Investigation of the anti-cancer effect of quercetin on HepG2 cells in vivo

Quercetin promotes the proportion and maturation of NK cells by binding to MYH9 and improves cognitive functions in aged mice

BACKGROUND

Quercetin is a flavonol compound widely distributed in plants that possesses diverse biological properties, including antioxidative, anti-inflammatory, anticancer, neuroprotective and senescent cell-clearing activities. It has been shown to effectively alleviate neurodegenerative diseases and enhance cognitive functions in various models. The immune system has been implicated in the regulation of brain function and cognitive abilities. However, it remains unclear whether quercetin enhances cognitive functions by interacting with the immune system.

RESULTS

In this study, middle-aged female mice were administered quercetin via tail vein injection. Quercetin increased the proportion of NK cells, without affecting T or B cells, and improved cognitive performance. Depletion of NK cells significantly reduces cognitive ability in mice. RNA-seq analysis revealed that quercetin modulated the RNA profile of hippocampal tissues in aging animals towards a more youthful state. In vitro, quercetin significantly inhibited the differentiation of Lin-CD117+ hematopoietic stem cells into NK cells. Furthermore, quercetin promoted the proportion and maturation of NK cells by binding to the MYH9 protein.

CONCLUSIONS

In summary, our findings suggest that quercetin promotes the proportion and maturation of NK cells by binding to the MYH9 protein, thereby improving cognitive performance in middle-aged mice.

Levofloxacin and Ciprofloxacin Co-Crystals with Flavonoids: Solid-State Investigation for a Multitarget Strategy against Helicobacter pylori

In this paper, we address the problem of antimicrobial resistance in the case of Helicobacter pylori with a crystal engineering approach. Two antibiotics of the fluoroquinolone class, namely, levofloxacin (LEV) and ciprofloxacin (CIP), have been co-crystallized with the flavonoids quercetin (QUE), myricetin (MYR), and hesperetin (HES), resulting in the formation of four co-crystals, namely, LEV∙QUE, LEV∙MYR, LEV2∙HES, and CIP∙QUE. The co-crystals were obtained from solution, slurry, or mechanochemical mixing of the reactants. LEV∙QUE and LEV∙MYR were initially obtained as the ethanol solvates LEV∙QUE∙xEtOH and LEV∙MYR∙xEtOH, respectively, which upon thermal treatment yielded the unsolvated forms. All co-crystals were characterized by powder X-ray diffraction and thermal gravimetric analysis. The antibacterial performance of the four co-crystals LEV∙QUE, LEV∙MYR, LEV2∙HES, and CIP∙QUE in comparison with that of the physical mixtures of the separate components was tested via evaluation of the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The results obtained indicate that the association with the co-formers, whether co-crystallized or forming a physical mixture with the active pharmaceutical ingredients (API), enhances the antimicrobial activity of the fluoroquinolones, allowing them to significantly reduce the amount of API otherwise required to display the same activity against H. pylori.

Total Flavonoids in Artemisia absinthium L. and Evaluation of Its Anticancer Activity

To overcome the shortcomings of traditional extraction methods, such as long extraction time and low efficiency, and considering the low content and high complexity of total flavonoids in Artemisia absinthium L., in this experiment, we adopted ultrasound-assisted enzymatic hydrolysis to improve the yield of total flavonoids, and combined this with molecular docking and network pharmacology to predict its core constituent targets, so as to evaluate its antitumor activity. The content of total flavonoids in Artemisia absinthium L. reached 3.80 ± 0.13%, and the main components included Astragalin, Cynaroside, Ononin, Rutin, Kaempferol-3-O-rutinoside, Diosmetin, Isorhamnetin, and Luteolin. Cynaroside and Astragalin exert their cervical cancer inhibitory functions by regulating several signaling proteins (e.g., EGFR, STAT3, CCND1, IGFIR, ESR1). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that the anticancer activity of both compounds was associated with the ErbB signaling pathway and FoxO signaling pathway. MTT results showed that total flavonoids of Artemisia absinthium L. and its active components (Cynaroside and Astragalin) significantly inhibited the growth of HeLa cells in a concentration-dependent manner with IC50 of 396.0 ± 54.2 μg/mL and 449.0 ± 54.8 μg/mL, respectively. Furthermore, its active components can mediate apoptosis by inducing the accumulation of ROS.

Molecular docking and molecular dynamics simulation analysis of bioactive compounds of Cichorium intybus L. seed against hepatocellular carcinoma

In this article, bioactive compounds present in Cichorium intybus L. seeds were collected from literature review and analyzed for probable remedy for hepatocellular carcinoma. Cichorium intybus L. is a traditional plant used all over the world mainly in hepatic disorders and renal diseases. This therapeutic plant has many bioactive compounds like chicoric acid, chlorogenic acid, sesquiterpne lactones, stigmasterols etc are found in seeds. Here, the target protein p53 (PDB ID: 2OCJ) which is involved in many cancerous pathways, is chosen. The preADMET study filtered out some compounds which were then subjected to molecular docking studies by Autodock tool 4.2. Afterwards, two best compounds (Esculetin and Isochlorogenic acid) were screened out on the basis of binding energy as compared to the standard compound (Doxorubicin). All these complexes were then analyzed for stability by molecular dynamics using online GROMACS tool. In the comparative simulation study, the compound Esculetin shows a stable interaction with the p53 over the 100 ns trajectory. Hepatocellular carcinoma accounts for high mortality of cancer related death worldwide. These findings suggest that these compound can be used to treat the hepatocellular carcinoma.Communicated by Ramaswamy H. Sarma.

Recent Advances in Anticancer Activity of Novel Plant Extracts and Compounds from Curcuma longa in Hepatocellular Carcinoma

PURPOSE

Among all forms of cancers, hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. There are several treatment options for HCC ranging from loco-regional therapy to surgical treatment. Yet, there is high morbidity and mortality. Recent research focus has shifted towards more effective and less toxic cancer treatment options. Curcumin, the active ingredient in the Curcuma longa plant, has gained widespread attention in recent years because of its multifunctional properties as an antioxidant, anti-inflammatory, antimicrobial, and anticancer agent.

METHODS

A systematic search of PubMed, Embase and Google Scholar was performed for studies reporting incidence of HCC, risk factors associated with cirrhosis and experimental use of curcumin as an anti-cancer agent.

RESULTS

This review exclusively encompasses the anti-cancer properties of curcumin in HCC globally and it's postulated molecular targets of curcumin when used against liver cancers.

CONCLUSIONS

This review is concluded by presenting the current challenges and future perspectives of novel plant extracts derived from C. longa and the treatment options against cancers.

An insight into anticancer, antioxidant, antimicrobial, antidiabetic and anti-inflammatory effects of quercetin: a review

Flavonoids are present naturally in many fruits and vegetables including onions, apples, tea, cabbage, cauliflower, berries and nuts which provide us with quercetin, a powerful natural antioxidant and cytotoxic compound. Due to antioxidant property, many nutraceuticals and cosmeceuticals products contain quercetin as a major ingredient nowadays. Current review enlightened sources and quercetin's role as an antioxidant, antimicrobial, antidiabetic, anticancerous and anti-inflammatory agent in medical field during last 5 to 6 years. Literature search was systematically done using scientific for the published articles of quercetin. A total of 345 articles were reviewed, and it was observed that more than 40% of articles were about quercetin's use as an antioxidant agent, more than 25% of studies were about its use as an anticancer agent, and articles on antimicrobial activity were more than 15%. 10% of the articles showed anti-inflamamatory effects of quercetin. Literature search also revealed that quercetin alone and its complexes with chitosan, metal ions and polymers possessed good antidiabetic properties. Thus, the review focuses on new therapeutic interventions and drug delivery system of quercetin in medical field for the benefit of mankind.

Naringenin and Quercetin Exert Contradictory Cytoprotective and Cytotoxic Effects on Tamoxifen-Induced Apoptosis in HepG2 Cells

Tamoxifen is commonly used to treat estrogen receptor-positive breast cancer and hepatocellular carcinoma. Phytoconstituents are considered candidates for chemopreventive drugs in cancer treatment. However, it remains unknown what would happen if tamoxifen and phytoconstituents were administrated simultaneously. We aimed to observe the synergistic antitumor effects of tamoxifen and naringenin/quercetin on human hepatic carcinoma and to explore the potential underlying molecular mechanisms. The HepG2 cell line was used as an in vitro model. Cell proliferation, invasion, migration, cycle progression and apoptosis were investigated along with reactive oxygen species (ROS) production and mitochondrial membrane potential (ΔΨm) repression. The signaling pathways involved were identified using real-time quantitative polymerase chain reaction analysis. As the results show, tamoxifen in combination with higher concentrations of naringenin or quercetin significantly inhibited cell growth compared to either agent alone. These antiproliferative effects were accompanied by the inhibition of cell migration and invasion but the stimulation of cell apoptosis and loss of ΔΨm, which depended on the ROS-regulated p53 signaling cascades. Conversely, lower concentrations of naringenin and quercetin inhibited the tamoxifen-induced cell antiproliferative effects by regulating cell migration, invasion, cycle and apoptosis. Taken together, our findings revealed that phytoconstituents exerted contradictory cytoprotective and cytotoxic effects induced by tamoxifen in human hepatic cancer.

A Comprehensive Analysis and Anti-Cancer Activities of Quercetin in ROS-Mediated Cancer and Cancer Stem Cells

Reactive oxygen species (ROS) induce carcinogenesis by causing genetic mutations, activating oncogenes, and increasing oxidative stress, all of which affect cell proliferation, survival, and apoptosis. When compared to normal cells, cancer cells have higher levels of ROS, and they are responsible for the maintenance of the cancer phenotype; this unique feature in cancer cells may, therefore, be exploited for targeted therapy. Quercetin (QC), a plant-derived bioflavonoid, is known for its ROS scavenging properties and was recently discovered to have various antitumor properties in a variety of solid tumors. Adaptive stress responses may be induced by persistent ROS stress, allowing cancer cells to survive with high levels of ROS while maintaining cellular viability. However, large amounts of ROS make cancer cells extremely susceptible to quercetin, one of the most available dietary flavonoids. Because of the molecular and metabolic distinctions between malignant and normal cells, targeting ROS metabolism might help overcome medication resistance and achieve therapeutic selectivity while having little or no effect on normal cells. The powerful bioactivity and modulatory role of quercetin has prompted extensive research into the chemical, which has identified a number of pathways that potentially work together to prevent cancer, alongside, QC has a great number of evidences to use as a therapeutic agent in cancer stem cells. This current study has broadly demonstrated the function-mechanistic relationship of quercetin and how it regulates ROS generation to kill cancer and cancer stem cells. Here, we have revealed the regulation and production of ROS in normal cells and cancer cells with a certain signaling mechanism. We demonstrated the specific molecular mechanisms of quercetin including MAPK/ERK1/2, p53, JAK/STAT and TRAIL, AMPKα1/ASK1/p38, RAGE/PI3K/AKT/mTOR axis, HMGB1 and NF-κB, Nrf2-induced signaling pathways and certain cell cycle arrest in cancer cell death, and how they regulate the specific cancer signaling pathways as long-searched cancer therapeutics.

Combination Anticancer Therapies Using Selected Phytochemicals

Cancer is still one of the most widespread diseases globally, it is considered a vital health challenge worldwide and one of the main barriers to long life expectancy. Due to the potential toxicity and lack of selectivity of conventional chemotherapeutic agents, discovering alternative treatments is a top priority. Plant-derived natural products have high potential in cancer treatment due to their multiple mechanisms of action, diversity in structure, availability in nature, and relatively low toxicity. In this review, the anticancer mechanisms of the most common phytochemicals were analyzed. Furthermore, a detailed discussion of the anticancer effect of combinations consisting of natural product or natural products with chemotherapeutic drugs was provided. This review should provide a strong platform for researchers and clinicians to improve basic and clinical research in the development of alternative anticancer medicines.

The Anti-Cancer Effects of Red-Pigmented Foods: Biomarker Modulation and Mechanisms Underlying Cancer Progression

Cancer is one the most malignant diseases that is a leading cause of death worldwide. Vegetables and fruits contain beneficial nutrients such as vitamins, minerals, folates, dietary fibers, and various natural bioactive compounds. These can prevent the pathological processes of many cancers and reduce cancer related mortality. Specifically, the anti-cancer effect of vegetables and fruits is largely attributable to the natural bioactive compounds present within them. A lot of bioactive compounds have very specific colors with pigments and the action of them in the human body varies by their color. Red-pigmented foods, such as apples, oranges, tomatoes, cherries, grapes, berries, and red wine, have been widely reported to elicit beneficial effects and have been investigated for their anti-tumor, anti-inflammatory, and antioxidative properties, as well as anti-cancer effect. Most of the anti-cancer effects of bioactive compounds in red-pigmented foods arise from the suppression of cancer cell invasion and metastasis, as well as the induction of apoptosis and cell cycle arrest. In this review, we assessed publications from the last 10 years and identified 10 bioactive compounds commonly studied in red-pigmented foods: lycopene, anthocyanin, β-carotene, pectin, betaine, rutin, ursolic acid, kaempferol, quercetin, and myricetin. We focused on the mechanisms and targets underlying the anti-cancer effect of the compounds and provided rationale for further investigation of the compounds to develop more potent anti-cancer treatment methods.

Selenium nanoparticles and quercetin suppress thioacetamide-induced hepatocellular carcinoma in rats: Attenuation of inflammation involvement

The current study investigates the anti-inflammatory and hepatoprotective effects of selenium (Se) formulated as nanoparticles (SeNPs) and in combination with quercetin (QCT) against thioacetamide (TAA)-induced hepatocellular carcinoma (HCC) in rats. ​​​​​​Seventy-two male Sprague-Dawley rats were divided into six groups (n = 12). Three control groups; normal, SeNPs; group received SeNPs only and HCC; group received TAA. In addition, three preventive groups; SeNPs + TAA, QCT + TAA, and QCT + SeNPs + TAA. Induction of HCC was detected histopathologically and by the raise of the serum level of alpha-fetoprotein (AFP). Oxidative stress was evaluated by the hepatic levels of reduced glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) spectrophotometrically. The oncogenic pathway of p53/β-catenin/cyclin D1 was assessed by immunohistochemistry. The inflammatory markers; interleukin-33 (IL-33), IL-6, and IL-1β were assessed by enzyme-linked immune sorbent assay. SeNPs prevented the elevation of serum AFP and hepatic IL-33, IL-1β, and IL-6 in comparison to HCC or QCT + TAA groups. SeNPs + TAA exhibited a lower positive hepatic staining of p53, β-catenin, and cyclin D1 in comparison to HCC or QCT + TAA groups. Moreover, SeNPs improved the overall oxidative balance indicated by low hepatic MDA and enhanced GSH and GPx when compared to HCC or QCT + TAA groups. ​​SeNPs alone and in combination with QCT were found to suppress the progression of HCC in rats via the enhancement of the oxidative stress and then inflammatory status and the prevention of the deregulation of the oncogenic axis pathway of p53/β-catenin/cyclin D.

Nutraceuticals and Cancer: Potential for Natural Polyphenols

Cancer is one of the leading causes of death globally, associated with multifactorial pathophysiological components. In particular, genetic mutations, infection or inflammation, unhealthy eating habits, exposition to radiation, work stress, and/or intake of toxins have been found to contribute to the development and progression of cancer disease states. Early detection of cancer and proper treatment have been found to enhance the chances of survival and healing, but the side effects of anticancer drugs still produce detrimental responses that counteract the benefits of treatment in terms of hospitalization and survival. Recently, several natural bioactive compounds were found to possess anticancer properties, capable of killing transformed or cancerous cells without being toxic to their normal counterparts. This effect occurs when natural products are associated with conventional treatments, thereby suggesting that nutraceutical supplementation may contribute to successful anticancer therapy. This review aims to discuss the current literature on four natural bioactive extracts mostly characterized by a specific polyphenolic profile. In particular, several activities have been reported to contribute to nutraceutical support in anticancer treatment: (1) inhibition of cell proliferation, (2) antioxidant activity, and (3) anti-inflammatory activity. On the other hand, owing to their attenuation of the toxic effect of current anticancer therapies, natural antioxidants may contribute to improving the compliance of patients undergoing anticancer treatment. Thus, nutraceutical supplementation, along with current anticancer drug treatment, may be considered for better responses and compliance in patients with cancer. It should be noted, however, that when data from studies with bioactive plant preparations are discussed, it is appropriate to ensure that experiments have been conducted in accordance with accepted pharmacological research practices so as not to disclose information that is only partially correct.

Quercetin as a Novel Therapeutic Approach for Lymphoma

Lymphoma is a name for malignant diseases of the lymphatic system including Hodgkin's lymphoma and non-Hodgkin's lymphoma. Although several approaches are used for the treatment of these diseases, some of them are not successful and have serious adverse effects. Therefore, other effective treatment methods might be interesting. Studies have indicated that plant ingredients play a key role in treating several diseases. Some plants have already shown a potential therapeutic effect on many malignant diseases. Quercetin is a flavonoid found in different plants and could be useful in the treatment of different malignant diseases. Quercetin has its antimalignant effects through targeting main survival pathways activated in tumor cells. In vitro/in vivo experimental studies have demonstrated that quercetin possesses a cytotoxic effect on lymphoid cancer cells. Regardless of the optimum results that have been obtained from both in vitro/in vivo studies, few clinical studies have analyzed the antitumor effects of quercetin in lymphoid cancers. Thus, it seems that more clinical studies should introduce quercetin as a therapeutic, alone or in combination with other chemotherapy agents. Here, in this study, we reviewed the anticancer effects of quercetin and highlighted the potential therapeutic effects of quercetin in various types of lymphoma.

Pt-Coated Au Nanoparticle Toxicity Is Preferentially Triggered Via Mitochondrial Nitric Oxide/Reactive Oxygen Species in Human Liver Cancer (HepG2) Cells

Reactive nitrogen species (RNS) that are formed from the reaction of versatile nitric oxide (NO) with reactive oxygen species (ROS) have been less explored in potential cancer therapy. This may be partly due to the fewer available agents that could induce NO in cells. Here, we report platinum-coated gold nanoparticles (Pt-coated Au NPs; 27 ± 20 nm) as a strong inducer of NO (assessed by live-cell imaging under NO-specific DAR-1 probe labeling and indirectly using a Griess reagent) in human liver carcinoma (HepG2) cells. In addition to NO, this study found a critical role of ROS from mitochondrial sources in the mechanism of toxicity caused by Pt-coated Au NPs. Cotreatment with a thiol-replenishing general antioxidant NAC (N-acetyl cysteine) led to significant amelioration of oxidative stress against NP-induced toxicity. However, NAC did not exhibit as much ameliorative potential against NP-induced oxidative stress as the superoxide radical (O2•-)-scavenging mitochondrial specific antioxidant mito-TEMPO did. The higher protective potential of mito-TEMPO in comparison to NAC reveals mitochondrial ROS as an active mediator of NP-induced toxicity in HepG2 cells. Moreover, the relatively unaltered NP-induced NO concentration under cotreatment of GSH modulators NAC and buthionine sulfoximine (BSO) suggested that NO production due to NP treatment is rather independent of the cellular thiols at least in HepG2 cells. Moreover, toxicity potentiation by exogenous H2O2 again suggested a more direct involvement of ROS/RNS in comparison to the less potentiation of toxicity due to GSH-exhausting BSO. A steeper amelioration in NP-induced NO and ROS and, consequently, cytotoxicity by mito-TEMPO in comparison to NAC reveal a pronounced role of NO and ROS via the mitochondrial pathway in the toxicity of Pt-coated Au NPs in HepG2 cells.

Manuka honey enhanced sensitivity of HepG2, hepatocellular carcinoma cells, for Doxorubicin and induced apoptosis through inhibition of Wnt/β-catenin and ERK1/2

Background

Recently, there is increasing awareness focused on the identification of naturally occurring anticancer agents derived from natural products. Manuka honey (MH) has been recognized for its biological properties as antimicrobial, antioxidant, and anticancer properties. However, its antiproliferative mechanism in hepatocellular carcinoma is not investigated. The current study focused mainly on investigating the molecular mechanism and synergistic effect of anticancer properties of MH on Doxorubicin (DOX)-mediated apoptotic cell death, using two different p53 statuses (HepG2 and Hep3B) and one non-tumorigenic immortalized liver cell line.

Results

MH treatment showed a proliferative inhibitory effect on tested cells in a dose-dependent manner with IC₅₀ concentration of (6.92 ± 0.005%) and (18.62 ± 0.07%) for HepG2 and Hep3B cells, respectively, and induced dramatic morphological changes of Hep-G2 cells, which considered as characteristics feature of apoptosis induction after 48 h of treatment. Our results showed that MH or combined treatments induced higher cytotoxicity in p53-wild type, HepG2, than in p53-null, Hep3B, cells. Cytotoxicity was not observed in normal liver cells. Furthermore, the synergistic effect of MH and Dox on apoptosis was evidenced by increased annexin-V-positive cells and Sub-G1 cells in both tested cell lines with a significant increase in the percentage of Hep-G2 cells at late apoptosis as confirmed by the flow cytometric analysis. Consistently, the proteolytic activities of caspase-3 and the degradation of poly (ADP-ribose) polymerase were also higher in the combined treatment which in turn accompanied by significant inhibitory effects of pERK1/2, mTOR, S6K, oncogenic β-catenin, and cyclin D1 after 48 h. In contrast, the MH or combined treatment-induced apoptosis was accompanied by significantly upregulated expression of proapoptotic Bax protein and downregulated expression of anti-apoptotic Bcl-2 protein after 48 h.

Conclusions

Our data showed a synergistic inhibitory effect of MH on DOX-mediated apoptotic cell death in HCC cells. To our knowledge, the present study provides the first report on the anticancer activity of MH and its combined treatment with DOX on HCC cell lines, introducing MH as a promising natural and nontoxic anticancer compound.

Quercetin induces autophagy in myelodysplastic bone marrow including hematopoietic stem/progenitor compartment

Myelodysplastic syndrome (MDS) is regarded as a spectrum of bone marrow failure disorders that share hemato-pathological state of cellular dysplasia and cytopenia. The modern treatment of cancers like chemotherapy and radiation therapy sometimes severely pounce on the basic hematopoietic stem/progenitor cellular (HSPC) compartment which gradually disclose the clinical symptoms of MDS. The present study involves flowcytometric protein expression analysis of insulin growth factor receptor (IGFR), PI3K-Akt-mTOR pathway, the autophagy related proteins (ATG's), the status of antioxidative molecules SOD2 and SDF1 and apoptosis profiling in ethyl-nitroso-urea induced myelodysplasia. The redox status that is, reactive oxygen species was estimated with dihydroetidium and the status of mitochondria and lysosomes were checked by Janus green B and neutral red staining respectively, pre and post quercetin treatment in MDS bone marrow. The results revealed the activated IGFR/PI3K/Akt axis in MDS bone marrow but unconventionally both p-mTOR and autophagy (p-ATG1, p-AT6, ATG7, ATG12) was downregulated. Interestingly, post quercetin treatment an upregulation of basal autophagocytosis, reversal of oxidative damage and proper functionality of mitochondria and lysosome was recorded. Taken together, the study hinted that the PI3K-Akt-mTOR pathway does not rule over the process of autophagocytosis in HSPC's of MDS bone marrow and the isoflavanoid quercetin remarkably restored autophagocytosis and hematopoietic oxidative status toward normalcy during the progression of myelodysplasia.

Nano Metal based Herbal theranostics for Cancer management: coalescing nature's boon with nanotechnological advancement

Cancer is amongst the leading public health problems globally with continuously increasing prevalence rate that demands for extensive and expensive treatment. Despite availability of number of potential cancer therapies, inadequate success has been achieved due to complexity and heterogeneity of tumors. Moreover, late/ terminal stage cancer leads to multidrug resistance, excruciating side effects, recurrence, etc. This is because of low penetrability and deleterious effects of drug on non-target cells/ tissues. This requires for cost effective, efficacious, alternative/ adjunct, complementary medicines with targeted drug delivery approach. A potential strategy to resolve this difficulty is to use theranostics i.e., formulations having both a therapeutic element and an imaging agent. Phytotherapeutics have been extensively used since times immemorial, having wide acceptability, easy availability, minimal side effects and comparatively inexpensive. These herbal formulations are mostly orally administered and thus subjected to adverse pH, enzymatic degradation, poor gut absorption, low bioavailability and non-targeted delivery that ultimately lead to their poor effectiveness. Constraints associated with conventional phyto-pharmaceuticals can be improved by designing and using "Nano Delivery Systems" (NDS). The foremost aim of metal based NDS is to provide sustained drug release, site-specific action, improved patient's compliance and enhanced efficacy. Metal Nanocarriers carrying herbal drugs will avoid these obstructions, so the drug can circulate into the blood for a longer period of time and provide optimal amount of the drug to the site of action. Besides, Herbal drugs with NDS thus would be efficacious as alternative/ complementary cancer theranostics. Present review describes about novel theranostic systems employing metal nanocarriers with diagnostic and therapeutic properties as are an effective strategy for cancer treatment. These systems when conjugated with herbal drugs provide an efficient management strategy for cancer.

Quercetin as an innovative therapeutic tool for cancer chemoprevention: Molecular mechanisms and implications in human health

Cancer is a life-threatening disease afflicting human health worldwide. Recent advances in drug discovery infrastructure and molecular approaches have helped a lot in identifying the novel drug targets for therapeutic intervention. Nevertheless, the morbidity and mortality rates because of this disease keep on rising at an alarming rate. Recently, the use of natural and synthetic molecules as innovative therapeutic tools for cancer prevention has lead to the development of cancer chemoprevention. Cancer chemoprevention is a prophylactic strategy that involves the chronic administration of one or more natural or synthetic agents to block, to inhibit, or to suppress the process of cancer development before it becomes an invasive disease. Quercetin, a dietary bioflavonoid, can specifically retard the growth of cancer cells and behaves as a potent cancer chemopreventive agent. Quercetin has multiple intracellular targets in a cancer cell. Therefore, many mechanisms have been postulated to explain its chemopreventive action. The chemopreventive effects elicited by this natural molecule in different model systems are believed to include antioxidant/pro-oxidant action, regulation of redox homeostasis, apoptosis, cell cycle arrest, anti-inflammatory action, modulation of drug metabolizing enzymes, alterations in gene expression patterns, inhibition of Ras gene expression, and modulation of signal transduction pathways. However, cell signaling networks have recently garnered attention as common molecular target for various chemopreventive effects of quercetin. In this review, we made an attempt to critically summarize the emerging knowledge on the role of quercetin in cancer chemoprevention and the underlying molecular mechanisms implicated in its chemopreventive and therapeutic effects.

Quercetin exerts bidirectional regulation effects on the efficacy of tamoxifen in estrogen receptor-positive breast cancer therapy: An in vitro study

Tamoxifen was widely applied in the therapy of estrogen receptor (ER)-positive breast cancer. With the purpose of determining the potential impacts of quercetin on its effectiveness, MCF-7 cells were selected as the in vitro model and several cellular biological behaviors (ie, cell proliferation, migration, invasion, cycle, apoptosis, and oxidative stress) were investigated. As results, quercetin showed contrasting dose-response to cellular behaviors dependent on the ROS-regulated p53 signaling pathways. In detail, quercetin promoted cell proliferation and inhibited cell apoptosis at low concentrations, whereas high-concentration resulted in apoptosis induction. Moreover, quercetin at a low concentration significantly inhibited tamoxifen-induced antiproliferation in MCF-7 cells, whereas high concentrations enhanced cell apoptosis in a synergetic manner. The real-time quantitative polymerase chain reaction analysis further implied that quercetin exerted its dual roles in tamoxifen-induced antiproliferative effects by regulated the gene expression involved in cell metastasis, cycle, and apoptosis through the ER pathways. Our present study provides a considerable support to the combination of quercetin and tamoxifen on human ER-positive breast carcinoma management.

Biological evaluation of gallic acid and quercetin derived from Ceriops tagal: insights from extensive in vitro and in silico studies

Gallic acid (PubChem CID: 370) and quercetin (PubChem CID: 5280343) are major phenolic compounds in many mangrove plants that have been related to health cure. In the present study, the active fractions namely gallic acid (1) and quercetin (2) were isolated from the methanolic extract of leaves of Ceriops tagal in a Tropical mangrove ecosystem of Andaman and Nicobar Island (ANI), India. The chemical structures were determined by spectroscopic analysis: Fourier-Transform Infrared spectroscopy (FT-IR), ¹H, ¹³C Nuclear Magnetic Resonance (NMR) spectroscopy, and High-resolution mass spectrometry (HRMS). The anticancer activity of isolated compounds (1) and (2) were evaluated by in vitro assays against two human cancer cell lines namely, HeLa (Cervical) and MDA-MB231 (Breast) cancer cells revealed that IC₅₀ values of gallic acid (HeLa: 4.179197 ± 0.45 µg/ml; MDA-MB231: 80.0427 ± 0.19 µg/ml at 24 h) and quercetin (HeLa: 99.914 ± 0.18 µg/ml; MDA-MB231: 18.288382 ± 0.12 µg/ml at 24 h), respectively. Antioxidant properties of gallic acid (1) and quercetin (2) are found to be IC₅₀ value of 0.77 ± 0.41 µg/ml and 1.897 ± 0.81 µg/ml, respectively. Molecular docking results explained that gallic acid (1) and quercetin (2) showed estimated binding free energy (ΔG) of -5.4 and -6.9 kcal/mol towards drug target Bcl-B protein, respectively. The estimated inhibition constant (Ki) for these two molecules are 110 and 8.75 μM, respectively. The MD simulation additionally supported that quercetin molecule is significantly improved the structural stability of Bcl-B protein. The present study provides key insights about the importance of polyphenols, and thus leads to open the therapeutic route for anti-cancer drug discovery process.Communicated by Ramaswamy H. Sarma.

Reactive oxygen species in cancer: a paradox between pro- and anti-tumour activities

Cancer constitutes a group of heterogeneous diseases that share common features. They involve the existence of altered cellular pathways which result in uncontrolled cell proliferation. Deregulation of production and/or elimination of reactive oxygen species (ROS) appear to be a relevant issue in most of them. ROS have a dual role in cell metabolism: they are compromised in normal cellular homeostasis, but their overproduction has been reported to promote oxidative stress (OS), a process that may induce the damage of cell structures. ROS accumulation is implicated in the activation of signaling pathways that promote cell proliferation and metabolic adaptations to tumour growth. One characteristic of cancer cells is the sensitivity to OS, which often results from the combination of high anabolic needs and hypoxic growth conditions. However, there is still no clear evidence about the levels of oxidant species that promote cellular transformation or, otherwise, if OS induction could be adequate as an antitumour therapeutic tool. There is a need for novel therapeutic strategies based on the new knowledge of cancer biology. Targeting oncogenic molecular mechanisms with non-classical agents and/or natural compounds would be beneficial as chemoprevention or new adjuvant therapies. In addition, epigenetics and environment, and particularly dietary factors may influence the development and prevention of cancer. This article will present a revision of the current research about molecular aspects proposed to be involved in the anticancer features of oxidant and antioxidant-based therapies targeting cancer cells, and their participation in the balance of oxidative species and cancer cell death.

Preventive effect of lemon seed flavonoids on carbon tetrachloride-induced liver injury in mice

The aim of this study was to determine the preventive effect of lemon seed flavonoids (LSF) on carbon tetrachloride-induced liver injury in mice. Liver injury was induced by injection with 2 mL kg-1 of carbon tetrachloride after administration of LSF by gavage. Liver index, serological parameters, and expression intensities of related mRNA and protein in the liver tissue were observed. The results indicated that LSF reduced liver weight and liver index, downregulated serum levels of AST, ALT, ALP, TG, TC, BUN, NO, and MDA, and upregulated levels of ALB, SOD, CAT, and GSH-Px in the mice with liver injury. It also downregulated serum cytokines, such as IL-6, IL-12, TNF-α, and IFN-γ in these mice. qPCR and western blot confirmed that LSF upregulated mRNA and protein expression of Mn-SOD, Cu/Zn-SOD, CAT, GSH-Px, and IκB-α, and downregulated expression of NF-κB-p65, iNOS, COX-2, TNF-α, IL-1β, and IL-6 in the liver tissue of mice with liver injury. The preventive effect on carbon tetrachloride-induced liver injury was attributed to (-)-epigallocatechin, caffeic acid, (-)-epicatechin, vitexin, quercetin, and hesperidin, which were active substances that were detected in LSF by HPLC. Moreover, the effect of LSF is similar to that of silymarin, but the synergistic effect of the five active substances working in concert acted to produce a more robust liver-protecting effect.

Antioxidant and Antitumor Activities of Novel Quercetin-Loaded Electrospun Cellulose Acetate/Polyethylene Glycol Fibrous Materials

The aim of present study was to obtain novel fibrous materials based on cellulose derivative and polyethylene glycol loaded with natural biologically active compound quercetin by electrospinning. Several methods including scanning electron microscopy (SEM), IR spectroscopy, X-ray diffraction analysis (XRD), water contact angle measurements, differential scanning calorimetry (DSC), and UV-VIS spectroscopy were utilized to characterize the obtained materials. The incorporation of polyethylene glycol in the fibrous material resulted in increased hydrophilicity and burst release of quercetin from the fibers. Quercetin-containing fibrous mats exhibited high antioxidant activity as estimated by DPPH free radical scavenging method. In vitro tests with HeLa tumor cells and SH-4 melanoma skin cells were performed in order to determine the cytotoxicity of the novel materials. It was found that the fibrous CA/PEG/QUE materials exhibited high cytotoxic effect against both cell lines. Therefore, the novel polymeric materials containing quercetin are promising candidates for biomedical and pharmaceutical applications.

Evaluation of binding and inhibition mechanism of dietary phytochemicals with sphingosine kinase 1: Towards targeted anticancer therapy

Sphingosine kinase 1 (SphK1) has recently gained attention as a potential drug target for its association with cancer and other inflammatory diseases. Here, we have investigated the binding affinity of dietary phytochemicals viz., ursolic acid, capsaicin, DL-α tocopherol acetate, quercetin, vanillin, citral, limonin and simvastatin with the SphK1. Docking studies revealed that all these compounds bind to the SphK1 with varying affinities. Fluorescence binding and isothermal titration calorimetric measurements suggested that quercetin and capsaicin bind to SphK1 with an excellent affinity, and significantly inhibits its activity with an admirable IC50 values. The binding mechanism of quercetin was assessed by docking and molecular dynamics simulation studies for 100 ns in detail. We found that quercetin acts as a lipid substrate competitive inhibitor, and it interacts with important residues of active-site pocket through hydrogen bonds and other non-covalent interactions. Quercetin forms a stable complex with SphK1 without inducing any significant conformational changes in the protein structure. In conclusion, we infer that quercetin and capsaicin provide a chemical scaffold to develop potent and selective inhibitors of SphK1 after required modifications for the clinical management of cancer.

Cynanchum atratum Ameliorates Airway Inflammation via Maintaining Alveolar Barrier and Regulating Mast Cell-Mediated Inflammatory Responses

Asthma is a common allergic airway inflammatory disease, characterized by abnormal breathing due to bronchial inflammation. Asthma aggravates the patient's quality of life and needs continuous pharmacological treatment. Therefore, discovery of drugs for the treatment of asthma is an important area of human health. The aim of the present study was to evaluate whether Cynanchum atratum extract (CAE) modulates the asthma-like allergic airway inflammation and to study its possible mechanism of action using ovalbumin (OVA)-induced airway inflammation and lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice, as well as a mast cell-based in vitro model. The histological analysis showed that CAE reduced the airway constriction and immune cell infiltration. CAE also inhibited release of β-hexosaminidase and expression of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-4, and IL-5 in bronchoalveolar lavage fluid and lung tissues. In addition, CAE reduced the OVA-specific immunoglobulin (Ig) E, total IgE, IgG1, and IgG2a levels in the serum. In the LPS-induced ALI model, CAE suppressed the LPS-induced lung barrier dysfunction and the release of proinflammatory cytokines. Because allergic airway inflammatory responses are associated with the activation of mast cells, RBL-2H3 cells were used to evaluate the underlying mechanism of CAE effects. In RBL-2H3 cells, CAE down-regulated release of β-hexosaminidase and histamine by reducing the intracellular calcium influx. In addition, CAE suppressed the expression of proinflammatory cytokines by inhibiting nuclear translocation of nuclear factor-κB. Taken together, our findings suggest that CAE may help in the prevention or treatment of airway inflammatory diseases.

One pot synthesis of water-soluble quercetin derived multifunctional nanoparticles with photothermal and antioxidation capabilities

As a member of flavonoids, the application of quercetin has been mainly focused on antioxidation study. Fabrication of multifunctional nanoplatforms with quercetin is limited. In the present study, water-soluble quercetin derived nanoparticles (QFNPs) were fabricated through the one pot synthesis strategy with Fe³⁺, quercetin and poly (vinyl pyrrolidone) (PVP). The raw materials were dissolved in absolute ethanol and the mixed together. After stirring at room temperature for 6 h, the QFNPs could be simply harvested by centrifugation without the need of time-consuming dialysis procedure. Due to the protective effect of PVP, the synthesized nanoparticles could be well dispersed in water with the hydrodynamic size about 23 nm. DPPH free radical scavenging capacity assay showed QFNPs could act as efficient antioxidant. Besides antioxidation activity, the QFNPs also exhibited good photothermal capacity. Temperature stability result suggested the good stability of QFNPs between 35 and 95 °C. MTT and hemolysis assay showed the good biocompatibility of QFNPs. What's more, the QFNPs showed good cellular antioxidation activity and efficient photothermal killing effect to cancer cells (4T1 cells). The QFNPs could be promising nanoplatform for biomedical application.

Quercetin shows anti-tumor effect in hepatocellular carcinoma LM3 cells by abrogating JAK2/STAT3 signaling pathway

Objective

Hepatocellular carcinima is one of the most common tumors in clinic and also one of the leading causes of death from cancer worldwide. Quercetin shows significant effects on blocking the development of various cancers.

Methods

We used the human hepatocellular carcinoma LM3 and nude mice tumor model to assess the effects of quercetin in hepatocellular carcinoma and clarify its mechanism of action. We collected LM3 cell line treated with different doses of quercetin at different time periods and determined the vital indexes. The liver tissues of mice were collected and used for western boltting (WB), Hematoxylin and Eosin (H&E) and TUNEL staining.

Results

Results indicated that quercetin suppressed the Hepatocellular carcinoma (HCC) growth both in vivo and in vitro. Quercetin could disturb LM3 cells proliferation and cell cycle distribution, thus inducing apoptosis. At the same time, quercetin inhibited LM3 cells migration and invasion and promoted HCC autophagy. These effects at least partly depended on the down‐regulation of the activation of JAK2 and STAT3 by quercetin.

Conclusion

Quercetin inhibited hepatocellular carcinoma progression by modulating cell apoptosis, migration, invasion, and autophagy; and its effects were at least partly related with the JAK2/STAT3 signaling pathway.

ROS-Mediated Cancer Cell Killing through Dietary Phytochemicals

Reactive oxygen species (ROS) promote carcinogenesis by inducing genetic mutations, activating oncogenes, and raising oxidative stress, which all influence cell proliferation, survival, and apoptosis. Cancer cells display redox imbalance due to increased ROS level compared to normal cells. This unique feature in cancer cells may, therefore, be exploited for targeted therapy. Over the past few decades, natural compounds have attracted attention as potential cancer therapies because of their ability to maintain cellular redox homeostasis with minimal toxicity. Preclinical studies show that bioactive dietary polyphenols exert antitumor effects by inducing ROS-mediated cytotoxicity in cancer cells. These bioactive compounds also regulate cell proliferation, survival, and apoptotic and antiapoptotic signalling pathways. In this review, we discuss (i) how ROS is generated and (ii) regulated and (iii) the cell signalling pathways affected by ROS. We also discuss (iv) the various dietary phytochemicals that have been implicated to have cancer therapeutic effects through their ROS-related functions.

Cytostatic and Anti-tumor Potential of Ajwa Date Pulp against Human Hepatocellular Carcinoma HepG2 Cells

Ajwa dates (Phoenix dactylifera L.) are used by traditional therapeutic practitioners for several health benefits but most remain to be scientifically validated. In this study, we evaluated the apoptosis-inducing effect of ethanolic extract of Ajwa date pulp (ADP) on human hepatocellular carcinoma (HCC) HepG2 cells. High performance liquid chromatography analysis revealed the presence of polysaccharide β-D-glucan in ADP extract. Treated HCC cells revealed morphological characteristics of apoptosis under phase contrast microscopy. MTT assay demonstrated significant (p < 0.05) dose- and time-dependent inhibition of HCC cell growth. HCC cells were found to be in late apoptotic stage on treatment with higher doses of ADP extract as depicted by acridine orange/ethidium bromide and Annexin V-FITC/PI double stain. Importantly, ADP extract increased the reactive oxygen species level and decreased the mitochondrial membrane potential in treated HCC cells. Flow cytometry analysis demonstrated that ADP extract induced elevation of S and G2/M phases of cell cycle. Moreover, ADP extract induced apoptosis in HCC cells independent of tumor suppressor genes viz. CHEK2, ATM and TP53. Interestingly, ADP extract did not display any significant effect on normal cell line Vero. This study provides validation that ADP extract can be considered as a safe and natural potential drug candidate against human liver cancer.

Cellular Uptake and Intracellular Antioxidant Activity of Zein/Chitosan Nanoparticles Incorporated with Quercetin

In this work, zein/chitosan nanoparticles (ZCPs-Q) were developed for encapsulating quercetin to overcome its lower water solubility and instability, and to concomitantly enhance its cellular uptake and intracellular antioxidant activity. This strategy enhanced quercetin solubility 753.6 and 9.95 times in water and PBS (7.4), respectively, and quercetin encapsulated in ZCPs remained stable after UV irradiation and heat treatment. ZCPs-Q could significantly attenuate AAPH induced erythrocyte hemolysis through the inhibition of ROS generation. It restored intracellular antioxidant enzyme (SOD and GSH-Px) activities to normal levels and inhibited intracellular malondialdehyde (MDA) formation. Simultaneously, ZCPs-Q showed a strong antioxidant activity in HepG2 cells with an EC₅₀ value of 31.18 μg/mL, which was lower than free quercetin's 41.02 μg/mL. ZCPs enhanced the uptake efficiency of quercetin in Caco-2 cells, which contributed to the improvement of cellular antioxidant activities (CAA) evaluated with the CAA assay and AAPH-induced erythrocyte hemolysis assay. The designed route is particularly suitable for the encapsulation of water-insoluble nutraceuticals and for enhancing cell uptake and CAA.

Glutathione depleting drugs, antioxidants and intestinal calcium absorption

Glutathione (GSH) is a tripeptide that constitutes one of the main intracellular reducing compounds. The normal content of GSH in the intestine is essential to optimize the intestinal Ca²⁺ absorption. The use of GSH depleting drugs such as DL-buthionine-S,R-sulfoximine, menadione or vitamin K₃, sodium deoxycholate or diets enriched in fructose, which induce several features of the metabolic syndrome, produce inhibition of the intestinal Ca²⁺ absorption. The GSH depleting drugs switch the redox state towards an oxidant condition provoking oxidative/nitrosative stress and inflammation, which lead to apoptosis and/or autophagy of the enterocytes. Either the transcellular Ca²⁺ transport or the paracellular Ca²⁺ route are altered by GSH depleting drugs. The gene and/or protein expression of transporters involved in the transcellular Ca²⁺ pathway are decreased. The flavonoids quercetin and naringin highly abrogate the inhibition of intestinal Ca²⁺ absorption, not only by restoration of the GSH levels in the intestine but also by their anti-apoptotic properties. Ursodeoxycholic acid, melatonin and glutamine also block the inhibition of Ca²⁺ transport caused by GSH depleting drugs. The use of any of these antioxidants to ameliorate the intestinal Ca²⁺ absorption under oxidant conditions associated with different pathologies in humans requires more investigation with regards to the safety, pharmacokinetics and pharmacodynamics of them.

Quercetin increases the antioxidant capacity of the ovary in menopausal rats and in ovarian granulosa cell culture in vitro

BACKGROUND

Menopause is the most important sign of aging in women, and the ovary is the organ most sensitive to aging. Quercetin is a potential antioxidant and free radical scavenger that is widely found in fruits, vegetables, and leaves. However, the effect of quercetin on ovarian aging has not been elucidated, and the mechanism underlying its antioxidative effect remains unclear. The purpose of the current study was to investigate whether quercetin protects ovarian function by decreasing oxidative stress.

METHODS

In an in vivo experiment, female menopausal rats (12 months old) were intragastrically administered quercetin at three doses (12.5 mg/kg, 25 mg/kg, and 50 mg/kg) for 90 days, and the estrous cycles were determined by vaginal smearing. In an in vitro experiment, rat primary ovarian granulosa cells were cultured and treated with H₂O₂ (400 μM) alone or H₂O₂ plus quercetin at 5 μM, 20 μM, or 50 μM. The levels of the hormones estradiol (E₂), progesterone (P), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were detected by radioimmunoassay. The serum levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-PX) and glutathione S-transferase (GST) were examined. The expression levels of the oxidative stress-related genes SOD-1, catalase (CAT) and glutathione synthetase (GSS) in the ovaries and ovarian granulosa cells were detected by Western blot.

RESULTS

The in vivo results demonstrated that quercetin had no effects on ovarian morphology, hormone secretion, or the estrous cycle in menopausal rats. Although no significant changes were detected in the serum levels of T-AOC, SOD, GSH, GSH-PX, and GST between the quercetin and control groups, the mRNA and protein expression levels of the oxidative stress-related genes SOD-1, CAT and GSS in menopausal rat ovaries were increased by low-dose quercetin. Moreover, the in vitro results demonstrated that quercetin significantly rescued the decrease in cell viability by H₂О₂-induced oxidative stress and enhanced the H₂O₂-induced decrease in expression of oxidative stress-related proteins.

CONCLUSIONS

Together, the results of this study indicated that quercetin increased the antioxidant capacity of the ovary by upregulating the expression of some oxidative stress-related genes both in vivo and in vitro.

Bioactivity In Vitro of Quercetin Glycoside Obtained in Beauveria bassiana Culture and Its Interaction with Liposome Membranes

Quercetin (Q) was used as substrate for regioselective glycosylation at the C-7 position catalyzed by Beauveria bassiana AM278 strain. As a result the glycoside quercetin 7-O-β-d-(4″-O-methyl)glucopyranoside (Q 7-MeGlu) was formed. The goal of the studies was to determine the anti-oxidative (liposome membrane protection against free radicals IC₅₀^{Q 7-MeGlu} = 5.47 and IC₅₀^Q = 4.49 µM) and anti-inflammatory (COX-1 and COX-2 enzymes activity inhibition) properties of Q 7-MeGlu as compared to Q. Every attempt was made to clarify the antioxidant activity of these molecules, which are able to interact with egg phosphatidylcholine liposomes, using a fluorometric method (by applying the probes MC540, TMA-DPH and DPH). The results indicated that Q 7-MeGlu and Q are responsible for increasing the packing order, mainly in the hydrophilic but also in hydrophobic regions of the membrane (Q > Q 7-MeGlu). These observations, confirmed by a ¹H-NMR method, are key to understanding their antioxidant activity which is probably caused by the stabilizing effect on the lipid membranes. The results showed that Q 7-MeGlu and Q have ability to quench the human serum albumin (HSA) intrinsic fluorescence through a static quenching mechanism. The results of thermodynamic parameters indicated that the process of formation complexes between studied molecules and HSA was spontaneous and caused through Van der Waals interactions and hydrogen bonding.