Current state of phenolic and terpenoidal dietary factors and natural products as non-coding RNA/microRNA modulators for improved cancer therapy and prevention

Plant-Derived Epi-Nutraceuticals as Potential Broad-Spectrum Anti-Viral Agents

Although the COVID-19 pandemic appears to be diminishing, the emergence of SARS-CoV-2 variants represents a threat to humans due to their inherent transmissibility, immunological evasion, virulence, and invulnerability to existing therapies. The COVID-19 pandemic affected more than 500 million people and caused over 6 million deaths. Vaccines are essential, but in circumstances in which vaccination is not accessible or in individuals with compromised immune systems, drugs can provide additional protection. Targeting host signaling pathways is recommended due to their genomic stability and resistance barriers. Moreover, targeting host factors allows us to develop compounds that are effective against different viral variants as well as against newly emerging virus strains. In recent years, the globe has experienced climate change, which may contribute to the emergence and spread of infectious diseases through a variety of factors. Warmer temperatures and changing precipitation patterns can increase the geographic range of disease-carrying vectors, increasing the risk of diseases spreading to new areas. Climate change may also affect vector behavior, leading to a longer breeding season and more breeding sites for disease vectors. Climate change may also disrupt ecosystems, bringing humans closer to wildlife that transmits zoonotic diseases. All the above factors may accelerate the emergence of new viral epidemics. Plant-derived products, which have been used in traditional medicine for treating pathological conditions, offer structurally novel therapeutic compounds, including those with anti-viral activity. In addition, plant-derived bioactive substances might serve as the ideal basis for developing sustainable/efficient/cost-effective anti-viral alternatives. Interest in herbal antiviral products has increased. More than 50% of approved drugs originate from herbal sources. Plant-derived compounds offer diverse structures and bioactive molecules that are candidates for new drug development. Combining these therapies with conventional drugs could improve patient outcomes. Epigenetics modifications in the genome can affect gene expression without altering DNA sequences. Host cells can use epigenetic gene regulation as a mechanism to silence incoming viral DNA molecules, while viruses recruit cellular epitranscriptomic (covalent modifications of RNAs) modifiers to increase the translational efficiency and transcript stability of viral transcripts to enhance viral gene expression and replication. Moreover, viruses manipulate host cells' epigenetic machinery to ensure productive viral infections. Environmental factors, such as natural products, may influence epigenetic modifications. In this review, we explore the potential of plant-derived substances as epigenetic modifiers for broad-spectrum anti-viral activity, reviewing their modulation processes and anti-viral effects on DNA and RNA viruses, as well as addressing future research objectives in this rapidly emerging field.

Melanoma Cellular Signaling Transduction Pathways Targeted by Polyphenols Action Mechanisms

Melanoma is the most aggressive type of skin cancer. Although different anti-melanoma treatments are available, their efficacy is still improvable, and the number of deaths continues to increase worldwide. A promising source of antitumor agents could be presented by polyphenols-natural plant-based compounds. Over the past decades, many studies have described multiple anticancer effects of polyphenols in melanoma, presenting their potential interactions with targeted molecules from different signaling pathways. However, to our knowledge, there is no comprehensive review on polyphenols-regulated mechanisms in melanoma cells available in the literature. To fulfill this gap, this article aims to summarize the current knowledge of molecular mechanisms of action regulated by polyphenols involved in melanoma initiation and progression. Here, we focus on in vitro and in vivo effects of polyphenol treatments on tumor-essential cellular pathways, such as cell proliferation, apoptosis, autophagy, inflammation, angiogenesis, and metastasis. Moreover, emerging studies regarding the well-marked role of polyphenols in the regulation of microRNAs (miRNAs), highlighting their contribution to melanoma development, are also epitomized. Finally, we hope this review will provide a firm basis for developing polyphenol-based therapeutic agents in melanoma treatment.

Potential Phytochemicals for Prevention of Familial Breast Cancer with BRCA Mutations

Breast cancer has remained a global challenge and the second leading cause of cancer mortality in women and family history. Hereditary factors are some of the major risk factors associated with breast cancer. Out of total breast cancer cases, 5-10% account only for familial breast cancer, and nearly 50% of all hereditary breast cancer are due to BRCA1/BRCA2 germline mutations. BRCA1/2 mutations play an important role not only in determining the clinical prognosis of breast cancer but also in the survival curves. Since this risk factor is known, a significant amount of the healthcare burden can be reduced by taking preventive measures among people with a known history of familial breast cancer. There is increasing evidence that phytochemicals of nutrients and supplements help in the prevention and cure of BRCA-related cancers by different mechanisms such as limiting DNA damage, altering estrogen metabolism, or upregulating expression of the normal BRCA allele, and ultimately enhancing DNA repair. This manuscript reviews different approaches used to identify potential phytochemicals to mitigate the risk of familial breast cancer with BRCA mutations. The findings of this review can be extended for the prevention and cure of any BRCAmutated cancer after proper experimental and clinical validation of the data.

Garmultin-A Incites Apoptosis in CB3 Cells Through miR-17-5p by Attenuating Poly (ADP-Ribose) Polymerase-1

Background

Leukemia accounts for a large number of deaths, worldwide, every year. Treating this ailment is always a challenging job. Recently, oncogenic miRNA leading to apoptosis are highly promising targets of many natural products. In this study, Garmultin-A (GA), isolated from the bark of Garcinia multiflora, was elucidated for its anti-leukemic effect in CB3 cells.

Methods

The effect of the compound on CB3 cell viability was detected by MTT assay and apoptosis by FITC Annexin V/PI and Hochest 33258 staining. The western blot analysis assessed the BAX, BCL2, cMYC, pERK, and PARP-1 protein levels. Autodock analysis predicted the ligand–protein interactions. q-RT-PCR quantified the miR-17-5p expression. Luciferase assay confirmed the interaction between PARP-1 and miR-17-5p.

Results

We uncover that GA leads to apoptosis by inducing overexpression of miR-17-5p and significantly downregulate PARP-1 protein levels in CB3 cells. The overexpression of miR-17-5p promotes apoptosis, and the miR-17-5p antagomirs restore GA-triggered apoptosis. Notably, we disclose that PARP-1 is a direct target of miR-17-5p. Increased pro-apoptotic and reduced anti-apoptosis protein levels were also observed in GA-treated CB3 cells.

Conclusion

These results provide critical insights that GA could induce apoptosis in CB3 cells through targeting miR-17-5p by attenuating PARP-1. Thus, GA could act as a novel therapeutic agent for erythroleukemia.

Zygo-Albuside A: New Saponin from Zygophyllum album L. with Significant Antioxidant, Anti-Inflammatory and Antiapoptotic Effects against Methotrexate-Induced Testicular Damage

Chemical investigation of the crude extract of the aerial part of Zygophyllum album L. (Z. album) led to the isolation of a new saponin, Zygo-albuside A (7), together with seven known compounds, one of them (caffeic acid, compound 4) is reported in the genus for the first time. NMR (1D and 2D) and mass spectrometric analysis, including high-resolution mass spectrometry (HRMS), were utilized to set up the chemical structures of these compounds. The present biological study aimed to investigate the protective antioxidant, anti-inflammatory, and antiapoptotic activities of the crude extract from the aerial part of Z. album and two of its isolated compounds, rutin and the new saponin zygo-albuside A, against methotrexate (MTX)-induced testicular injury, considering the role of miRNA-29a. In all groups except for the normal control group, which received a mixture of distilled water and DMSO (2:1) as vehicle orally every day for ten days, testicular damage was induced on the fifth day by intraperitoneal administration of MTX at a single dose of 20 mg/kg. Histopathological examination showed that pre-treatment with the crude extract of Z. album, zygo-albuside A, or rutin reversed the testicular damage induced by MTX. In addition, biochemical analysis in the protected groups showed a decrease in malondialdehyde (MDA), interleukin-6 (IL-6) and IL-1β, Bcl-2-associated-protein (Bax), and an increase in B-cell lymphoma 2 (Bcl-2) protein, catalase (CAT), superoxide dismutase (SOD) in the testis, along with an increase in serum testosterone levels compared with the unprotected (positive control) group. The mRNA expression levels of nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), p53, and miRNA-29a were downregulated in the testicular tissues of the protected groups compared with the unprotected group. In conclusion, the study provides sufficient evidence that Z. album extract, and its isolated compounds, zygo-albuside A and rutin, could alleviate testicular damage caused by the chemotherapeutic agent MTX.

Marrubium alysson L. Ameliorated Methotrexate-Induced Testicular Damage in Mice through Regulation of Apoptosis and miRNA-29a Expression: LC-MS/MS Metabolic Profiling

Despite the efficient anti-cancer capabilities of methotrexate (MTX), it may induce myelosuppression, liver dysfunction and testicular toxicity. The purpose of this investigation was to determine whether Marrubium alysson L. (M. alysson L.) methanolic extract and its polyphenol fraction could protect mouse testicles from MTX-induced damage. We also investigated the protective effects of three selected pure flavonoid components of M. alysson L. extract. Mice were divided into seven groups (n = 8): (1) normal control, (2) MTX, (3) Methanolic extract + MTX, (4) Polyphenolic fraction + MTX, (5) Kaempferol + MTX, (6) Quercetin + MTX, and (7) Rutin + MTX. Pre-treatment of mice with the methanolic extract, the polyphenolic fraction of M. alysson L. and the selected pure compounds ameliorated the testicular histopathological damage and induced a significant increase in the serum testosterone level and testicular antioxidant enzymes along with a remarkable decline in the malondialdehyde (MDA) level versus MTX alone. Significant down-regulation of nuclear factor kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), p53 and miRNA-29a testicular expression was also observed in all the protected groups. Notably, the polyphenolic fraction of M. alysson L. displayed a more pronounced decline in the testicular levels of interleukin-1β (IL-1β), interleukin-6 (IL-6) and MDA, with higher testosterone levels relative to the methanolic extract. Further improvements in the Johnsen score, histopathological results and all biochemical assays were achieved by pre-treatment with the three selected pure compounds kaempferol, quercetin and rutin. In conclusion, M. alysson L. could protect against MTX-induced testicular injury by its antioxidant, anti-inflammatory, antiapoptotic activities and through the regulation of the miRNA-29a testicular expression. The present study also included chemical profiling of M. alysson L. extract, which was accomplished by LC-ESI-TOF-MS/MS analysis. Forty compounds were provisionally assigned, comprising twenty compounds discovered in the positive mode and seventeen detected in the negative mode.

Using ncRNAs as Tools in Cancer Diagnosis and Treatment-The Way towards Personalized Medicine to Improve Patients' Health

Although the first discovery of a non-coding RNA (ncRNA) dates back to 1958, only in recent years has the complexity of the transcriptome started to be elucidated. However, its components are still under investigation and their identification is one of the challenges that scientists are presently facing. In addition, their function is still far from being fully understood. The non-coding portion of the genome is indeed the largest, both quantitatively and qualitatively. A large fraction of these ncRNAs have a regulatory role either in coding mRNAs or in other ncRNAs, creating an intracellular network of crossed interactions (competing endogenous RNA networks, or ceRNET) that fine-tune the gene expression in both health and disease. The alteration of the equilibrium among such interactions can be enough to cause a transition from health to disease, but the opposite is equally true, leading to the possibility of intervening based on these mechanisms to cure human conditions. In this review, we summarize the present knowledge on these mechanisms, illustrating how they can be used for disease treatment, the current challenges and pitfalls, and the roles of environmental and lifestyle-related contributing factors, in addition to the ethical, legal, and social issues arising from their (improper) use.

Potential Gonado-Protective Effect of Cichorium endivia and Its Major Phenolic Acids against Methotrexate-Induced Testicular Injury in Mice

Cichorium endivia L. (Asteraceae) is a wide edible plant that grows in the Mediterranean region. In this study, a phytochemical investigation of C. endivia L. ethanolic extract led to the isolation of stigmasterol (1), ursolic acid (2), β-amyrin (3), azelaic acid (4), vanillic acid (5), (6S, 7E)-6-hydroxy-4,7-megastigmadien-3,9-dione (S(+)-dehydrovomifoliol) (6), 4-hydroxy phenyl acetic acid (7), vomifoliol (8), ferulic acid (9), protocatechuic acid (10), kaempferol (11), p. coumaric acid (12), and luteolin (13). In addition, the total phenolic content as well as the in vitro antioxidant activity of C. endivia L. extract were estimated. Moreover, we inspected the potential gonado-protective effect of C. endivia crude extract, its phenolic fraction, and the isolated coumaric, vanillic, and ferulic acids against methotrexate (MTX)-induced testicular injury in mice. There were seven groups: normal control, MTX control, MTX + C. endivia crude extract, MTX + C. endivia phenolic fraction, MTX + isolated coumaric acid, MTX + isolated vanillic acid, and MTX + isolated ferulic acid. MTX was given by i.p. injection of a 20 mg/kg single dose. The crude extract and phenolic fraction were given with a dose of 100 mg/kg/day, whereas the compounds were given at a dose of 10 mg/kg/day. A histopathological examination was done. The testosterone level was detected in serum together with the testicular content of malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), interleukin 1β (IL-1β), IL-6, tumor necrosis factor alpha (TNF-α), nuclear factor kappa B (NF-κB), B-cell lymphoma 2 (Bcl-2), Bcl-2 associated x protein (Bax), p53, and miR-29a. C. endivia crude extract, the phenolic fraction, and the isolated compounds showed significant elevation in their levels of testosterone, CAT, SOD, Bcl-2 with a significant decrease in their levels of MDA, TNF-α, IL-1β, IL-6, NF-κB, Bax, P53, and miR-29a compared to those of the MTX control group. In conclusion, C. endivia mitigated MTX-induced germ cell toxicity via anti-inflammatory, antioxidant, and antiapoptotic effects.

Effects of Polyphenols on ncRNAs in cancer - An update

In recent years, oncotherapy has received considerable attention concerning plant polyphenols. Increasing evidence suggests that due to the efficiency of polyphenols, they may have antitumor effects in various cancers. However, their regulatory structures remain elusive. Long non-coding RNAs (LncRNAs) have been identified in the regulation of various forms of tumorigenesis and tumor development. Long non-coding RNAs (LncRNAs) have recently emerged as regulatory eukaryotic transcripts and therapeutic targets with important and diverse functions in health and diseases. LncRNAs may be associated with the initiation, development, and progression of cancer. This review summarizes the research on the modulatory effects of LncRNAs and their roles in mediating cellular processes. The mechanisms of action of polyphenols underlying their therapeutic effects on cancers are also discussed. Based on our review, polyphenols might facilitate a significant epigenetic modification as part of their tissue-/cell-related biological effects. This finding may be attributed to their interaction with cellular signaling pathways involved in chronic diseases. Certain LncRNAs might be the target of specific polyphenols, and some critical signaling processes involved in the intervention of cancers might mediate the therapeutic roles of polyphenols. This article is protected by copyright. All rights reserved.

Neochlorogenic Acid Attenuates Hepatic Lipid Accumulation and Inflammation via Regulating miR-34a In Vitro

Neochlorogenic acid (5-Caffeoylquinic acid; 5-CQA), a major phenolic compound isolated from mulberry leaves, possesses anti-oxidative and anti-inflammatory effects. Although it modulates lipid metabolism, the molecular mechanism is unknown. Using an in-vitro model of nonalcoholic fatty liver disease (NAFLD) in which oleic acid (OA) induced lipid accumulation in HepG2 cells, we evaluated the alleviation effect of 5-CQA. We observed that 5-CQA improved OA-induced intracellular lipid accumulation by downregulating sterol regulatory element-binding protein 1 (SREBP1) and fatty acid synthase (FASN) expression, which regulates the fatty acid synthesis, as well as SREBP2 and HMG-CoA reductases (HMG-CoR) expressions, which regulate cholesterol synthesis. Treatment with 5-CQA also increased the expression of fatty acid β-oxidation enzymes. Remarkably, 5-CQA attenuated OA-induced miR-34a expression. A transfection assay with an miR-34a mimic or miR-34a inhibitor revealed that miR-34a suppressed Moreover, Sirtuin 1 (SIRT1) expression and inactivated 5’ adenosine monophosphate-activated protein kinase (AMPK). Our results suggest that 5-CQA alleviates lipid accumulation by downregulating miR-34a, leading to activation of the SIRT1/AMPK pathway.

Biological Role and Clinical Implications of microRNAs in BRCA Mutation Carriers

Women with pathogenic germline mutations in BRCA1 and BRCA2 genes have an increased risk to develop breast and ovarian cancer. There is, however, a high interpersonal variability in the modality and timing of tumor onset in those subjects, thus suggesting a potential role of other individual’s genetic, epigenetic, and environmental risk factors in modulating the penetrance of BRCA mutations. MicroRNAs (miRNAs) are small noncoding RNAs that can modulate the expression of several genes involved in cancer initiation and progression. MiRNAs are dysregulated at all stages of breast cancer and although they are accessible and evaluable, a standardized method for miRNA assessment is needed to ensure comparable data analysis and accuracy of results. The aim of this review was to highlight the role of miRNAs as potential biological markers for BRCA mutation carriers. In particular, biological and clinical implications of a link between lifestyle and nutritional modifiable factors, miRNA expression and germline BRCA1 and BRCA2 mutations are discussed with the knowledge of the best available scientific evidence.

Targeting miRNA by Natural Products: A Novel Therapeutic Approach for Nonalcoholic Fatty Liver

The increasing prevalence of nonalcoholic fatty liver disease (NAFLD) as multifactorial chronic liver disease and the lack of a specific treatment have begun a new era in its treatment using gene expression changes and microRNAs. This study aimed to investigate the potential therapeutic effects of natural compounds in NAFLD by regulating miRNA expression. MicroRNAs play essential roles in regulating the cell's biological processes, such as apoptosis, migration, lipid metabolism, insulin resistance, and adipocyte differentiation, by controlling the posttranscriptional gene expression level. The impact of current NAFLD pharmacological management, including drug and biological therapies, is uncertain. In this context, various dietary fruits or medicinal herbal sources have received worldwide attention versus NAFLD development. Natural ingredients such as berberine, lychee pulp, grape seed, and rosemary possess protective and therapeutic effects against NAFLD by modifying the gene's expression and noncoding RNAs, especially miRNAs.

Cure lies in nature: medicinal plants and endophytic fungi in curbing cancer

Success of targeted cancer treatment modalities has generated an ambience of plausible cure for cancer. However, cancer remains to be the major cause of mortality across the globe. The emergence of chemoresistance, relapse after treatment and associated adverse effects has posed challenges to the present therapeutic regimes. Thus, investigating new therapeutic agents of natural origin and delineating the underlying mechanism of action is necessary. Since ages and still in continuum, the phytochemicals have been the prime source of identifying bioactive agents against cancer. They have been exploited for isolating targeted specific compounds to modulate the key regulating signaling pathways of cancer pathogenesis and progression. Capsaicin (alkaloid compound in chilli), catechin, epicatechin, epigallocatechin and epigallocatechin-3-gallate (phytochemicals in green tea), lutein (carotenoid found in yellow fruits), Garcinol (phenolic compound present in kokum tree) and many other naturally available compounds are also very valuable to develop the drugs to treat the cancer. An alternate repository of similar chemical diversity exists in the form of endophytic fungi inhabiting the medicinal plants. There is a high diversity of plant associated endophytic fungi in nature which are potent producers of anti-cancer compounds and offers even stronger hope for the discovery of an efficient anti-cancer drug. These fungi provide various bioactive molecules, such as terpenoids, flavonoids, alkaloids, phenolic compounds, quinines, steroids etc. exhibiting anti-cancerous property. The review discusses the relevance of phytochemicals in chemoprevention and as modulators of miRNA. The perspective advocates the imperative role of anti-cancerous secondary metabolites containing repository of endophytic fungi, as an alternative route of drug discovery.

Natural lactucopicrin alleviates importin-α3-mediated NF-κB activation in inflammated endothelial cells and improves sepsis in mice

Lactucopicrin, a bitter sesquiterpene lactone of leafy vegetables, such as chicory, curly escarole, and lettuce, possesses anti-malarial, anti-cancer and analgesic properties. However, it remains unknown whether lactucopicrin could inhibit vascular endothelial nuclear factor-κB (NF-κB) activation, a hallmark of vascular inflammatory diseases including sepsis. In tumor necrosis factor-α-stimulated human or mouse aortic endothelial cells, lactucopicrin dose-dependently inhibited NF-κB activation, and concomitantly repressed both vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1)-mediated monocyte adhesion. The lactucopicrin effect was not due to modulation of inhibitor of NF-κB kinases (IKK) α/β/γ, inhibitor of NF-κB alpha (IκBα), and NF-κB/p65 DNA binding activity. Instead, lactucopicrin inhibited importin-α3 expression by destabilization of its mRNA, an effect mediating the lactucopicrin effect on NF-κB activity. More importantly, in lipopolysaccharide (LPS)-elicited septic mice, oral gavage with lactucopicrin decreased mortality by 30.5% as compared with the control treatment. This effect was associated with inhibited importin-α3 expression, suppressed NF-κB activation and VCAM-1/ICAM-1 expression, and inhibited leukocyte influx in the vascular endothelium of both lung and aorta. Collectively, our novel data suggest that dietary supplementation with lactucopicrin inhibits endothelial NF-κB activation by down-regulation of importin-α3 and thereby improves sepsis.

Intake of Natural Compounds and Circulating microRNA Expression Levels: Their Relationship Investigated in Healthy Subjects With Different Dietary Habits

Diet has a strong influence on many physiological processes, which in turn have important implications on a variety of pathological conditions. In this respect, microRNAs (miRNAs), a class of small non-coding RNAs playing a relevant epigenetic role in controlling gene expression, may represent mediators between the dietary intake and the healthy status. Despite great advances in the field of nutri-epigenomics, it remains unclear how miRNA expression is modulated by the diet and, specifically, the intake of specific nutrients. We investigated the whole circulating miRNome by small RNA-sequencing performed on plasma samples of 120 healthy volunteers with different dietary habits (vegans, vegetarians, and omnivores). Dietary intakes of specific nutrients were estimated for each subject from the information reported in the food-frequency questionnaire previously validated in the EPIC study. We focused hereby on the intake of 23 natural compounds (NCs) of the classes of lipids, micro-elements, and vitamins. We identified 78 significant correlations (rho > 0.300, p-value < 0.05) among the estimated daily intake of 13 NCs and the expression levels of 58 plasma miRNAs. Overall, vitamin D, sodium, and vitamin E correlated with the largest number of miRNAs. All the identified correlations were consistent among the three dietary groups and 22 of them were confirmed as significant (p-value < 0.05) by age-, gender-, and body-mass index-adjusted Generalized Linear regression Model analysis. miR-23a-3p expression levels were related with different NCs including a significant positive correlation with sodium (rho = 0.377) and significant negative correlations with lipid-related NCs and vitamin E. Conversely, the estimated intake of vitamin D was negatively correlated with the expression of the highest number of circulating miRNAs, particularly miR-1277-5p (rho = −0.393) and miR-144-3p (rho = −0.393). Functional analysis of the targets of sodium intake-correlated miRNAs highlighted terms related to cardiac development. A similar approach on targets of those miRNAs correlated with vitamin D intake showed an enrichment in genes involved in hormone metabolisms, while the response to chronic inflammation was among the top enriched processes involving targets of miRNAs negatively related with vitamin E intake. Our findings show that nutrients through the habitual diet influence circulating miRNA profiles and highlight that this aspect must be considered in the nutri-epigenomic research.

Dietary molecules and experimental evidence of epigenetic influence in cancer chemoprevention: An insight

The world-wide rate of incidence of cancer disease has been only modestly contested by the past and current preventive and interventional strategies. Hence, the global effort towards novel ideas to contain the disease still continues. Constituents of human diets have in recent years emerged as key regulators of carcinogenesis, with studies reporting their inhibitory potential against all the three stages vis-a-vis initiation, promotion and progression. Unlike drugs which usually act on single targets, these dietary factors have an advantage of multi-targeted effects and pleiotropic action mechanisms, which are effective against cancer that manifest as a micro-evolutionary and multi-factorial disease. Since most of the cellular targets have been identified and their consumption considered relatively safe, these diet-derived agents often appear as molecules of interest in repurposing strategies. Currently, many of these molecules are being investigated for their ability to influence the aberrant alterations in cell's epigenome for epigenetic therapy against cancer. Targeting the epigenetic regulators is a new paradigm in cancer chemoprevention which acts to reverse the warped-up epigenetic alterations in a cancer cell, thereby directing it towards a normal phenotype. In this review, we discuss the significance of dietary factors and natural products as chemopreventive agents. Further, we corroborate the experimental evidence from existing literature, reflecting the ability of a series of such molecules to act as epigenetic modifiers in cancer cells, by interfering with molecular events that map the epigenetic imprints such as DNA methylation, histone acetylation and non-coding RNA mediated gene regulation.

Ginkgo biloba Extract Attenuates Methotrexate-Induced Testicular Injury in Rats: Cross-talk Between Oxidative Stress, Inflammation, Apoptosis, and miRNA-29a Expression

Ginkgo biloba leaf extract (GIN) is a popular Chinese herbal medicine. It has a nephroprotective effect against the nephrotoxicity induced by the chemotherapeutic agent methotrexate (MTX). This work was designed to explore the testicular protective role of GIN on MTX-induced testicular injury in a rat model. The experimental protocol lasted for 10 days for the 4 studied groups. First group: received saline (normal control, NC group). The second group was administered GIN (100 mg/kg/day) orally for 10 days (GIN C). Third group: injected with MTX (20 mg/kg ip) only on the fifth day (MTX group). Fourth group: administered GIN for 10 days with MTX injection on the fifth day (GIN+MTX group). MTX induced testicular injury as evident by a marked rise in the malondialdehyde (MDA) content, interleukin-6 (IL-6) and IL-1β protein levels, nuclear factor kappa-B (NF-κB) protein expression, bcl-2 associated × protein (Bax) mRNA expression, p53 mRNA and protein expressions, and miRNA29-a expression along with a marked decline in the serum level of testosterone and superoxide dismutase (SOD) content in testicular tissue in relation to the NC group. Moreover, histopathological testicular damage with a notable decrease in the Johnsen score together with a significant elevation in the testicular injury score was observed in the MTX group in comparison to the NC group. The administration of GIN ameliorated the biochemical changes as well as the testicular histopathological findings and scores. GIN could protect against MTX-induced gonadotoxicity by its antioxidant, anti-inflammatory, antiapoptotic activities plus the regulation of the miRNA-29a testicular expression.

MicroRNAs in diabetic nephropathy: From molecular mechanisms to new therapeutic targets of treatment

Despite considerable investigation in diabetic nephropathy (DN) pathogenesis and possible treatments, current therapies still do not provide competent prevention from disease progression to end-stage renal disease (ESRD) in most patients. Therefore, investigating exact molecular mechanisms and important mediators underlying DN may help design better therapeutic approaches for proper treatment. MicroRNAs (MiRNAs) are a class of small non-coding RNAs that play a crucial role in post-transcriptional regulation of many gene expression within the cells and present an excellent opportunity for new therapeutic approaches because their profile is often changed during many diseases, including DN. This review discusses the most important signaling pathways involved in DN and changes in miRNAs profile in each signaling pathway. We also suggest possible approaches for miRNA derived interventions for designing better treatment of DN.

Pharmacokinetic and Metabolic Profiling of Key Active Components of Dietary Supplement Magnolia officinalis Extract for Prevention against Oral Carcinoma

Among the three key active components (KACs) of Magnolia officinalis bark extract (ME), 4-O-methylhonokiol and honokiol showed higher antiproliferation activities than magnolol in the oral squamous cancer cell lines (Cal-27, SCC-9, and SCC-4). Oral bioavailabilities of ME-KACs were poor (<0.2%) in C57BL/6 mice primarily due to their extensive first-pass phase II metabolism and poor solubilities. High plasma concentration of glucuronides upon oral administration and faster rate of glucuronidation by intestinal microsomes indicated intestine as one of the major metabolic organs for ME-KACs. Despite the increase in bioavailabilities of ME-KACs (∼8-10-fold) and decrease in AUC_0-24 of glucuronides (∼10-fold) upon ME solubility enhancement, systemic exposure of ME-KACs failed to improve meaningfully. In conclusion, we propose a quality-controlled and chemically defined ME mixture, containing an optimized ratio of three KACs, delivered locally in the oral cavity as the most promising strategy for ME use as an oral cancer chemopreventive dietary supplement.

Advances in the discovery of microRNA-based anticancer therapeutics: latest tools and developments

Introduction: MicroRNAs (miRNAs) are small endogenous non-coding RNAs that repress the expression of their target genes by reducing mRNA stability and/or inhibiting translation. miRNAs are known to be aberrantly regulated in cancers. Modulators of miRNA (mimics and antagonists) have emerged as novel therapeutic tools for cancer treatment.Areas covered: This review summarizes the various strategies that have been applied to correct the dysregulated miRNA in cancer cells. The authors also discuss the recent advances in the technical development and preclinical/clinical evaluation of miRNA-based therapeutic agents.Expert opinion: Application of miRNA-based therapeutics for cancer treatment is appealing because they are able to modulate multiple dysregulated genes and/or signaling pathways in cancer cells. Major obstacles hindering their clinical development include drug delivery, off-target effects, efficacious dose determination, and safety. Tumor site-specific delivery of novel miRNA therapeutics may help to minimize off-target effects and toxicity. Combination of miRNA therapeutics with other anticancer treatment modalities could provide a synergistic effect, thus allowing the use of lower dose, minimizing off-target effects, and improving the overall safety profile in cancer patients. It is critical to identify individual miRNAs with cancer type-specific and context-specific regulation of oncogenes and tumor-suppressor genes in order to facilitate the precise use of miRNA anticancer therapeutics.

Cytoprotective Effects of Natural Compounds against Oxidative Stress

Oxidative stress, an imbalance between reactive oxygen species and antioxidants, has been witnessed in pathophysiological states of many disorders. Compounds identified from natural sources have long been recognized to ameliorate oxidative stress due to their inherent antioxidant activities. Here, we summarize the cytoprotective effects and mechanisms of natural or naturally derived synthetic compounds against oxidative stress. These compounds include: caffeic acid phenethyl ester (CAPE) found in honey bee propolis, curcumin from turmeric roots, resveratrol abundant in grape, and 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl] imidazole (CDDO-Im), a synthetic triterpenoid based on naturally occurring oleanolic acid. Cytoprotective effects of these compounds in diseases conditions like cardiovascular diseases and obesity to decrease oxidative stress are discussed.

Resveratrol analogue, trans-4,4'-dihydroxystilbene (DHS), inhibits melanoma tumor growth and suppresses its metastatic colonization in lungs

The prevalence of melanoma and the lack of effective therapy for metastatic melanoma warrant extensive and systematic evaluations of small molecules in cellular and pre-clinical models. We investigated, herein, the antitumor and anti-metastatic effects of trans-4,4'-dihydroxystilbene (DHS), a natural product present in bark of Yucca periculosa, using in vitro and in vivo melanoma murine models. DHS showed potent melanoma cytotoxicity, as determined by MTT and clonogenic assay. Further, DHS induced cytotoxicity was mediated through apoptosis, which was assessed by annexin V-FITC/PI, sub-G1 and caspase activation assays. In addition, DHS inhibited cell proliferation by inducing robust cell cycle arrest in G1-phase. Imperatively, these inhibitory effects led to a significant reduction of melanoma tumor in pre-clinical murine model. DHS also inhibited cell migration and invasion of melanoma cells, which were examined using wound healing and Transwell migration/invasion assays. Mechanistically, DHS modulated the expressions of several key metastasis regulating proteins e.g., MMP-2/9, N-cadherin, E-cadherin and survivin. We also showed the anti-metastatic effect of DHS in a melanoma mediated lung metastasis model in vivo. DHS significantly reduced large melanoma nodule formation in the parenchyma of lungs. Therefore, DHS may represent a promising natural drug in the repertoire of treatment against melanoma tumor growth and metastasis.

Non-coding RNA/microRNA-modulatory dietary factors and natural products for improved cancer therapy and prevention: Alkaloids, organosulfur compounds, aliphatic carboxylic acids and water-soluble vitamins

Non-coding small RNA molecules, the microRNAs (miRNAs), contribute decisively to the epigenetic regulation processes in cancer cells. Problematic pathogenic properties of cancer cells and the response of cancers towards anticancer drugs are highly influenced by miRNAs. Both increased drug activity and formation of tumor resistance are regulated by miRNAs. Further to this, the survival and proliferation of cancer cells and the formation of metastases is based on the modulated expression of certain miRNAs. In particular, drug-resistant cancer stem-like cells (CSCs) depend on the presence and absence of specific miRNAs. Fortunately, several small molecule natural compounds were discovered that target miRNAs involved in the modulation of tumor aggressiveness and drug resistance. This review gives an overview of the effects of a selection of naturally occurring small molecules (alkaloids, organosulfur compounds, aliphatic carboxylic acids and water-soluble vitamins) on miRNAs that are closely tangled with cancer diseases.