Quercetin, a Natural Flavonoid Interacts with DNA, Arrests Cell Cycle and Causes Tumor Regression by Activating Mitochondrial Pathway of Apoptosis

Acute toxicity analysis of Disarib, an inhibitor of BCL2

Small molecule inhibitors targeting BCL2 are explored as anticancer therapeutics. Previously, we have reported identification and characterization of a novel BCL2 inhibitor, Disarib. Disarib induced cancer cell death in a BCL2 dependent manner in different cancer cell lines and mouse tumor models when it was administered intraperitoneally. In the present study, using two syngeneic mouse models, breast adenocarcinoma (EAC) and Dalton’s lymphoma (DLA), we show that oral administration of Disarib resulted in significant tumor regression in a concentration dependent manner. Importantly, tumor developed in both female and male mice were equally sensitive to Disarib. Further, we have investigated the toxicity of Disarib in normal cells. Single dose toxicity analysis of Disarib in male and female mice after oral administration revealed no significant variations compared to control group for parameters such as body weight, food and water consumption and behavioural changes which were analysed for the entire period of study. Haematological and histopathological analyses also did not show any significant difference from the control groups. Thus, our results reveal safe use of Disarib as a small molecule inhibitor and provide the foundation for investigation of other preclinical studies.

Radio-sensitizing effect of a cocktail of phytochemicals on HepG2 cell proliferation, motility and survival

Radio-resistance is a major hurdle challenging oncologist worldwide. Despite their anti-cancer characteristics, the implication of phytochemicals in clinical trials is still limited. This study is designed to evaluate the anticancer characteristics and radio-sensitizing effect of a cocktail of seven phytochemicals on HepG2 cells. Characterization of phytochemicals combination phenolic and flavonoids content as well as their scavenging activity were tested. The effective concentration of BSG that will be used as a radio-sensitizing dose was calculated using AlamarBlue assay. Treatment of HepG2 cells with BSG and/or ionizing radiations led to significant downregulation at cell proliferation as indicated by the decrease of colony formation ratio, proliferation marker (Ki67) expression as well as G2/M cell cycle arrest. The combined treatment stimulated P53-dependent apoptosis which was indicated by the significant increase of early apoptosis marker (Annexin V) expression, DNA fragmentation, expression of P53 & Bax and downregulation of Bcl2 expression. Combined treatment significantly attenuated HepG2 cell motility which was validated using wound healing migration assay and the significant reduction at CD95 expression. This study demonstrates the anti-cancer effect of BSG and its fundamental role in provoking cell responsiveness to IR leading to a significant inhibition at HepG2 cell proliferation, survival and migration.

Flavonoid Nanoparticles: A Promising Approach for Cancer Therapy

Flavonoids, a ubiquitous group of naturally occurring polyphenolic compounds, have recently gained importance as anticancer agents. Unfortunately, due to low solubility, absorption, and rapid metabolism of dietary flavonoids, their anticancer potential is not sufficient. Nanocarriers can improve the bioavailability of flavonoids. In this review we aimed to evaluate studies on the anticancer activity of flavonoid nanoparticles. A review of English language articles published until 30 June 2020 was conducted, using PubMed (including MEDLINE), CINAHL Plus, Cochrane, and Web of Science data. Most studies determining the anticancer properties of flavonoid nanoparticles are preclinical. The potential anticancer activity focuses mainly on MCF-7 breast cancer cells, A549 lung cancer cells, HepG2 liver cancer cells, and melanoma cells. The flavonoid nanoparticles can also support the anti-tumour effect of drugs used in cancer therapy by enhancing the anti-tumour effect or reducing the systemic toxicity of drugs.

Role of Antioxidant Molecules and Polymers in Prevention of Bacterial Growth and Biofilm Formation

Background:

Antioxidants are multifaceted molecules playing a crucial role in several cellular functions. There is by now a well-established knowledge about their involvement in numerous processes associated with aging, including vascular damage, neurodegenerative diseases and cancer. An emerging area of application has been lately identified for these compounds in relation to the recent findings indicating their ability to affect biofilm formation by some microbial pathogens, including Staphylococcus aureus, Streptococcus mutans, and Pseudomonas aeruginosa.

Methods:

A structured search of bibliographic databases for peer-reviewed research literature was performed using a focused review question. The quality of retrieved papers was appraised using standard tools.

Results:

One hundred sixty-five papers extracted from pubmed database and published in the last fifteen years were included in this review focused on the assessment of the antimicrobial and antibiofilm activity of antioxidant compounds, including vitamins, flavonoids, non-flavonoid polyphenols, and antioxidant polymers. Mechanisms of action of some important antioxidant compounds, especially for vitamin C and phenolic acids, were identified.

Conclusion:

The findings of this review confirm the potential benefits of the use of natural antioxidants as antimicrobial/antibiofilm compounds. Generally, gram-positive bacteria were found to be more sensitive to antioxidants than gram-negatives. Antioxidant polymeric systems have also been developed mainly derived from functionalization of polysaccharides with antioxidant molecules. The application of such systems in clinics may permit to overcome some issues related to the systemic delivery of antioxidants, such as poor absorption, loss of bioactivity, and limited half-life. However, investigations focused on the study of antibiofilm activity of antioxidant polymers are still very limited in number and therefore they are strongly encouraged in order to lay the foundations for application of antioxidant polymers in treatment of biofilm-based infections.

Galenia africana plant extract exhibits cytotoxicity in breast cancer cells by inducing multiple programmed cell death pathways

Globally, breast cancer is the most common malignancy in women and the second most common cause of cancer-related death among women. There is therefore a need to identify more efficacious therapies for this neoplasm. Galenia africana (Kraalbos) is a perennial shrub found in Southern Africa and is used by the indigenous people to treat various ailments. There has therefore been much interest to establish the scientific basis for the medicinal properties of Kraalbos. This study aimed to investigate and characterise the anti-cancer activity of an ethanolic extract of Kraalbos leaves, KB2, against oestrogen receptor positive (MCF-7) and triple negative (MDA-MB-231) breast cancer cells. LC-MS/MS analyses identified the phytochemicals 7′-hydroxyflavanone, 5′,7'-dihydroxyflavanone, 2′,4′-dihydroxydihydrochalcone and 2′,4′-dihydroxychalcone in KB2. KB2 exhibited an IC₅₀ of 114 µg/ml and 130.5 µg/ml in MCF-7 and MDA-MB-231 cells respectively, selectively inhibited their long-term survival and reduced their migration which correlated with a decrease in EMT markers. It induced oxidative stress (ROS), DNA damage (increased levels of γ-H2AX), and triggered cell cycle arrests in MCF-7 and MDA-MB-231 cells. Importantly, KB2 activated intrinsic (cleaved caspase 9) and extrinsic (cleaved caspase 8) apoptosis, necroptosis (p-RIP3 and the downstream target of the necrosome, pMLKL) and autophagy (LC3II). Co-treatment of the breast cancer cells with KB2 and the autophagy inhibitor bafilomycin A1 resulted in a significant increase in cell viability which suggests that KB2 induced autophagy is a cell death mechanism.

Despite Blocking Doxorubicin-Induced Vascular Damage, Quercetin Ameliorates Its Antibreast Cancer Activity

Quercetin is a naturally occurring flavonol present in many foods. Doxorubicin is an effective anticancer agent despite its dose-limiting cardiovascular toxicity. Herein, we investigated the potential protective effects of quercetin against doxorubicin-induced vascular toxicity and its effect on the therapeutic cytotoxic profile of doxorubicin in breast cancer cell lines. The incubation of isolated aortic rings with doxorubicin produced concentration-dependent exaggeration of vasoconstriction responses to phenylephrine but impaired vasodilation responses to acetylcholine. Coincubation with quercetin completely blocked the exaggerated vasoconstriction responses and the impaired vasodilation. In addition, doxorubicin incubation increased reactive oxygen species generation from the isolated aorta, while coincubation with quercetin inhibited ROS generation back to normal values. On the other hand, quercetin in combination with doxorubicin, doubled the IC₅₀ of doxorubicin alone in MCF-7 cells from 0.4 ± 0.03 to 0.8 ± 0.06 μM. To a lesser extent, the IC₅₀ of doxorubicin did not change after combination with quercetin in MDA-MB-231 cells. These findings indicate a significant antagonistic interaction between quercetin and doxorubicin in the aforementioned cell lines. Only in T47D cells, quercetin combination with doxorubicin was an additive interaction (CI − value = 1.17). Yet, quercetin significantly impaired the immediate phase of intracellular ROS generation by doxorubicin within breast cancer cells from 125.2 ± 3.6% to 102.5 ± 3.9% of control cells. Using annexin-V/FITC staining technique, the quercetin/doxorubicin combination showed a significantly lower percent of apoptotic cells compared to doxorubicin alone treated cells. Cell cycle distribution in breast cancer cells was performed using DNA content flowcytometry after propidium iodide staining. Quercetin induced significant accumulation of cells in the S phase as well as in the G₂/M phase within both MCF-7 and MDA-MB-231 cell lines and interfered with doxorubicin-induced cell cycle effects. Interestingly, quercetin was found to inhibit the P-glycoprotein ATPase subunit with a consequent enhanced intracellular concentration of doxorubicin in MDA-MB-231 and T47D cells. In conclusion, quercetin, despite its potent vascular protective activity against doxorubicin, was found to influence doxorubicin-induced antibreast cancer effects via pharmacodynamic as well as cellular pharmacokinetic aspects.

Phytochemical Profile, and Antiproliferative and Proapoptotic Effects of Pouteria ramiflora (Mart.) Radlk. Leaf Extract, and Its Synergism with Cisplatin in HepG2 Cells

Different species of the genus Pouteria have been used in folk medicine for the treatment of inflammation, fever, ulcers, diabetes, and diarrhea. We analyzed the phytochemical profile of the hydroethanolic extract from Pouteria ramiflora leaves by electrospray ionization ion trap tandem mass spectrometry and high-performance liquid chromatography-diode array detection, and examined whether it alone and in combination with cisplatin interfered with cell proliferation and death processes in HepG2 (human hepatocellular carcinoma) and FGH (human gingival fibroblasts) cells. Five compounds were identified in the extract: gallic acid, myricetin-3-O-α-l-arabinopyranoside, quercetin-3-O-β-d-galactopyranoside, myricetin-3-O-α-l-rhamnopyranoside, and myricetin-3-O-β-d-galactopyranoside. The extract was cytotoxic to both cell lines by inducing apoptotic cell death and acted in synergy with cisplatin; such effect was stronger in HepG2 cells than in FGH cells, demonstrating some selectivity to tumor cells. In HepG2 cells, the extract exerted antiproliferative effect mediated by induction of cell cycle arrest at the S and G2/M phases. Association of the extract with cisplatin enhanced the latter's antiproliferative effect, arrested the cell cycle at the S phase by CDK2 modulation, and reduced the number of anti-cyclin D1-stained HepG2 cells. Simultaneous treatment with the extract and cisplatin increased the latter's cytotoxicity, apoptotic cell death, and BAX expression in HepG2 cells. Altogether, the results reported herein indicate that P. ramiflora extract is a possible adjuvant to cancer therapy, which can circumvent the cisplatin-mediated resistance mechanisms in cancer cells.

Investigation of the role of quercetin as a heat shock protein inhibitor on apoptosis in human breast cancer cells

High expression of heat shock proteins (Hsp) in breast cancer has been closely associated with tumor cell proliferation and thus a poor clinical outcome. Quercetin, a good Hsp inhibitor as a dietary flavonoid, possesses anticarcinogenic properties. Although there are many studies on the effects of quercetin on Hsp levels in human breast cancer cells, research on elucidation of its molecular mechanism continues. Herein, we aimed to investigate the effect of quercetin on Hsp levels and whether quercetin is a suitable therapeutic for two breast cancer cell lines (MCF-7 and MDA-MB-231) representing breast tumors which differed in hormone receptor, aggressiveness and treatment responses. To examine the response to high and low doses of quercetin, the cells were treated with three doses of quercetin (10, 25 and 100 μM) determined by MTT. The effects of quercetin on Hsp levels, apoptosis and DNA damage were examined by western blot analysis, caspase activity assay, comet assay and microscopy in human breast cancer cells. Compared to MDA-MB231 cells, MCF-7 cells were more affected by quercetin treatments. Quercetin effectively suppressed the expression of Hsp27, Hsp70 and Hsp90. While quercetin did not induce DNA damage, it triggered apoptosis at high levels. Although an increase in NF-κB levels is observed in the cells exposed to quercetin, the net result is the anticancer effect in case of Hsp depletion and apoptosis induction. Taken together our findings suggested that quercetin can be an effective therapeutic agent for breast cancer therapy regardless of the presence or absence of hormone receptors.

Flavonoid calycopterin triggers apoptosis in triple-negative and ER-positive human breast cancer cells through activating different patterns of gene expression

Breast cancer is the most common cause of death related to cancer in women, and several studies proved that flavonoids could induce apoptosis in this cancer through different pathways. Calycopterin is a flavonoid which was shown to induce preferential antiproliferative effects on some cancers; however, no information is available on its effect on breast cancer. Therefore, in this paper, the apoptotic effect of calycopterin and its underlying mechanism in two different breast cancer cells, MDA-MB-231 and MCF7 cell lines were investigated. MTT assay showed that calycopterin reduced the proliferation of both cancer lines with no adverse effect on normal cells. The clonogenic assay showed that calycopterin treatments decreased the colony numbers and sizes, and wound healing assay demonstrated the inhibition of migration in both cancer cells. Cell cycle and annexin/PI analyses indicated that calycopterin augmented sub-G1 population and annexin/PI-positive cells. Gene expression revealed that Bax/Bcl2 increased in the MDA-MB-231 cell line, while no change was observed in that of the MCF7 line. Expression of gene caspase-8 was augmented in both lines, although increased expression of caspase-3 was found just in MDA-MB-231 cells. Our results validated the apoptotic effect of calycopterin on both breast cancer lines with more potency on triple-negative ones.

Phytochemical profile and antiproliferative effect of Ficus crocata extracts on triple-negative breast cancer cells

Background

Some species of the Ficus genus show pharmacological activity, including antiproliferative activity, in cell lines of several cancer Types. ficus crocata is distributed in Mexico and used in traditional medicine, as it is believed to possess anti-inflammatory, analgesic, and antioxidant properties. However, as of yet, there are no scientific reports on its biological activity. This study aims to evaluate the phytochemical profile of F. crocata leaf extracts and their effects on breast cancer MDA-MB-231 cells proliferation. Moreover, the study aims to unearth possible mechanisms involved in the decrease of cell proliferation.

Methods

The extracts were obtained by the maceration of leaves with the solvents hexane, dichloromethane, and acetone. The phytochemical profile of the extracts was determined using gas chromatography coupled with mass analysis. Cell proliferation, apoptosis, and cell cycle analysis in MDA-MB-231 cells were determined using a Crystal violet assay, MTT assay, and Annexin-V/PI assay using flow cytometry. The data were analyzed using ANOVA and Dunnett’s test.

Results

The hexane (Hex-EFc), dichloromethane (Dic-EFc), and acetone (Ace-EFc) extracts of F. crocata decreased the proliferation of MDA-MB-231 cells, with Dic-EFc having the strongest effect. Dic-EFc was fractioned and its antiproliferative activity was potentiated, which enhanced its ability to induce apoptosis in MDA-MB-231 cells, as well as increased p53, procaspase-8, and procaspase-3 expression.

Conclusions

This study provides information on the biological activity of F. crocata extracts and suggests their potential use against triple-negative breast cancer.

Combination of Resveratrol and Quercetin Causes Cell Growth Inhibition, DNA Damage, Cell Cycle Arrest, and Apoptosis in Oral Cancer Cells

Resveratrol and quercetin alone are well reported to have anticancer potential, but their combination studies are very inadequate. We have examined their combination in Cal-33 and SCC-15 oral cancer cells (OCCs) and noncancerous HEK-293 cells. Combination of 10 μM concentration of each resveratrol and quercetin brought additive effect on cellular growth, DNA damage, S-phase cell cycle arrest, and cell death in Cal-33 cells but not in the HEK-293 cells. Augmentation of the cell cycle regulatory protein, Cyclin E, and downregulation of Cyclin A possibly caused S-phase arrest in Cal-33 cancer cells. Comet formation and presence of gamma-H2AX foci confirmed DNA damage, and cleavage of PARP1 and upregulation in Bax level specified apoptosis after combined treatment. Ratio of transcription activation and repression histone marks was found increased after alone as well as combined treatment. Histone deacetylase (HDAC)1, HDAC3, and HDAC8 were downregulated by resveratrol alone and combined treatment. Conclusively, combination of resveratrol and quercetin brings cell growth inhibition, DNA damage, and cell cycle arrest in OCCs but not in normal cells. Additionally, combined treatment causes downregulation of HDACs and apoptosis in cancer cells and it could be an incisive strategy against oral cancer.

Novel 3'-Substituted-1',2',4'-Oxadiazole Derivatives of 18βH-Glycyrrhetinic Acid and Their O-Acylated Amidoximes: Synthesis and Evaluation of Antitumor and Anti-Inflammatory Potential In Vitro and In Vivo

A series of novel 18βH-glycyrrhetinic acid (GA) derivatives containing 3'-(alkyl/phenyl/pyridin(-2″, -3″, and -4″)-yl)-1',2',4'-oxadiazole moieties at the C-30 position were synthesized by condensation of triterpenoid's carboxyl group with corresponding amidoximes and further cyclization. Screening of the cytotoxicity of novel GA derivatives on a panel of tumor cell lines showed that the 3-acetoxy triterpenoid intermediates-O-acylated amidoxime 3a-h-display better solubility under bioassay conditions and more pronounced cytotoxicity compared to their 1',2',4'-oxadiazole analogs 4f-h (median IC50 = 7.0 and 49.7 µM, respectively). Subsequent replacement of the 3-acetoxy group by the hydroxyl group of pyridin(-2″, 3″, and -4″)-yl-1',2',4'-oxadiazole-bearing GA derivatives produced compounds 5f-h, showing the most pronounced selective toxicity toward tumor cells (median selectivity index (SI) > 12.1). Further detailed analysis of the antitumor activity of hit derivative 5f revealed its marked proapoptotic activity and inhibitory effects on clonogenicity and motility of HeLa cervical carcinoma cells in vitro, and the metastatic growth of B16 melanoma in vivo. Additionally, the comprehensive in silico study revealed intermediate 3d, bearing the tert-butyl moiety in O-acylated amidoxime, as a potent anti-inflammatory candidate, which was able to effectively inhibit inflammatory response induced by IFNγ in macrophages in vitro and carrageenan in murine models in vivo, probably by primary interactions with active sites of MMP9, neutrophil elastase, and thrombin. Taken together, our findings provide a basis for a better understanding of the structure-activity relationship of 1',2',4'-oxadiazole-containing triterpenoids and reveal two hit molecules with pronounced antitumor (5f) and anti-inflammatory (3d) activities.

Mechanism of antioxidant properties of quercetin and quercetin-DNA complex

Quercetin is the most abundant flavonoid with potent antioxidant activities. In the current research, the antioxidant properties of quercetin and quercetin-DNA complex were investigated theoretically and experimentally. Free radical scavenging experiments with thiobarbituric acid-reactive substances (TBARS) and 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) indicate that quercetin can protect DNA from free radical damage, and the antioxidant activity of the quercetin-DNA complex is stronger than quercetin. Deoxyriboseadenine-quercetin-dimethylphosphinic acid (DA-Q-P) model was extracted from molecular docking. The contributions of hydroxyl groups in quercetin and DA-Q-P model molecules to the antioxidant activity were investigated by computation of bond dissociation enthalpy (BDE) parameter and Fukui function, at B3LYP/6-311++G(2d,2p) level of theory. The results outlined that the hydroxyl groups from the B ring (3'-OH and 4'-OH) have a lower BDE compared with the ones from the A and C rings (3-OH, 5-OH, and 7-OH) and hence define antioxidant activity. The computational result based on Fukui function shows that the B ring is an electrophilic region. The interaction of antioxidant with DNA discovered at the molecular level could provide the structural basis of the antioxidant property of active ingredients in the flavonoids. It is of great significance to study the interaction mechanism between the small drug molecules with DNA at the molecular level.

Comprehensive study of the interaction between Puerariae Radix flavonoids and DNA: From theoretical simulation to structural analysis to functional analysis

Puerariae Radix (PR) is a natural herb whose active ingredient is mainly flavonoids. To explore the interaction between PR flavonoids and DNA not only has important biological implications for understanding the mechanism of action, but also helps develop PR products for the design of appropriate dietary interventions to aid cancer treatment. In this work, we comprehensively studied the interaction between six kinds of PR flavonoids and DNA from four different and progressive levels, including molecular docking, multi-spectral analysis, and functional analysis in vitro and in cell. Results show that the DNA binding affinity of six flavonoids is in an order of quercetin > formononetin > daidzein > puerarin > 4'-methoxy puerarin > puerarin 6″-O-xyloside (POS), in which quercetin can significantly inhibit DNA amplification owing to its strongest binding affinity. The binding between quercetin and DNA is further revealed to be intercalated binding, which can cause conformational changes in DNA, thereby exhibiting an activity of cell cycle arrest and anti-proliferative. This property of quercetin can be utilized for the further development of flavonoids with anticancer activity. In addition to the potential application, this work also provides a platform for the comprehensive study of the interaction between micromolecules and DNA.

Biological Evaluation of 3-Benzylidenechromanones and Their Spiropyrazolines-Based Analogues

A series of 3-benzylidenechrmanones 1, 3, 5, 7, 9 and their spiropyrazoline analogues 2, 4, 6, 8, 10 were synthesized. X-ray analysis confirms that compounds 2 and 8 crystallize in a monoclinic system in P21/n space groups with one and three molecules in each asymmetric unit. The crystal lattice of the analyzed compounds is enhanced by hydrogen bonds. The primary aim of the study was to evaluate the anti-proliferative potential of 3-benzylidenechromanones and their spiropyrazoline analogues towards four cancer cell lines. Our results indicate that parent compounds 1 and 9 with a phenyl ring at C2 have lower cytotoxic activity against cancer cell lines than their spiropyrazolines analogues. Analysis of IC50 values showed that the compounds 3 and 7 exhibited higher cytotoxic activity against cancer cells, being more active than the reference compound (4-chromanone or quercetin). The results of this study indicate that the incorporation of a pyrazoline ring into the 3-arylideneflavanone results in an improvement of the compounds' activity and therefore it may be of use in the search of new anticancer agents. Further analysis allowed us to demonstrate the compounds to have a strong inhibitory effect on the cell cycle. For instance, compounds 2, 10 induced 60% of HL-60 cells to be arrested in G2/M phase. Using a DNA-cleavage protection assay we also demonstrated that tested compounds interact with DNA. All compounds at the concentrations corresponding to cytotoxic properties are not toxic towards red blood cells, and do not contribute to hemolysis of RBCs.

Novel fusion protein NGR-sIL-24 for targetedly suppressing cancer cell growth via apoptosis

Pro-apoptotic peptides have attracted much attention as promising anticancer agents due to their high activity. However, poor cellular uptake of the peptides is often associated with limited therapeutic application. Cell-penetrating homing peptides (CPHPs) were found to increase cell internalization as well as anticancer efficacy of the peptide conjugates. In this study, we developed a novel recombinant fusion protein composed of sIL-24 peptide as a pro-apoptotic moiety and asparagine-glycine-arginine (NGR) motif as a CD13-targeting CPHP component. In silico analysis demonstrated that flexible GGGGS linker provided the best structure and stability for our designed fusion protein. Cell adhesion experiments showed a significant binding affinity toward high CD13-expressing cells (U937 and A549) for NGR-sIL-24. Moreover, confocal microscopy revealed that NGR strongly facilitated the binding and cellular uptake of sIL-24 in U937 and A549 cancer cells. NGR-sIL-24 treatment markedly inhibited the growth of U937 and A549 cancer cells in a dose and time-dependent manner, without affecting the normal cell line MRC-5. Flow cytometric analysis and Hoechst 33342 staining exhibited potent apoptosis induction in U937 and A549 cells treated with NGR-sIL-24. Further mechanism elucidation uncovered that apoptotic death promoted by NGR-sIL-24 was attributed to upregulation of BiP/GRP78, Bax/Bcl-2, GADD34, cytochrome c release, and cleavage of caspase-3, suggesting NGR-sIL-24 penetration into cancerous cells and subsequent apoptosis induction, mainly through endoplasmic reticulum (ER) stress-dependent and mitochondria-dependent signaling pathways. Our results indicate that the designed recombinant fusion protein NGR-sIL-24 may serve as a potential targeted therapy agent for cancers with high expression of CD13.

Quercetin and cancer: new insights into its therapeutic effects on ovarian cancer cells

Ovarian cancer is known as a serious malignancy that affects women's reproductive tract and can considerably threat their health. A wide range of molecular mechanisms and genetic modifications have been involved in ovarian cancer pathogenesis making it difficult to develop effective therapeutic platforms. Hence, discovery and developing new therapeutic approaches are required. Medicinal plants, as a new source of drugs, could potentially be used alone or in combination with other medicines in the treatment of various cancers such as ovarian cancer. Among various natural compounds, quercetin has shown great anti-cancer and anti-inflammatory properties. In vitro and in vivo experiments have revealed that quercetin possesses a cytotoxic impact on ovarian cancer cells. Despite obtaining good results both in vitro and in vivo, few clinical studies have assessed the anti-cancer effects of quercetin particularly in the ovarian cancer. Therefore, it seems that further clinical studies may introduce quercetin as therapeutic agent alone or in combination with other chemotherapy drugs to the clinical setting. Here, we not only summarize the anti-cancer effects of quercetin but also highlight the therapeutic effects of quercetin in the ovarian cancer.

Eriodictyol Inhibits Proliferation, Metastasis and Induces Apoptosis of Glioma Cells via PI3K/Akt/NF-κB Signaling Pathway

Glioma is the most common type of malignant brain tumor. Due to its highly aggressive and metastatic features, glioma is associated with poor prognosis and a lack of effective treatments. Eriodictyol, a natural flavonoid compound, has been reported to possess anti-inflammatory and antioxidant effects. However, the anti-tumor effects of eriodictyol and the underlying mechanisms have rarely been reported. In this study, we found that eriodictyol has anti-tumor activity in lung, colon, breast, pancreas, and liver cancer, and most significantly in glioma cell lines. Eriodictyol dose- and time-dependently suppresses cell proliferation, migration, and invasion in U87MG and CHG-5 glioma cells. In addition, eriodictyol induces apoptosis in U87MG and CHG-5 cells, as evaluated by flow cytometry, immunofluorescence, and Western blot. Furthermore, eriodictyol downregulates the phosphoinositide 3-kinase (PI3K)/Akt/NF-κB signaling pathway in a concentration-dependent manner. Moreover, the effects of eriodictyol on the apoptosis of glioma cells are enhanced by LY294002 (a PI3K inhibitor) and reversed by 740 Y-P (a PI3K agonist). In a mouse xenograft model, eriodictyol not only dramatically suppressed tumor growth but also induced apoptosis in tumor cells. In summary, our data illustrate that eriodictyol effectively inhibits proliferation and metastasis and induces apoptosis of glioma cell lines, which might be a result of the blockade of the PI3K/Akt/NF-κB signaling pathway.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

Bauerane Induces S-Phase Cell Cycle Arrest, Apoptosis, and Inhibition of Proliferation of A549 Human Lung Cancer Cells Through the Phosphoinositide 3-Kinase (PI3K)/AKT and Signal Transducer and Activator of Transcription 3 (STAT3) Signaling Pathway

BACKGROUND Bauerane is a triterpenoid derived from the dandelion root (Taraxacum officinale). This study aimed to investigate the effects of bauerane on cell proliferation of A549 human lung cancer cells and the molecular mechanisms involved. MATERIAL AND METHODS A549 human lung adenocarcinoma cells and normal MRC-5 lung fibroblasts were grown in culture and treated with increasing doses of bauerane at 0, 2.5, 5, 10, 20, 40, 80, and 160 µM. The MTT assay was used to measure cell proliferation. Cell apoptosis was assessed by 4', 6-diamidino-2-phenylindole (DAPI), and acridine orange/ethidium bromide (AO/EB) staining. The cell cycle was evaluated by flow cytometry. Western blot measured the protein expression levels of cytochrome c, Bax, cyclin B1, Bcl-2, PI3K, p-PI3K, Akt, p-Akt, and STAT3 proteins. RESULTS Bauerane inhibited the proliferation of A549 lung cancer cells in a dose-dependent manner, with an IC₅₀ of 10 µM, with no cytotoxicity for MRC-5 cells. Bauerane treatment induced apoptosis of A549 cells, which was associated with the upregulation of Bax and down-regulation of Bcl-2. Bauerane induced S-phase arrest of A549 cells, which was dose-dependent and associated with reduced expression of cyclin B1. The findings from Western blot showed that bauerane inhibited the phosphorylation of PI3K/AKT and STAT3 signaling pathways. CONCLUSIONS Bauerane inhibited the proliferation of A549 lung cancer cells in vitro and induced cell apoptosis and cell cycle arrest in a dose-dependent manner.

Dasatinib plus quercetin prevents uterine age-related dysfunction and fibrosis in mice

The uterine fibrosis contributes to gestational outcomes. Collagen deposition in the uterus is related to uterine aging. Senolytic therapies are an option for reducing health complications related to aging. We investigated effects of aging and the senolytic drug combination of dasatinib plus quercetin (D+Q) on uterine fibrosis. Forty mice, 20 young females (03-months) and 20 old females (18-months), were analyzed. Young (Y) and old (O) animals were divided into groups of 10 mice, with one treatment (T) group (YT and OT) and another control © group (YC and OC). Comparative analysis of Pi3k/Akt1/mTor and p53 gene expression and related microRNAs (miR34a, miR34b, miR34c, miR146a, miR449a, miR21a, miR126a, and miR181b) among groups was performed to test effects of age and treatment on collagen deposition pathways. Aging promoted downregulation of the Pi3k/Akt1/mTor signaling pathway (P = 0.005, P = 0.031, and P = 0.028, respectively) as well as a reduction in expression of miR34c (P = 0.029), miR126a (P = 0.009), and miR181b (P = 0.007). D+Q treatment increased p53 gene expression (P = 0.041) and decreased miR34a (P = 0.016). Our results demonstrate a role for the Pi3k/Akt1/mTor signaling pathway in uterine aging and suggest for the first time a possible anti-fibrotic effect in the uterus of D+Q senolytic therapy.

The Influence of In Vitro Gastrointestinal Digestion on the Anticancer Activity of Manuka Honey

Manuka honey (MH) is a natural food with many beneficial properties to human health, thanks to its high variety of bioactive compounds; however, little is known about its bioaccessibility. The aim of this study was to evaluate and compare the polyphenol compounds, the antioxidant capacity and the anticancer activity of MH subjected to an in vitro gastrointestinal digestion in human HCT-116 colon cancer cells. Raw MH and digested MH (DMH) were assessed for total polyphenols and flavonoids by spectrophotometric and HPLC-ESI-MS/MS analysis, and total antioxidant capacity (TAC) using different methods. Cell viability, intracellular ROS production, apoptosis, cell cycle and colony formation capacity were tested after treatment with MH or DMH. Results showed that total polyphenols, total flavonoids and TAC were significantly (p < 0.05) reduced after in vitro digestion. In addition, MH and DMH at 8, 16 and 24 mg/mL had similar effects in inducing intracellular ROS production and in inhibiting the colon formation ability; MH induced a more marked apoptosis compared to DMH, while cell cycle was blocked in S phase by MH and in Sub G1 phase by DMH. Our results increase knowledge of the effect of gastrointestinal digestion on the biological effect of honey against colorectal cancer.

Molecular docking-assisted design and synthesis of an anti-tumor quercetin–Se(iv) complex

Design and synthesis of an anti-tumor quercetin–Se(iv) complex under the guidance of molecular docking and visualized DNA binding activity.

Chenopodium Botrys Essential Oil as A Source of Sesquiterpenes to Induce Apoptosis and G1 Cell Cycle Arrest in Cervical Cancer Cells

Conducting cell apoptosis pathways is a novel strategy in cancer treatment. This study aimed to explain that C. botrys essential oil could induce apoptosis and arrest the cell cycle in HeLa cells. Cytotoxic and apoptogenic effects of the essential oil of Jerusalem-oak (Chenopodium botrys L.), which was obtained from the aerial parts of the plant, were evaluated in HeLa cells. Cell viability was assessed by MTT and LDH assays, and the mechanism of cell apoptosis was investigated using flow cytometry. Expression of the apoptosis-related genes was assessed using real-time polymerase chain reaction (PCR). GC-MS analysis of the herbal essential oil revealed 37 components. The major components were α-Eudesmol (16.81%), Elemol acetate (13.2%), Elemol (9.0%), and α-Chenopodiol-6-acetate (7.9%). The essential oil inhibited the growth of HeLa cells and increased the expression of p21 and p53. In addition, essential oil treatment increased the sub-G1 DNA content and induced apoptosis due to the increased Bax/Bcl-2 ratio and up-regulation of caspase-3 gene expression. According to the results, C. botrys essential oil exhibited anticancer effects through intrinsic apoptosis pathways and arresting cell proliferation.

Quercetin loaded folate targeted plasmonic silver nanoparticles for light activated chemo-photothermal therapy of DMBA induced breast cancer in Sprague Dawley rats

Novel plasmonic (>800 nm) pentagonal QRC-FA-AgNPs synthesized through simple chemical technique induces light activated combined chemo-photothermal efficacy against breast cancer.

Avicularin inhibits cell proliferation and induces cell apoptosis in cutaneous squamous cell carcinoma

Avicularin (AL), quercetin-3-α-L-arabinofuranoside, has various pharmacological properties such as anticancer and anti-infective effects. However, the potential molecular mechanism via which AL exerts its anticancer activity is not fully understood. Cutaneous squamous cell carcinoma (CSCC) is the second most common skin cancer, where metastasis has resulted in in effective clinical treatments. The aim of the present in vitro study was to investigate the anticancer effects and underlying mechanism of AL on human CSCC. The present results suggested that AL dose-dependently inhibited SCC13 cell viability and induced apoptosis. In addition, the present results suggested that AL induced apoptosis via repression of the mitogen-activated protein kinase kinase (MEK)/NF-κB signal pathway, thereby affecting the expression of apoptosis-related genes. Bax expression level was increased, while Bcl-2 expression level was decreased in SCC13 cells following AL treatment. In addition, the MEK/NF-κB signaling pathway-related genes p-MEK and phosphorylated-p65 were also decreased. The present results suggested that AL treatment increased the expression level of E-cadherin, but decreased the expression levels of N-cadherin, matrix metalloproteinase (MMP)-9 and vimentin in SCC13 cells. Collectively, the present results suggested that AL may have an anti-CSCC effect by inhibiting cell viability, inducing apoptosis and inhibiting epithelial-mesenchymal transition (EMT) of CSCC cells. The mechanism of these anti-CSCC effects was suggested to be via the regulation of apoptosis-related genes and EMT-related genes, and the inhibition of the MEK/NF-κB signaling pathway.

Dietary Polyphenols and Mitochondrial Function: Role in Health and Disease

Mitochondria are cytoplasmic double-membraned organelles that are involved in a myriad of key cellular regulatory processes. The loss of mitochondrial function is related to the pathogenesis of several human diseases. Over the last decades, an increasing number of studies have shown that dietary polyphenols can regulate mitochondrial redox status, and in some cases, prevent or delay disease progression. This paper aims to review the role of four dietary polyphenols - resveratrol, curcumin, epigallocatechin-3-gallate nd quercetin - in molecular pathways regulated by mitochondria and their potential impact on human health. Cumulative evidence showed that the aforementioned polyphenols improve mitochondrial functions in different in vitro and in vivo experiments. The mechanisms underlying the polyphenols' beneficial effects include, among others, the attenuation of oxidative stress, the regulation of mitochondrial metabolism and biogenesis and the modulation of cell-death signaling cascades, among other mitochondrial-independent effects. The understanding of the chemicalbiological interactions of dietary polyphenols, namely with mitochondria, may have a huge impact on the treatment of mitochondrial dysfunction-related disorders.

Evaluation of cytotoxicity, cell cycle arrest and apoptosis induced by Anethum graveolens L. essential oil in human hepatocellular carcinoma cell line

Anethum graveolens L. (A. graveolens) commonly known as dill, is an essential oil bearing plant extensively being used in traditional system of medicine. However, the reports on the components and biological responses of A. graveolens essential oil (AG-EO) from Saudi Arabia are scarce. The present study was designed to explore the presence of basic constituents and apoptosis induced by AG-EO in HepG2 cells. The constituents in AG-EO was analyzed by Gas chromatography-Mass spectroscopy (GC-MS). Cytotoxicity of AG-EO was measured by MTT assay and cell cycle arrest and apoptosis assays were conducted by using flow cytometer. Based on GC-MS analysis, the main constituents present in AG-EO were carvone (53.130%), dillapole (25.420%), dihydrocarvone 2 (11.350%) and dihydrocarvone 1 (6.260%). A few other minor components were also identified viz. cis-dihydrocarveol (0.690%), limonene (0.580%), isodihydrocarveol (0.370%), myristicin (0.210%) and cis-arsone (0.190%). The cytotoxicity results showed that AG-EO decrease the cell viability and inhibit the cell growth of HepG2 cells in a concentration-dependent manner. The inhibitory activity of AG-EO was found with IC50 = 59.6 ± 5.64. The cell cycle arrest results showed that HepG2 cells exposed to AG-EO exhibited an increase in G2/M and pre-G1 cell population after 24 h exposure. Furthermore, the flow cytometry data revealed the primarily activation of cell death by apoptosis manners in HepG2 cells exposed to AG-EO. Overall, results from this study highlighted the anticancer potential of AG-EO, which could be considered as a new agent for the management of hepatocellular carcinoma.

Chemomodulatory effects of Alysicarpus vaginalis extract via mitochondria-dependent apoptosis and necroptosis in breast cancer

The present study intended to assess the anticancer potential of Alysicarpus vaginalis ethyl acetate fraction (AVEAF) in breast cancer cell lines (MCF-7 and MDA-MB-453) and against N-methyl-N-nitrosourea (MNU) induced mammary carcinoma in Sprague-Dawley rats which resemble the human estrogen dependent breast cancer. The SRB assay showed that the maximum growth inhibition rate of AVEAF on MCF-7 cell was 27.12 at 100 µg/ml. Flow cytometry analysis observed that AVEAF induced the cell cycle arrest at the S phases and decreased in mitochondrial membrane potential on the MCF-7 cells. AVEAF elevated intracellular ROS level in the MCF-7 cells which were reversed with N-acetycysteine (2 mM) pretreatment indicating that AVEAF induced mitochondrial-mediated apoptosis via augmentation of intracellular ROS. Western blotting exhibited that AVEAF increased the expression of pro-apoptotic protein Bax while decreasing anti-apoptotic proteins Bcl-2 and Bcl-xL expression which promoted the cleavage of caspase-9, PARP1, RIPK 1, and RIPK 3. Additionally, AVEAF exerted anticancer effect on tumor-bearing rats and the tumor inhibition rate is 50%. Data of the study indicate that AVEAF exhibits In Vitro and In Vivo anticancer activities that associate with its ROS-mediated mitochondrial-mediated intrinsic pathway of apoptosis and necroptosis in MCF-7 cells and may serve as a potential against breast cancer.

Antitumor activity of an Artemisia annua herbal preparation and identification of active ingredients

BACKGROUND

Artemisia annua L. has gained increasing attention for its anticancer activity. However, beside artemisinin, less is known about the possible bioactive ingredients of Artemisia annua and respective herbal preparations. We hypothesized that, in addition to artemisinin, Artemisia annua preparations might contain multiple ingredients with potential anticancer activity.

METHODS

MDA-MB-231 triple negative human breast cancer (TNBC) cells along with other treatment resistant, metastatic cancer cell lines were used to investigate in vitro and in vivo the anticancer efficacy of an Artemisia annua extract marketed as a herbal preparation, which contained no detectable artemisinin (limit of detection = 0.2 ng/mg). The extract was characterized by HPLC-DAD and the most abundant compounds were identified by ¹H- and ¹³C NMR spectroscopy and quantified by UHPLC-MS/MS. Cell viability and various apoptotic parameters were quantified by flow cytometry. In vitro data were validated in two in vivo cancer models, the chick chorioallantoic membrane (CAM) assay and in orthotopic breast cancer xenografts in nude mice.

RESULTS

The Artemisia annua extract, the activity of which could be enhanced by acetonitrile maceration, inhibited the viability of breast (MDA-MB-231 and MCF-7), pancreas (MIA PaCa-2), prostate (PC-3), non-small cell lung cancer (A459) cells, whereas normal mammary epithelial cells, lymphocytes, and PBMC were relatively resistant to extract treatment. Likewise, the extract's most abundant ingredients, chrysosplenol D, arteannuin B, and casticin, but not arteannuic acid or 6,7-dimethoxycoumarin, inhibited the viability of MDA-MB-231 breast cancer cells. The extract induced accumulation of multinucleated cancer cells within 24 h of treatment, increased the number of cells in the S and G₂/M phases of the cell cycle, followed by loss of mitochondrial membrane potential, caspase 3 activation, and formation of an apoptotic hypodiploid cell population. Further, the extract inhibited cancer cell proliferation, decreased tumor growth, and induced apoptosis in vivo in TNBC MDA-MB-231 xenografts grown on CAM as well as in nude mice.

CONCLUSION

An extract of an artemisinin-deficient Artemisia annua herbal preparation exhibits potent anticancer activity against triple negative human breast cancer. New active ingredients of Artemisia annua extract with potential anticancer activity have been identified.

Hydrogen Ion Dynamics of Cancer and a New Molecular, Biochemical and Metabolic Approach to the Etiopathogenesis and Treatment of Brain Malignancies

The treatment of cancer has been slowly but steadily progressing during the last fifty years. Some tumors with a high mortality in the past are curable nowadays. However, there is one striking exception: glioblastoma multiforme. No real breakthrough has been hitherto achieved with this tumor with ominous prognosis and very short survival. Glioblastomas, being highly glycolytic malignancies are strongly pH-dependent and driven by the sodium hydrogen exchanger 1 (NHE1) and other proton (H⁺) transporters. Therefore, this is one of those pathologies where the lessons recently learnt from the new pH-centered anticancer paradigm may soon bring a promising change to treatment. This contribution will discuss how the pH-centric molecular, biochemical and metabolic perspective may introduce some urgently needed and integral novel treatments. Such a prospective therapeutic approach for malignant brain tumors is developed here, either to be used alone or in combination with more standard therapies.

Quercetin modulates signaling pathways and induces apoptosis in cervical cancer cells

Cancer cells have the unique ability to overcome natural defense mechanisms, undergo unchecked proliferation and evade apoptosis. While chemotherapeutic drugs address this, they are plagued by a long list of side effects and have a poor success rate. This has spurred researchers to identify safer bioactive compounds that possess chemopreventive and therapeutic properties. A wide range of experimental as well as epidemiological data encourage the use of dietary agents to impede or delay different stages of cancer. In the present study, we have examined the anti-ancer property of ubiquitous phytochemical quercetin by using cell viability assay, flow cytometry, nuclear morphology, colony formation, scratch wound assay, DNA fragmentation and comet assay. Further, qPCR analysis of various genes involved in apoptosis, cell cycle regulation, metastasis and different signal transduction pathways was performed. Proteome profiler was used to quantitate the expression of several of these proteins. We find that quercetin decreases cell viability, reduces colony formation, promotes G2-M cell cycle arrest, induces DNA damage and encourages apoptosis. Quercetin induces apoptosis via activating both apoptotic pathways with a stronger effect of the extrinsic pathway relying on the combined power of TRAIL, FASL and TNF with up-regulation of caspases and pro-apoptotic genes. Quercetin could inhibit anti-apoptotic proteins by docking studies. Further, quercetin blocks PI3K, MAPK and WNT pathways. Anticancer effect of quercetin observed in cell-based assays were corroborated by molecular biology studies and yielded valuable mechanistic information. Quercetin appears to be a promising candidate with chemopreventive and chemotherapeutic potential and warrants further research.

Insight into the binding of a synthetic nitro-flavone derivative with human poly (ADP-ribose) polymerase 1

Flavones are important bioactive compounds, many of which are effective in cancer therapy for their ability to target enzymes related to DNA repair and cell proliferation. In this report, the interaction of a synthetic nitroflavone, 2,4-nitrophenylchromen-4-one (4NCO) with human poly (ADP-ribose) polymerase 1 (hPARP1) was investigated to explore its inhibitory action. Its interaction with hPARP1 was compared with that of other inhibitors through molecular docking studies. Further insight into the 4NCO-hPARP1 interaction was obtained from competitive docking and molecular dynamic simulation studies. In silico mutagenesis studies and per-residue interaction energy calculations were carried out. Quantitative Structure Activity Relationship analysis was also performed to calculate its predictive percent inhibitory activity. Our results indicated that 4NCO exhibited competitive mode of binding to hPARP1. It formed a stable interaction with the protein thereby hindering any further molecular interaction to render it inactive with a predictive inhibition of 96%. It also had good ADMET properties and showed best Autodock binding free energy values compared to other known inhibitors. 4NCO showed good hPARP1 inhibitory properties with higher bioavailability and lower probability of getting effluxed. Development of inhibitors against hPARP1 is important for cell proliferative disorders, where 4NCO can be predicted as a potential new drug.

PDIA3-regulted inflammation and oxidative stress contribute to the traumatic brain injury (TBI) in mice

Traumatic brain injury (TBI) is a leading cause of death and disability throughout the world. However, the molecular mechanism contributing to TBI still remains unclear. Protein disulfide isomerases (PDI) are a family of redox chaperones, which catalyze formation or isomerization of disulfide bonds in proteins. PDIA3, a critical member of PDI family, is a multi-functional protein, playing critical roles in modulating inflammation, apoptosis and oxidative stress under various kinds of disease conditions. Nevertheless, its regulatory effects on TBI have far from to be known. In the present study, we attempted to explore the modulation of neuroinflammatory responses by PDIA3 and its contribution to oxidative stress and cell death after TBI in the wild type (PDIA^+/+) and PDIA3 knockout (PDIA3^+/+) C57BL/6 mice. Results here suggested that PDIA3 expression was markedly up-regulated in the late trauma human brain tissues, which was verified in the PDIA3^+/+ mice at 24 h after TBI. PDIA^-/- provided significant improvements in cognitive impairments and contusion volume induced by TBI. Apoptosis in brain samples was also alleviated in TBI mice with PDIA3 deficiency. Significantly, PDIA3^-/- mitigated neuroinflammation after TBI in mice, as evidenced by the reduced expression of pro-inflammatory factors interleukin (IL)-6, tumor necrosis factor-α (TNF-α) and IL-1β, while the enhanced anti-inflammatory regulator IL-10. These anti-inflammatory activities by PDIA3^-/- were associated with the decrease in phosphorylated nuclear factor kappa B (NF-κB)/p65. PDIA3^-/- mice following TBI showed attenuated oxidative stress, as proved by the restored superoxide dismutase (SOD) and glutathione (GSH) activities, and the down-regulated malondialdehyde (MDA) levels in brain samples. These effects regulated by PDIA3 were confirmed in OGDR-treated astrocytes. Collectively, these data demonstrated a detrimental role of PDIA3 in regulating TBI, providing an effective therapeutic target for TBI treatment in future.

Quercetin facilitates cell death and chemosensitivity through RAGE/PI3K/AKT/mTOR axis in human pancreatic cancer cells

The triggering of gemcitabine (GEM) drug resistance in pancreatic cancer by the receptor for advanced glycation end products (RAGE) has been demonstrated. Hence, finding a safe and effective adjuvant for preventing pancreatic cancer progression is imperative. Quercetin is a flavonoid that is abundant in apples, grapes, red raspberry, and onions and has been reported to inhibit RAGE. This research aimed to investigate the mechanisms of quercetin in regulating cell death and enhancing drug effects through RAGE reduction, especially in GEM-resistant pancreatic cancer cells. Our results showed that silencing RAGE expression by RAGE-specific siRNA transfection significantly increased cell death by apoptosis, autophagy and GEM-induced cytotoxicity by suppressing the PI3K/AKT/mTOR axis in MIA Paca-2 and MIA Paca-2 ^GEMR cells (GEM-resistant cells). Notably, quercetin showed a dramatic effect similar to RAGE silencing that effectively attenuated RAGE expression to facilitate cell cycle arrest, autophagy, apoptosis, and GEM chemosensitivity in MIA Paca-2 ^GEMR cells, suggesting that an additional reaction occurred under combined quercetin and GEM treatment. In conclusion, the results demonstrated that the molecular mechanisms of quercetin in regulating apoptosis and autophagy-related pathways and increasing GEM chemosensitivity in pancreatic cancer cells involved inhibition of RAGE expression.