan polysaccharides. The elevated levels of inflammatory cytokines tumor necrosis factor-α and nitric oxide were significantly ameliorated in DMBA-administered rats treated with ulvan polysaccharides as compared to DMBA-administered control.

CONCLUSION

In conclusion, ulvan polysaccharides at the level of initiation and promotion might have potential chemopreventive effects against breast carcinogenesis. These preventive effects may be mediated through the augmentation of apoptosis, suppression of oxidative stress and inflammation, and enhancement of antioxidant defense system.

Recent advances on the anti-cancer properties of Nigella sativa, a widely used food additive

The use of naturally-occurring agents to regulate tumorigenesis is on the rise. Several herbal extracts, pure plant-derived active constituents, and food additives have been reported to possess potent anti-cancer properties and cancer-ameliorating effects. The wide-range anti-cancer effects of Nigella sativa, also known as black seed or black cumin, have been extensively studied using different in vitro and in vivo models. Here, we provide a comprehensive, analytical review of the reported anti-cancer properties of N. sativa seed extracts. This review focuses on analyzing experimental findings related to the ability of N. sativa to exert anti-proliferative, pro-apoptotic, anti-oxidant, cytotoxic, anti-mutagenic, anti-metastatic, and NK cytotoxic activity enhancing effects against various primary cancer cells and cancer cell lines. Moreover, we underline the molecular mechanisms of action and the signal transduction pathways implicated in the suppression of tumorigenesis by N. sativa. The major signaling pathway utilized by N. sativa to manifest its anti-cancer activity is the iNOS signaling pathway. This review underscores the recent developments that highlight an effective therapeutic potential of N. sativa to suppress tumor development, reduce tumor incidence, and ameliorate carcinogenesis. In sum, experimental findings reported in the last two decades strongly suggest that N. sativa fractions could serve, alone or in combination with known chemotherapeutic drugs, as effective agents to control tumor initiation, growth, and metastasis, and hence, treatment of a wide range of cancers.

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N. sativa exerts cytotoxic, pro-apoptotic, anti-proliferative, anti-oxidant, anti-mutagenic, and anti-metastatic effects.

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Augmentation of NK cytotoxic activity is a one molecular mechanism by which N. sativa manifests its anti-cancer activity.

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The anti-cancer effects of N. sativa are primarily mediated via iNOS, p53, and caspase signaling pathways.

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N. sativa extracts can potentially be employed in the development of effective anti-cancer therapeutic agents.

Effects of Lycopene Alone or Combined with Melatonin on Methotrexate-Induced Nephrotoxicity in Rats

Methotrexate (Mtx), used for its anticancer and immunsuppresive properties, is known to be a nephrotoxic agent. We aimed to investigate the effects of lycopene (Lyc) alone or combined with melatonin (Mel) on Mtx- induced nephrotoxicity since both of these agents have antioxidant and anti-inflammatory effects. Nephrotoxicity was induced by intraperitoneal administration of methotrexate at a dose of 20 mg/kg. Treatment both with Lyc alone and Lyc combined with Mel provided significant reduction in tumor necrosis factor-alpha, interleukin 1-beta and ceruloplasmin levels in Mtx administered rats. Hovewer, Lyc combined with Mel provided a significant reduction also in NO levels. Hstopathological examination showed that there was an obvious improvement in the degenerative changes compared to Mtx administrated group with the Lyc combined Mel group giving best protection. In conclusion Lyc alone and combined with Mel provided significant improvement against renal damage caused by Mtx, preseumably via antioxidant and anti-inflammatory activities.

Chemical composition of Nigella sativa Linn: Part 2 Recent advances

The black cumin or Nigella sativa L. seeds have many acclaimed medicinal properties such as bronchodilatory, hypotensive, antibacterial, antifungal, analgesic, anti-inflammatory and immunopotentiating. This review article is an update on the previous article published on Nigella sativa L. in this journal in 1999. It covers the medicinal properties and chemical syntheses of the alkaloids isolated from the seeds of the herb.

Thymoquinone Could Increase The Efficacy of Tamoxifen Induced Apoptosis in Human Breast Cancer Cells: An In Vitro Study

Objective

Thymoquinone (TQ), as the main component of Nigella Sativa plant, shows anticancer properties. This study was aimed to evaluate the combined effect of TQ and Tamoxifen (TAM) on viability and apoptosis of human breast cancer cell lines.

Materials and Methods

In this experimental study, estrogen positive MCF-7 and estrogen negative MDA-MB-231 human breast cancer cell lines were induced by TAM (2 µM) or different doses of TQ (50, 75, 100, 150 µM), individually or in combination. Cell viability and apoptosis were investigated by MTT assay and TdT-mediated deoxy-uracil nick end labeling (TUNEL) assay; Acridine orange (AO)/Ethidium bromide (EB) staining respectively. Data were analyzed by one way ANOVA and P<0.05 was considered significant.

Results

In 24 hours treatment, TAM and all doses of TQ, solely or in combination, significantly reduced cell viability of both cell lines, except in MCF-7 cells treated with 50 µM TQ, and MDA-MB-231 cells treated with 50 or 75 µM TQ (P<0.01). After 48 hours treatment, cell viability of both cell lines was reduced in all treated groups (P<0.05). Remarkable apoptotic index was observed in combination treatment of MCF-7 or MDA-MB-231 cell lines with TAM and TQ (P<0.001).

Conclusion

The synergistic effect of TQ and TAM on human breast cancer cell lines showed cell viability reduction as well as apoptosis induction, independent to estrogen.

Melatonin, an inhibitory agent in breast cancer

BACKGROUND

The heterogeneous nature of breast cancer makes it one of the most challenging cancers to treat. Due to the stimulatory effect of estrogen in mammary cancer progression, anti-estrogenic agents like melatonin have found their way into breast cancer treatment. Further studies confirmed a reverse correlation between nocturnal melatonin levels and the development of mammary cancer. In this study we reviewed the molecular inhibitory effects of melatonin in breast cancer therapy.

METHODS

To open access the articles, Google scholar and science direct were used as a motor search. We used from valid external and internal databases. To reach the search formula, we determined mean key words like breast cancer, melatonin, cell proliferation and death. To retrieval the related articles, we continuously search the articles from 1984 to 2015. The relevance and the quality of the 480 articles were screened; at least we selected 80 eligible articles about melatonin molecular mechanism in breast cancer.

RESULT

The results showed that melatonin not only inhibits breast cancer cell growth, but also is capable of inhibiting angiogenesis, cancer cell invasion, and telomerase activity. Interestingly this hormone is able to induce apoptosis through the suppression or induction of a wide range of signaling pathways. Moreover, it seems that the concomitant administration of melatonin with other conventional chemotherapy agents had beneficial effects for patients with breast cancer, by alleviating unfavorable effects of those agents and enhancing their efficacy.

CONCLUSION

The broad inhibitory effects of melatonin in breast cancer make it a promising agent and may add it to the list of potential drugs in treatment of this cancer.

Melatonin: an inhibitor of breast cancer

The present review discusses recent work on melatonin-mediated circadian regulation, the metabolic and molecular signaling mechanisms that are involved in human breast cancer growth, and the associated consequences of circadian disruption by exposure to light at night (LEN). The anti-cancer actions of the circadian melatonin signal in human breast cancer cell lines and xenografts heavily involve MT1 receptor-mediated mechanisms. In estrogen receptor alpha (ERα)-positive human breast cancer, melatonin suppresses ERα mRNA expression and ERα transcriptional activity via the MT1 receptor. Melatonin also regulates the transactivation of other members of the nuclear receptor superfamily, estrogen-metabolizing enzymes, and the expression of core clock and clock-related genes. Furthermore, melatonin also suppresses tumor aerobic metabolism (the Warburg effect) and, subsequently, cell-signaling pathways critical to cell proliferation, cell survival, metastasis, and drug resistance. Melatonin demonstrates both cytostatic and cytotoxic activity in breast cancer cells that appears to be cell type-specific. Melatonin also possesses anti-invasive/anti-metastatic actions that involve multiple pathways, including inhibition of p38 MAPK and repression of epithelial-mesenchymal transition (EMT). Studies have demonstrated that melatonin promotes genomic stability by inhibiting the expression of LINE-1 retrotransposons. Finally, research in animal and human models has indicated that LEN-induced disruption of the circadian nocturnal melatonin signal promotes the growth, metabolism, and signaling of human breast cancer and drives breast tumors to endocrine and chemotherapeutic resistance. These data provide the strongest understanding and support of the mechanisms that underpin the epidemiologic demonstration of elevated breast cancer risk in night-shift workers and other individuals who are increasingly exposed to LEN.

Melatonin: an inhibitor of breast cancer

The present review discusses recent work on melatonin-mediated circadian regulation, the metabolic and molecular signaling mechanisms that are involved in human breast cancer growth, and the associated consequences of circadian disruption by exposure to light at night (LEN). The anti-cancer actions of the circadian melatonin signal in human breast cancer cell lines and xenografts heavily involve MT1 receptor-mediated mechanisms. In estrogen receptor alpha (ERα)-positive human breast cancer, melatonin suppresses ERα mRNA expression and ERα transcriptional activity via the MT1 receptor. Melatonin also regulates the transactivation of other members of the nuclear receptor superfamily, estrogen-metabolizing enzymes, and the expression of core clock and clock-related genes. Furthermore, melatonin also suppresses tumor aerobic metabolism (the Warburg effect) and, subsequently, cell-signaling pathways critical to cell proliferation, cell survival, metastasis, and drug resistance. Melatonin demonstrates both cytostatic and cytotoxic activity in breast cancer cells that appears to be cell type-specific. Melatonin also possesses anti-invasive/anti-metastatic actions that involve multiple pathways, including inhibition of p38 MAPK and repression of epithelial-mesenchymal transition (EMT). Studies have demonstrated that melatonin promotes genomic stability by inhibiting the expression of LINE-1 retrotransposons. Finally, research in animal and human models has indicated that LEN-induced disruption of the circadian nocturnal melatonin signal promotes the growth, metabolism, and signaling of human breast cancer and drives breast tumors to endocrine and chemotherapeutic resistance. These data provide the strongest understanding and support of the mechanisms that underpin the epidemiologic demonstration of elevated breast cancer risk in night-shift workers and other individuals who are increasingly exposed to LEN.

The effect of physical training on the N-methyl-N-nitrosourea-induced mammary carcinogenesis of Sprague-Dawley rats

The impact of physical activity on carcinogenesis has been demonstrated in many studies. Taking into account the discrepant results of physical exercise on the cell proliferation and apoptosis of breast cancer, we aimed to examine the impact of physical training on N-methyl-N-nitrosourea-(MNU)-induced mammary carcinogenesis. Fifty female rats were divided into four groups according to the intensity of physical activity they undertook. The number of developed tumors, tumor volume, and histopathological diagnoses were noted. Apoptosis and cell proliferation were studied by the number of TUNEL-positive and Ki-67-expressing cells. We demonstrated a statistically significant decrease in the tumor number between all trained groups and the control group. The results were most pronounced in the group with a moderate intensity of training. Moreover, we showed a decrease in tumor volume as training intensity increased, though the differences were not statistically significant. The mean number of TUNEL-positive cancer cells was significantly higher in the training groups than in the control group. These data suggest that physical training, especially of moderate intensity, may alleviate MNU-induced mammary carcinogenesis. The results could suggest that physical exercise-induced apoptosis may be a protective mechanism.

Cardio-protective and anti-cancer therapeutic potential of Nigella sativa

Nigella sativa is the miraculous plant having a lot of nutritional and medicinal benefits, and attracts large number of nutrition and pharmacological researchers. N. sativa seed composition shows that it is the blessing of nature and it contains and many bioactive compounds like thymoquinone, α-hederin, alkaloids, flavonoids, antioxidants, fatty acids many other compounds that have positive effects on curing of different diseases. Several medicinal properties of N. sativa like its anti-cancer, anti-inflammatory, anti-diabetic, antioxidant activities and many others are well acknowledged. However, this article focuses on activity of N. sativa against cardiovascular diseases and cancer. For gathering required data the authors went through vast number of articles using search engines like Science direct, ELSEVIER, Pub Med, Willey on Line Library and Google scholar and the findings were classified on the basis of relevance of the topic and were reviewed in the article. N. sativa is rich source of different biologically active compounds and is found effective in controlling number of cardiovascular diseases and various cancers both in vivo and in vitro studies.

Tangeretin, a citrus pentamethoxyflavone, exerts cytostatic effect via p53/p21 up-regulation and suppresses metastasis in 7,12-dimethylbenz(α)anthracene-induced rat mammary carcinoma

Breast cancer is the most commonly diagnosed cancer among women worldwide, which is characterized by unregulated cell growth and metastasis. Many bioactive compounds of plant origin such as tangeretin have been shown to possess potent antioxidant and anticancerous properties. In the present study we have investigated the chemotherapeutic effect of tangeretin against 7,12-dimethylbenz(α)anthracene (DMBA)-induced rat mammary carcinogenesis and studied its underlying mechanism of action. Breast cancer was induced by "air pouch technique" with a single dose of 25mg/kg of DMBA. Tangeretin (50 mg/kg) was administered orally for four weeks. Remarkably, tangeretin treatment controlled the growth of cancer cells which was clearly evidenced by morphological and histological analysis. Also, serum levels of estradiol, progesterone and prolactin; lipid bound sialic acid and total sialic acid and the tissue levels of nitric oxide and protein carbonyls of cancer induced animals were decreased upon tangeretin treatment. Staining of breast tissues for nucleolar organizer regions, mast cells, glycoproteins, lipids and collagen showed that tangeretin treatment to breast cancer induced rats significantly reduced tumorigenesis. Oral tangeretin treatment also effectively reduced the tumor cell proliferation markers such as PCNA, COX-2 and Ki-67. Further, tangeretin treatment arrested the cancer cell division at the G1/S phase via p53/p21 up-regulation and inhibited metastasis by suppressing matrix metalloproteinase (MMP)-2, MMP-9 and vascular endothelial growth factor. Taken together, the data provides new evidence on the mechanism of action of tangeretin in breast cancer and hence extends the hypothesis supporting its potential use in chemotherapy.

Supplementation of fish oil augments efficacy and attenuates toxicity of 5-fluorouracil in 1,2-dimethylhydrazine dihydrochloride/dextran sulfate sodium-induced colon carcinogenesis

PURPOSE

5-Fluorouracil (5-FU) is used for the treatment of colorectal cancer, but has low therapeutic response rate and severe side effects. Recently, fish oil (FO) rich in n-3 polyunsaturated fatty acids has been preferred to chemosensitize tumor cells to anticancer drugs. Therefore, the current study is designed to evaluate chemotherapeutic efficacy and toxicity profile of 5-FU in combination with FO in 1,2-dimethylhydrazine dihydrochloride/dextran sulfate sodium (DMH/DSS)-induced colon cancer model.

METHODS

The therapeutic efficacy of 5-FU along with FO was analyzed through assessment of survival rate, tumor burden, volume, serum sialic acid levels, cytokeratin 19 (CK19) expression and index of cell proliferation such as cell cycle progression. Toxicological aspects were evaluated by standard functional and structural parameters related to spleen, gastrointestinal, liver and kidney.

RESULTS

In the present study, 5-FU in combination with FO increased the survival rate in carcinogen-treated animals. Synergism of 5-FU and FO was also reflected in significant inhibition in tumor growth and serum sialic acid levels in DMH/DSS model. Moreover, the combination dosage significantly augmented the inhibition of cell cycle progression, as shown by CK19 expression. Additionally, FO ameliorated hematologic depression, gastrointestinal, hepatic and renal toxicity caused by 5-FU as substantiated by a marked improvement in structural and functional alterations of these organs.

CONCLUSION

The supplementation of FO is potentially a promising option for increasing the therapeutic potential and mitigating the side effects of 5-FU.

Therapeutic Implications of Black Seed and Its Constituent Thymoquinone in the Prevention of Cancer through Inactivation and Activation of Molecular Pathways

The cancer is probably the most dreaded disease in both men and women and also major health problem worldwide. Despite its high prevalence, the exact molecular mechanisms of the development and progression are not fully understood. The current chemotherapy/radiotherapy regime used to treat cancer shows adverse side effect and may alter gene functions. Natural products are generally safe, effective, and less expensive substitutes of anticancer chemotherapeutics. Based on previous studies of their potential therapeutic uses, Nigella sativa and its constituents may be proved as good therapeutic options in the prevention of cancer. Black seeds are used as staple food in the Middle Eastern Countries for thousands of years and also in the treatment of diseases. Earlier studies have shown that N. sativa and its constituent thymoquinone (TQ) have important roles in the prevention and treatment of cancer by modulating cell signaling pathways. In this review, we summarize the role of N. sativa and its constituents TQ in the prevention of cancer through the activation or inactivation of molecular cell signaling pathways.

A meta-analysis on dose-response relationship between night shift work and the risk of breast cancer

This study aimed to conduct a systematic review to sum up evidence of the associations between different aspects of night shift work and female breast cancer using a dose-response meta-analysis approach. We systematicly searched all cohort and case-control studies published in English on MEDLINE, Embase, PSYCInfo, APC Journal Club and Global Health, from January 1971 to May 2013. We extracted effect measures (relative risk, RR; odd ratio, OR; or hazard ratio, HR) from individual studies to generate pooled results using meta-analysis approaches. A log-linear dose-response regression model was used to evaluate the relationship between various indicators of exposure to night shift work and breast cancer risk. Downs and Black scale was applied to assess the methodological quality of included studies. Ten studies were included in the meta-analysis. A pooled adjusted relative risk for the association between 'ever exposed to night shift work' and breast cancer was 1.19 [95% confidence interval (CI) 1.05-1.35]. Further meta-analyses on dose-response relationship showed that every 5-year increase of exposure to night shift work would correspondingly enhance the risk of breast cancer of the female by 3% (pooled RR = 1.03, 95% CI 1.01-1.05; Pheterogeneity < 0.001). Our meta-analysis also suggested that an increase in 500-night shifts would result in a 13% (RR = 1.13, 95% CI 1.07-1.21; Pheterogeneity = 0.06) increase in breast cancer risk. This systematic review updated the evidence that a positive dose-response relationship is likely to present for breast cancer with increasing years of employment and cumulative shifts involved in the work.

Molecular mechanisms of melatonin's inhibitory actions on breast cancers

Melatonin is involved in many physiological functions and it plays an important role in many pathological processes as well. Melatonin has been shown to reduce the incidence of experimentally induced cancers and can significantly inhibit the growth of some human tumors, namely hormone-dependent cancers. The anticancer effects of melatonin have been observed in breast cancer, both in in vivo with models of chemically induced rat mammary tumors, and in vitro studies on human breast cancer cell lines. Melatonin acts at different physiological levels and its antitumoral properties are supported by a set of complex, different mechanisms of action, involving apoptosis activation, inhibition of proliferation, and cell differentiation.

Human breast adenocarcinoma cytotoxicity and modulation of 7,12-dimethylbenz[a]anthracene-induced mammary carcinoma in Balb/c mice by Acacia catechu (L.f.) Wild heartwood

OBJECTIVE

The chemopreventive potential of (+)-catechin-rich extract of Acacia catechu (L.f.) Willd. heartwood (AQCE) was evaluated against human breast adenocarcinoma cell line (MCF-7) and 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary carcinoma in Balb/c mice.

METHODS

Cell cytotoxicity was investigated using different colorimetric assays. Apoptosis was observed using diphenylamine assay and fluorescent microscopy. AQCE was further evaluated for antitumor activity against DMBA-induced mammary carcinoma. The levels of tumor markers and oxidative stress were measured. Furthermore, level of transcription factors was measured by enzyme-linked immunosorbent assay.

RESULTS

The results showed that administration of AQCE showed a dose-dependent growth inhibition response and DNA fragmentation in MCF-7 cells. Tumor multiplicity was significantly decreased to 42.91% with AQCE when compared with DMBA-treated animals. The levels of tumor markers such as total sialic acid and lipid-associated sialic acid were substantially increased after DMBA treatment. However, AQCE treatment restored tumor markers level. AQCE also significantly reduced elevated levels of nitrite and malondialdehyde in DMBA-treated animals. Additionally, AQCE also increased the activities of antioxidant enzymes, viz., catalase, superoxide dismutase, total thiol, reduced glutathione, protein thiol, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase in the mammary tissue and liver mitochondria of DMBA-administered animals. Significant increase in the protein levels of p53, c-jun, and p65 were observed in DMBA-treated mice, whereas less expression was observed in AQCE-treated animals. Eventually, AQCE also significantly improved body weight and maintained the mammary tissue architecture in normal range.

CONCLUSIONS

The present data strongly suggest that anticancer potentiality of (+)-catechin-rich AQCE may be attributable to its ability to positively modulate tumor markers as well as the antioxidant system that could decompose the peroxides and, thereby, offer a protection against lipid peroxidation and linked to the expression of transcription factors during DMBA-induced mammary carcinoma.

Anticancer activity of Nigella sativa (black seed) - a review

Nigella sativa (N. sativa) seed has been an important nutritional flavoring agent and natural remedy for many ailments for centuries in ancient systems of medicine, e.g. Unani, Ayurveda, Chinese and Arabic Medicines. Many active components have been isolated from N. sativa, including thymoquinone, thymohydroquinone, dithymoquinone, thymol, carvacrol, nigellimine-N-oxide, nigellicine, nigellidine and alpha-hederin. In addition, quite a few pharmacological effects of N. sativa seed, its oil, various extracts and active components have been identified to include immune stimulation, anti-inflammation, hypoglycemic, antihypertensive, antiasthmatic, antimicrobial, antiparasitic, antioxidant and anticancer effects. Only a few authors have reviewed the medicinal properties of N. sativa and given some description of the anticancer effects. A literature search has revealed that a lot more studies have been recently carried out related to the anticancer activities of N. sativa and some of its active compounds, such as thymoquinone and alpha-hederin. Acute and chronic toxicity studies have recently confirmed the safety of N. sativa oil and its most abundant active component, thymoquinone, particularly when given orally. The present work is aimed at summarizing the extremely valuable work done by various investigators on the effects of N. sativa seed, its extracts and active principles against cancer. Those related to the underlying mechanism of action, derivatives of thymoquinone, nano thymoquinone and combinations of thymoquinone with the currently used cytotoxic drugs are of particular interest. We hope this review will encourage interested researchers to conduct further preclinical and clinical studies to evaluate the anticancer activities of N. sativa, its active constituents and their derivatives.

Prevention of rat breast cancer by genistin and selenium

Breast cancer is the second leading cause of cancer death among women and the third most common cancer. In this study, we investigated the chemoprevention efficacy of each of soy genistin, selenium or a combination of them against breast cancer. Seventy-five female rats were divided into five groups : control group (I); 7,12-dimethylbenz(a)anthracene (DMBA) group (II); DMBA treated with genistin group (III); DMBA treated with selenium group (IV); and DMBA treated with genistin combined with selenium group (V). The treatments were daily administered for 3 months. There were a significant decrease in body weight and serum total antioxidant, while a significant elevation in serum total sialic acid, carcinoembryonic antigen, prolactin, estradiol, nitric oxide, and malondialdhyde of DMBA injected rats compared with control group. Administration of genistin and selenium was associated with decreasing levels of tumorigenicity, endocrine derangement, and oxidative stress. Formation of breast carcinoma in DMBA-induced rats and abnormal changes were ameliorated in the rats treated with genistin/selenium or genistin alone. Supplementation of genistin alone or with selenium provided antioxidant defense with high-potential chemopreventive activity against DMBA-induced mammary tumors more than selenium alone.

Anticancer activities of Nigella sativa (black cumin)

Nigella sativa has been used as traditional medicine for centuries. The crude oil and thymoquinone (TQ) extracted from its seeds and oil are effective against many diseases like cancer, cardiovascular complications, diabetes, asthma, kidney disease etc. It is effective against cancer in blood system, lung, kidney, liver, prostate, breast, cervix, skin with much safety. The molecular mechanisms behind its anticancer role is still not clearly understood, however, some studies showed that TQ has antioxidant role and improves body's defense system, induces apoptosis and controls Akt pathway. Although the anti-cancer activity of N. sativa components was recognized thousands of years ago but proper scientific research with this important traditional medicine is a history of last 2∼3 decades. There are not so many research works done with this important traditional medicine and very few reports exist in the scientific database. In this article, we have summarized the actions of TQ and crude oil of N. sativa against different cancers with their molecular mechanisms.

Nigella sativa: reduces the risk of various maladies

Coinage of terms like nutraceuticals, functional, and pharma foods has diverted the attention of human beings to where they are seeking more natural cures. Though pharmaceutical drugs have been beneficial for human health and have cured various diseases but they also impart some side effects. Numerous plants have been tested for their therapeutic potential; Nigella sativa, commonly known as black cumin, is one of them. It possesses a nutritional dense profile as its fixed oil (lipid fraction), is rich in unsaturated fatty acids while essential oil contains thymoquinone and carvacrol as antioxidants. N. sativa seeds also contain proteins, alkaloids (nigellicines and nigelledine), and saponins (alpha-hederin) in substantial amounts. Recent pharmacological investigations suggested its potential role, especially for the amelioration of oxidative stress through free radical scavenging activity, the induction of apoptosis to cure various cancer lines, the reduction of blood glucose, and the prevention of complications from diabetes. It regulates hematological and serological aspects and can be effective in dyslipidemia and respiratory disorders. Moreover, its immunopotentiating and immunomodulating role brings balance in the immune system. Evidence is available supporting the utilization of Nigella sativa and its bioactive components in a daily diet for health improvement. This review is intended to focus on the composition of Nigella sativa and to elaborate its possible therapeutic roles as a functional food to prevent an array of maladies.

In vitro and in vivo antitumor activity of melatonin receptor agonists

Melatonin has been shown to inhibit the proliferation of estrogen receptor α (ERα)-positive human breast cancer cells in vitro and suppress the growth of carcinogen-induced mammary tumors in rats. Melatonin's antiproliferative effect is mediated, at least in part, through the MT1 melatonin receptor and mechanisms involving modulation of the estrogen-signaling pathway. To develop melatonin analogs with greater therapeutic effects, we have examined the in vitro and in vivo antimitotic activity of two MT1/MT2 melatonin receptor agonists, S23219-1 and S23478-1. In our studies, both agonists are quite effective at suppressing the growth of MCF-7 human breast cancer cells. At a concentration of 10⁻⁶ m, S23219-1 and S23478-1 inhibited the growth of MCF-7 cells by 60% and 73%, respectively. However, S23478-1 is more effective than melatonin and S23219-1 at repressing the expression and transactivation of the ERα, and modulating the expression of pancreatic spasmolytic polypeptide (pS2), an estrogen-regulated gene. The melatonin agonist S23478-1 exhibited enhanced antitumor potency in the subsequent studies in our animal model. At a dosage of 25 mg/kg/day, S23478-1 is more efficacious than melatonin at inducing regression of the established N-nitroso-N-methyl-urea-induced rat mammary tumors. This dose of S23478-1 (25 mg/kg/day) generated a significant (P < 0.05) overall regression response of 52%. Furthermore, at this dosage, S23478-1 is more effective than melatonin at suppressing the estrogen-signaling pathway and promoting tumor cell apoptosis, significantly increasing the expression of the pro-apoptotic protein Bax, while decreasing the expression of ERα and the anti-apoptotic protein Bcl-2.

Evaluation of the role of oxidative stress in chemopreventive action of fish oil and celecoxib in the initiation phase of 7,12-dimethyl benz(α)anthracene-induced mammary carcinogenesis

Cyclooxygenase-2 (COX-2) enzyme plays an important role in cancer development. COX-2 inhibition by non-steroidal anti-inflammatory drugs is a useful approach for cancer prevention, but its usage has been associated with side effects. n-3 polyunsaturated fatty acids also exhibit a chemopreventive effect mediated by COX-2 inhibition. Therefore, the present study was designed to evaluate the effect of combined dosage of celecoxib and fish oil in experimental mammary carcinogenesis. Female Wistar rats were distributed as control, 7,12-dimethyl benz(α)anthracene (DMBA) treated, celecoxib + fish oil (20 mg/kg b.w. + 0.5 ml), celecoxib + fish oil (30 mg/kg b.w. + 0.25 ml), and their corresponding controls treated with fish oil or celecoxib only. The treatment was given for 7 days, and on the 8th day animals of all the groups except the control group received DMBA orally and sacrificed after 90 days. The histopathology, DNA fragmentation, total sialic acid (TSA), lipid-associated sialic acid (LASA), and oxidative stress were measured in mammary tissue and liver mitochondrial fraction. The results showed ductal hyperplasia and an increase in TSA, LASA, lipid peroxidation, and nitrite levels with a decrease in the antioxidants on DMBA treatment. Pretreatment with celecoxib and fish oil in DMBA-treated animals led to normal histology, increase in DNA fragmentation, and decrease in TSA and LASA levels with reduced oxidative stress, and the effect was more pronounced than animals pretreated with either celecoxib/fish oil alone suggesting a synergistic effect of the two regimens. To conclude, a combination of celecoxib and fish oil is a better strategy for cancer chemoprevention than celecoxib/fish oil alone.

Cancer chemopreventive potential of volatile oil from black cumin seeds, Nigella sativa L., in a rat multi-organ carcinogenesis bioassay

Nigella sativa (N. sativa) is a herbal plant of the Ranunculaceae family that has been widely used for various medicinal and nutritional purposes. Volatile oil extracts along with its major constituents, such as thymoquinone, have recently attracted considerable attention for their antioxidant, immunoprotective and antitumor properties. The present study was conducted to assess the chemopreventive potential of crude oils in N. sativa on tumor formation using a well-established rat multi-organ carcinogenesis model featuring initial treatment with five different carcinogens. Post-initiation administration of 1000 or 4000 ppm N. sativa volatile oil in the diet of male Wistar rats for 30 weeks significantly reduced malignant and benign colon tumor sizes, incidences and multiplicities. The treatment also significantly decreased the incidences and multiplicities of tumors in the lungs and in different parts of the alimentary canal, particularly the esophagus and forestomach. Bromodeoxyuridine labeling indices, reflecting cell proliferation were significantly decreased in various organs and lesions after treatment with the two doses of N. sativa. The plasma levels of insulin growth factor, triglycerides and prostaglandin E2 were also altered. The findings show, for the first time, that N. sativa administration exerts potent inhibitory effects on rat tumor development and on cellular proliferation in multiple organ sites. In particular, the ability to significantly inhibit murine colon, lung, esophageal and forestomach tumors was demonstrated in the post-initiation phase, with no evidence of clinical side effects. The mechanisms are likely to be related to suppression of cell proliferation.

Evidence for a biphasic apoptotic pathway induced by melatonin in MCF-7 breast cancer cells

Previous investigations demonstrated that melatonin exerts an oncostatic action on estrogen-responsive breast cancer, both in vitro and in vivo. Nevertheless, the pro-apoptotic effect of melatonin is still a matter of debate. An experimental study was undertaken to focus on melatonin-related apoptosis and to identify the apoptotic pathways involved. Whole cell-count, flow-cytometry analysis and proteins involved in apoptotic pathways [p53, p73, murine double minute 2 (MDM2), caspases-9,-7,-6, cleaved-poly ADP ribose polymerase (PARP), Bcl-2, Bax and apoptotic inducing factor (AIF)] were investigated in human MCF-7 breast cancer cells treated with physiological (1 nM) concentration of melatonin. Melatonin exerts a significant growth-inhibitory effect on MCF-7 cells, becoming evident after 72 hr and thereafter increasing linearly up to 144 hr. In this model, the growth-inhibition is transforming growth factor beta 1 (TGFbeta1)-dependent and it might be reversed by adding an anti-TGFbeta1 antibody. Melatonin induces a significant rise in apoptotic rate, at both 24 and 96 hr. The anti-TGFbeta1 antibody almost completely suppresses melatonin-related late apoptosis; however, early apoptosis is unaffected. Early programmed cell death is associated with a significant increase in the p53/MDM2 ratio and in AIF release, without modifications in caspase activity or cleaved-PARP levels. Activated caspases-9 and -7 and cleaved-PARP increased significantly at 96 hr, concomitantly with a down-regulation of the Bcl-2/Bax ratio. These data suggest that two distinct apoptotic processes are triggered by melatonin in MCF-7 cells: an early, TGFbeta1 and caspase-independent response, and a late apoptotic TGFbeta1-dependent process in which activated-caspase-7 is likely to be the terminal effector.

Chemopreventive effect of lycopene alone or with melatonin against the genesis of oxidative stress and mammary tumors induced by 7,12 dimethyl(a)benzanthracene in sprague dawely female rats

Breast cancer is the principle cause of death among women worldwide. In this study, we investigated the anti-tumor potential of lycopene (Lyco) alone or combined with melatonin (Lyco + Mel) for 120 days against a single oral dose of (50 mg/kg B.W.) 7,12-dimethylbenz(a)anthracene (DMBA)-induced oxidative stress and mammary carcinogenesis in female rats. The treatment protocol started from the day immediately after DMBA administration. Results obtained indicated that there was an elevation in the levels of malondialdhyde and nitric oxide in serum and breast tissues of DMBA injected rats. The combined treatment (Lyco + Mel) group showed a potential reduction of these parameters more than lyco individually. The activities of SOD, CAT, and GPx were found to be significantly high than lyco alone treated rats. In DMBA group a negative significant correlation between weight and serum nitric oxide (r = -0.59), and a positive significant correlation between NO and MDA (r = 0.81) was observed. Histopathological examination revealed the formation of tumor and angiogenesis in DMBA-induced rats and these abnormal changes were ameliorated by combined treatment with Lyco + Mel. In conclusion, these results suggested that supplementation of diet with lycopene with melatonin provided antioxidant defense with strong chemo preventive activity against DMBA-induced mammary tumors.