Diallyl Disulfide-Induced Apoptosis in a Breast-Cancer Cell Line (MCF-7) May Be Caused by Inhibition of Histone Deacetylation

Prognostic significance of natural products against multidrug tumor resistance

Cancer is a pervasive, constantly evolving, and significant public health concern. The number of new cancer cases has risen dramatically in the last decades, making it one of the top causes of poor health and mortality worldwide. Although various treatment strategies, including surgery, radiation, and pharmaceutical therapies, have evolved into more sophisticated, precise methods, there is not much improvement in the cancer-related death toll. Consequently, natural product-based therapeutic discoveries have recently been considered an alternative approach. According to an estimate, one-third of the top twenty medications in today's market have a natural plant-product-based origin. Accordingly, primary prevention is an essential component of worldwide cancer control. This review provides an overview of the mechanisms of action of bioactive ingredients in natural dietary products that may contribute to the prevention and management of multiple malignancies.

Updates on the anticancer potential of garlic organosulfur compounds and their nanoformulations: Plant therapeutics in cancer management

Garlic (Allium sativum L.) possesses numerous pharmacological potential, including antibacterial, antiarthritic, antithrombotic, anticancer, hypoglycemic, and hypolipidemic effects. The anti-cancer action of garlic is likely the best researched of the many advantageous pharmacological effects, and its use offers significant protection against the risk of developing cancer. A few active metabolites of garlic have been reported to be essential in the destruction of malignant cells due to their multi-targeted activities and lack of significant toxicity. The bioactive compounds in garlic having anticancer properties include diallyl trisulfide, allicin, allyl mercaptan diallyl disulfide, and diallyl sulphide. Different garlic-derived constituents and their nanoformulations have been tested for their effects against various cancers including skin, ovarian, prostate, gastric, breast, and lung, colorectal, liver, oral, and pancreatic cancer. The objective of this review is to summarize the antitumor activity and associated mechanisms of the organosulfur compounds of garlic in breast carcinoma. Breast cancer continues to have a significant impact on the total number of cancer deaths worldwide. Global measures are required to reduce its growing burden, particularly in developing nations where incidence is increasing quickly and fatality rates are still high. It has been demonstrated that garlic extract, its bioactive compounds, and their use in nanoformulations can prevent breast cancer in all of its stages, including initiation, promotion, and progression. Additionally, these bioactive compounds affect cell signaling for cell cycle arrest and survival along with lipid peroxidation, nitric oxide synthase activity, epidermal growth factor receptor, nuclear factor kappa B (NF-κB), and protein kinase C in breast carcinoma. Hence, this review deciphers the anticancer potential of garlic components and its nanoformulations against several breast cancer thereby projecting it as a potent drug candidate for efficient breast cancer management.

Prospective Epigenetic Actions of Organo-Sulfur Compounds against Cancer: Perspectives and Molecular Mechanisms

Major epigenetic alterations, such as chromatin modifications, DNA methylation, and miRNA regulation, have gained greater attention and play significant roles in oncogenesis, representing a new paradigm in our understanding of cancer susceptibility. These epigenetic changes, particularly aberrant promoter hypermethylation, abnormal histone acetylation, and miRNA dysregulation, represent a set of epigenetic patterns that contribute to inappropriate gene silencing at every stage of cancer progression. Notably, the cancer epigenome possesses various HDACs and DNMTs, which participate in the histone modifications and DNA methylation. As a result, there is an unmet need for developing the epigenetic inhibitors against HDACs and DNMTs for cancer therapy. To date, several epigenetically active synthetic inhibitors of DNA methyltransferases and histone deacetylases have been developed. However, a growing body of research reports that most of these synthetic inhibitors have significant side effects and a narrow window of specificity for cancer cells. Targeting tumor epigenetics with phytocompounds that have the capacity to modulate abnormal DNA methylation, histone acetylation, and miRNAs expression is one of the evolving strategies for cancer prevention. Encouragingly, there are many bioactive phytochemicals, including organo-sulfur compounds that have been shown to alter the expression of key tumor suppressor genes, oncogenes, and oncogenic miRNAs through modulation of DNA methylation and histones in cancer. In addition to vitamins and microelements, dietary phytochemicals such as sulforaphane, PEITC, BITC, DADS, and allicin are among a growing list of naturally occurring anticancer agents that have been studied as an alternative strategy for cancer treatment and prevention. Moreover, these bioactive organo-sulfur compounds, either alone or in combination with other standard cancer drugs or phytochemicals, showed promising results against many cancers. Here, we particularly summarize and focus on the impact of specific organo-sulfur compounds on DNA methylation and histone modifications through targeting the expression of different DNMTs and HDACs that are of particular interest in cancer therapy and prevention.

How Does Allium Leafy Parts Metabolome Differ in Context to Edible or Inedible Taxa? Case Study in Seven Allium Species as Analyzed Using MS-Based Metabolomics

Genus Allium (F. Amaryllidaceae) includes a wide variety of edible foods widely consumed for their nutritive as well as health benefits. Seven Allium species, viz., chives, Egyptian leek, French leek, red garlic, white garlic, red onion, and white onion aerial parts were assessed for metabolome heterogeneity targeting both aroma and nutrients phytochemicals. A headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were employed. Results revealed extensive variation in volatiles and nutrients profile among the seven Allium species represented by a total of 77 nutrients and 148 volatiles. Among edible Allium species, French leek encompassed high levels of nutrients, viz., sugars, fatty acids/esters, organic acids, and amino acids, compared to Egyptian leek. Sulfur aroma compounds appeared as the most discriminatory among Allium, taxa accounting for its distinct flavor. Furthermore, chemometric analysis of both datasets showed clear discrimination of the seven Allium species according to several key novel markers. This study provides the first comparative approach between edible and inedible aerial leafy parts of Allium species providing novel insight into their use as functional foods based on such holistic profiling.

Diallyl Disulfide: A Bioactive Garlic Compound with Anticancer Potential

Cancer is a life-threatening disease caused by the uncontrolled division of cells, which culminates in a solid mass of cells known as a tumor or liquid cancer. It is the leading cause of mortality worldwide, and the number of cancer patients has been increasing at an alarming rate, with an estimated 20 million cases expected by 2030. Thus, the use of complementary or alternative therapeutic techniques that can help prevent cancer has been the subject of increased attention. Garlic, the most widely used plant medicinal product, exhibits a wide spectrum of biological activities, including antibacterial, hypo-lipidemic, antithrombotic, and anticancer effects. Diallyl disulfide (DADS) is a major organosulfur compound contained within garlic. Recently, several experimental studies have demonstrated that DADS exhibits anti-tumor activity against many types of tumor cells, including gynecological cancers (cervical cancer, ovarian cancer), hematological cancers (leukemia, lymphoma), lung cancer, neural cancer, skin cancer, prostate cancer, gastrointestinal tract and associated cancers (esophageal cancer, gastric cancer, colorectal cancer), hepatocellular cancer cell line, etc. The mechanisms behind the anticancer action of DADS include epithelial-mesenchymal transition (EMT), invasion, and migration. This article aims to review the available information regarding the anti-cancer potential of DADS, as well as summarize its mechanisms of action, bioavailability, and pharmacokinetics from published clinical and toxicity studies.

Prospective Medicinal Plants and Their Phytochemicals Shielding Autoimmune and Cancer Patients Against the SARS-CoV-2 Pandemic: A Special Focus on Matcha

Background

Being "positive" has been one of the most frustrating words anyone could hear since the end of 2019. This word had been overused globally due to the high infectious nature of SARS-CoV-2. All citizens are at risk of being infected with SARS-CoV-2, but a red warning sign has been directed towards cancer and immune-compromised patients in particular. These groups of patients are not only more prone to catch the virus but also more predisposed to its deadly consequences, something that urged the research community to seek other effective and safe solutions that could be used as a protective measurement for cancer and autoimmune patients during the pandemic.

Aim

The authors aimed to turn the spotlight on specific herbal remedies that showed potential anticancer activity, immuno-modulatory roles, and promising anti-SARS-CoV-2 actions.

Methodology

To attain the purpose of the review, the research was conducted at the States National Library of Medicine (PubMed). To search databases, the descriptors used were as follows: "COVID-19"/"SARS-CoV-2", "Herbal Drugs", "Autoimmune diseases", "Rheumatoid Arthritis", "Asthma", "Multiple Sclerosis", "Systemic Lupus Erythematosus" "Nutraceuticals", "Matcha", "EGCG", "Quercetin", "Cancer", and key molecular pathways.

Results

This manuscript reviewed most of the herbal drugs that showed a triple action concerning anticancer, immunomodulation, and anti-SARS-CoV-2 activities. Special attention was directed towards "matcha" as a novel potential protective and therapeutic agent for cancer and immunocompromised patients during the SARS-CoV-2 pandemic.

Conclusion

This review sheds light on the pivotal role of "matcha" as a tri-acting herbal tea having a potent antitumorigenic effect, immunomodulatory role, and proven anti-SARS-CoV-2 activity, thus providing a powerful shield for high-risk patients such as cancer and autoimmune patients during the pandemic.

Drug Delivery of Natural Products Through Nanocarriers for Effective Breast Cancer Therapy: A Comprehensive Review of Literature

Despite recent advances in the diagnosis and treatment of breast cancer (BC), it remains a global health issue affecting millions of women annually. Poor prognosis in BC patients is often linked to drug resistance as well as the lack of effective therapeutic options for metastatic and triple-negative BC. In response to these unmet needs, extensive research efforts have been devoted to exploring the anti-BC potentials of natural products owing to their multi-target mechanisms of action and good safety profiles. Various medicinal plant extracts/essential oils and natural bioactive compounds have demonstrated anti-cancer activities in preclinical BC models. Despite the promising preclinical results, however, the clinical translation of natural products has often been hindered by their poor stability, aqueous solubility and bioavailability. There have been attempts to overcome these limitations, particularly via the use of nano-based drug delivery systems (NDDSs). This review highlights the tumour targeting mechanisms of NDDSs, the advantages and disadvantages of the major classes of NDDSs and their current clinical status in BC treatment. Besides, it also discusses the proposed anti-BC mechanisms and nanoformulations of nine medicinal plants' extracts/essential oils and nine natural bioactive compounds; selected via the screening of various scientific databases, including PubMed, Scopus and Google Scholar, based on the following keywords: "Natural Product AND Nanoparticle AND Breast Cancer". Overall, these nanoformulations exhibit improved anti-cancer efficacy against preclinical BC models, with some demonstrating biocompatibility with normal cell lines and mouse models. Further clinical studies are, however, warranted to ascertain their efficacy and biocompatibility in humans.

Biological Functions of Diallyl Disulfide, a Garlic-Derived Natural Organic Sulfur Compound

Garlic is widely accepted as a functional food and an excellent source of pharmacologically active ingredients. Diallyl disulfide (DADS), a major bioactive component of garlic, has several beneficial biological functions, including anti-inflammatory, antioxidant, antimicrobial, cardiovascular protective, neuroprotective, and anticancer activities. This review systematically evaluated the biological functions of DADS and discussed the underlying molecular mechanisms of these functions. We hope that this review provides guidance and insight into the current literature and enables future research and the development of DADS for intervention and treatment of multiple diseases.

Garlic (Allium sativum L.): Its Chemistry, Nutritional Composition, Toxicity and Anticancer Properties

The current review discuss the chemistry, nutritional composition, toxicity, and biological functions of garlic and its bioactive compounds against various types of cancers via different anticancer mechanisms. Several scientific documents were found in reliable literature and searched in databases viz Science Direct, PubMed, Web of Science, Scopus and Research Gate were carried out using keywords such as "garlic", "garlic bioactive compounds", "anticancer mechanisms of garlic", "nutritional composition of garlic", and others. Garlic contains several phytoconstituents with activities against cancer, and these compounds such as diallyl trisulfide (DATS), allicin, and diallyl disulfide (DADS), diallyl sulfide (DAS), and allyl mercaptan (AM). The influence of numerous garlic-derived products, phytochemicals, and nanoformulations on the liver, oral, prostate, breast, gastric, colorectal, skin, and pancreatic cancers has been studied. Based on our search, the bioactive molecules in garlic were found to inhibit the various phases of cancer. Moreover, the compounds in this plant also abrogate the peroxidation of lipids, activity of nitric oxide synthase, epidermal growth factor (EGF) receptor, nuclear factor-kappa B (NF-κB), protein kinase C, and regulate cell cycle and survival signaling cascades. Hence, garlic and its bioactive molecules exhibit the aforementioned mechanistic actions and thus, they could be used to inhibit the induction, development and progression of cancer. The review describes the nutritional Composition of garlic, its bioactive molecules, and nanoformulations against various types of cancers, as well as the potential for developing these agents as antitumor drugs.

Garlic constituents for cancer prevention and therapy: From phytochemistry to novel formulations

Garlic (Allium sativum L.) is one of the oldest plants cultivated for its dietary and medicinal values. This incredible plant is endowed with various pharmacological attributes, such as antimicrobial, antiarthritic, antithrombotic, antitumor, hypoglycemic, and hypolipidemic activities. Among the various beneficial pharmacological effects of garlic, the anticancer activity is presumably the most studied. The consumption of garlic provides strong protection against cancer risk. Taking into account the multi-targeted actions and absence of considerable toxicity, a few active metabolites of garlic are probably to play crucial roles in the killing of cancerous cells. Garlic contains several bioactive molecules with anticancer actions and these include diallyl trisulfide, allicin, diallyl disulfide, diallyl sulfide, and allyl mercaptan. The effects of various garlic-derived products, their phytoconstituents and nanoformulations have been evaluated against skin, prostate, ovarian, breast, gastric, colorectal, oral, liver, and pancreatic cancers. Garlic extract, its phytocompounds and their nanoformulations have been shown to inhibit the different stages of cancer, including initiation, promotion, and progression. Besides, these bioactive metabolites alter the peroxidation of lipid, activity of nitric oxide synthetase, nuclear factor-κB, epidermal growth factor receptor, and protein kinase C, cell cycle, and survival signaling. The current comprehensive review portrays the functions of garlic, its bioactive constituents and nanoformulations against several types of cancers and explores the possibility of developing these agents as anticancer pharmaceuticals.

Anticancer potential of garlic and its bioactive constituents: A systematic and comprehensive review

Vegetables of the Allium genus, such as garlic (Allium sativum L.), onions, shallots, leaks, and chives, have been used for many years for food consumption and for medicinal purposes. Historical medical texts have indicated the therapeutic applications of garlic as an antitumor, laxative, diuretic, antibacterial and antifungal agent. Specifically, garlic's antitumor abilities have been traced back 3500 years as a chemotherapeutic agent used in Egypt. Other beneficial effects of garlic consumption include lowering blood pressure, blood cholesterol, sugar and lipids. The processing and aging of garlic result in the production of non-toxic organosulfur by-products. These sulfur-containing compounds, such as allicin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, alliin, S-allylcysteine, and S-allylmercaptocysteine, impact various stages of carcinogenesis. The anticancer mechanisms of action of these garlic-derived phytochemicals include altering mitochondrial permeability, inhibiting angiogenesis, enhancing antioxidative and proapoptotic properties, and regulating cell proliferation. All these effects of garlic's sulfur-compounds have been demonstrated in various human cancers. The intent of this literature research is to explore the potential of garlic-derived products and bioactive organosulfur compounds as cancer chemopreventive and chemotherapeutic agents. This investigation employs criteria for systematic review and critically analyzes published in vitro, in vivo and clinical studies. Concerns and limitations that have arisen in past studies regarding standards of measurement, bioavailability, and method of delivery are addressed. Overall, it is hoped that through this systematic and comprehensive review, future researchers can be acquainted with the updated data assembled on anticancer properties of garlic and its phytoconstituents.

Recent Progress in Histone Deacetylase Inhibitors as Anticancer Agents

Histone Deacetylase (HDAC) inhibitors are a relatively new class of anti-cancer agents that play important roles in epigenetic or non-epigenetic regulation, inducing death, apoptosis, and cell cycle arrest in cancer cells. Recently, their use has been clinically validated in cancer patients resulting in the approval by the FDA of four HDAC inhibitors, vorinostat, romidepsin, belinostat and panobinostat, used for the treatment of cutaneous/peripheral T-cell lymphoma and multiple myeloma. Many more HDAC inhibitors are at different stages of clinical development for the treatment of hematological malignancies as well as solid tumors. Also, clinical trials of several HDAC inhibitors for use as anti-cancer drugs (alone or in combination with other anti-cancer therapeutics) are ongoing. In the intensifying efforts to discover new, hopefully, more therapeutically efficacious HDAC inhibitors, molecular modelingbased rational drug design has played an important role. In this review, we summarize four major structural classes of HDAC inhibitors (hydroxamic acid derivatives, aminobenzamide, cyclic peptide and short-chain fatty acids) that are in clinical trials and different computer modeling tools available for their structural modifications as a guide to discover additional HDAC inhibitors with greater therapeutic utility.

Breast Tumor Microenvironment: Emerging target of therapeutic phytochemicals

Triple negative breast cancer (TNBC) is the most aggressive and challenging form of breast cancers. Tumor microenvironment (TME) of TNBC is associated with induction of metastasis, immune system suppression, escaping immune detection and drug resistance. TME is highly complex and heterogeneous, consists of tumor cells, stromal cells and immune cells. The rapid expansion of tumors induce hypoxia, which concerns the reprogramming of TME components. The reciprocal communication of tumor cells and TME cells predisposes cancer cells to metastasis by modulation of developmental pathways, Wnt, notch, hedgehog and their related mechanisms in TME. Dietary phytochemicals are non-toxic and associated with various human health benefits and remarkable spectrum of biological activities. The phytochemicals serve as vital resources for drug discovery and also as a source for breast cancer therapy. The novel properties of dietary phytochemicals propose platform for modulation of tumor signaling, overcoming drug resistance, and targeting TME. Therefore, TME could serve as promising target for the treatment of TNBC. This review presents current status and implications of experimentally evaluated therapeutic phytochemicals as potential targeting agents of TME, potential nanosystems for targeted delivery of phytochemicals and their current challenges and future implications in TNBC treatment. The dietary phytochemicals especially curcumin with significant delivery system could prevent TNBC development as it is considered safe and well tolerated in phase II clinical trials.

Garlic and its Active Compounds: A Potential Candidate in The Prevention of Cancer by Modulating Various Cell Signalling Pathways

BACKGROUND

Cancer is a multi-factorial disease including alterations in the cell signalling pathways. Currently, several drugs are in use to treat cancer but such drugs show negative side effects on normal cells and cause severe toxicity.

METHODS

The current research is mainly focused on medicinal plants with potential therapeutic efficacy in the treatment of cancer without any adverse effects on normal cells. In this regard, garlic and its active compounds including diallyl sulfide, diallyl trisulfide, ajoene, and allicin have been established to suppress the growth of cancer and killing of cancer cells.

RESULT

The review focuses on garlic and its active compounds chemopreventive effect through modulating various cell signalling pathways. Additionally, garlic and its active compound were established to induce cell cycle arrest at the G0/G1 phase and G2/M phases in cancer cells, increase the expression of tumor suppressor genes, inhibit the angiogenesis process, induction of apoptosis and modulation of various other genetic pathways.

CONCLUSION

This review sketches the diverse chemopreventive activities of garlic and their active ingredients in the management of cancer mainly focusing on cell signalling pathways.

A novel DNA repair inhibitor, diallyl disulfide (DADS), impairs DNA resection during DNA double-strand break repair by reducing Sae2 and Exo1 levels

Combining natural products with chemotherapy and/or radiotherapy may increase the efficacy of cancer treatment. It has been hypothesized that natural products may inhibit DNA repair and sensitize cancer cells to DNA damage-based cancer therapy. However, the molecular mechanisms underlying these activities remain unclear. In this study, we found that diallyl disulfide (DADS), an organosulfur compound, increased the sensitivity of yeast cells to DNA damage and has potential for development as an adjuvant drug for DNA damage-based cancer therapy. We induced HO endonuclease to generate a specific DNA double-strand break (DSB) by adding galactose to yeast and used this system to study how DADS affects DNA repair. In this study, we found that DADS inhibited DNA repair in single-strand annealing (SSA) system and sensitized SSA cells to a single DSB. DADS impaired DNA repair by inhibiting the protein levels of the DNA resection-related proteins Sae2 and Exo1. We also found that the recruitment of MRX and the Mec1-Ddc2 complex to a DSB was prevented by DADS. This result suggests that DADS counteracts G2/M DNA damage checkpoint activation in a Mec1 (ATR)- and Tel1 (ATM)-dependent manner. Only by elucidating the molecular mechanisms by which DADS influences DNA repair will we be able to discover new adjuvant drugs to improve chemotherapy and/or radiotherapy.

Anticancer Activities of Thymus vulgaris L. in Experimental Breast Carcinoma in Vivo and in Vitro

Naturally-occurring mixtures of phytochemicals present in plant foods are proposed to possess tumor-suppressive activities. In this work, we aimed to evaluate the antitumor effects of Thymus vulgaris L. in in vivo and in vitro mammary carcinoma models. Dried T. vulgaris (as haulm) was continuously administered at two concentrations of 0.1% and 1% in the diet in a chemically-induced rat mammary carcinomas model and a syngeneic 4T1 mouse model. After autopsy, histopathological and molecular analyses of rodent mammary carcinomas were performed. In addition, in vitro evaluations using MCF-7 and MDA-MB-231 cells were carried out. In mice, T. vulgaris at both doses reduced the volume of 4T1 tumors by 85% (0.1%) and 84% (1%) compared to the control, respectively. Moreover, treated tumors showed a substantial decrease in necrosis/tumor area ratio and mitotic activity index. In the rat model, T. vulgaris (1%) decreased the tumor frequency by 53% compared to the control. Analysis of the mechanisms of anticancer action included well-described and validated diagnostic and prognostic markers that are used in both clinical approach and preclinical research. In this regard, the analyses of treated rat carcinoma cells showed a CD44 and ALDH1A1 expression decrease and Bax expression increase. Malondialdehyde (MDA) levels and VEGFR-2 expression were decreased in rat carcinomas in both the T. vulgaris treated groups. Regarding the evaluations of epigenetic changes in rat tumors, we found a decrease in the lysine methylation status of H3K4me3 in both treated groups (H3K9m3, H4K20m3, and H4K16ac were not changed); up-regulations of miR22, miR34a, and miR210 expressions (only at higher doses); and significant reductions in the methylation status of four gene promoters—ATM serin/threonine kinase, also known as the NPAT gene (ATM); Ras-association domain family 1, isoform A (RASSF1); phosphatase and tensin homolog (PTEN); and tissue inhibitor of metalloproteinase-3 (TIMP3) (the paired-like homeodomain transcription factor (PITX2) promoter was not changed). In vitro study revealed the antiproliferative and proapoptotic effects of essential oils of T. vulgaris in MCF-7 and MDA-MB-231 cells (analyses of 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS); 5-bromo-20-deoxyuridine (BrdU); cell cycle; annexin V/PI; caspase-3/7; Bcl-2; PARP; and mitochondrial membrane potential). T. vulgaris L. demonstrated significant chemopreventive and therapeutic activities against experimental breast carcinoma.

Natural Products and Chemical Biology Tools: Alternatives to Target Epigenetic Mechanisms in Cancers

DNA methylation and histone acetylation are widely studied epigenetic modifications. They are involved in numerous pathologies such as cancer, neurological disease, inflammation, obesity, etc. Since the discovery of the epigenome, numerous compounds have been developed to reverse DNA methylation and histone acetylation aberrant profile in diseases. Among them several were inspired by Nature and have a great interest as therapeutic molecules. In the quest of finding new ways to target epigenetic mechanisms, the use of chemical tools is a powerful strategy to better understand epigenetic mechanisms in biological systems. In this review we will present natural products reported as DNMT or HDAC inhibitors for anticancer treatments. We will then discuss the use of chemical tools that have been used in order to explore the epigenome.

Plant natural modulators in breast cancer prevention: status quo and future perspectives reinforced by predictive, preventive, and personalized medical approach

In contrast to the genetic component in mammary carcinogenesis, epigenetic alterations are particularly important for the development of sporadic breast cancer (BC) comprising over 90% of all BC cases worldwide. Most of the DNA methylation processes are physiological and essential for human cellular and tissue homeostasis, playing an important role in a number of key mechanisms. However, if dysregulated, DNA methylation contributes to pathological processes such as cancer development and progression. A global hypomethylation of oncogenes and hypermethylation of tumor-suppressor genes are characteristic of most cancer types. Moreover, histone chemical modifications and non-coding RNA-associated multi-gene controls are considered as the key epigenetic mechanisms governing the cellular homeostasis and differentiation states. A number of studies demonstrate dietary plant products as actively affecting the development and progression of cancer. "Nutri-epigenetics" focuses on the influence of dietary agents on epigenetic mechanisms. This approach has gained considerable attention; since in contrast to genetic alterations, epigenetic modifications are reversible affect early carcinogenesis. Currently, there is an evident lack of papers dedicated to the phytochemicals/plant extracts as complex epigenetic modulators, specifically in BC. Our paper highlights the role of plant natural compounds in targeting epigenetic alterations associated with BC development, progression, as well as its potential chemoprevention in the context of preventive medicine. Comprehensive measures are stated with a great potential to advance the overall BC management in favor of predictive, preventive, and personalized medical services and can be considered as "proof-of principle" model, for their potential application to other multifactorial diseases.

Diallyl disulfide effect on the invasion and migration ability of HL-60 cells with a high expression of DJ-1 in the nucleus through the suppression of the Src signaling pathway

The present study examined the effect of diallyl disulfide (DADS) on the invasion and migration ability of HL-60 cells with a high expression of parkinsonism associated deglycase (DJ-1) in the nucleus (HHDN), and its molecular mechanism. A western blot assay was used to measure the effects of DADS and an Src inhibitor on the expression of DJ-1 and the Src signal pathway in HHDN. The effects of DADS and Src inhibitors on the invasion and migration ability of HHDN was detected using Transwell migration and invasion chamber experiments. The experiments were divided into three groups: A control group (HL-60 cells), an empty vector group and a high expression group (HHDN cells). Western blot assays revealed that the expression of DJ-1 in HHDN was inhibited in a time-dependent manner following treatment with DADS for 24, 48 and 72 h. Following DADS treatment, the expression of phosphorylated Src (p-Src) and phosphorylated Fak (p-Fak) were significantly decreased in all groups compared with the untreated groups, however the expression level of Src, Fak and integrin did not change significantly. Western blot analysis results revealed that following treatment with DADS and Src inhibitor, the expression levels of p-Src and p-Fak significantly decreased in all three groups compared with untreated groups, whereas the expression levels of Src, Fak and integrin did not change significantly. The expression of DJ-1 in HHND was inhibited in time-dependent manner following treatment with DADS and Src inhibitor for 24, 48 and 72 h. Transwell migration and invasion assay results revealed that DADS and Src inhibitors may suppress migration and invasion in leukemic cells, and a combination of the two treatments may result in more efficient suppression. DADS may downregulate DJ-1-mediated invasion and migration in leukemic cells through suppressing the Src-Fak-Integrin signaling pathway, and the Src inhibitor may enhance the antitumor effect of DADS.

The Role of Actin Dynamics and Actin-Binding Proteins Expression in Epithelial-to-Mesenchymal Transition and Its Association with Cancer Progression and Evaluation of Possible Therapeutic Targets

Metastasis causes death of 90% of cancer patients, so it is the most significant issue associated with cancer disease. Thus, it is no surprise that many researchers are trying to develop drugs targeting or preventing them. The secondary tumour site formation is closely related to phenomena like epithelial-to-mesenchymal and its reverse, mesenchymal-to-epithelial transition. The change of the cells' phenotype to mesenchymal involves the acquisition of migratory potential. Cancer cells movement is possible due to the development of invasive structures like invadopodia, lamellipodia, and filopodia. These changes are dependent on the reorganization of the actin cytoskeleton. In turn, the polymerization and depolymerization of actin are controlled by actin-binding proteins. In many tumour cells, the actin and actin-associated proteins are accumulated in the cell nucleus, suggesting that it may also affect the progression of cancer by regulating gene expression. Once the cancer cell reaches a new habitat it again acquires epithelial features and thus proliferative activity. Targeting of epithelial-to-mesenchymal or/and mesenchymal-to-epithelial transitions through regulation of their main components expression may be a potential solution to the problem of metastasis. This work focuses on the role of these processes in tumour progression and the assessment of therapeutic potential of agents targeting them.

3,6-Dihydroxyflavone regulates microRNA-34a through DNA methylation

BACKGROUND

Breast cancer is the common cancer in China. In previous study, we determined that 3,6-dihydroxyflavone (3,6-DHF) increases miR-34a significantly in breast carcinogenesis, but the mechanism remains unclear.

METHODS

We used qRT-PCR to analyze miR-34a and ten-eleven translocation (TET)1, TET2, TET3 levels in breast cancer cells. With a cellular breast carcinogenesis model and an experimental model of carcinogenesis in rats, TET1 levels were evaluated by western blot analysis and immunofluorescence. TET1 and 5hmC (5-hydroxymethylcytosine) levels were evaluated by immunofluorescence in nude mouse xenografts of MDA-MB-231 cells. Chromatin immunoprecipitation(ChIP) assayed for TET1 on the TET1 promoter, and dot blot analysis of DNA 5hmC was performed in MDA-MB-231 cells. We evaluated the mechanism of 3,6-DHF on the expression of tumor suppressor miR-34a by transfecting them with DNA methyltransferase (DNMT)1 plasmid and TET1 siRNA in breast cancer cells. Methylation-specific PCR detected methylation of the miR-34a promoter.

RESULTS

First, we found that 3,6-DHF promotes the expression of TET1 during carcinogen-induced breast carcinogenesis in MCF10A cells and in rats. 3,6-DHF also increased TET1 and 5hmC levels in MDA-MB-231 cells. Further study indicated that TET1 siRNA and pcDNA3/Myc-DNMT1 inhibited the 3,6-DHF reactivation effect on expression of miR-34a in breast cancer cells. Methylation-specific PCR assays indicated that TET1 siRNA and pcDNA3/Myc-DNMT1 inhibit the effect of 3,6-DHF on the demethylation of the miR-34a promoter.

CONCLUSIONS

Our study showed that 3,6-DHF effectively increases TET1 expression by inhibiting DNMT1 and DNA hypermethylation, and consequently up-regulates miR-34a in breast carcinogenesis.

Dietary Natural Products for Prevention and Treatment of Breast Cancer

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

Involvement of calreticulin in cell proliferation, invasion and differentiation in diallyl disulfide-treated HL-60 cells

Diallyl disulfide (DADS) has shown potential as a therapeutic agent in various cancers. Previously, calreticulin (CRT) was found to be downregulated in differentiated HL-60 cells treated with DADS. The present study investigated the role of CRT proteins in DADS-induced proliferation, invasion and differentiation in HL-60 cells. The present study demonstrated that DADS treatment significantly changed the morphology of HL-60 cells and caused the significant time-dependent downregulation of CRT. Small interfering RNA (siRNA)-mediated knockdown of CRT expression significantly inhibited proliferation, decreased invasion ability, increased the expression of cluster of differentiation (CD)11b and reduced the expression of CD33 in DADS-treated HL-60 cells. DADS also significantly affected cell proliferation, invasion and differentiation in CRT-overexpressed HL-60 cells. Nitroblue tetrazolium (NBT) reduction assays showed decreased NBT reduction activity in the CRT overexpression group and increased NBT reduction in the CRT siRNA group. Following treatment with DADS, the NBT reduction abilities in all groups were increased. In conclusion, the present study clearly demonstrates the downregulation of CRT during DADS-induced differentiation in HL-60 cells and indicates that CRT is involved in cell proliferation, invasion and differentiation in DADS-treated HL-60 cells.

PTEN activation through K163 acetylation by inhibiting HDAC6 contributes to tumour inhibition

Phosphatase and tensin homologue deleted on chromosome 10 (PTEN), an important tumour-suppressor gene, is mutated, downregulated or dysfunctional in many tumours. The phosphatase activity of PTEN depends on membrane translocation (activation). As promising anti-cancer agents, histone deacetylase (HDAC) inhibitors, particularly trichostatin A (TSA), can promote PTEN membrane translocation, but the underlying mechanism remains unknown. In this study, we revealed that non-selective HDAC inhibitors, namely, TSA or suberoylanilide hydroxamic acid (SAHA), induced PTEN membrane translocation through PTEN acetylation at K163 by inhibiting HDAC6. K163 acetylation inhibited the interaction of the PTEN C-tail with the remaining part of PTEN, resulting in PTEN membrane translocation. Overexpression of wild-type PTEN, but not K163-mutated PTEN, facilitated the inhibition of cell proliferation, migration and invasion, as well as xenograft tumour growth, induced by SAHA or tubastatin A, an HDAC6-specific inhibitor. These results indicated that PTEN activation by inhibiting HDAC6 significantly contributed to tumour inhibition. Therefore, non-selective HDAC or HDAC6-specific inhibitors may be more clinically suitable to treat tumours without PTEN mutations or deletions.

Diallyl disulfide inhibits growth and metastatic potential of human triple-negative breast cancer cells through inactivation of the β-catenin signaling pathway

SCOPE

Although diallyl disulfide (DADS), an important garlic (Allium sativum) derivative, has exhibited potential anticancer activity, the molecular mechanism of this activity remains unknown. In this study, we evaluated the antitumor activity of DADS in triple-negative breast cancer (TNBC) cell lines based in vitro and in vivo models.

METHODS AND RESULTS

We found that treatment with DADS resulted in decreased viability, increased apoptosis, and suppression of metastatic potential in TNBC cells. Furthermore, DADS induced dysregulation of B-cell lymphoma (Bcl)-2 family members, downregulation of matrix metalloproteinase (MMP)-9 and reversal of the epithelial-mesenchymal transition (EMT). Interestingly, DADS significantly inhibited activation of the β-catenin signaling pathway, which regulated Bcl-2 family members, MMP-9 and EMT in TNBC cells. Consistent with these in vitro findings, we also verified the anticancer potential of DADS in MDA-MB-231 xenograft mice. Treatment with DADS significantly reduced tumor volume and weight and increased apoptosis in these mice, while the expression of active β-catenin was decreased, and the downstream molecules were dysregulated.

CONCLUSION

Our results show that the antitumor effect of DADS on TNBC cells is mediated by the β-catenin pathway, suggesting that DADS could be used as a potential therapeutic agent for treating or preventing breast cancer.

Current Perspectives on Epigenetic Modifications by Dietary Chemopreventive and Herbal Phytochemicals

Studies during the last two decades have revealed the involvement of epigenetic modifications in the development of human cancer. It is now recognized that the interplay of DNA methylation, post-translational histone modification, and non-coding RNAs can interact with genetic defects to drive tumorigenesis. The early onset, reversibility, and dynamic nature of such epigenetic modifications enable them to be developed as promising cancer biomarkers and preventive/therapeutic targets. In addition to the recent approval of several epigenetic therapies in the treatment of human cancer, emerging studies have indicated that dietary phytochemicals might exert cancer chemopreventive effects by targeting epigenetic mechanisms. In this review, we will present the current understanding of the epigenetic alterations in carcinogenesis and highlight the potential of targeting these mechanisms to treat/prevent cancer. The latest findings, published in the past three years regarding the effects of dietary phytochemicals in modulating epigenetic mechanisms will also be discussed.

Diallyl disulfide suppresses SRC/Ras/ERK signaling-mediated proliferation and metastasis in human breast cancer by up-regulating miR-34a

Diallyl disulfide (DADS) is one of the major volatile components of garlic oil. DADS has various biological properties, including anticancer, antiangiogenic, and antioxidant effects. However, the anticancer mechanisms of DADS in human breast cancer have not been elucidated, particularly in vivo. In this study, we demonstrated that the expression of miR-34a was up-regulated in DADS-treated MDA-MB-231 cells. miR-34a not only inhibited breast cancer growth but also enhanced the antitumor effect of DADS, both in vitro and in vivo. Furthermore, Src was identified as a target of miR-34a, with miR-34a inhibiting SRC expression and consequently triggering the suppression of the SRC/Ras/ERK pathway. These results suggest that DADS could be a promising anticancer agent for breast cancer. miR-34a may also demonstrate a potential gene therapy agent that could enhance the antitumor effects of DADS.

Effects of garlic oil on pancreatic cancer cells

BACKGROUND

To investigate the preventive and therapeutic potential of garlic oil on human pancreatic carcinoma cells.

METHODS

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay was performed to study the effects of garlic oil on three human pancreatic cancer cell lines, AsPC-1, Mia PaCa-2 and PANC-1. Cell cycle progression and apoptosis were detected by flow cytometry (FCM), staining with PI and annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI), respectively. Morphologic changes of pancreatic cancer cells were observed under transmission electron microscopy (TEM) after treatment with garlic oil at low inhibitory concentrations (2.5 μM and 10 μM) for 24 hours.

RESULTS

Proliferation of the AsPC-1, PANC-1, and Mia PaCa-2 cells was obviously inhibited in the first 24 hours with the MTT assay. The inhibition effect was more significant after 48 hours. When cells were exposed to garlic oil at higher concentrations, an early change of the apoptotic tendency was detected by FCM and TEM.

CONCLUSION

Garlic oil could inhibit the proliferation of AsPC-1, PANC-1, and Mia PaCa-2 cells in this study. Moreover, due to programmed cell death, cell cycle arrest, or both, pro-apoptosis effects on AsPC-1 cells were induced by garlic oil in a dose and time dependent manner in vitro.

Diallyl disulfide induces G2/M arrest and promotes apoptosis through the p53/p21 and MEK-ERK pathways in human esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor with high incidence and mortality worldwide. Diallyl disulfide (DADS) is a natural organosulfur compound, isolated from garlic. In this study, MTT assay showed that DADS significantly reduced cell viability in a dose- and time-dependent manner in ESCC cells, with lower toxicity in normal liver cells. Cell cycle analysis revealed that DADS made G2/M phase arrest. Molecular analysis suggested that this cell cycle arrest was likely made by the decrease of cyclin B1, cdc2, p-cdc2, cdc25c in concomitance with activation of the p53/p21 pathway. Apoptosis was detected by Annexin V/PI staining. The molecule markers showed that DADS induced apoptosis through activating caspases, altering the Bax/Bcl-2 balance and suppressing the MEK-ERK pathway. Our data indicated that DADS has the potential to be an effective and safe anticancer agent for ESCC therapy in the near future.

DADS suppresses human esophageal xenograft tumors through RAF/MEK/ERK and mitochondria-dependent pathways

Diallyl disulfide (DADS) is a natural organosulfur compound isolated from garlic. DADS has various biological properties, including anticancer, antiangiogenic, and antioxidant effects. However, the anticancer mechanisms of DADS in human esophageal carcinoma have not been elucidated, especially in vivo. In this study, MTT assay showed that DADS significantly reduced cell viability in human esophageal carcinoma ECA109 cells, but was relatively less toxic in normal liver cells. The pro-apoptotic effect of DADS on ECA109 cells was detected by Annexin V-FITC/propidium iodide (PI) staining. Flow cytometry analysis showed that DADS promoted apoptosis in a dose-dependent manner and the apoptosis rate could be decreased by caspase-3 inhibitor Ac-DEVD-CHO. Xenograft study in nude mice showed that DADS treatment inhibited the growth of ECA109 tumor in both 20 and 40 mg/kg DADS groups without obvious side effects. DADS inhibited ECA109 tumor proliferation by down-regulating proliferation cell nuclear antigen (PCNA). DADS induced apoptosis by activating a mitochondria-dependent pathway with the executor of caspase-3, increasing p53 level and Bax/Bcl-2 ratio, and downregulating the RAF/MEK/ERK pathway in ECA109 xenograft tumosr. Based on studies in cell culture and animal models, the findings here indicate that DADS is an effective and safe anti-cancer agent for esophageal carcinoma.

Diallyl sulphide, a component of garlic, abrogates ferric nitrilotriacetate-induced oxidative stress and renal damage in rats

Ferric nitrilotriacetate (Fe-NTA) induces tissue necrosis as a result of lipid peroxidation (LPO) and oxidative damage that leads to high incidence of renal carcinomas. The present study was undertaken to evaluate the effect of diallyl sulphide (DAS) against Fe-NTA-induced nephrotoxicity. A total of 30 healthy male rats were randomly divided into 5 groups of 6 rats each: (1) control, (2) DAS (200 mg kg−1), (3) Fe-NTA (9 g Fe kg−1), (4) DAS (100 mg kg−1) + Fe-NTA (9 mg Fe kg−1) and (5) DAS (200 mg kg−1) + Fe-NTA (9 mg Fe kg−1). Fe-NTA + DAS-treated groups were given DAS for a period of 1 week before Fe-NTA administration. The intraperitoneal administration of Fe-NTA enhanced blood urea nitrogen and creatinine levels with reduction in levels of antioxidant enzymes. However, significant restoration of depleted renal glutathione and its dependent enzymes (glutathione reductase and glutathione- S-transferase) was observed in DAS pretreated groups. DAS also attenuated Fe-NTA-induced increase in LPO, hydrogen peroxide generation and protein carbonyl formation ( p < 0.05). The results indicate that DAS may be beneficial in ameliorating the Fe-NTA-induced renal oxidative damage in rats.

Diallyl disulfide suppresses proliferation and induces apoptosis in human gastric cancer through Wnt-1 signaling pathway by up-regulation of miR-200b and miR-22

The purpose of this study was to identify a mechanism related to miRNA pathway which plays a role in the anti-tumor effects of Diallyl disulfide. Alterations in miRNA expression were observed in Diallyl disulfide-treated MGC-803 cells, including up-regulation of miR-200b and miR-22 expression. Furthermore, Wnt-1 was identified as a target of both miR-200b and miR-22. MiR-200b and miR-22 not only synergistically inhibited gastric cancer growth, but also enhanced the antitumor effect of Diallyl disulfide both in vitro and in vivo. It indicated that miR-200b and miR-22 may serve as potential gene therapy and enhance Diallyl disulfide antitumor effects.