Low concentrations of quercetin and ellagic acid synergistically influence proliferation, cytotoxicity and apoptosis in MOLT-4 human leukemia cells

An integrative computational approach for the identification of dual inhibitors of isocitrate dehydrogenase 1 and 2 from phytocompounds of Phyllantus amarus

Genetic alterations of the genes encoding the isocitrate dehydrogenase (IDH) enzymes have been identified in about 20% of acute myeloid leukemia (AML) cases as well as many other forms of cancers. Notable among these alterations are the neomorphic IDH1_R132H and IDH2_R140Q mutations which lead to the production of an oncometabolite. Hence, their inhibition is widely considered a therapeutic strategy in the treatment of many cancers. While many inhibitors of the mutant enzymes have been developed, an inhibitor that is capable of co-inhibiting both enzymes are currently lacking while drug resistance has also limited the clinical usage of previously identified mono inhibitors. Consequently, this study employed molecular modeling approaches, such as molecular docking, molecular mechanics generalized Born Surface area (MM/GBSA), molecular dynamics (MD) simulation, and density functional theory (DFT) analysis to identify potential dual inhibitors of the previously mentioned mutant IDH1/2 from the phytocompounds of Phyllantus amarus. Of the 31 phytocompounds identified, 20 showed good binding affinities for both IDH1 _R132H and IDH2 _R140Q (ranging from -5.2 Kca/mol to -9.6 Kcal/mol) and had desirable pharmacokinetic properties. However, ellagic acid and pinoresinol possessed better pharmacokinetic properties, rendering suitable hits. Investigation of the behavior of the IDH1_R132H and IDH2_R140Q complexes with ellagic acid and pinoresinol via the RMSD, RMSF, and contact map analyses showed that all the complexes-maintained stability throughout the simulation time. Ultimately, ellagic acid and pinoresinol were identified as promising hits for the development of IDH1_R132H and IDH2_R140Q dual inhibitors. However, further experimental studies are needed to confirm their potential as therapies.Communicated by Ramaswamy H. Sarma.

MicroRNA-21 in urologic cancers: from molecular mechanisms to clinical implications

The three most common kinds of urologic malignancies are prostate, bladder, and kidney cancer, which typically cause substantial morbidity and mortality. Early detection and effective treatment are essential due to their high fatality rates. As a result, there is an urgent need for innovative research to improve the clinical management of patients with urologic cancers. A type of small noncoding RNAs of 22 nucleotides, microRNAs (miRNAs) are well-known for their important roles in a variety of developmental processes. Among these, microRNA-21 (miR-21) stands out as a commonly studied miRNA with implications in tumorigenesis and cancer development, particularly in urological tumors. Recent research has shed light on the dysregulation of miR-21 in urological tumors, offering insights into its potential as a prognostic, diagnostic, and therapeutic tool. This review delves into the pathogenesis of miR-21 in prostate, bladder, and renal cancers, its utility as a cancer biomarker, and the therapeutic possibilities of targeting miR-21.

Berberis vulgaris L. extract supplementation exerts regulatory effects on the lifespan and healthspan of Drosophila through its antioxidant activity depending on the sex

Worldwide the aging population continues to increase, so the concept of healthy longevity medicine has become increasingly significant in modern society. Berberis vulgaris L. fruits serve as a functional food supplement with a high concentration of bioactive compounds, which offer numerous health-promoting benefits. The goal of this study was to investigate the geroprotective effect of Berberis vulgaris L. extract. Here we show that extract of Berberis vulgaris L. can, depending on concentrate, increases lifespan up to 6%, promote healthspan (stress resistance up to 35%, locomotor activity up to 25%, integrity of the intestinal barrier up to 12%, metabolic rate up to 5%) of Drosophila melanogaster (in vitro) and exhibits antioxidant (using red blood cell tests) and antiglycation activity (using glycation of bovine serum albumin) (in vitro). In addition to this, the extract does not exhibit cytotoxic properties in vitro, unlike the well-known polyphenolic compound quercetin. qRT-PCR has revealed the involvement of metabolic, heat shock response and lipid metabolism genes in the observed effects.

Multiplicative Effects of Essential Oils and Other Active Components on Skin Tissue and Skin Cancers

Naturally derived essential oils and their active components are known to possess various properties, ranging from anti-oxidant, anti-inflammatory, anti-bacterial, anti-fungal, and anti-cancer activities. Numerous types of essential oils and active components have been discovered, and their permissive roles have been addressed in various fields. In this comprehensive review, we focused on the roles of essential oils and active components in skin diseases and cancers as discovered over the past three decades. In particular, we opted to highlight the effectiveness of essential oils and their active components in developing strategies against various skin diseases and skin cancers and to describe the effects of the identified essential-oil-derived major components from physiological and pathological perspectives. Overall, this review provides a basis for the development of novel therapies for skin diseases and cancers, especially melanoma.

Exploring the Remarkable Chemotherapeutic Potential of Polyphenolic Antioxidants in Battling Various Forms of Cancer

Plant-derived compounds, specifically antioxidants, have played an important role in scavenging the free radicals present under diseased conditions. The persistent generation of free radicals in the body leads to inflammation and can result in even more severe diseases such as cancer. Notably, the antioxidant potential of various plant-derived compounds prevents and deregulates the formation of radicals by initiating their decomposition. There is a vast literature demonstrating antioxidant compounds' anti-inflammatory, anti-diabetic, and anti-cancer potential. This review describes the molecular mechanism of various flavonoids, such as quercetin, kaempferol, naringenin, epicatechin, and epicatechin gallate, against different cancers. Additionally, the pharmaceutical application of these flavonoids against different cancers using nanotechnologies such as polymeric, lipid-based nanoparticles (solid-lipid and liquid-lipid), liposomes, and metallic nanocarriers is addressed. Finally, combination therapies in which these flavonoids are employed along with other anti-cancer agents are described, indicating the effective therapies for the management of various malignancies.

The potential anti-cancer effects of quercetin on blood, prostate and lung cancers: An update

Cancer is caused by abnormal proliferation of cells and aberrant recognition of the immune system. According to recent studies, natural products are most likely to be effective at preventing cancer without causing any noticeable complications. Among the bioactive flavonoids found in fruits and vegetables, quercetin is known for its anti-inflammatory, antioxidant, and anticancer properties. This review aims to highlight the potential therapeutic effects of quercetin on some different types of cancers including blood, lung and prostate cancers.

Crosstalk between xanthine oxidase (XO) inhibiting and cancer chemotherapeutic properties of comestible flavonoids- a comprehensive update

Gout is an inflammatory disease caused by metabolic disorder or genetic inheritance. People throughout the world are strongly dependent on ethnomedicine for the treatment of gout and some receive satisfactory curative treatment. The natural remedies as well as established drugs derived from natural sources or synthetically made exert their action by mechanisms that are closely associated with anticancer treatment mechanisms regarding inhibition of xanthine oxidase, feedback inhibition of de novo purine synthesis, depolymerization and disappearance of microtubule, inhibition of NF-ĸB activation, induction of TRAIL, promotion of apoptosis, and caspase activation and proteasome inhibition. Some anti-gout and anticancer novel compounds interact with same receptors for their action, e.g., colchicine and colchicine analogues. Dietary flavonoids, i.e., chrysin, kaempferol, quercetin, fisetin, pelargonidin, apigenin, luteolin, myricetin, isorhamnetin, phloretinetc etc. have comparable IC₅₀ values with established anti-gout drug and effective against both cancer and gout. Moreover, a noticeable number of newer anticancer compounds have already been isolated from plants that have been using by local traditional healers and herbal practitioners to treat gout. Therefore, the anti-gout plants might have greater potentiality to become selective candidates for screening of newer anticancer leads.

Phenolic-rich feijoa extracts from flesh, peel and whole fruit activate apoptosis pathways in the LNCaP cell line

This study aimed to explore the potential anticancer activity of phenolic-rich feijoa extracts from the flesh, peel, and whole fruit on the human prostate cancer cell line (LNCaP). Results showed that feijoa extracts had cancer-specific anti-proliferative activity on the LNCaP cell line. The anticancer activity of feijoa extracts was shown through activation of the caspase-dependent apoptosis pathway based on the increase of sub-G1 phase in the cell cycle, the decrease of mitochondrial membrane potential, as well as the elevated caspase 3, 8, and 9 activity in the treated LNCaP cells. The anti-cancer activity of feijoa extracts could be attributed to the high total phenolic contents (0.14-0.37 mg GAE/mg dw) and, in particular, the high ellagic acid content (2.662-9.119 μg/mg dw). The successful activation of the caspase-dependent apoptosis pathway indicates that phenolic-rich feijoa extracts have a good potential to be utilized as a functional ingredient in foods and nutraceuticals.

Phytochemicals from medicinal plants from African forests with potentials in rheumatoid arthritis management

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by inflammation, pain, and cartilage and bone damage. There is currently no cure for RA. It is however managed using nonsteroidal anti-inflammatory drugs, corticosteroids and disease-modifying anti-rheumatic drugs, often with severe side effects. Hidden within Africa's lush vegetation are plants with diverse medicinal properties including anti-RA potentials. This paper reviews the scientific literature for medicinal plants, growing in Africa, with reported anti-RA activities and identifies the most abundant phytochemicals deserving research attention. A search of relevant published scientific literature, using the major search engines, such as Pubmed/Medline, Scopus, Google Scholar, etc. was conducted to identify medicinal plants, growing in Africa, with anti-RA potentials.

KEY FINDINGS

Twenty plants belonging to 17 families were identified. The plants are rich in phytochemicals, predominantly quercetin, rutin, catechin, kaempferol, etc., known to affect some pathways relevant in RA initiation and progression, and therefore useful in its management.

SUMMARY

Targeted research is needed to unlock the potentials of medicinal plants by developing easy-to-use technologies for preparing medicines from them. Research attention should focus on how best to exploit the major phytochemicals identified in this review for the development of anti-RA 'green pharmaceuticals'.

The Cooperative Anti-Neoplastic Activity of Polyphenolic Phytochemicals on Human T-Cell Acute Lymphoblastic Leukemia Cell Line MOLT-4 In Vitro

Acute lymphoblastic leukemia (ALL) is the most common hematological malignancy affecting pediatric patients. ALL treatment regimens with cytostatics manifest substantial toxicity and have reached the maximum of well-tolerated doses. One potential approach for improving treatment efficiency could be supplementation of the current regimen with naturally occurring phytochemicals with anti-cancer properties. Nutraceuticals such as quercetin, curcumin, resveratrol, and genistein have been studied in anti-cancer therapy, but their application is limited by their low bioavailability. However, their cooperative activity could potentially increase their efficiency at low, bioavailable doses. We studied their cooperative effect on the viability of a human ALL MOLT-4 cell line in vitro at the concentration considered to be in the bioavailable range in vivo. To analyze their potential side effect on the viability of non-tumor cells, we evaluated their toxicity on a normal human foreskin fibroblast cell line (BJ). In both cell lines, we also measured specific indicators of cell death, changes in cell membrane permeability (CMP), and mitochondrial membrane potential (MMP). Even at a low bioavailable concentration, genistein and curcumin decreased MOLT-4 viability, and their combination had a significant interactive effect. While resveratrol and quercetin did not affect MOLT-4 viability, together they enhanced the effect of the genistein/curcumin mix, significantly inhibiting MOLT-4 population growth in vitro. Moreover, the analyzed phytochemicals and their combinations did not affect the BJ cell line. In both cell lines, they induced a decrease in MMP and correlating CMP changes, but in non-tumor cells, both metabolic activity and cell membrane continuity were restored in time. (4) Conclusions: The results indicate that the interactive activity of analyzed phytochemicals can induce an anti-cancer effect on ALL cells without a significant effect on non-tumor cells. It implies that the application of the combinations of phytochemicals an anti-cancer treatment supplement could be worth further investigation regardless of their low bioavailability.

Preparation, Characterization, Solubility, and Antioxidant Capacity of Ellagic Acid-Urea Complex

Ellagic acid (EA), a natural polyphenol found in berries, has high antioxidant capacity. This study aimed to improve EA solubility by complex formation with urea (UR) using solvent evaporation method and evaluate its solubility, antioxidant capacity, and physical properties. The solubility test (25 °C, 72 h) showed that the solubility of EVP (EA/UR = 1/1) was approximately two-fold higher than that of EA (7.13 µg/mL versus 3.99 µg/mL). Moreover, the IC₅₀ values of EA and EVP (EA/UR = 1/1) (1.50 µg/mL and 1.30 µg/mL, respectively) showed higher antioxidant capacity of EVP than that of EA. DSC analysis revealed that the UR peak at 134 °C disappeared, and a new endothermic peak was observed at approximately 250 °C for EVP (EA/UR = 1/1). PXRD measurements showed that the characteristic peaks of EA at 2θ = 12.0° and 28.0° and of UR at 2θ = 22.0°, 24.3°, and 29.1° disappeared and that new peaks were identified at 2θ = 10.6°, 18.7°, and 26.8° for EVP (EA/UR = 1/1). According to 2D NOESY NMR spectroscopy, cross-peaks were observed between the -NH and -OH groups, suggesting intermolecular interactions between EA and UR. Therefore, complexation was confirmed in EA/UR = 1/1 prepared by solvent evaporation, suggesting that it contributed to the improvement in solubility and antioxidant capacity of EA.

Characterization of Quercetin Derivatives in Crossing Combination of Habanero White and Capsicum annuum Peppers and of Anti-Inflammatory and Cytotoxic Activity

The overproduction of reactive oxygen species and the exposure of the human body to free radicals contribute to the aetiology of many chronic health problems, such as cardiovascular disease and cancer. Supplementation with natural antioxidants could be helpful, preventing free-radical-induced tissue damage through the inhibition of the radicals’ formation. Quercetin derivatives have recently been shown to inhibit the production of inflammatory mediators and to reduce the proliferation of tumoral cells, thus being valid compounds to be promoted as dietary supplements. In this work, an HPLC-MS/MS investigation on the derivatives of quercetin in a methanolic extract of peppers deriving from an original crossing combination between Habanero white and Capsicum annuum revealed the occurrence of nine glycoconjugates, either monosaccharide, disaccharide or trisaccharide, as well as an acylated disaccharidic derivative (i.e., quercetin rhamnoside-(feruloyl-hexoside)). Due to the great variability in the quercetin derivatives’ profiles, the Habanero white hybrid pepper extract was subjected to in vitro cytotoxicity assays. The pepper extract under study was proved to have anti-inflammatory activity comparable to that shown by a Capsicum annuum pepper extract since it reduced ROS levels compared to activated cells. Due to its beneficial effects, it could be exploited as a natural constituent of nutraceutical formulations.

Molecular Action of Polyphenols in Leukaemia and Their Therapeutic Potential

Leukaemia is a malignant disease of the blood. Current treatments for leukaemia are associated with serious side-effects. Plant-derived polyphenols have been identified as potent anti-cancer agents and have been shown to work synergistically with standard chemotherapy agents in leukaemia cell lines. Polyphenols have multiple mechanisms of action and have been reported to decrease cell proliferation, arrest cell cycle and induce apoptosis via the activation of caspase (3, 8 and 9); the loss of mitochondrial membrane potential and the release of cytochrome c. Polyphenols have been shown to suppress activation of transcription factors, including NF-kB and STAT3. Furthermore, polyphenols have pro-oxidant properties, with increasing evidence that polyphenols inhibit the antioxidant activity of glutathione, causing oxidative DNA damage. Polyphenols also induce autophagy-driven cancer cell death and regulate multidrug resistance proteins, and thus may be able to reverse resistance to chemotherapy agents. This review examines the molecular mechanism of action of polyphenols and discusses their potential therapeutic targets. Here, we discuss the pharmacological properties of polyphenols, including their anti-inflammatory, antioxidant, anti-proliferative, and anti-tumour activities, and suggest that polyphenols are potent natural agents that can be useful therapeutically; and discuss why data on bioavailability, toxicity and metabolism are essential to evaluate their clinical use.

Amalgamation of quercetin with anastrozole and capecitabine: A novel combination to treat breast and colon cancers – An in vitro study

Context

Globally, cancer stands as the principle cause of mortality and immediate attention on its treatment options is required. Natural compounds stay at first priority in encountering novel therapeutics without adverse effects.

Aim

The aim of the study is to extract flavonol quercetin from leafy vegetables of Anethum graveolens L. and Raphanus sativus L. and find out its potential in combination with drugs used for chemotherapy to reduce the adverse effects of drugs.

Settings and Design

Observational study.

Materials And Methods

Column chromatography is used for quercetin extraction and anticancer activity of quercetin + anastrozole and quercetin + capecitabine were determined by (4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay (MTT), apoptosis assay, cell cycle analysis, mitochondrial membrane potential, and caspase 3 expression.

Statistical Analysis Used

Cytotoxic assay results were assessed by mean, standard deviation and ANOVA; and results were compared for determining its significance.

Results

The results noted that quercetin at very less concentration (16 and 31 μg/ml on Michigan Cancer Foundation-7 and 43 and 46 μg/ml on COLO 320) in combination with anastrozole and capecitabine was able to control the growth of cells, increase cell death, arrest cell cycle, and induce mitochondrial depolarization and expression of caspase 3.

Conclusions

The natural compound used in the present study is effective in treating breast and colon cancer at minimal concentrations in combination with the drugs. This combinational treatment appears to be reported for the first time in the present study.

Natural Health Products (NHP's) and Natural Compounds as Therapeutic Agents for the Treatment of Cancer; Mechanisms of Anti-Cancer Activity of Natural Compounds and Overall Trends

Most cancer therapeutics, such as tubulin-targeting chemotherapy drugs, cause cytotoxic, non-selective effects. These harmful side-effects drastically reduce the cancer patient's quality of life. Recently, researchers have focused their efforts on studying natural health products (NHP's) which have demonstrated the ability to selectively target cancer cells in cellular and animal models. However, the major hurdle of clinical validation remains. NHP's warrant further clinical investigation as a therapeutic option since they exhibit low toxicity, while retaining a selective effect. Additionally, they can sensitize cancerous cells to chemotherapy, which enhances the efficacy of chemotherapeutic drugs, indicating that they can be utilized as supplemental therapy. An additional area for further research is the investigation of drug-drug interactions between NHP's and chemotherapeutics. The objectives of this review are to report the most recent results from the field of anticancer NHP research, and to highlight the most recent advancements in possible supplemental therapeutic options.

Plant Polyphenolic Compounds Potentiates Therapeutic Efficiency of Anticancer Chemotherapeutic Drugs: A Review

BACKGROUND

Scientific research continues to develop more efficacious drugs to treat and cure cancer, the dreadful disease threatening the human race. Chemotherapy is an essential means in cancer therapy, however, plant drugs having pharmacological safety, can be used alone or as additions to current chemotherapeutic agents to enhance therapeutic efficacy and minimize chemotherapyinduced adverse effects.

OBJECTIVE

A combination therapy where the synergistic effect on multiple targets is possible has gained significance because a one-drug one-target approach fails to yield the desired therapeutic effect. Therefore, a detailed description of important plant polyphenolic compounds with anticancer activity and their role in potentiating chemotherapeutic efficiency of existing anticancer drugs is provided in this review. Systematically screening combinations of active pharmaceutical ingredients for potential synergy with plant compounds may be especially valuable in cancer therapy.

METHODS

We extensively have gone through reviews and research articles available in the literature. We made use of databases such as Google Scholar, Research Gate, PubMed, Science Direct, etc. The following keywords were used in our literature search: "Chemotherapy, drug development, cancer drugs, plant-derived polyphenolics, synergistic studies, combination therapy, diagnosis and genetics."

CONCLUSION

Systematic research studies on screening combinations of plant phytochemicals with potential chemotherapeutic pharmaceuticals shed light on their synergistic effects, mechanisms of actions paving the way to develop more efficient anticancer therapeutics to treat and cure the cancer menace, to nullify chemotherapy-induced adverse effects and our review substantially contributes in this direction.

Chemopreventive Properties of Extracts Obtained from Blueberry (Vaccinium myrtillus L.) and Jabuticaba (Myrciaria cauliflora Berg.) in Combination with Probiotics

The association of probiotics and fruit extracts may influence the chemopreventive effect of colorectal cancer. In this context, antiproliferative activity was evaluated to select the best extracts that would be added probiotics, after addition of Bifidobacterium or Lactobacillus in the extracts the antiradical and antioxidant activity, quinone reductase (QR) assay and apoptosis assay were evaluated. Four extracts were isolated: E1: rich in total phenolic compounds; E2: rich in water-soluble phenolic compounds; E3: rich in most apolar phenolic compounds and E4: rich in anthocyanins. The antiproliferative results showed that the best extracts for blueberry and jabuticaba were, respectively the extract E4 and E2. After addition of the probiotic bacteria in these best extracts, it was observed that E2 from jabuticaba presented significantly higher antiradical and antioxidant activity values compared to E4 from blueberry before and after addition of probiotics. There was also a 9-fold increase in activity of QR by the E2 from jabuticaba with Lactobacillus (JL). Likewise, this same extract showed a significant increase both in apoptotic and necrotic cells for both cells. In conclusion, extract rich in water-soluble phenolic compounds (E2) from jabuticaba presented a greater chemopreventive effect compared to the others.

Antiproliferative effects of combinational therapy of Lycopodium clavatum and quercetin in colon cancer cells

Background Colorectal cancer (CRC) is the third most prevalent form of cancer and fourth leading cause of morbidity worldwide. Surgical resection remains the only curative approach for CRC, but recurrence following surgery is the main problem and ultimate cause of death. Lycopodium clavatum and quercetin have been found to exert its anticancer properties. The aim of the present study is to investigate whether quercetin or L. clavatum extract and combination of both have any profound role in reducing major inflammatory cytokines in Colo-320 cells. Methods L. clavatum and Quercetin alone or in combination was administered to colon cancer cells and various toxicity markers, gene expression analyses of apototic genes and gelatin zymmography were performed. Results Quercetin (50 μm) in combination with L. clavatum extract (10 μL) distinctly reduced cell growth and highlighted their potential effects in extirpation of colon cancer cells. Treatment with increased dose of L. clavatum extract in combination with quercetin reduced the colony size and proliferation potential when compared to the sole treatment of plant extracts. In the antimicrobial assays, it was observed that Lycopodium alone exhibited antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa. Characterization of L. clavatum extract and quercetin was performed and confirmed the presence of flavonoids and alkaloids. Treatment with Lycopodium and quercetin combination induced significant down-regulation in activities of MMP2 and MMP9 tested by gelatin zymography. The combined treatment greatly affected the mRNA expression of p53, Bcl2, Bax, Caspase 3, Wnt 1, Cyclin D1, and Catalase genes in colon cancer cells. Conclusion The synergistic effect between Lycopodium and quercetin might bring forward the enhanced antitumorigenic properties of combinational therapy with natural products to successfully combat the cancer progression with minimal side effects and resistance to drugs.

Optimization of Eugenia punicifolia (Kunth) D. C. leaf extraction using a simplex centroid design focused on extracting phenolics with antioxidant and antiproliferative activities

Eugenia punicifolia (Kunth) D. C. (Myrtaceae) has been showing interesting biological activities in the literature which was correlated to its phenolic compounds. In the sense of a better recovering of phenolics with the best antioxidant and antiproliferative activities, an extraction, based on multivariate analytical approach, was developed from E. punicifolia leaves. The different extractor solvents (ethanol, methanol and water) and their binary and ternary combinations were evaluated using a simplex-centroid mixture design and surface response methodology. The optimized crude extracts were investigated for phenol and flavonoid content and compared to their antioxidant (EC₅₀) and antiproliferative properties against HEp-2 (cell line derived from the oropharyngeal carcinoma) and mononuclear viability cells. Ethanolic extracts showed the best phenolic content with the highest antioxidant activity and moderated activity antiproliferative to HEp-2. ESI-QTOF–MS revealed the presence of quercetin and myricetin derivatives, which was correlated to activities tested. Then, simplex-centroid design allowed us to correlate the Eugenia punicifolia biological activities with the extracts obtained from solvent different polarity mixtures.

Efficient synergistic combination effect of Quercetin with Curcumin on breast cancer cell apoptosis through their loading into Apo ferritin cavity

Combination of natural agents has received a great attention in cancer treatment because of synergistically increased apoptotic effect on cancer cell lines by triggering several apoptotic signaling pathways. However, the hydrophobic nature, poor bioavailability and low cellular uptake of most natural agents limit their therapeutic effectiveness. The purpose of this study was to design Apoferritin nanoparticles loaded with Quercetin and Curcumin (Que-Cur-HoS-Apo NPs) and to test their synergistic antitumor properties on a breast cancer cell line (MCF7). The physico-chemical characterization of the Que-Cur-HoS-Apo NPs by Size Exclusion Chromatography (FPLC) and Dynamic Light Scattering (DLS) confirmed the encapsulation of the compounds in the protein cage with narrow size distribution in the range 17.4 ± 1.2 nm. Cell viability study indicated that Que-Cur-HoS-Apo NPs were able to exert a more pronounced effect at lower dose on the MCF7 cell line when compared to the free combination of the drugs. The Que-Cur-HoS-Apo system allowed cellular uptake of natural agents thus triggering enhanced apoptosis. These effects were confirmed by Annexin-V/7-AAD Staining Assay and intracellular Reactive Oxygen Species (ROS) quantitative detection. These results suggest the potential of Que-Cur-HoS-Apo NPs as a promising anti-cancer agent in breast cancer therapy and pave the way to examine Que-Cur-HoS-Apo NPs effect in vivo.

Targeting hallmarks of cancer with a food-system-based approach

Although extensive resources are dedicated to the development and study of cancer drugs, the cancer burden is expected to rise by about 70% over the next 2 decade. This highlights a critical need to develop effective, evidence-based strategies for countering the global rise in cancer incidence. Except in high-risk populations, cancer drugs are not generally suitable for use in cancer prevention owing to potential side effects and substantial monetary costs (Sporn, 2011). There is overwhelming epidemiological and experimental evidence that the dietary bioactive compounds found in whole plant-based foods have significant anticancer and chemopreventative properties. These bioactive compounds often exert pleiotropic effects and act synergistically to simultaneously target multiple pathways of cancer. Common bioactive compounds in fruits and vegetables include carotenoids, glucosinolates, and polyphenols. These compounds have been shown to target multiple hallmarks of cancer in vitro and in vivo and potentially to address the diversity and heterogeneity of certain cancers. Although many studies have been conducted over the past 30 y, the scientific community has still not reached a consensus on exactly how the benefit of bioactive compounds in fruits and vegetables can be best harnessed to help reduce the risk for cancer. Different stages of the food processing system, from "farm-to-fork," can affect the retention of bioactive compounds and thus the chemopreventative properties of whole foods, and there are opportunities to improve handling of foods throughout the stages in order to best retain their chemopreventative properties. Potential target stages include, but are not limited to, pre- and postharvest management, storage, processing, and consumer practices. Therefore, there is a need for a comprehensive food-system-based approach that not only taking into account the effects of the food system on anticancer activity of whole foods, but also exploring solutions for consumers, policymakers, processors, and producers. Improved knowledge about this area of the food system can help us adjust farm-to-fork operations in order to consistently and predictably deliver desired bioactive compounds, thus better utilizing them as invaluable chemopreventative tools in the fight to reduce the growing burden of cancer worldwide.

Both the mono- and di-anions of ellagic acid are effective inhibitors of the serine β-lactamase CTX-M-15

Ellagic acid, a δ-lactone with ionisable phenolic residues, is an efficient time-dependent inhibitor of the serine β-lactamase enzyme CTX-M-15. The pH-dependence of the rate of inhibition shows that both the mono- and di-anionic species of ellagic acid are effective inhibitors, both with second order rate constants of ∼1.5 × 104 M-1 s-1. The structurally similar δ-lactone urolithin A, which lacks the geometrically appropriate phenolic residue, shows only modest inhibitory activity against CTX-M-15. It is proposed that this inhibition by ellagic acid anions involves acylation of the active site serine and that the negative charge on the inhibitor is required for binding to the active site.

An integrated approach for the valorization of mango seed kernel: Efficient extraction solvent selection, phytochemical profiling and antiproliferative activity assessment

A novel valorization strategy is proposed in this work for the sustainable utilization of a major mango processing waste (i.e. mango seed kernel, MSK), integrating green pressurized-liquid extraction (PLE), bioactive assays and comprehensive HRMS-based phytochemical characterization to obtain bioactive-rich fractions with high antioxidant capacity and antiproliferative activity against human colon cancer cells. Thus, a two steps PLE procedure was proposed to recover first the non-polar fraction (fatty acids and lipids) and second the polar fraction (polyphenols). Efficient selection of the most suitable solvent for the second PLE step (ethanol/ethyl acetate mixture) was based on the Hansen solubility parameters (HSP) approach. A comprehensive GC- and LC-Q-TOF-MS/MS profiling analysis allowed the complete characterization of the lipidic and phenolic fractions obtained under optimal condition (100% EtOH at 150 °C), demonstrating the abundance of oleic and stearic acids, as well as bioactive xanthones, phenolic acids, flavonoids, gallate derivatives and gallotannins. The obtained MSK-extract exhibited higher antiproliferative activity against human colon adenocarcinoma cell line HT-29 compared to traditional extraction procedures described in literature for MSK utilization (e.g. Soxhlet), demonstrating the great potential of the proposed valorization strategy as a valuable opportunity for mango processing industry to deliver a value-added product to the market with health promoting properties.

Aonla phytochemicals: extraction, identification and quantification

Methanolic, ethanolic and ethyl acetate extracts of five aonla varieties were analyzed for phytochemical characterization using RP-HPLC. Five compounds viz. ascorbic acid, gallic acid, ellagic acid, ethyl gallate and quercetin were identified in aonla extracts by RP-HPLC at 270 nm. Significant variations were observed in amount of identified phytochemical among the varieties. The highest level of phytochemical was observed in methanolic extract of variety Desi followed by varieties Kanchan, NA-7, Banarasi and Chakaiya. Among the solvent, methanol extracted the maximum phytochemicals while yield was least in ethyl acetate extract of aonla varieties. Gallic acid and ellagic acid were the most abundant phenolic compounds in extracts of aonla varieties. Ellagic acid (349.51 mg/100 g) and gallic acid (233.49 mg/100 g) were found maximum in methanolic extract of Desi variety. Results of the present study suggested that aonla is a good source of phenolic and flavonoid compounds.

Flavonoids in Cancer and Apoptosis

Cancer is the second leading cause of death globally. Although, there are many different approaches to cancer treatment, they are often painful due to adverse side effects and are sometimes ineffective due to increasing resistance to classical anti-cancer drugs or radiation therapy. Targeting delayed/inhibited apoptosis is a major approach in cancer treatment and a highly active area of research. Plant derived natural compounds are of major interest due to their high bioavailability, safety, minimal side effects and, most importantly, cost effectiveness. Flavonoids have gained importance as anti-cancer agents and have shown great potential as cytotoxic anti-cancer agents promoting apoptosis in cancer cells. In this review, a summary of flavonoids and their effectiveness in cancer treatment targeting apoptosis has been discussed.

Phenolic Profiles, Antioxidant and Antimicrobial Activities of Pawpaw Pulp (Asimina triloba [L.] Dunal) at Different Ripening Stages

In this study, the phenolic components, as well as the antioxidant and antimicrobial activities, of the ripe and unripe fruit of pawpaw (Asimina triloba [L.] Dunal) extracted using five different solvents (distilled water, 95% methanol, 80% methanol, 95% ethanol, and 80% ethanol) were analyzed. The total phenolic content and total flavonoid content were the highest in the 95% ethanol (149.50 mg CAE/g) and 80% ethanol (5.62 mg RE/g) extracts of the unripe fruit, respectively. Analysis of 17 phenolic compounds in pawpaw extracts revealed that epigallocatechin, epicatechin, and p-coumaric acid were the as major compounds, and the amounts of all components significantly decreased with the ripening (P < 0.05). In all antioxidant assays, the 95% ethanol extract of the unripe fruit showed the highest antioxidant activity (EC₅₀ 0.22 to 0.93 mg/mL). The pawpaw extracts were more sensitive against Corynebacterium xerosis and Clostridium perfringens. In particular, the 95% ethanol extract of the ripe fruit notably inhibited C. xerosis growth, with minimum inhibitory concentration of 1.56 mg/mL. These results showed that the unripe fruit of pawpaw has abundant phenolic compounds and superior antioxidant activity, and that the 95% ethanol extract of the ripe fruit shows strong inhibitory activity against various microorganisms. Therefore, pawpaw fruit can be utilized as an attractive source of nutrients and therapeutic agents. PRACTICAL APPLICATION: In this study, we identified that the unripe fruit of pawpaw is rich in phenolic compounds and shows strong antioxidant activities. The 95% ethanol extract of the ripe fruit showed strong high inhibitory effect against various microorganisms. These results suggest that pawpaw fruit can serve as a source of antioxidants and delay the aging process. In addition, the fruit could also potentially be utilized as a potential antimicrobial agent.

Evaluation of Antioxidant Properties, Phenolic Compounds, Anthelmintic, and Cytotoxic Activities of Various Extracts Isolated from Nepeta cadmea: An Endemic Plant for Turkey

Nepeta cadmea Boiss. is a species endemic to Turkey that belongs to the Nepeta genus. Several species of this genus are used in folk medicine. This study was designed to investigate the phenolic compounds, antioxidant, anthelmintic, and cytotoxic activities of various extracts (ethanol, methanol, acetone, and water) of N. cadmea. The antioxidant activities of these extracts were analyzed using scavenging methods (DPPH, ABTS, and H₂ O₂ scavenging activity), the β-carotene/linoleic acid test system, the phosphomolybdenum method, and metal chelating activity. Among the 4 different extracts of N. cadmea that were evaluated, the water extract showed the highest amount of radical scavenging (DPPH, 25.54 μg/mL and ABTS, 14.51 μg/mL) and antioxidant activities (β-carotene, 86.91%). In the metal chelating and H₂ O₂ scavenging activities, the acetone extract was statistically different from the other extracts. For the phosphomolybdenum method, the antioxidant capacity of the extracts was in the range of 8.15 to 80.40 μg/mg. The phenolic content of the ethanol extract was examined using HPLC and determined some phenolics: epicatechin, chlorogenic, and caffeic acids. With regard to the anthelmintic properties, dose-dependent activity was observed in each of the extracts of N. cadmea. All the extracts exhibited high cytotoxic activities. The results will provide additional information for further studies on the biological activities of N. cadmea, while also helping us to understand the importance of this species. Furthermore, based on the results obtained, N. cadmea may be considered as a potentially useful supplement for the human diet, as well as a natural antioxidant for medicinal applications.

PRACTICAL APPLICATION

The plants of the Nepeta genus have been extensively used as traditional herbal medicines. Nepeta cadmea Boiss., one of the species belonging to the Nepeta genus, is a species endemic to Turkey. In our study, we demonstrated the antioxidant capacities, total phenolic, flavonoid, tannin content, anthelmintic, and cytotoxic activities of various extracts of Nepeta cadmea. The present study could well supply valuable data for future investigations and further information on the potential use of this endemic plant for humans, in both dietary and pharmacological applications.

Cytotoxic activity of halogenated sesquiterpenes from Laurencia dendroidea

Red algae of the genus Laurencia J. V. Lamouroux are found in tropical and subtropical regions throughout the world and are an extremely rich source of active secondary metabolites with diverse structural features. In the present study, 6 sesquiterpenes (obtusol, (-)-elatol, dendoidiol, debrome-elatol, triquinane, and obtusane) isolated from Laurencia dendroidea were investigated for their cytotoxicity, using 4 cancer cell lines (U937, Jurkat, B16F10, and Colo-205). Among all sesquiterpenes tested, obtusol and (-)-elatol showed a promising activity in the treatment of Colo-205 strain, with IC₅₀ of 1.2 ± 1.4 and 2.5 ± 1.3 μg/ml, respectively. In addition, fluorescence microscopy results indicated that, at 100 μg/ml, obtusol induced apoptosis at 79% and (-)-elatol at 95%. Activation of Caspases 2, 4, 6, and 8 showed to be involved in (-)-elatol activity and only Caspase 6 in obtusol activity. These data demonstrated the effective apoptosis-inducing activity of the sesquiterpene (-)-elatol and obtusol in the treatment of Colo-205 strain. Therefore, more studies should be done so that the sesquiterpenes (-)-elatol and obtusol might become promising chemotherapy.

Resveratrol Potently Counteracts Quercetin Starvation-Induced Autophagy and Sensitizes HepG2 Cancer Cells to Apoptosis

SCOPE

Resveratrol (RSV) has been described as a potent antioxidant, antisteatotic, and antitumor compound, and it has also been identified as a potent autophagy inducer. On the other hand, quercetin (QCT) is a dietary flavonoid with known antitumor, anti-inflammatory, and antidiabetic effects. Additionally, QCT increases autophagy. To study the hypothetical synergistic effect of both compounds, we test the combined effect of QCT and RSV on the autophagy process in HepG2 cells.

METHODS AND RESULTS

Autophagy is studied by western blotting, real-time RT-PCR, and cellular staining. Our results clearly indicate a bifunctional molecular effect of RSV. Both polyphenols are individually able to promote autophagy. Strikingly, when RSV is combined with QCT, it promotes a potent reduction of QCT-induced autophagy and influences proapoptotic signaling.

CONCLUSION

RSV acts differentially on the autophagic process depending on the cellular energetic state. We further characterize the molecular mechanisms related to this effect, and we observe that AMP-activated protein kinase (AMPK) phosphorylation, heme oxygenase 1 (HO-1) downregulation, lysosomal membrane permeabilization (LMP), and Zinc (Zn²⁺ ) dynamics could be important modulators of such RSV-related effects and could globally represent a promising strategy to sensitize cancer cells to QCT treatment.

Synergistic Induction of Apoptosis by Quercetin and Curcumin in Chronic Myeloid Leukemia (K562) Cells

Chronic myeloid leukemia is a major hematopoietic malignancy characterized by expansion of myeloid cells. In this study, we have investigated whether quercetin, curcumin and their combination induce apoptosis and inhibit growth of K562 cells. We have observed that quercetin and curcumin combination induced apoptosis accompanied by increased ROS and decreased GSH levels as well as loss of mitochondrial membrane potential. Our mRNA and protein expression results suggested that cytochrome c was released from mitochondria causing PARP and caspase-9 cleavages, the hallmarks of mitochondrial apoptotic pathway. We believe that triggering of apoptosis is mostly via mitochondrial pathway and ROS generation may induce impairment of mitochondrial membrane potential. The use of quercetin and curcumin combination potentiates individual apoptotic effects of the polyphenols and reduces their effective dose thereby preventing potential toxic effects on normal cells. Additional preclinical studies and clinical trials are certainly required to further validate their usefulness as potent anticancer agents.

CS-PEG decorated PLGA nano-prototype for delivery of bioactive compounds: A novel approach for induction of apoptosis in HepG2 cell line

PURPOSE

Polymer-based nanoparticles are used as vectors for cancer drug delivery. The bioactive compounds (quercetin, ellagic acid and gallic acid) are well known to be not only antioxidants but also chemopreventive candidates against various types of cancers. To circumvent the low bioavailability and the short half-life time obstacles, we hypothesized a novel PLGA nano-platform functionalized with CS and PEG to encapsulate these phytochemicals. This encapsulation will protect the compounds from the phagocytic uptake and deliver PLGA-CS-PEG nano-prototype with high biodegradability and biosafety.

MATERIALS AND METHODS

Three consequent types of PLGA-based nanocomposites were prepared and characterized. Furthermore, we investigated the newly synthesized nano-formulations against human hepatocellular carcinoma (HepG2) and colorectal cancer (HCT 116) cell lines using cell growth inhibition assays, followed by apoptosis and necrosis assays using flow cytometry to detect the underlying mechanism of HepG2 cell death.

RESULTS

Through Malvern Zeta Sizer, we recorded that the average diameters of the nano-prototypes ranged from 150 to 300nm. The cytotoxic activity of quercetin, ellagic acid, and gallic acid-encapsulated PLGA, PLGA-CS, and PLGA-CS-PEG nano-prototypes it has been found that they reduce the IC50s of the HepG2 cells values by 2.2, 2.9, 2.8-folds, 1, 1.5, 2.7-folds, and 0.9, 0.7, 1.5-folds, respectively. Mechanistically, the nano-platforms of quercetin seem to be dependent on both apoptosis and necrosis, while those of ellagic acid and gallic acid are mainly dependent on apoptosis.

CONCLUSIONS

CS-PEG-blended PLGA nano-delivery system of quercetin, ellagic acid and gallic acid can potentiate apoptosis-mediated cell death in HepG2 cell line.

Nanostructured lipid carriers employing polyphenols as promising anticancer agents: Quality by design (QbD) approach

Cancer is one of the leading causes of death worldwide. There are several hurdles in cancer therapy because of side-effects which limits its usage. Nanoparticulate drug delivery systems have been tested against cancer in a range of scientific studies. In the recent years, advanced research on Nanostructured Lipid Carriers (NLCs) has garnered considerable attention owing to the advantages over their first-generation counterparts, Solid Lipid Nanoparticles (SLN). NLCs facilitate efficient loading of poorly water soluble drugs with simple methods of drug loading. Recently, there is an increased interest in polyphenols because of the evidence of their promising role in prevention of cancer. Polyphenols are produced as secondary metabolites by plants. Their role in prevention of development of tumors through variety of mechanisms and reduction of tumor cell mass has been reported. This article aims to review the science behind development of NLCs and role of polyphenols as promising anticancer agents. Principles of Quality by Design (QbD) have also been explained which are used in formulation-development of many nanoparticles, including NLCs, as reported in literature.

Antiproliferative activity in tumor cell lines, antioxidant capacity and total phenolic, flavonoid and tannin contents of Myrciaria floribunda

Myrciaria floribunda (H. West ex Willd.) O. Berg, Myrtaceae, is a native plant species of the Atlantic Rain Forest, from north to south of Brazil. The lyophilized ethyl acetate extract from the leaves of M. floribunda was investigated for its antiproliferative activity in tumor cell lines, antioxidant capacity and its total phenolic, flavonoid and tannin contents. Antiproliferative activity was tested in vitro against seven human cancer cells and against immortalized human skin keratinocytes line (HaCat, no cancer cell). Antioxidant activity was determined using 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbing capacity (ORAC) assays and total phenolic, flavonoid and tannin contents were determined by spectrophotometric techniques. Ethyl acetate extract of M. floribunda exhibited antiproliferative activity against cancer cell lines with total growth inhibition (TGI) between 69.70 and 172.10 µg/mL. For HaCat cell, TGI value was 213.60 µg/mL. M. floribunda showed a strong antioxidant potential: EC50 of 45.89±0.42 µg/mL and 0.55±0.05 mmol TE/g for DPPH and ORAC, respectively. Total phenolic content was 0.23±0.013g gallic acid equivalents (GAE)/g extract and exhibited 13.10±1.60% of tannins content. The content of flavonoid was 24.08±0.44% expressed as rutin equivalents. These results provide a direction for further researches about the antitumoral potential of M. floribunda.

Representative literature on the phytonutrients category: Phenolic acids

Research concerning the benefits derived from dietary polyphenols, a significant class within the family of phytonutrients, has increased considerably in the last decade. Prior to the late 1990s, the nutritional spotlight focused on the antioxidant capabilities of carotenoids, vitamins, and minerals. More recently, however, research has emerged in strong support of the antioxidant capacity of polyphenols and their role in the prevention and/or treatment of certain cancers, diabetes, cardiovascular diseases, and inflammation. Polyphenols are categorized according to the nature of their carbon skeleton, ranging from basic phenolic molecules to highly complex compounds, such as flavonoids, the most common and widely studied of all phenolic compounds. The most prevalent phenolic acids include ellagic acid, gallic acid, tannic acid, and capsaicin.

Ellagic acid alleviates adjuvant induced arthritis by modulation of pro- and anti-inflammatory cytokines

Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown aetiology, but it is now clear that pro-inflammatory cytokines play a central role in its pathogenesis. Ellagic acid (EA) has a variety of biological activities including anti-oxidant, anti-inflammatory, and anti-cancer properties. The aim of the present study was to evaluate the potential effect of ellagic acid on the prevention and/or treatment of adjuvant induced arthritis (AIA) model in mice. Ellagic acid treatment was started one week before AIA induction and continued for three weeks after induction of AIA. Ellagic acid treatment significantly (p < 0.01) inhibited foot paw oedematous swelling and attenuated AIA-associated pathology. Ellagic acid significantly (p < 0.01) reduced serum levels of pro-inflammatory cytokines: interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), and interleukin 17 (IL-17). However, serum levels of IL-10 and interferon γ (IFN-γ) significantly increased (p < 0.01 and p < 0.05, respectively), while serum level of transforming growth factor β (TGF-β) did not significantly alter with EA treatment. In conclusion, these results suggest that EA attenuated AIA-associated pathology in the mouse model by downregulation of pro-inflammatory cytokines and upregulation of anti-inflammatory cytokines.

Transformed Root Extract of Leonurus sibiricus Induces Apoptosis through Intrinsic and Extrinsic Pathways in Various Grades of Human Glioma Cells

This study determines the influence of transformed root (TR) extract of Leonurus sibiricus L. on various grades (I-III) of human glioma cells derived from patients. This plant occurs in southern Asia and Siberia and is widely used as a medicinal plant with various biological activities. Chromatographic profile of TR extract have revealed the presence of various polyphenolic compounds (4-hydroxybenzoic acid, gentisic acid, vanilic acid, 1,3-dicaffeoylquinic acid, α-resorcylic acid). We found TR root extract to have antiproliferative activity on glioma cells after 24 h of treatment. TR root extract induces apoptosis on various grades (I-III) of human glioma cells by the generation of reactive oxygen species (ROS) along with concurrent loss of mitochondrial membrane potential, enhanced S and G2/M phases of the cell cycle, and altered mRNA levels of Bax, Bcl-2, p53, Cas-3, Cas-8 and Cas-9 factors involved in apoptosis. This work for the first time demonstrate that TR extract from L. sibiricus root has the potential to activate apoptosis in grade I-III human glioma cells through the intrinsic and extrinsic pathways.

Established Human Cell Lines as Models to Study Anti-leukemic Effects of Flavonoids

Despite the extensive work on pathological mechanisms and some recent advances in the treatment of different hematological malignancies, leukemia continues to present a significant challenge being frequently considered as incurable disease. Therefore, the development of novel therapeutic agents with high efficacy and low toxicity is urgently needed to improve the overall survival rate of patients. In this comprehensive review article, the current knowledge about the anticancer activities of flavonoids as plant secondary polyphenolic metabolites in the most commonly used human established leukemia cell lines (HL-60, NB4, KG1a, U937, THP-1, K562, Jurkat, CCRF- CEM, MOLT-3, and MOLT-4) is compiled, revealing clear anti-proliferative, pro-apoptotic, cell cycle arresting, and differentiation inducing effects for certain compounds. Considering the low toxicity of these substances in normal blood cells, the presented data show a great potential of flavonoids to be developed into novel anti-leukemia agents applicable also in the malignant cells resistant to the current conventional chemotherapeutic drugs.

Specificity of Hydrolysable Tannins from Rhus typhina L. to Oxidants in Cell and Cell-Free Models

Polyphenols of plant origin with wide range of antiradical activity can prevent diseases caused by oxidative and inflammatory processes. In this study, we show using ESR method that the purified water-soluble extract from leaves of Rhus typhina L. containing hydrolysable tannins and its main component, 3,6-bis-O-di-O-galloyl-1,2,4-tri-O-galloyl-β-D-glucose (C₅₅H₄₀O₃₄), displayed a strong antiradical activity against the synthetic 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) in homogenous (solution) and heterogeneous systems (suspension of DPPH containing liposomes) in the range of 1-10 μg/ml. The C₅₅H₄₀O₃₄ and extract at 1-30 μg/ml also efficiently, but to a various degree, decreased reactive oxygen and nitrogen species (RONS) formation induced in erythrocytes by oxidants, following the sequence: tert-butyl hydroperoxide (tBuOOH) > peroxynitrite (ONOO^-) >hypochlorous acid (HClO). The explanation of these differences should be seen in the specificity of scavenging different RONS types. These relationships can be represented for C₅₅H₄₀O₃₄ and the extract by the following order of selectivity: O^.-₂ ≥ NO· > ·OH > ¹O₂. The extract exerted a more pronounced antiradical effect in reaction with DPPH and ROS in all models of oxidative stress in erythrocytes in comparison with C₅₅H₄₀O₃₄. The redox processes between the extract components and their specificity in relation to RONS can underlie this effect.

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

Naturally occurring compounds are considered as attractive candidates for cancer treatment and prevention. Quercetin and ellagic acid are naturally occurring flavonoids abundantly seen in several fruits and vegetables. In the present study, we evaluate and compare antitumor efficacies of quercetin and ellagic acid in animal models and cancer cell lines in a comprehensive manner. We found that quercetin induced cytotoxicity in leukemic cells in a dose-dependent manner, while ellagic acid showed only limited toxicity. Besides leukemic cells, quercetin also induced cytotoxicity in breast cancer cells, however, its effect on normal cells was limited or none. Further, quercetin caused S phase arrest during cell cycle progression in tested cancer cells. Quercetin induced tumor regression in mice at a concentration 3-fold lower than ellagic acid. Importantly, administration of quercetin lead to ~5 fold increase in the life span in tumor bearing mice compared to that of untreated controls. Further, we found that quercetin interacts with DNA directly, and could be one of the mechanisms for inducing apoptosis in both, cancer cell lines and tumor tissues by activating the intrinsic pathway. Thus, our data suggests that quercetin can be further explored for its potential to be used in cancer therapeutics and combination therapy.

Combination chemoprevention with grape antioxidants

Antioxidant ingredients present in grape have been extensively investigated for their cancer chemopreventive effects. However, much of the work has been done on individual ingredients, especially focusing on resveratrol and quercetin. Phytochemically, whole grape represents a combination of numerous phytonutrients. Limited research has been done on the possible synergistic/additive/antagonistic interactions among the grape constituents. Among these phytochemical constituents of grapes, resveratrol, quercetin, kaempferol, catechin, epicatechin, and anthocyanins (cyanidin and malvidin) constitute more than 70% of the grape polyphenols. Therefore, these have been relatively well studied for their chemopreventive effects against a variety of cancers. While a wealth of information is available individually on cancer chemopreventive/anti-proliferative effects of resveratrol and quercetin, limited information is available regarding the other major constituents of grape. Studies have also suggested that multiple grape antioxidants, when used in combination, alone or with other agents/drugs show synergistic or additive anti-proliferative response. Based on strong rationale emanating from published studies, it seems probable that a combination of multiple grape ingredients alone or together with other agents could impart 'additive synergism' against cancer.

Antioxidant and dual dose-dependent antigenotoxic and genotoxic properties of an ethanol extract of propolis

Propolis is a resinous product made by honeybees from plant-derived materials, with high content of polyphenols associated to beneficial bioactivities with potential use as a natural food additive for preservation and as a functional food ingredient.