Effects of emodin on the demethylation of tumor-suppressor genes in pancreatic cancer PANC-1 cells

Protective effects of emodin on subchondral bone and articular cartilage in osteoporotic osteoarthritis rats: A preclinical study

BACKGROUND

Osteoporotic osteoarthritis (OP-OA) is a severe pathological form of OA, urgently requiring precise management strategies and more efficient interventions. Emodin (Emo), an effective ingredient found in the traditional Chinese medicine rhubarb, has been dEmonstrated to promote osteogenesis and inhibit extracellular matrix degradation. In this study, we aimed to investigate the interventional effects of Emo on the subchondral bone and cartilage of the knee joints in OP-OA model rats.

METHODS

Thirty-two SD rats were randomly and equally divided into sham, OP-OA, Emo low-dose, and Emo high-dose groups. Micro-CT scanning was conducted to examine the bone microstructure of the rat knee joints. H&E and Safranin O and Fast Green staining (SO&FG) were performed for the pathomorphological evaluation of the rat cartilage tissues. ELISA was used to estimate the rat serum expression levels of inflammatory factors, including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Additionally, the CCK-8 assay was utilized for determining the viability of Emo-treated BMSCs. Western blot and real-time PCR analyses were also employed to measure the bone formation indexes and cartilage synthesis and decomposition indexes. Lastly, the osteogenic and chondrogenic differentiation efficiency of the BMSCs was investigated via Alizarin Red and Alcian Blue staining.

RESULTS

Emo intervention alleviated the bone microstructural disruption of the subchondral bone and articular cartilage in the OP-OA rats and up-regulated the expression of bone and cartilage anabolic metabolism indicators, decreased the expression of cartilage catabolism indicators, and diminished the expression of inflammatory factors in the rat serum (P<0.05). Furthermore, Emo reversed the decline in the osteogenic and chondrogenic differentiation ability of the BMSCs (P<0.05).

CONCLUSION

Emo intervention mitigates bone loss and cartilage damage in OP-OA rats and promotes the osteogenic and chondrogenic differentiation of BMSCs.

Recent findings regarding the synergistic effects of emodin and its analogs with other bioactive compounds: Insights into new mechanisms

CONTEXT

Emodin is a natural bioactive ingredient mainly extracted from traditional Chinese herbs. Increasing lines of evidence suggest that emodin and its analogs exert notable synergistic pharmacological effects with other bioactive compounds.

OBJECTIVE

This review provides an overview of the pharmacological activity of emodin and its analogs in combination with other physiologically active substances, describes the related molecular mechanisms, and discusses future prospects in this field.

METHODS

Information from multiple scientific databases, such as PubMed, the China Knowledge Resource Integrated Database from the China National Knowledge Infrastructure (CNKI), the Web of Science, Google Scholar, and Baidu Scholar, was collected between January 2006 and August 2022. The subject terms used in the literature search were emodin, pharmaceutical activities, analogs, aloe emodin, rhein, and synergistic effects.

RESULTS

The comprehensive literature analysis suggested that combinations of emodin or its analogs with other bioactive compounds exert notable synergistic anticancer, anti-inflammatory, and antimicrobial effects and that such combinations improve glucose and lipid metabolism and central nervous system diseases.

DISCUSSION AND CONCLUSIONS

Further assessments of the dose-effect relationship and the differences in the efficacy of emodin or its analogs with other bioactive compounds among various modes of administration are needed, and a drug safety evaluation of these combinations needs to be carefully performed. Future studies should also focus on determining the optimal drug combinations for specific diseases.

OMICS Applications for Medicinal Plants in Gastrointestinal Cancers: Current Advancements and Future Perspectives

Gastrointestinal cancers refer to a group of deadly malignancies of the gastrointestinal tract and organs of the digestive system. Over the past decades, considerable amounts of medicinal plants have exhibited potent anticancer effects on different types of gastrointestinal cancers. OMICS, systems biology approaches covering genomics, transcriptomics, proteomics and metabolomics, are broadly applied to comprehensively reflect the molecular profiles in mechanistic studies of medicinal plants. Single- and multi-OMICS approaches facilitate the unravelling of signalling interaction networks and key molecular targets of medicinal plants with anti-gastrointestinal cancer potential. Hence, this review summarizes the applications of various OMICS and advanced bioinformatics approaches in examining therapeutic targets, signalling pathways, and the tumour microenvironment in response to anticancer medicinal plants. Advances and prospects in this field are also discussed.

Natural Bioactive Compounds Targeting Epigenetic Pathways in Cancer: A Review on Alkaloids, Terpenoids, Quinones, and Isothiocyanates

Cancer is one of the most complex and systemic diseases affecting the health of mankind, causing major deaths with a significant increase. This pathology is caused by several risk factors, of which genetic disturbances constitute the major elements, which not only initiate tumor transformation but also epigenetic disturbances which are linked to it and which can induce transcriptional instability. Indeed, the involvement of epigenetic disturbances in cancer has been the subject of correlations today, in addition to the use of drugs that operate specifically on different epigenetic pathways. Natural molecules, especially those isolated from medicinal plants, have shown anticancer effects linked to mechanisms of action. The objective of this review is to explore the anticancer effects of alkaloids, terpenoids, quinones, and isothiocyanates.

Advances in the study of emodin: an update on pharmacological properties and mechanistic basis

Rhei Radix et Rhizoma, also known as rhubarb or Da Huang, has been widely used as a spice and as traditional herbal medicine for centuries, and is currently marketed in China as the principal herbs in various prescriptions, such as Da-Huang-Zhe-Chong pills and Da-Huang-Qing-Wei pills. Emodin, a major bioactive anthraquinone derivative extracted from rhubarb, represents multiple health benefits in the treatment of a host of diseases, such as immune-inflammatory abnormality, tumor progression, bacterial or viral infections, and metabolic syndrome. Emerging evidence has made great strides in clarifying the multi-targeting therapeutic mechanisms underlying the efficacious therapeutic potential of emodin, including anti-inflammatory, immunomodulatory, anti-fibrosis, anti-tumor, anti-viral, anti-bacterial, and anti-diabetic properties. This comprehensive review aims to provide an updated summary of recent developments on these pharmacological efficacies and molecular mechanisms of emodin, with a focus on the underlying molecular targets and signaling networks. We also reviewed recent attempts to improve the pharmacokinetic properties and biological activities of emodin by structural modification and novel material-based targeted delivery. In conclusion, emodin still has great potential to become promising therapeutic options to immune and inflammation abnormality, organ fibrosis, common malignancy, pathogenic bacteria or virus infections, and endocrine disease or disorder. Scientifically addressing concerns regarding the poor bioavailability and vague molecular targets would significantly contribute to the widespread acceptance of rhubarb not only as a dietary supplement in food flavorings and colorings but also as a health-promoting TCM in the coming years.

Integrative Management of Pancreatic Cancer (PDAC): Emerging Complementary Agents and Modalities

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. The standard first-line treatment for PDAC is gemcitabine chemotherapy which, unfortunately, offers only limited chance of a lasting cure. This review further evaluates the hypothesis that the effectiveness of gemcitabine can be improved by combining it with evidence-based complementary measures. Previously, supported by clinical trial data, we suggested that a number of dietary factors and nutraceuticals can be integrated with gemcitabine therapy. Here, we evaluate a further 10 agents for which no clinical trials have (yet) been carried out but there are promising data from in vivo and/or in vitro studies including experiments involving combined treatments with gemcitabine. Two groups of complementary agents are considered: Dietary factors (resveratrol, epigallocatechin gallate, vitamin B9, capsaicin, quercetin and sulforaphane) and nutraceutical agents (artemisinin, garcinol, thymoquinone and emodin). In addition, we identified seven promising agents for which there is currently only basic (mostly in vitro) data. Finally, as a special case of combination therapy, we highlighted synergistic drug combinations involving gemcitabine with "repurposed" aspirin or metformin. We conclude overall that integrated management of PDAC currently is likely to produce the best outcome for patients and for this a wide range of complementary measures is available.

Traditional Chinese medicine may be further explored as candidate drugs for pancreatic cancer: A review

Pancreatic cancer is a disease with a high mortality rate. Although survival rates for different types of cancers have improved in recent years, the five-year survival rate of pancreatic cancer stands at 8%. Moreover, the current first-line therapy, gemcitabine, results in low remission rates and is associated with drug resistance problems. Alternative treatments for pancreatic cancer such as surgery, chemotherapy and radiation therapy provide marginal remission and survival rates. This calls for the search of more effective drugs or treatments. Traditional Chinese medicine contains numerous bioactive ingredients some of which show activity against pancreatic cancer. In this review, we summarize the mechanisms of five types of traditional Chinese medicine monomers. In so-doing, we provide new potential drug candidates for the treatment of pancreatic cancer.

Dietary natural products as epigenetic modifiers in aging-associated inflammation and disease

Covering: up to 2020Chronic, low-grade inflammation is linked to aging and has been termed "inflammaging". Inflammaging is considered a key contributor to the development of metabolic dysfunction and a broad spectrum of diseases or disorders including declines in brain and heart function. Genome-wide association studies (GWAS) coupled with epigenome-wide association studies (EWAS) have shown the importance of diet in the development of chronic and age-related diseases. Moreover, dietary interventions e.g. caloric restriction can attenuate inflammation to delay and/or prevent these diseases. Common themes in these studies entail the use of phytochemicals (plant-derived compounds) or the production of short chain fatty acids (SCFAs) as epigenetic modifiers of DNA and histone proteins. Epigenetic modifications are dynamically regulated and as such, serve as potential therapeutic targets for the treatment or prevention of age-related disease. In this review, we will focus on the role for natural products that include phytochemicals and short chain fatty acids (SCFAs) as regulators of these epigenetic adaptations. Specifically, we discuss regulators of methylation, acetylation and acylation, in the protection from chronic inflammation driven metabolic dysfunction and deterioration of neurocognitive and cardiac function.

Pharmacoepigenetics and pharmacoepigenomics of gastrointestinal cancers

Our understanding of the epigenetic changes occurring in gastrointestinal cancers has gained tremendous advancements in recent years, and some epigenetic biomarkers are already translated into the clinics for cancer diagnostics. In parallel, pharmacoepigenetics and pharmacoepigenomics of solid tumors are relevant novel, but emerging and promising fields. Areas covered: A comprehensive review of the literature to summarize and update the emerging field of pharmacoepigenetics and pharmacoepigenomics of gastrointestinal cancers. Expert commentary: Several epigenetic modifications have been proposed to account for interindividual variations in drug response in gastrointestinal cancers. Similarly, single-agent or combined strategies with high doses of drugs that target epigenetic modifications (epi-drugs) were scarcely tolerated by the patients, and current research has moved to their combination with standard therapies to achieve chemosensitization, radiosensitization, and immune modulation of cancerous cells. In parallel, recent genome-wide technologies are revealing the pathways that are epigenetically deregulated during cancer-acquired resistance, including those targeted by non-coding RNAs. Indeed, novel, less toxic, and more specific molecules are under investigation to specifically target those pathways. The field is rapidly expanding and gathering together information coming from these investigations has the potential to lead to clinical applications in the coming new years.

Impact of Natural Compounds on DNA Methylation Levels of the Tumor Suppressor Gene RASSF1A in Cancer

Epigenetic inactivation of tumor suppressor genes (TSG) is a fundamental event in the pathogenesis of human cancer. This silencing is accomplished by aberrant chromatin modifications including DNA hypermethylation of the gene promoter. One of the most frequently hypermethylated TSG in human cancer is the Ras Association Domain Family 1A (RASSF1A) gene. Aberrant methylation of RASSF1A has been reported in melanoma, sarcoma and carcinoma of different tissues. RASSF1A hypermethylation has been correlated with tumor progression and poor prognosis. Reactivation of epigenetically silenced TSG has been suggested as a therapy in cancer treatment. In particular, natural compounds isolated from herbal extracts have been tested for their capacity to induce RASSF1A in cancer cells, through demethylation. Here, we review the treatment of cancer cells with natural supplements (e.g., methyl donors, vitamins and polyphenols) that have been utilized to revert or prevent the epigenetic silencing of RASSF1A. Moreover, we specify pathways that were involved in RASSF1A reactivation. Several of these compounds (e.g., reseveratol and curcumin) act by inhibiting the activity or expression of DNA methyltransferases and reactive RASSF1A in cancer. Thus natural compounds could serve as important agents in tumor prevention or cancer therapy. However, the exact epigenetic reactivation mechanism is still under investigation.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Emodin inhibits migration and invasion of MHCC-97H human hepatocellular carcinoma cells

Emodin, an anthraquinone derivative from the root and rhizome of Rheum palmatum L., was found to have antitumor effects in different types of cancer by regulating multi-molecular targets. The aim of the present study was to explore the effect of emodin on the migration and invasion of MHCC-97H human hepatocellular carcinoma cells and the underlying molecular mechanisms. Firstly, it was demonstrated that emodin can inhibit cell proliferation and induce apoptosis of cells in a time- and dose-dependent manner, using a MTT assay and flow cytometry, respectively. However, when emodin concentration was <50 µmol/l, it had little effect on the inhibition of proliferation or the induction of apoptosis. Then, it was observed that emodin can significantly suppress cell migration and invasion with a treatment dose <50 µmol/l compared with the control (P<0.05), which was not attributed to a decrease in cell number. Further study demonstrated that emodin significantly suppressed the expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 compared with the control, which may be mediated by the activation of the p38 mitogen-activated protein kinases (MAPK) signaling pathway and suppression of extracellular signal regulated kinase (ERK)/MAPK and phosphatidylinositol 3-kinase/Akt signaling pathways. Therefore, the present study, for the first time, used MHCC-97H cells, which have the high potential of malignant invasion, to demonstrate that emodin may inhibit cell migration and invasion.

EMODIN EFFICACY ON THE AKT, MAPK, ERK AND DNMT EXPRESSION PATTERN DURING DMBA-INDUCED ORAL CARCINOMA IN GOLDEN SYRIAN HAMSTERS

Background:

The present study has evaluated the Emodin efficacy on the Akt, MAPK, ERK and DNMT expression pattern during 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinoma in golden Syrian hamsters, in order to explore its antitumor potential.

Materials and methods:

Oral tumors were developed in the buccal pouches of golden Syrian hamsters using the carcinogen, DMBA.

Results:

While the incidence of tumor formation was 100% in hamsters treated with DMBA alone, the tumor formation was not noticed in DMBA+ Emodin treated hamsters. Also, Emodin reduced the severity of precancerous pathological lesions such as dysplasia, in the hamsters treated with DMBA. Emodin administration corrected the abnormalities in the expression pattern of Akt, MAPK, ERK and DNMT in the buccal mucosa of hamsters treated with DMBA.

Conclusions:

The present study thus suggests that the tumor preventive potential of Emodin is partly related to its modulating effect on the Akt, MAPK, ERK and DNMT expression pattern, as these molecular markers have a pivotal role in the process of cell proliferation, inflammation, invasion, and apoptosis.

Anthraquinones and Derivatives from Marine-Derived Fungi: Structural Diversity and Selected Biological Activities

Anthraquinones and their derivatives constitute a large group of quinoid compounds with about 700 molecules described. They are widespread in fungi and their chemical diversity and biological activities recently attracted attention of industries in such fields as pharmaceuticals, clothes dyeing, and food colorants. Their positive and/or negative effect(s) due to the 9,10-anthracenedione structure and its substituents are still not clearly understood and their potential roles or effects on human health are today strongly discussed among scientists. As marine microorganisms recently appeared as producers of an astonishing variety of structurally unique secondary metabolites, they may represent a promising resource for identifying new candidates for therapeutic drugs or daily additives. Within this review, we investigate the present knowledge about the anthraquinones and derivatives listed to date from marine-derived filamentous fungi's productions. This overview highlights the molecules which have been identified in microorganisms for the first time. The structures and colors of the anthraquinoid compounds come along with the known roles of some molecules in the life of the organisms. Some specific biological activities are also described. This may help to open doors towards innovative natural substances.

Emodin enhances the demethylation by 5-Aza-CdR of pancreatic cancer cell tumor-suppressor genes P16, RASSF1A and ppENK

5-Aza-2'-deoxycytidine (5-Aza-CdR) is currently acknowledged as a demethylation drug, and causes a certain degree of demethylation in a variety of cancer cells, including pancreatic cancer cells. Emodin, a traditional Chinese medicine (TCM), is an effective monomer extracted from rhubarb and has been reported to exhibit antitumor activity in different manners in pancreatic cancer. In the present study, we examined whether emodin caused demethylation and increased the demethylation of three tumor-suppressor genes P16, RASSF1A and ppENK with a high degree of methylation in pancreatic cancer when combined with 5-Aza-CdR. Our research showed that emodin inhibited the growth of pancreatic cancer Panc-1 cells in a dose- and time-dependent manner. Dot-blot results showed that emodin combined with 5-Aza-CdR significantly suppressed the expression of genome 5mC in PANC-1 cells. In order to verify the effect of methylation, methylation-specific PCR (MSP) and bisulfite genomic sequencing PCR (BSP) combined with TA were selected for the cloning and sequencing. Results of MSP and BSP confirmed that emodin caused faint demethylation, and 5-Aza-CdR had a certain degree of demethylation. When emodin was combined with 5-Aza-CdR, the demethylation was more significant. At the same time, fluorescent quantitative PCR and western blot analysis results confirmed that when emodin was combined with 5-Aza-CdR, the expression levels of P16, RASSF1A and ppENK were increased more significantly compared to either treatment alone. In contrast, the expression levels of DNA methyltransferase 1 (DNMT1) and DNMT3a were more significantly reduced with the combination treatment than the control or either agent alone, further proving that emodin in combination with 5-Aza-CdR enhanced the demethylation effect of 5-Aza-CdR by reducing the expression of methyltransferases. In conclusion, the present study confirmed that emodin in combination with 5-Aza-CdR enhanced the demethylation by 5-Aza-CdR of tumor-suppressor genes p16, RASSF1A and ppENK by reducing the expression of methyltransferases DNMT1 and DNMT3a.