Melatonin and cancer suppression: insights into its effects on DNA methylation.

Melatonin is an important naturally occurring hormone in mammals. Melatonin-mediated biological effects include the regulation of circadian rhythms, which is important for optimal human health. Also, melatonin has a broad range of immunoenhancing actions. Moreover, its oncostatic properties, especially regarding breast cancer, involve a variety cancer-inhibitory processes and are well documented. Due to their promising effects on the prognosis of cancer patients, anti-cancer drugs with epigenetic actions have attracted a significant amount of attention in recent years. Epigenetic modifications of cancers are categorized into three major processes including non-coding RNAs, histone modification, and DNA methylation. Hence, the modification of the latter epigenetic event is currently considered an effective strategy for treatment of cancer patients. Thereby, this report summarizes the available evidence that investigated melatonin-induced effects in altering the status of DNA methylation in different cancer cells and models, e.g., malignant glioma and breast carcinoma. Also, we discuss the role of artificial light at night (ALAN)-mediated inhibitory effects on melatonin secretion and subsequent impact on global DNA methylation of cancer cells.

Effects of therapeutic probiotics on modulation of microRNAs.

Probiotics are beneficial bacteria that exist within the human gut, and which are also present in different food products and supplements. They have been investigated for some decades, due to their potential beneficial impact on human health. Probiotics compete with pathogenic microorganisms for adhesion sites within the gut, to antagonize them or to regulate the host immune response resulting in preventive and therapeutic effects. Therefore, dysbiosis, defined as an impairment in the gut microbiota, could play a role in various pathological conditions, such as lactose intolerance, gastrointestinal and urogenital infections, various cancers, cystic fibrosis, allergies, inflammatory bowel disease, and can also be caused by antibiotic side effects. MicroRNAs (miRNAs) are short non-coding RNAs that can regulate gene expression in a post-transcriptional manner. miRNAs are biochemical biomarkers that play an important role in almost all cellular signaling pathways in many healthy and disease states. For the first time, the present review summarizes current evidence suggesting that the beneficial properties of probiotics could be explained based on the pivotal role of miRNAs. Video Abstract.

Effect of Lactobacillusplantarum containing probiotics on blood pressure: A systematic review and meta-analysis.

Previous studies have recommended that probiotics may have blood pressure (BP)-lowering effects. However, they examined all probiotic strains (multi/single probiotics) simultaneously. In respect to strain specificity properties of probiotic, the aim of the present study was to systematically investigate the role of Lactobacillus plantarum as an anti-hypertensive agent by performing a meta-analysis of randomized controlled trials. PubMed, Scopus, Cochrane Library and Google Scholar were used from inception until October 2018 to identify eligible trials. We used random-effects model as the preferable method to assess the combined treatment effect. We further conducted sensitivity analysis and stratified analysis. Seven studies with 653 participants were included in the meta-analysis. The pooled weighted mean difference (WMD) with the random effects model showed a significant effects of Lactobacillus plantarum supplementation on improvement of SBP with no statistically significant heterogeneity (WMD: -1.58 mmHg, 95 % CI: -3.05 to 0.11) (heterogeneity P = 0.14; I² = 36 %). The overall effect in the DBP showed significant pooled estimates (WMD: -0.92 mmHg, 95 % CI: -1.49 to -0.35) with a complete homogeneity between the studies (heterogeneity P = 0.46; I² = 0 %). The findings of the present meta-analysis study support the use of Lactobacillus plantarum supplementation for lowering systolic and diastolic blood pressure. The clinical significance of blood pressure-lowering effect of Lactobacillus Plantarum supplementation is not considerable; however, given the overarching benefits evident and concurrent lack of specific side effects, further trials are warranted to clarify the effects of Lactobacillus Plantarum probiotics particularly for hypertensive patients.

Melatonin as a Promising Agent for Cancer Treatment: Insights into its Effects on the Wnt/beta-catenin Signaling Pathway.

In recent years, substantial advances have been made in cancer treatment modalities. Yet, within the last three decades, neither cancer incidence nor the cancer-induced mortality rate has changed. Available anti-cancer chemotherapeutics possess remarkably restricted effectiveness and often have severe adverse effects. Hence, the identification of novel pharmaceutical agents that do not exhibit these major disadvantages is imperative. Melatonin, an important endogenous molecule synthesized and secreted by the pineal gland, is a promising chemical agent that has been comprehensively assessed over the last decades for its anti-inflammatory and anti-cancer properties. Melatonin is reportedly a significant inhibitor of cancer initiation, progression, and metastasis. The anti-- cancer potential of melatonin is principally mediated by reversing the up-regulated amounts of different transcription factors, growth factors, inflammatory cytokines, protein kinases, and other oncogenic agents. Also, melatonin often has signifcant inhibitory effects on cancer cell proliferation through either promoting apoptosis or inducing cell cycle arrest. The current review provides an insight into melatonin-induced effects against various human cancers with a particular focus on the regulation of Wnt/ß-catenin signaling pathway.

The therapeutic effects of berberine for gastrointestinal cancers.

Cancer is one of the most serious human health issues. Drug therapy is the major common way to treat cancer. There is a growing interest in using natural compounds to overcome drug resistance, adverse reactions, and target specificity of certain types of drugs that may affect several targets with fewer side effects and be beneficial against various types of cancer. In this regard, the use of herbal medicines alone or in combination with the main anticancer drugs is commonly available. Berberine (BBR), a nature-driven phytochemical component, is a well-known nutraceutical due to its wide variety of pharmacological activities, including antioxidant, anti-inflammatory, antibacterial, antifungal, antiparasitic, antidiabetic, antihypertensive, and hypolipidemic. In addition, BBR exerts anticancer activities. In present article, we summarized the information available on the therapeutic effects of BBR and its mechanisms on five types of the most prevalent gastrointestinal cancers, including esophageal, gastric, colorectal, hepatocarcinoma, and pancreatic cancers.

Melatonin for gastric cancer treatment: where do we stand?

Gastric cancer (GC) is the third leading reason of death in men and the fourth in women. Studies have documented an inhibitory function of melatonin on the proliferation, progression and invasion of GC cells. MicroRNAs (miRNAs) are small, non-coding RNAs that play an important function in regulation of biological processes and gene expression of the cells. Some studies reported that melatonin can suppress the progression of GC by regulating the exosomal miRNAs. Thus, melatonin represents a promising potential therapeutic agent for subjects with GC. Herein, we evaluate the existing data of both in vivo and in vitro studies to clarify the molecular processes involved in the therapeutic effects of melatonin in GC. The data emphasize the critical function of melatonin in several signaling ways by which it may inhibit cancer cell proliferation, decrease chemo-resistance, induce apoptosis as well as limit invasion, angiogenesis, and metastasis. This review provides a resource that identifies some of the mechanisms by which melatonin controls GC enlargement. In light of the findings, melatonin should be considered a novel and testable therapeutic mediator for GC treatment.

Melatonin and cisplatin co-treatment against cancer: A mechanistic review of their synergistic effects and melatonin's protective actions.

Combination chemotherapy appears to be a preferable option for some cancer patients, especially when the medications target multiple pathways of oncogenesis; individuals treated with combination treatments may have a better prognosis than those treated with single agent chemotherapy. However, research has revealed that this is not always the case, and that this technique may just enhance toxicity while having little effect on boosting the anticancer effects of the medications. Cisplatin (CDDP) is a chemotherapeutic medicine that is commonly used to treat many forms of cancer. However, it has major adverse effects such as cardiotoxicity, skin necrosis, testicular toxicity, and nephrotoxicity. Many research have been conducted to investigate the effectiveness of melatonin (MLT) as an anticancer medication. MLT operates in a variety of ways, including decreasing cancer cell growth, causing apoptosis, and preventing metastasis. We review the literature on the role of MLT as an adjuvant in CDDP-based chemotherapies and discuss how MLT may enhance CDDP's antitumor effects (e.g., by inducing apoptosis and suppressing metastasis) while protecting other organs from its adverse effects, such as cardio- and nephrotoxicity.

Melatonin affects the expression of microRNA-21: A mini-review of current evidence.

Melatonin (MLT) is an endogenous hormone produced by pineal gland which possess promising anti-tumor effects. Anti-inflammatory and anti-oxidant properties of MLT, along with its immunomodulatory, proapoptotic, and anti-angiogenic properties, are often referred to the main mechanisms of its anti-tumor effects. Recent evidence has suggested that epigenetic alterations are also involved in the anti-tumor properties of MLT. Among these MLT-induced epigenetic alterations is modulation of the expression of several oncogenic and tumor suppressor microRNAs(miRNAs). MiRNAs are among the most promising and potential therapeutic and diagnostic tools in different diseases and enhanced the development of better therapeutic drugs. Suppression of oncomicroRNAs such as microRNA-21, - 20a, and - 27a as well as, up-regulation of microRNA-34 a/c are among the most important effects of MLT on microRNAs homeostasis. Recently, miR-21 has attracted the attention of scientists due to the its wide range of effects on different cancers and diseases. Regulation of this RNA may be a key to the development of better therapeutic targets. The present review will summarize the findings of in vitro and experimental studies of MLT-induced impacts on the expression of microRNAs which are involved in different models and numerous stages of tumor initiation, growth, metastasis, and chemo-resistance.

An epigenetic modulator with promising therapeutic impacts against gastrointestinal cancers: A mechanistic review on microRNA-195.

Due to their high prevalence, gastrointestinal cancers are one of the key causes of cancer-related death globally. The development of drug-resistant cancer cell populations is a major factor in the high mortality rate, and it affects about half of all cancer patients. Because of advances in our understanding of cancer molecular biology, non-coding RNAs (ncRNAs) have emerged as critical factors in the initiation and development of gastrointestinal cancers. Gene expression can be controlled in several ways by ncRNAs, including through epigenetic changes, interactions between microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) and proteins, and the function of lncRNAs as miRNA precursors or pseudogenes. As lncRNAs may be detected in the blood, circulating ncRNAs have emerged as a promising new class of non-invasive cancer biomarkers for use in the detection, staging, and prognosis of gastrointestinal cancers, as well as in the prediction of therapy efficacy. In this review, we assessed the role lncRNAs play in the progression, and maintenance of colorectal cancer, and how they might be used as therapeutic targets in the future.

Modulation of Long Non-coding RNAs and MicroRNAs by Quercetin as a Potential Therapeutical Approach in Cancer: A Comprehensive Review.

Cancer can take years to develop, both at its beginning and during its development. All typical epithelial cancers have a long latency period, sometimes 20 years or more, and if they are clinically detected, distinct genes may include infinite mutations. Long non-coding RNAs (LncRNAs) are a subset of RNAs that regulate many biological processes, including RNA processing, epigenetic control, and signal transduction. Current studies show that lncRNAs, which are dysregulated in cancer, play a significant function in the growth and spread of the illness. LncRNAs have been connected to the overexpression of specific proteins that function in tumors' spread and growth. Moreover, through translational inhibition, microRNAs (miRNAs) regulates gene expression sequence specifically. Apart from that, non-coding RNAs known as miRNAs, with a length of around 22 nucleotides, controls gene expressions in a sequence-specific way either by preventing translation or degrading messenger RNA (mRNA). Quercetin appears to have a significant role in altering miRNA and lncRNA expression, which is linked to variations in the production of oncogenes, tumor suppressors, and proteins produced from cancer. Quercetin may change the earliest epigenetic modifications related to cancer prevention in addition to its usual antioxidant or anti-inflammatory effects. It would be beneficial to have more in-depth information on how Quercetin modulates miRNAs and lncRNAs to use it as a cancer therapeutic strategy. Here, we go through what is known about Quercetin's potential to modulate miRNAs and lncRNAs in various malignancies.

Resveratrol Effects on Molecular Pathways and MicroRNAs in Gastrointestinal Cancers.

Gastrointestinal (GI) cancers are one of the most prevalent types of neoplasms worldwide. The incidence of GI cancers is increasing rapidly. Despite all advances in the management of GI cancers, treatment options for these disorders are still limited and there are no effective therapeutic approaches. Hence, finding new treatment strategies seems to be necessary to decrease mortality in patients with such cancers. The application of natural products has found a prominent role in the management of some neoplastic disorders. Resveratrol is a phytochemical found in various fruits and plants such as red grapes and tea. Recently, the effects of resveratrol on the microRNAs in the management of some neoplastic disorders have been investigated. This review is aimed to illustrate the molecular pathways related to resveratrol and evaluate the impacts of resveratrol on the different microRNAs in the milieu of the prevention and treatment of GI cancers.

MicroRNA and gynecological cancers: Focus on miR-195.

Different cancer types have been shown to have down-regulated expression levels of miR-195 as an anti-tumor agent. MiR-195 family members can inhibit cancer cell proliferation, angiogenesis, epithelial-mesenchymal transition and metastases, immunosuppression, glycolysis, drug resistance, and cancer stem cell development by targeting the 3'-UTR of the mRNA of different pro-tumor genes. MiR-195 identified as a tumor suppressor miR in a variety of cancers, most notably gynecological malignancies such as cervical, endometrial, and ovarian carcinoma. As a result, restoring miR-195 expression should be regarded as a potential therapy for either prevention or treatment of gynecological cancers. This review will present the most recent data about miR-195-mediated anti-tumor effects in gynecological malignancies, emphasizing its downstream signaling pathways and target genes, as well as prospective treatment techniques.

Modulation of long non-coding RNAs by resveratrol as a potential therapeutic approach in cancer: A comprehensive review.

LncRNAs, or long non-coding RNAs, are a subset of RNAs that play a regulatory role in a wide range of biological functions, including RNA processing, epigenetic regulation, and signal transduction. Recent research indicates that lncRNAs play a key role in the development and spread of cancer by being dysregulated in the disease. In addition, lncRNAs have been linked to the overexpression of certain proteins that are involved in tumor development and progression. Resveratrol has anti-inflammatory and anti-cancer properties that it exerts through regulating different lncRNAs. By the regulation of tumor-supportive and tumor-suppressive lncRNAs, resveratrol acts as an anti-cancer agent. By downregulating the tumor-supportive lncRNAs DANCR, MALAT1, CCAT1, CRNDE, HOTAIR, PCAT1, PVT1, SNHG16, AK001796, DIO3OS, GAS5 and H19, and upregulating MEG3, PTTG3P, BISPR, PCAT29, GAS5, LOC146880, HOTAIR, PCA3, NBR2, this herbal remedy causes apoptosis and cytotoxicity. For the purpose of using polyphenols in cancer therapy, it would be helpful to have more in-depth knowledge about lncRNA modulation via resveratrol. Here, we discuss the current knowledge and future promise of resveratrol as modulators of lncRNAs in different cancers.

Resveratrol in Cancer Treatment with a Focus on Breast Cancer.

Acute liver injury (ALI) is a critical and fatal disorder associated with excessive Although considerable advances have been made in the early diagnosis and treatment of breast cancer, it is still one of the major causes of global cancer-related death in women over the last several decades. Phytochemicals have been shown to be promising agents in the prevention and treatment of breast cancer. Resveratrol is an important plant-derived polyphenolic compound with a variety of potent biological activities. It has been suggested that resveratrol can be used to prevent and treat various types of cancer, including breast cancer. Resveratrol can affect numerous signaling pathways in vitro, leading to the induction of cell cycle arrest and apoptosis, suppression of proliferation, reduction of inflammatory responses, and the inhibition of angiogenesis and metastasis. Nevertheless, studies of resveratrol in animal models of breast cancer have so far been disappointing.

Potential of natural products in osteosarcoma treatment: Focus on molecular mechanisms.

Osteosarcoma is the most frequent type of bone cancer found in children and adolescents, and commonly arises in the metaphyseal region of tubular long bones. Standard therapeutic approaches, such as surgery, chemotherapy, and radiation therapy, are used in the management of osteosarcoma. In recent years, the mortality rate of osteosarcoma has decreased due to advances in treatment methods. Today, the scientific community is investigating the use of different naturally derived active principles against various types of cancer. Natural bioactive compounds can function against cancer cells in two ways. Firstly they can act as classical cytotoxic compounds by non-specifically affecting macromolecules, such as DNA, enzymes, and microtubules, which are also expressed in normal proliferating cells, but to a greater extent by cancer cells. Secondly, they can act against oncogenic signal transduction pathways, many of which are activated in cancer cells. Some bioactive plant-derived agents are gaining increasing attention because of their anti-cancer properties. Moreover, some naturally-derived compounds can significantly promote the effectiveness of standard chemotherapy drugs, and in certain cases are able to ameliorate drug-induced adverse effects caused by chemotherapy. In the present review we summarize the effects of various naturally-occurring bioactive compounds against osteosarcoma.

Silymarin (milk thistle extract) as a therapeutic agent in gastrointestinal cancer.

Silymarin contains a group of closely-related flavonolignan compounds including silibinin, and is extracted from Silybum marianum species, also called milk thistle. Silymarin has been shown to protect the liver in both experimental models and clinical studies. The chemopreventive activity of silymarin has shown some efficacy against cancer both in vitro and in vivo. Silymarin can modulate apoptosis in vitro and survival in vivo, by interfering with the expression of cell cycle regulators and apoptosis-associated proteins. In addition to its anti-metastatic activity, silymarin has also been reported to exhibit anti-inflammatory activity. The chemoprotective effects of silymarin and silibinin (its major constituent) suggest they could be applied to reduce the side effects and increase the anti-cancer effects of chemotherapy and radiotherapy in various cancer types, especially in gastrointestinal cancers. This review examines the recent studies and summarizes the mechanistic pathways and down-stream targets of silymarin in the therapy of gastrointestinal cancer.

An Update on the Effects of Probiotics on Gastrointestinal Cancers.

Because of their increasing prevalence, gastrointestinal (GI) cancers are regarded as an important global health challenge. Microorganisms residing in the human GI tract, termed gut microbiota, encompass a large number of living organisms. The role of the gut in the regulation of the gut-mediated immune responses, metabolism, absorption of micro- and macro-nutrients and essential vitamins, and short-chain fatty acid production, and resistance to pathogens has been extensively investigated. In the past few decades, it has been shown that microbiota imbalance is associated with the susceptibility to various chronic disorders, such as obesity, irritable bowel syndrome, inflammatory bowel disease, asthma, rheumatoid arthritis, psychiatric disorders, and various types of cancer. Emerging evidence has shown that oral administration of various strains of probiotics can protect against cancer development. Furthermore, clinical investigations suggest that probiotic administration in cancer patients decreases the incidence of postoperative inflammation. The present review addresses the efficacy and underlying mechanisms of action of probiotics against GI cancers. The safety of the most commercial probiotic strains has been confirmed, and therefore these strains can be used as adjuvant or neo-adjuvant treatments for cancer prevention and improving the efficacy of therapeutic strategies. Nevertheless, well-designed clinical studies are still needed for a better understanding of the properties and mechanisms of action of probiotic strains in mitigating GI cancer development.

Antimetastatic Effects of Curcumin in Oral and Gastrointestinal Cancers.

Gastrointestinal (GI) cancers are known as frequently occurred solid malignant tumors that can cause the high rate mortality in the world. Metastasis is a significant destructive feature of tumoral cells, which directly correlates with decreased prognosis and survival. Curcumin, which is found in turmeric, has been identified as a potent therapeutic natural bioactive compound (Curcuma longa). It has been traditionally applied for centuries to treat different diseases, and it has shown efficacy for its anticancer properties. Numerous studies have revealed that curcumin inhibits migration and metastasis of GI cancer cells by modulating various genes and proteins, i.e., growth factors, inflammatory cytokines and their receptors, different types of enzymes, caspases, cell adhesion molecules, and cell cycle proteins. Herein, we summarized the antimetastatic effects of curcumin in GI cancers, including pancreatic cancer, gastric cancer, colorectal cancer, oral cancer, and esophageal cancer.

Quercetin as an anticancer agent: Focus on esophageal cancer.

Esophageal cancer (EC) is regarded as the sixth highest contributor to all cancer-related mortality, worldwide. In spite of advances in the treatment of EC, currently used methods remain ineffective. Quercetin, as a dietary antioxidant, is a plant flavonol from the flavonoid group of polyphenols, and can be found in numerous vegetables, fruits, and herbs. Quercetin can affect the processes of cancer-related diseases via cell proliferation inhibitory effects, potential apoptosis effects, and antioxidant properties. Of the various types of cancer, the use of quercetin has now become prominent in the treatment of EC. In this review, we discuss how quercetin may be an important supplement for the prevention, treatment, and management of EC, owing to its natural origin, and low-cost relative to synthetic cancer drugs. However, most findings cited in the current study are based on in vitro and in vivo studies, and thus, further human-based research is necessitated. PRACTICAL APPLICATIONS: In spite of advances in the treatment of esophageal cancer, currently used methods remain ineffective, therefore, an alternative or complementary therapy is required. Quercetin, as a dietary antioxidant, can affect the processes of cancer-related diseases via cell proliferation inhibitory effects, potential proapoptotic functions, and antioxidant properties. Quercetin may be an important supplement for the prevention, treatment, and management of EC, owing to its natural origin. The low cost of quercetin as supplement or dietary intake, relative to synthetic cancer drugs, is an advantage of the compound which should be considered.

The therapeutic potential of resveratrol in a mouse model of melanoma lung metastasis.

Resveratrol is an anticancer phytochemical polyphenol isolated from a natural origin, without any significant side effects. Resveratrol was investigated in immunocompetent mice with regards to its possible effect on lung cancer metastasis. Cytotoxicity was assessed in three melanoma cell lines (B16F10, B6, and A375) by administration of 20 and 40 µM resveratrol. B16F10 cells were transfected with pT-tdTomato vector to express red fluorescent protein (RFP). RFP-B16F10 cells were injected IV into 3 groups of 20 C57BL/6 mice (ten for tests and others for survival). The three groups include PBS, no treatment, and resveratrol 40 mg/kg IP (4X/week for 3 weeks). Lung tissues were analyzed by TUNEL assay, Western blot, and immunohistochemistry. The in vitro growth of all melanoma cell lines was significantly suppressed by 40 µM resveratrol for 3 days. The mean survival rate of mice was enhanced and the lung tumor growth was inhibited by in vivo IP injection of 40 mg/kg resveratrol. Increased CXCL10 and IFN-γ levels and decreased angiogenesis and less tumor infiltration by Tregs were found in the lung tumors. In conclusion, lung metastasis of melanoma was effectively inhibited by resveratrol treatment.