In-Vitro Analysis of Glucose and Quercetin Effects on m-TOR and Nrf-2 Expression in HepG2 Cell Line (Diabetes and Cancer Connection)

Natural small molecule thymoquinone increases the chemosensitivity of glioblastoma to temozolomide through inhibiting Wnt/β-catenin signaling pathway to downregulate MGMT expression: In vitro and in vivo validation

Temozolomide (TMZ) is the only one oral first-line chemotherapeutic drug for glioblastoma treatment. However, O6-methylguanine-DNA methyltransferase (MGMT) can repair the lethal O6-methylguaine (O6-MeG) lesion produced by TMZ, thus imparting resistance to TMZ. Currently, the clinical utility of small molecule covalent MGMT inhibitors is limited by the occurrence of severe hematological toxicity. Therefore, developing new strategies for overcoming MGMT-mediated resistance is highly urgent. Here, we explored the feasibility that modulating Wnt/β-catenin signaling pathway in glioblastoma to inhibit MGMT expression to overcome TMZ resistance. From eight natural products or approved drugs with inhibitory effects on Wnt/β-catenin pathway, we found thymoquinone (TQ) completely suppressed MGMT expression in glioblastoma SF763 and SF767 cell lines within 24 h. As expected, TQ exhibited synergistic killing effects with TMZ in SF763 and SF767 cells, while in MGMT-negative SF126 cells only additive effect observed. Moreover, TQ remarkably enhanced the inhibition of TMZ on cell proliferation, clone formation, invasion and migration, and promoted cell apoptosis. In resistant SF763 mice tumor xenograft model, TQ significantly increased the suppression of TMZ on tumor growth, meanwhile maintaining good biosafety. Western blotting analysis indicated that TQ significantly inhibited the nuclear translocation of β-catenin and the expression of downstream proteins Cyclin D1 and MGMT. The addition of Wnt activator LiCl reversed the nuclear translocation of β-catenin and the expression of Cyclin D1 and MGMT induced by TQ. For the first time, our findings indicate that TQ can considerably increase the sensitivity of glioblastoma to TMZ by interfering Wnt/β-catenin pathway to downregulate MGMT expression.

Quercetin Promote the Chemosensitivity in Organoids Derived from Patients with Breast Cancer

Aim

The study aimed to culture organoids from tissues of patients with breast cancer (BC) and use the organoids to measure the sensitivity to quercetin and its combination with chemotherapeutic agents.

Methods

Four patient-derived organoids (PDOs) of BC were cultured. The proliferative activity and morphology of PDOs were evaluated on different generations and after resuscitation. H&E and immunohistochemical (IHC) staining were used to identify the pathological changes and the expression of biomarkers. The sensitivity to quercetin and chemotherapeutic agents and their combinations were evaluated using adenosine triphosphate (ATP) viability assays.

Results

We successfully obtained all PDOs from BC tissues. PDOs preserved their activity and morphology during generation passage. In addition, the pathological changes and expression patterns of estrogen receptor (ER), human epidermal growth factor receptor (HER2), and Ki67 of each PDO were consistent with their original tissues. All four PDOs were highly sensitive to quercetin, and their IC50 values were less than 22 μM. PDOs showed better sensitivity to docetaxel and epirubicin hydrochloride, but less sensitivity to cis-platinum. Combination with quercetin promoted the sensitivity to three chemotherapeutic agents. In particular, the IC50 value of cis-platinum greatly decreased.

Conclusion

We successfully established PDOs from patients with BC and demonstrated that quercetin can promote the sensitivity of chemotherapeutic agents in these PDOs.

Advances in the mechanisms of Gardenia jasminoides Ellis in improving diabetes and its complications

Gardenia jasminoides Ellis (Zhi-zi), which belongs to the Rubiaceae family, has been used mainly with its fry fruit for thousands of years, and it is an herb with the homology of medicine and food. In traditional Chinese medicine (TCM) theory, Zhi-zi can be used for "Quench Xiaoke", meaning for therapying diabetes in modern medicine. Based on numerous pharmacological studies, Gardenia jasminoides Ellis (Zhi-zi), and its ingredients, mainly including iridoid glycosides and carotenoids (crocins), possess potent antioxidant and anti-inflammatory properties, and can promote insulin secretion and sensitization, stimulate GLP-1 pathway activity, and protect islet β cells and the macro- and microvascular systems. These properties are the primary reasons why Zhi-zi and its ingredients are effective in reducing glucose levels, treating diabetes, and preventing its complications. This review aims to summarize the current situation and the advances of the studies on the mechanisms of Zhi-zi in improving diabetes and its complications, and it is expected to provide useful and systematic references for future research and clinical application of Zhi-zi and its active ingredients in the therapy of diabetes and complications.

Notch Signaling Suppression by Golden Phytochemicals: Potential for Cancer Therapy

Cancer is one of the main causes of mortality worldwide. Cancer cells are characterized by unregulated cellular processes, including proliferation, progression, and angiogenesis. The occurrence of these processes is due to the dysregulation of various signaling pathways such as NF-κB (nuclear factor-κB), Wnt/beta-catenin, Notch signaling and MAPK (mitogen-activated protein kinases). Notch signaling pathways cause the progression of various types of malignant tumors. Among the phytochemicals for cancer therapy, several have attracted great interest, including curcumin, genistein, quercetin, silibinin, resveratrol, cucurbitacin and glycyrrhizin. Given the great cellular and molecular heterogeneity within tumors and the high toxicity and side effects of synthetic chemotherapeutics, natural products with pleiotropic effects that simultaneously target numerous signaling pathways appear to be ideal substitutes for cancer therapy. With this in mind, we take a look at the current status, impact and potential of known compounds as golden phytochemicals on key signaling pathways in tumors, focusing on the Notch pathway. This review may be useful for discovering new molecular targets for safe and efficient cancer therapy with natural chemotherapeutics.

Exploring monocarboxylate transporter inhibition for cancer treatment

Cells are separated from the environment by a lipid bilayer membrane that is relatively impermeable to solutes. The transport of ions and small molecules across this membrane is an essential process in cell biology and metabolism. Monocarboxylate transporters (MCTs) belong to a vast family of solute carriers (SLCs) that facilitate the transport of certain hydrophylic small compounds through the bilipid cell membrane. The existence of 446 genes that code for SLCs is the best evidence of their importance. In-depth research on MCTs is quite recent and probably promoted by their role in cancer development and progression. Importantly, it has recently been realized that these transporters represent an interesting target for cancer treatment. The search for clinically useful monocarboxylate inhibitors is an even more recent field. There is limited pre-clinical and clinical experience with new inhibitors and their precise mechanism of action is still under investigation. What is common to all of them is the inhibition of lactate transport. This review discusses the structure and function of MCTs, their participation in cancer, and old and newly developed inhibitors. Some suggestions on how to improve their anticancer effects are also discussed.

Role of polyphenols in the management of diabetic complications

BACKGROUND

Diabetes Mellitus is an endocrine disorder that will affect, about 693 million adults by 2045 worldwide, (>50% increase from 2017). The conventional treatment of the disease, include the oral hypoglycemic drugs which are given in combination with other drugs and are known to possess various adverse effects like gastrointestinal disturbance, nausea, water retention etc. PURPOSE: Due to the urgent need of combating this disorder without side effects, the alternative and complementary therapies should be explored due to their natural origins and comparable safety. Herbal sources serve as new leads, due to the presence of phytoconstituents with potential therapeutic properties, efficacy and safety. In this review, we tried to summarise the polyphenolic phytoconstituents effective in the treatment of diabetic complications.

METHODS

A systematic literature search was conducted using 4 databases (Google scholar, Pubmed, Scopus, Embase) for the identification of relevant data. Search was performed using various key words such as "diabetes", "polyphenols", "marine sources","anti-diabetic polyphenols". The in vitro studies involving the cell lines used in diabetes and animal models were also considered for inclusion. Additional research papers were identified by reviewing abstracts, scrutinizing reference lists, and reviewing previously published review articles.

RESULTS

Polyphenols, a group of phytoconstituents are known worldwide for their tremendous antioxidant potential. So, various research groups have explored their mechanism and therapeutic value in diabetic complications, to improve the insulin sensitivity and glucose metabolism, in controlling the glycemic conditions.

CONCLUSION

Polyphenols exhibit effective therapeutic potential in managing diabetic complications through their multifaceted mechanism of action. They exhibit antioxidative, anti-inflammatory, and anti-glycemic properties, which collectively contribute to their beneficial effects in mitigating diabetic complications. Thus, the inclusion of polyphenols into the diet, may be cosidered as an approach of managing diabetes on long term basis. In this review, we have tried to identify polyphenols effective in diabetes and summarize their mechanism of action along with their potential, for the treatment of diabetic complications.

Investigation of the combined cytotoxicity induced by sodium butyrate and a flavonoid quercetin treatment on MCF-7 breast cancer cells

Quercetin (QUE) belonging to the flavonoid class is a common phytochemical present in the daily diet of some individuals. Quercetin is an important source of free radical scavengers. This property makes this flavonoid a reliable antioxidant with the following properties: anti-inflammatory, anti-diabetic, antimicrobial and anti-carcinogenic. Sodium butyrate (NaBu) acts as a histone deacetylase inhibitor (HDACi) and is known to regulate apoptosis in cancer cells. Combining natural flavonoids such as QUE with different substances may synergistically enhance their anti-carcinogenic capacity. Thus, the aim of this study was to examine the combined treatment effects of QUE and NaBu in hormone-sensitive breast cancer cells in vitro. MCF-7 breast cancer cells were treated with QUE alone, NaBu alone, as well as QUE and NaBu combined to determine the following: cell proliferation, levels of protein annexin A5 (ANXA5) and reactive oxygen species (ROS), mRNA protein expression, as well as cell and nuclear morphology. Data demonstrated that either QUE or NaBu alone inhibited cell proliferation, and reduced levels protein ANXA5, ROS and mRNA protein expression, The combination of QUE and NaBu produced a significant synergistic inhibitory effect compared to treatment groups of QUE or NaBu alone. In conclusion, our findings showed that the combination treatment of QUE and NaBu may constitute a promising therapeutic approach to breast cancer treatment but this needs further molecular and in vivo investigations.

Exploring the effects and mechanisms of Guizhigancao Decoction on heart failure using an integrated approach based on experimental support and network pharmacology strategy

Background and aim

HF (Heart Failure) is the leading cause of mortality and is a significant clinical problem affecting millions of patients worldwide. To date, the mechanisms of HF remain largely elusive. The effective treatments contributing to HF remain incompletely understood. Therefore, the development of an effective strategy for HF is urgently needed.

Experimental procedure

In the present study, we devoted to investigating the effective treatments and sought to systematically decipher the related molecular mechanisms of Guizhigancao Decoction (GZGCD, Cinnamomum cassia Presl and Glycyrrhizae Radix Et Rhizoma Praeparata Cum Melle) for treating HF. We examined the therapeutic effect of GZGCD on HF in vivo. An integrative approach combining biomarker examination, echocardiography, myocardial fibrosis and cardiac apoptosis condition using Masson and TUNEL staining was performed to assess the efficacy of GZGCD against HF. Subsequently, comprehensive network pharmacology analyses were performed to explore the mechanisms involved in GZGCD therapeutic effects on HF.

Results and conclusions

The results showed that GZGCD could reverse cardiac function in rats with HF by reducing NT-proBNP, increasing EF, decreasing LVESV, LVEDV, LVIDs, LVIDd, increasing running time, and ameliorate myocardial collagen fiber hyperplasia and cardiomyocyte apoptosis. We showed that GZGCD might contribute to HF treatment via oxidative related pathways through bioinformatics. Eventually, promising compound quercetin in GZGCD for HF therapeutics was proposed in database-based analysis. Collectively, our findings indicate that GZGCD has a treatment effect on HF. We proposed that GZGCD might contribute HF treatment via oxidative response-related pathways.

Nosip is a potential therapeutic target in hepatocellular carcinoma cells

Nitric oxide synthase-interacting protein (Nosip) interacts with nitric oxide synthase (NOS) and regulates NO synthesis and release, which participates in various critical physiological and pathological processes. However, the role of Nosip in hepatocellular carcinoma (HCC) is unclear. In this study, Nosip expression was found to be elevated in HCC tissues and cells. Nosip siRNA transfection inhibited the proliferation and motility of HCC cells and promoted apoptosis. In contrast, overexpression of Nosip promoted proliferation and migration and invasion, and inhibited apoptosis of HCC cells. As a natural compound, quercetin exerted the effect of inhibiting the proliferation and motility of HCC cells, and this anticancer activity probably via repressing the expression of Nosip. Our results suggest that Nosip could act as an oncogene in the progression of HCC and that quercetin may be a potential natural compound for treating HCC by inhibiting the expression of Nosip.

Quercetin targets VCAM1 to prevent diabetic cerebrovascular endothelial cell injury

INTRODUCTION

Endothelial cells play important roles in neurodegenerative diseases caused by diabetes, therefore, we aimed at investigating the mechanisms through which endothelial cells are involved in diabetes development.

METHODS

Single cell analysis was performed to identify the major endothelial cell subtypes in cardiovascular tissues that are involved in diabetes development. A cell-cell communication approach was then used to identify ligand-receptor interaction pairs between these cell types. Differential expression analysis between the two experimental groups [standard chow diet group and diabetogenic diet with cholesterol (DDC) group] was used to identify diabetes-related differentially expressed genes (DEGs). The upregulated genes were used to identify candidate ligands or receptors, as well as the corresponding cell types. Cell trajectory inference was performed to identify the stage of cell development and changes in expression of candidate ligands or receptors during cell development. Gene set enrichment analysis (GSEA) was conducted to investigate the biological functions of genes of purpose. Finally, molecular dynamics simulations (MDSs) were used to predict potential drugs with the ability to target the proteins of purpose.

RESULTS

Seven cell types, including five endothelial cell subtypes (EC_1, EC_2, EC_3, EC_4, and EC_EndMT), were identified from endothelial cell-enriched single cell samples from the heart and aorta of mice. Cell-cell communication analysis revealed the potential ligand-receptor interactions between these cell types while five important ligand-receptor-associated genes, including Fn1, Vcam1, Fbn1, Col4a1, and Col4a2, were established by differential expression analysis. Among them, Vcam1 is mainly expressed in EC_EndMT and is involved in interactions between EC_EndMT and other cells. Cell trajectory extrapolation analysis revealed a shift from EC_2/EC_4 to EC_EndMT and a shift from EC_EndMT to EC_3/EC_1 during the progression of diabetes. GSEA analysis revealed that upregulation of VCAM1 may have inhibitory effects on cell growth and energy metabolism.

CONCLUSION

EC_EndMT subtypes have a complex role in neurodegenerative diseases caused by diabetes. Through mechanisms involved in cell-cell communication, Vcam1 may play an important role in dysregulation of biological functions of EC_ EndMT. Molecular docking results of the quercetin-VCAM1 complex suggest that quercetin may be an effective drug for targeting this protein.

Protective effect of phillyrin against cerebral ischemia/reperfusion injury in rats and oxidative stress-induced cell apoptosis and autophagy in neurons

This study explored the role and potential molecular mechanism of phillyrin in cerebral ischemia/reperfusion (I/R) injury. The rat middle cerebral artery occlusion (MCAO)/R model was constructed, and cerebral infarction volume, brain water content, and neurological score were measured. Neuron morphological structures in brain tissues and primary neuron apoptosis were detected using hematoxylin and eosin (H&E) staining and Hoechst 33258 staining, respectively. In MCAO/R rats, phillyrin markedly reduced cerebral infarction volume, neurological score, and brain water content and inhibited neuron apoptosis. In vitro experiments showed that phillyrin remarkably increased viability and decreased lactate dehydrogenase (LDH) release of H₂O₂-injured neurons. Moreover, phillyrin remarkably downregulated the proportion of apoptosis-related protein B-associated X (Bax)/B-cell lymphoma protein 2 (Bcl-2) and reduced procaspase-3, phospho-Akt (p-Akt-1), and phosphorylation-mammalian target of rapamycin (p-mTOR) levels in H₂O₂-injured neurons. Furthermore, phosphatidylinositol-3 kinase (PI3K) inhibitor ZSTK474 weakened the effects of phillyrin on p-mTOR, p-Akt-1, characteristic proteins of autophagy 3-II (LC3-II) and beclin-1 levels, and H₂O₂-induced neuronal apoptosis and autophagy. Taken together, phillyrin alleviates I/R injury by inhibiting neuronal cell apoptosis and autophagy pathway, which may provide a new treatment strategy for cerebral I/R injury.

Increased Expression of YAP Inhibited the Autophagy Level by Upregulating mTOR Signal in the Eutopic ESCs of Endometriosis

We first reported that the Hippo-YAP signaling pathway plays a critical role in the pathogenesis of endometriosis (EMS). Autophagy is also related to the invasion ability of endometrial cells and is involved in the pathogenesis of EMS through multi-levels. However, the precise regulatory mechanism of YAP on autophagy in the eutopic endometrial stromal cells (ESCs) is still unclear. Primary eutopic ESCs of EMS patients (n = 12) and control patients without EMS (n = 9) were isolated and cultured to investigate the expressions of YAP and mTOR, the role of YAP in autophagy, and the effect of the YAP-autophagy signal on the decidualization of the eutopic ESCs. Endometriosis-related sequencing data (GSE51981) in the GEO database were used to find the genes significantly correlated with YAP. We found 155 genes with significant differences in the interaction with YAP in EMS from the dataset, and the autophagy pathway was significantly enriched. Following on from our previous studies of YAP knockdown, overexpression of YAP resulted in an increased expression of mTOR and decreased ratio of LC3-II/LC3-I and autophagy markers, in the eutopic ESCs; transmission electron microscope observation also showed fewer autophagosomes compared with the control cells. Furthermore, ESCs of the Rapamycin-treated group showed significant decidual-like changes with significantly increased decidual prolactin level at 72 h after in vitro decidualization. These results demonstrate that the increased YAP inhibited the level of autophagy by upregulating the mTOR signal in the eutopic ESCs of endometriosis. The YAP-autophagy signal plays an important role in the pathogenesis of endometriosis-associated infertility.

The effect of platelet-rich plasma-fibrin glue dressing in combination with oral vitamin E and C for treatment of non-healing diabetic foot ulcers: a randomized, double-blind, parallel-group, clinical trial

OBJECTIVE

The current study assesses the effects of platelet-rich plasma-fibrin glue (PRP-FG) dressing along with oral vitamin E and C on wound healing and biochemical markers in patients with non-healing diabetic foot ulcers (non-healing DFU).

METHODS

This randomized controlled trial was performed on 25 patients with non-healing DFU. Patients were treated with PRP-FG dressing plus oral vitamin E and C (intervention group) or PRP-FG dressing plus placebo (control group) for 8 weeks.

RESULTS

Eight weeks after treatment, six wounds in the intervention group and two wounds in the control group were completely closed, and also wound size significantly reduced in both intervention and control groups (p < 0.05). This reduction in wound size was significantly greater in the intervention group compared to the control group (p = 0.019). Also, a significant decrease in prooxidant-antioxidant balance (PAB) , ESR, and hs-CRP was observed in the intervention group compared to the control group (p < 0.05).

CONCLUSION

Our results showed that PRP-FG dressing along with oral vitamin E and C could be used to increase wound healing in patients with non-healing DFU by enhancing the wound healing process and reducing oxidative stress.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT04315909).

The phytoestrogen, quercetin, in serum, uterus and ovary as a potential treatment for dehydroepiandrosterone-induced polycystic ovary syndrome in the rat

The exact mechanisms of polycystic ovary syndrome (PCOS) are unknown and there is no effective cure for the disease. The aim of this study was to evaluate the alterations in serum oestradiol and adiponectin levels and in the expression of some important genes in the uterine and ovarian tissues of PCOS rats. The therapeutic effect of quercetin on PCOS was also assessed. Rats were divided into five groups: control, ethanol, quercetin (Q), PCOS and PCOS+Q. After 30 days of oral treatments, the rats' ovaries and uteri were removed and nesfatin-1, aromatase and adipoR1 expressions were quantified with real-time polymerase chain reaction. Serum adiponectin and oestradiol levels were evaluated using enzyme-linked immunosorbent assay technique. The results of this study showed that expression of nesfatin-1 and adipoR1 genes and adiponectin serum levels decreased in the PCOS rats, but aromatase expression and oestradiol level increased. Treatment with quercetin increased the adiponectin level and expression of adipoR1 and nesfatin-1 and decreased both the expression of aromatase and the oestradiol level. Quercetin improved PCOS by phytoestrogenic effects and mimicking oestrogen's function. Quercetin also affects important factors in both the uterus and ovary and could improve the obesity and the diabetic and infertility symptoms of PCOS.

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.

Flavonoids modulate tight junction barrier functions in hyperglycemic human intestinal Caco-2 cells

OBJECTIVES

Diabetes mellitus is a chronic disease requiring lifelong medical attention. With hundreds of millions suffering worldwide and a rapidly rising incidence, diabetes mellitus poses a great burden on health care systems. Recent studies investigating the underlying mechanisms involved in disease development in diabetes point to the role of the dysregulation of the intestinal barrier. Hyperglycemia-mediated tight junction deformity is known to contribute to leaky gut in various metabolic disorders. The present study aimed to investigate the role of oxidative stress on intestinal epithelial tight junction (TJ) barrier functions in hyperglycemia. Because many flavonoids are known to influence the cellular redox state, exploring these flavonoids may help to understand the role of TJ barrier in hyperglycemia-mediated oxidative stress, which in turn might unfold the association of oxidative stress and dysfunction of barrier-forming TJs.

METHODS

Caco-2 cells were stimulated with high glucose (HG), with or without flavonoids (quercetin, morin, naringenin), for 24 h. We determined cellular viability, levels of reactive oxygen species, and mitochondrial membrane potential in flavonoids treated HG-Caco-2 cells. The levels of the proinflammatory cytokines, glucose uptake, and expression of glucose transporters were determined on flavonoids treatment. We investigated the effect of flavonoids on TJs functions by measuring transepithelial electrical resistance (a TJ integrity marker), membrane permeability using tracer compounds, and the expressions levels of TJs related molecules on hyperglycemic Caco-2 cell monolayers.

RESULTS

We found that high glucose treatment resulted in reduced cell viability, increased reactive oxygen species production, measurable mitochondrial dysfunction, and decreased transepithelial electrical resistance, with increased membrane permeability. Treatment with the test flavonoids produced increased cell viability and reduced glucose uptake of HG-Caco-2 cells. A concomitant decrease in reactive oxygen species production, proinflammatory cytokines, and Glut-associated genes and proteins were identified with flavonoid treatment. Flavonoids prevented derangement of TJs protein interaction and stabilized membrane permeability.

CONCLUSIONS

These findings indicate that flavonoids confer protection against hyperglycemia-mediated oxidative stress and enhance intestinal barrier functions by modulating underlying intracellular molecular mechanisms.

Nicotine attenuates global genomic DNA methylation by influencing DNMTs gene expression in human endometrial stromal cells

BACKGROUND

There is increasing evidence indicating an incidence of infertility and also the risk of endometrial cancers among smokers. However, the mechanism underlying nicotine adverse effect on female reproduction remains unclear. Growing evidence has suggested that environmental exposures such as nicotine could modulate the epigenome. No study has yet been published to evaluate the direct effect of nicotine on the epigenome profiling of human endometrial stromal cells (HESC). Herein, we decided to examine the direct effects of nicotine on global genomic DNA methylation status and DNA methyl- transferases (DNMTs) gene expression in HESC. HESC were treated with different doses of nicotine (0 or control, 10- 11, 10- 8 and 10- 6) M for 24 h and their genomic global DNA methylation and gene expression of DNMTs (DNMT1, DNMT3A, and DNMT3B) were investigated using ELISA and real-time PCR, respectively.

RESULTS

Nicotine treatments reduced the average level of DNMTs gene expression by 90, 79, and 73.4% in 10- 11, 10- 8 and 10- 6 M of nicotine treated cells as compared to control cells, respectively (p < 0.05). Also, 10- 8 and 10- 6 M of nicotine concentrations effectively reduced the amounts of 5-methylated cytosine (5-mC) by 1.09 and 1.87% compared to control cells, respectively (p < 0.05). The 5-mC percentages were positively correlated with the relative cellular DNMTs expression in HESC as verified by the Pearson correlation test.

CONCLUSION

An interesting possibility raised by the current study is that the reduced genomic global DNA methylation level in HESC may be partly due to the suppression of DNMTs gene expression caused by nicotine in these cells.

GRAPHICAL ABSTRACT

The Anti-Cancer Effect of Quercetin: Molecular Implications in Cancer Metabolism

Cancer is a problem with worldwide importance and is the second leading cause of death globally. Cancer cells reprogram their metabolism to support their uncontrolled expansion by increasing biomass (anabolic metabolism-glycolysis) at the expense of their energy (bioenergetics- mitochondrial function) requirements. In this aspect, metabolic reprogramming stands out as a key biological process in understanding the conversion of a normal cell into a neoplastic precursor. Quercetin is the major representative of the flavonoid subclass of flavonols. Quercetin is ubiquitously present in fruits and vegetables, being one of the most common dietary flavonols in the western diet. The anti-cancer effects of quercetin include its ability to promote the loss of cell viability, apoptosis and autophagy through the modulation of PI3K/Akt/mTOR, Wnt/-catenin, and MAPK/ERK1/2 pathways. In this review, we discuss the role of quercetin in cancer metabolism, addressing specifically its ability to target molecular pathways involved in glucose metabolism and mitochondrial function.