Polyphenols are responsible for the proapoptotic properties of pomegranate juice on leukemia cell lines

An insight into the neuroprotective effects and molecular targets of pomegranate (Punica granatum) against Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease that still has no permanent cure. The drugs prescribed in the present days are only for symptomatic relief for the patients. Many studies correlating the reduction in the incidence of AD with the diet consumed have been published. These studies showed that a diet rich in polyphenols is associated with a decrease in the incidence of AD. The present review is focused on the ability of pomegranate and its bioactive components to ameliorate the progression of AD and their ability to exert a neuroprotective effect. Various studies showing the ability of pomegranate in inhibiting enzymes, reducing reactive oxygen species, inhibition of microglial activation, inhibition of tau protein hyperphosphorylation, maintenance of synaptic plasticity, anti-inflammatory activity and its ability to inhibit Beta secretase-1 (BACE-1) has been reviewed in this article. In spite of the lack of studies on humans, there are compelling evidence indicating that pomegranate can reduce various risk factors involved in the causation of AD and thus can be used as a persistent nutraceutical to slow ageing and for providing neuroprotection for the treatment of AD.Highlights An overview of traditional and pharmacological uses of pomegranate (POM).Potential of POM in the treatment of neurodegenerative diseases especially in AD.Insight into the molecular mechanisms of neuroprotective effects of POM in AD.Clinical evaluation studies involving POM and its bioactive components.

Pomegranate Seeds and Peel Ethanolic Extracts Anticancer Potentials and Related Genetic, Histological, Immunohistochemical, Apoptotic and Oxidative Stress Profiles: In vitro Study

Introduction

Owing to their great quantity of hydrolyzable anthocyanins and tannins, the peel and seeds of pomegranate are edible and possess potent anti-oxidant and anti-inflammatory characteristics. This work aims to trace the pomegranate seed and peel ethanolic extracts' anticancer activity against liver cancer cell line, namely HepG2 and related histopathological, immunohistochemical, genetic and oxidative stress profile.

Methods

In vitro study for both seed and peel extract showed the prevalence of phenols, polyphenols and acids, those have anti-proliferative potential against liver cancer cell line (HepG2) with 50% inhibitory concentration (IC50) of seed significantly reduced that of peel. Toxicity of test extracts was concentration dependent and accompanied with cell cycle arrest and cell death at theG0/G1 and S phases but not at the G2/M phase. Cell arrest was supplemented with raised ROS, MDA and decreased SOD, GSH and Catalase.

Results and discussion

Apoptosis-related genes showed significant up-expression of pro-apoptotic gene (P53), Cy-C, Bax, and casp-3 and down expression of anti-apoptotic gene (Bcl-2). Also, Casp-3 and P53 proteins were substantially expressed under the effect of test extracts. Histopathological study demonstrated that the untreated cells (control group) were regular cells with nuclear pleomorphism and hyperchromatic nuclei, while seed and peel extracts-treated cells showed necrosis, mixed euchromatin and heterochromatin, intra-nuclear eosinophilic structures, burst cell membranes, and the shrunken apoptotic cells with nuclear membranes and irregular cells. Finally, PCNA gene detected by immunohistochemistry was down regulated significantly under the effect of seed extract treatment than in case of cell medication with peel extract.

The efficacy of applying some plants and herbs in cancer therapy for humans and animals – a comperhensive review

Cancer is a challenging ailment and represents the main reason for death worldwide for humans and animals. Although great developments have hindered cancer progression, several adverse effects are associated with modern chemotherapy. Natural remedies, such as the usage of medicinal plant or their products in cancer treatment, may decrease prejudicial side properties. Recently, the modern research scheme and innovative screening practices for herbs or plants have enabled phytochemical discovery for the prevention and treatment of cancer. This criticism highlights herbs such as acacia, basil, black seeds, cedar, castus, ficus, garlic, ginger, indigo, onion, pomegranate, quince, and thyme, promising anticancer effects. The present review also revealed the mode of action of each herb as anticancer effects at level in vitro and in vivo studies. The item also totalizes the vital mechanisms and signaling molecules involved in preventing cancer diseases. This will fill the investigate gap in the exploration of using natural molecules and encourage researchers in clinical trials of anticancer agents from herbs for humans and animals.

Possible Beneficial Effects of Fresh Pomegranate Juice in SARS-CoV-2 Infection Conditions

Rather than the prophylactic vaccination, any effective synthetic, natural, or nutritional therapy or regimen that may cure or remedy, albeit partially, the complications of SARS-CoV-2 should be highly acknowledged. Here, we reviewed and discussed possible beneficial biological effects of pomegranate juice in such diseased condition of viral infection based on the current published evidence (direct and indirect) and owing to the robust evidence that fresh pomegranate juice is highly rich with unique bioactive compounds that are approved in various occasions to be effective in several chronic diseased conditions. All related references that serve our aim are accessed through available electronic databases, particularly PubMed and Scopus. In summary, there is accepted evidence that pomegranate juice may be beneficial in SARS-CoV-2 infection conditions, especially for patients with the clinical history of chronic diseases such as hypertension, cardiovascular disease, diabetes, and cancer. However, the interventional studies that directly probe and confirm the effectiveness of fresh pomegranate juice in the management of SARS-CoV-2 infection are mandatory.

Punicalagin, a pomegranate compound, induces apoptosis and autophagy in acute leukemia

Background

Punicalagin is the major phenolic compound found in pomegranate peels. It has several reported medical benefits, including antioxidant, anti-inflammatory, and anticancer properties. The present study investigated the anti-leukemic effects and the molecular mechanism of punicalagin on NB4 and MOLT-4 leukemic cell lines.

Methods

Leukemic cells were treated with punicalagin and cell viability was determined using MTS assay. Apoptosis and autophagy were analyzed by flow cytometry using Annexin V-FITC/PI and anti-LC3/FITC antibodies staining, respectively. Apoptotic and autophagic mRNA expression were determined using reverse transcription-quantitative PCR. STITCH bioinformatics tools were used to predict the interaction between punicalagin and its proposed target proteins.

Results

Results indicated that punicalagin decreased NB4 and MOLT-4 cell viability in a dose-dependent manner. Punicalagin, in combination with daunorubicin, exhibited synergistic cytotoxic effects. Punicalagin induced apoptosis through the upregulation of caspase-3/-8/-9, Bax and the downregulation of Bcl-2 expression. Punicalagin also promoted autophagy via the downregulation of mTOR and the upregulation of ULK1 expression. Cyclooxygenase-2 and toll-like receptor 4 were found to be involved in punicalagin-induced cell death in punicalagin-targeted protein interactions.

Conclusions

These results suggest that punicalagin exerts cytotoxic activities by suppressing proliferation and promoting apoptosis and autophagy by activating the caspase cascade, altering Bax and Bcl-2, and regulating autophagy via mTOR/ULK1 signaling.

Secondary metabolic profiles and anticancer actions from fruit extracts of immature pomegranates

Immature fruits from Punica granatum L. thinning are a neglected side product of pomegranate production with cumbersome disposal costs for farmers. To explore value potential of immature fruits from pomegranate ‘Wonderful’ cultivars, the compositional landscapes and antitumorigenic activities of pomegranate extracts from two different stages of maturation were assessed. Cancer cell proliferation and cytotoxicity was quantified in human lung H1299 and colon HCT116 adenocarcinomas by crystal violet staining, MTS assay and caspase-3 activity. High performance liquid chromatography—diode array detector (HPLC/DAD) and high performance liquid chromatography—electrospray ionization—mass spectrometry (HPLC/ESI-MS) analyses indicate that immature fruits are rich sources of gallotannins and ellagitannins, with the highest amounts contained in immature fruit peels. Biological investigations reveal a robust anticancer activity by those immature P. granatum fruit extracts, which reflected induction of tumor cytotoxicity and cell death mechanisms. Together, present observations suggest P. granatum byproducts from the thinning process may provide unexplored values for virtuous circular economy.

Urolithin A and B Alter Cellular Metabolism and Induce Metabolites Associated with Apoptosis in Leukemic Cells

Leukemia is persistently a significant cause of illness and mortality worldwide. Urolithins, metabolites of ellagic acid and ellagitannins produced by gut microbiota, showed better bioactive compounds liable for the health benefits exerted by ellagic acid and ellagitannins containing pomegranate and walnuts. Here, we assessed the potential antileukemic activities of both urolithin A and urolithin B. Results showed that both urolithin A and B significantly inhibited the proliferation of leukemic cell lines Jurkat and K562, among which urolithin A showed the more prominent antiproliferative capability. Further, urolithin treatment alters leukemic cell metabolism, as evidenced by increased metabolic rate and notable changes in glutamine metabolism, one-carbon metabolism, and lipid metabolism. Next, we evidenced that both urolithins equally promoted apoptosis in leukemic cell lines. Based on these observations, we concluded that both urolithin A and B alter leukemic cell metabolome, resulting in a halt of proliferation, followed by apoptosis. The data can be used for designing new combinational therapies to eradicate leukemic cells.

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.

Characterization of pomegranate peel extracts obtained using different solvents and their effects on cell cycle and apoptosis in leukemia cells

Pomegranate (Punica granatum L.) has been used in traditional herbal medicine by several cultures as an anti-inflammatory, antioxidant, antihyperglycemic, and for treatment and prevention of cancer and other diseases. Different parts of the fruit, extraction methods, and solvents can define the chemical profile of the obtained extracts and their biological activities. This study aimed to characterize the chemical profile of peel extracts collected using different extraction solvents and their biological effects on the cell cycle and apoptosis of THP-1 leukemic cells. Aqueous extract presented the highest content of punicalagins (α pun = 562.26 ± 47.14 mg/L and β pun = 1,251.13 ± 22.21 mg/L) and the lowest content of ellagic acid (66.38 ± 0.21 mg/L), and it promoted a significant impairment of the cell cycle S phase. In fact, punicalagin-enriched fraction, but not an ellagic acid-enriched fraction, caused an S phase cell cycle arrest. All extracts increased the number of apoptotic cells. Punicalagin-enriched fraction increased the percentage of cells with fragmented DNA, which was intensified by ellagic acid combination. The treatment combining punicalagin and ellagic acid fractions increased the apoptotic cleaved PARP1 protein and reduced the activation of the growth-related mTOR pathway. Thus, these results evidence that solvent choice is critical for the phenolic compounds profile of pomegranate peel extracts and their biological activities.

Pomegranate juice as a functional food: a comprehensive review of its polyphenols, therapeutic merits, and recent patents

Pomegranate (Punica granatum) is an ancient perennial plant species of the Punicaceae family and is regarded as the 'miracle fruit' for its seeds being consumed as food, juice and as a functional food. Significant modern pharmacological and clinical evidence has highlighted the wide medicinal applications of pomegranate fruit parts and its juice. Pomegranate juice (PJ) that is superior to other fruit juices is a fortified source of dietary polyphenols with potential antioxidant capacity. Polyphenols of PJ include tannins, anthocyanins, and flavonoids. The presence of these beneficial phytochemicals is directly linked to its favourable health benefits viz., obesity and diabetes management and anti-inflammatory effects. This comprehensive review capitalizes on PJ with emphasis on the interrelationship between its holistic chemical composition, metabolism and biological effects. Moreover, the review recapitulates on the diverse health benefits of PJ and related patents in the field of PJ production to ensure the best produced juice quality.

Quantification of punicalagins in commercial preparations and pomegranate cultivars, by liquid chromatography-mass spectrometry

BACKGROUND

Pomegranate (Punica granatum L.) - a delicious fruit once used in Ayurvedic medicine - is now largely known for the antioxidant properties of its juice, which has also been considered to have health benefits against diseases such as cancer and cardiovascular diseases. These beneficial effects are associated with the fruit's high content of polyphenolic compounds. High demand and lower production levels drive pomegranate prices up, which leads to the possibility of pomegranate products being adulterated, diluted or substituted. To ensure the presence of pomegranate in various preparations labeled as containing pomegranate, a simple method was developed to screen and quantify the specific punicalagins by mass spectrometry.

RESULTS

The present method was used to analyze several pure and mixed beverages from the US market, and also to quantify punicalagins in the juice of 14 pomegranate cultivars. Punicalagins were detected in all cultivars, with higher concentrations in whole fruit juices compared with aril juices. Amongst the 20 commercial beverages, punicalagins were not detected in four preparations.

CONCLUSION

The liquid chromatographic-mass spectrometric method presented herein enables an easy and rapid quantification of the specific punicalagins. The latter was detected in all cultivar samples, thus supporting that punicalagin is a suitable marker of these 14 pomegranate cultivars in commercial juices. Absence of the specific marker in four commercial preparations shows the necessity of having simple and rapid methods to evaluate the presence of pomegranate in preparations. © 2019 Society of Chemical Industry.

Punica granatum (Pomegranate) activity in health promotion and cancer prevention

Cancer has become one of the most fatal diseases in most countries. In spite of the medical care developing, cancer still remains a significant problem. The majority of the cancers are resistant to treatment. Thus, the research for novel, more efficient and less side effect treatment methods continues. Pomegranate contains strong antioxidant activity, with potential health interests. Research concern in pomegranate is increasing because of their anticancer potential due to possess rich in polyphenols. We highlight the pomegranate potential health benefits and mechanism of cancer progression inhibition. Pomegranate has indicated antiproliferative, anti-metastatic and anti-invasive effects on different cancer cell line in vitro, in vivo and clinical trial. The aim of this review is to evaluate functional properties and the medical benifits of pomegranate against various cancer diseases. In addition, pomegranate properties in in vitro and in vivo experimental human and animal clinical trials and its future use are explored. The available data suggest that Punica granatum (pomegranate) might be used in the control and potential therapeutic for some disease conditions and benefits human health status. This review summarizes in vitro, in vivo and clinical trial studies highlighting the pomegranate role in prevent and treatment of breast, prostate, lung, colon, skin and hepatocellular cell cancers.

Ellagitannins from Rubus idaeus L. Exert Geno- and Cytotoxic Effects against Human Colon Adenocarcinoma Cell Line Caco-2

Ellagitannins possess several biological activities, including anticancer properties. The goal of the present study was to investigate the cyto- and genotoxic activities of a red raspberry ellagitannin preparation (REP) in the concentration range of 2.5-160 μg/mL, as well as that of the main individual raspberry ellagitannins, sanguiin H-6 (SH-6, 12.8-256 μM) and lambertianin C (LC, 9.3-378 μM), against human colon adenocarcinoma cell line Caco-2. The ellagitannin concentrations used in the study correspond to those found in foodstuffs containing raspberry fruit. REP, SH-6, and LC exhibited strong concentration-dependent genotoxic properties, inducing DNA damage ranging from 7.3 ± 1.3 to 56.8 ± 4.3%, causing double-strand breaks and oxidation of DNA bases. At IC₅₀ (124 μg/mL) the REP affected the nuclear morphology and induced the apoptosis of Caco-2 cells. Because the REP has been found to possess chemopreventive activity, it can be used as a natural food additive to enhance the health benefits of foodstuffs.

Antiproliferative and Antiangiogenic Effects of Punica granatum Juice (PGJ) in Multiple Myeloma (MM)

Multiple myeloma (MM) is a clonal B-cell malignancy characterized by an accumulation of clonal plasma cells (PC) in the bone marrow (BM) leading to bone destruction and BM failure. Despite recent advances in pharmacological therapy, MM remains a largely incurable pathology. Therefore, novel effective and less toxic agents are urgently necessary. In the last few years, pomegranate has been studied for its potential therapeutic properties including treatment and prevention of cancer. Pomegranate juice (PGJ) contains a number of potential active compounds including organic acids, vitamins, sugars, and phenolic components that are all responsible of the pro-apoptotic effects observed in tumor cell line. The aim of present investigation is to assess the antiproliferative and antiangiogenic potential of the PGJ in human multiple myeloma cell lines. Our data demonstrate the anti-proliferative potential of PGJ in MM cells; its ability to induce G0/G1 cell cycle block and its anti-angiogenic effects. Interestingly, sequential combination of bortezomib/PGJ improved the cytotoxic effect of the proteosome inhibitor. We investigated the effect of PGJ on angiogenesis and cell migration/invasion. Interestingly, we observed an inhibitory effect on the tube formation, microvessel outgrowth aorting ring and decreased cell migration and invasion as showed by wound-healing and transwell assays, respectively. Analysis of angiogenic genes expression in endothelial cells confirmed the anti-angiogenic properties of pomegranate. Therefore, PGJ administration could represent a good tool in order to identify novel therapeutic strategies for MM treatment, exploiting its anti-proliferative and anti-angiogenic effects. Finally, the present research supports the evidence that PGJ could play a key role of a future therapeutic approach for treatment of MM in order to optimize the pharmacological effect of bortezomib, especially as adjuvant after treatment.

Role of dietary bioactive natural products in estrogen receptor-positive breast cancer

Estrogen receptor (ER)-positive breast cancer, including luminal-A and -B, is the most common type of breast cancer. Extended exposure to estrogen is associated with an increased risk of breast cancer. Both ER-dependent and ER-independent mechanisms have been implicated in estrogen-mediated carcinogenesis. The ER-dependent pathway involves cell growth and proliferation triggered by the binding of estrogen to the ER. The ER-independent mechanisms depend on the metabolism of estrogen to generate genotoxic metabolites, free radicals and reactive oxygen species to induce breast cancer. A better understanding of the mechanisms that drive ER-positive breast cancer will help optimize targeted approaches to prevent or treat breast cancer. A growing emphasis is being placed on alternative medicine and dietary approaches toward the prevention and treatment of breast cancer. Many natural products and bioactive compounds found in foods have been shown to inhibit breast carcinogenesis via inhibition of estrogen induced oxidative stress as well as ER signaling. This review summarizes the role of bioactive natural products that are involved in the prevention and treatment of estrogen-related and ER-positive breast cancer.

Effect of different polyphenol sources on the efficiency of ellagic acid release by Aspergillus niger

Fungal hydrolysis of ellagitannins produces hexahydroxydiphenic acid, which is considered an intermediate molecule in ellagic acid release. Ellagic acid has important and desirable beneficial health properties. The aim of this work was to identify the effect of different sources of ellagitannins on the efficiency of ellagic acid release by Aspergillus niger. Three strains of A. niger (GH1, PSH and HT4) were assessed for ellagic acid release from different polyphenol sources: cranberry, creosote bush, and pomegranate used as substrate. Polyurethane foam was used as support for solid-state culture in column reactors. Ellagitannase activity was measured for each of the treatments. Ellagic acid was quantified by high performance liquid chromatography. When pomegranate polyphenols were used, a maximum value of ellagic acid (350.21 mg/g) was reached with A. niger HT4 in solid-state culture. The highest amount of ellagitannase (5176.81 U/l) was obtained at 8h of culture when cranberry polyphenols and strain A. niger PSH were used. Results demonstrated the effect of different polyphenol sources and A. niger strains on ellagic acid release. It was observed that the best source for releasing ellagic acid was pomegranate polyphenols and A. niger HT4 strain, which has the ability to degrade these compounds for obtaining a potent bioactive molecule such as ellagic acid.

Apoptotic effects of non-edible parts of Punica granatum on human multiple myeloma cells

Multiple myeloma is of great concern since existing therapies are unable to cure this clinical condition. Alternative therapeutic approaches are mandatory, and the use of plant extracts is considered interesting. Punica granatum and its derived products were suggested as potential anticancer agents due to the presence of bioactive compounds. Thus, polypenolic-rich extracts of the non-edible parts of P. granatum were investigated for their antiproliferative and apoptotic effects on U266 multiple myeloma cells. We demonstrated that there were dose-dependent decreases in the proliferation of U266 cells in response to P. granatum extracts. Also, exposure to the extracts triggered apoptosis with significant increases in loss of mitochondrial membrane potential in U266 cells exposed to the leaves and stem extracts, while the flower extract resulted in slight increases in loss of MMP. These results were confirmed by Annexin-V analysis. These results documented the cytotoxic and apoptotic effects of P. granatum extracts on human U266 multiple myeloma cells via disruption of mitochondrial membrane potential and increasing cell cycle arrest. The data suggest that the extracts can be envisaged in cancer chemoprevention and call for further exploration into the potential application of these plant parts.

Potential Effects of Pomegranate Polyphenols in Cancer Prevention and Therapy

Cancer is the second leading cause of death and is becoming the leading one in old age. Vegetable and fruit consumption is inversely associated with cancer incidence and mortality. Currently, interest in a number of fruits high in polyphenols has been raised due to their reported chemopreventive and/or chemotherapeutic potential. Pomegranate has been shown to exert anticancer activity, which is generally attributed to its high content of polyphenols. This review provides a comprehensive analysis of known targets and mechanisms along with a critical evaluation of pomegranate polyphenols as future anticancer agents. Pomegranate evokes antiproliferative, anti-invasive, and antimetastatic effects, induces apoptosis through the modulation of Bcl-2 proteins, upregulates p21 and p27, and downregulates cyclin-cdk network. Furthermore, pomegranate blocks the activation of inflammatory pathways including, but not limited to, the NF-κB pathway. The strongest evidence for its anticancer activity comes from studies on prostate cancer. Accordingly, some exploratory clinical studies investigating pomegranate found a trend of efficacy in increasing prostate-specific antigen doubling time in patients with prostate cancer. However, the genotoxicity reported for pomegranate raised certain concerns over its safety and an accurate assessment of the risk/benefit should be performed before suggesting the use of pomegranate or its polyphenols for cancer-related therapeutic purposes.

The effects of herbs and fruits on leukaemia

In developing countries, herbal therapy is the first and basis form of treatment for most types of diseases. About 75-80% of the world's population prefers herbal therapy as a major treatment due to its better adequacy and satisfactoriness, which enhance human body's symmetry with minimal side effects. Fruits and plants have been presented from the past as promising tools in becoming a natural anticancer agents. Many of these plant extracts are currently used in cancer therapy and prevention. This review paper will particularly explore and emphasize on herbs and fruits used in the treatment of the leukaemia.

Differential effects of polyphenols on proliferation and apoptosis in human myeloid and lymphoid leukemia cell lines

BACKGROUND

Mortality rates for leukemia are high despite considerable improvements in treatment. Since polyphenols exert pro-apoptotic effects in solid tumors, our study investigated the effects of polyphenols in haematological malignancies. The effect of eight polyphenols (quercetin, chrysin, apigenin, emodin, aloe-emodin, rhein, cis-stilbene and trans-stilbene) were studied on cell proliferation, cell cycle and apoptosis in four lymphoid and four myeloid leukemic cells lines, together with normal haematopoietic control cells.

METHODS

Cellular proliferation was measured by CellTiter-Glo(®) luminescent assay; and cell cycle arrest was assessed using flow cytometry of propidium iodide stained cells. Apoptosis was investigated by caspase-3 activity assay using flow cytometry and apoptotic morphology was confirmed by Hoescht 33342 staining.

RESULTS

Emodin, quercetin, and cis-stilbene were the most effective polyphenols at decreasing cell viability (IC50 values of 5-22 μM, 8-33 μM, and 25-85 μM respectively) and inducing apoptosis (AP50 values (the concentration which 50% of cells undergo apoptosis) of 2-27 μM, 19-50 μM, and 8-50 μM respectively). Generally, lymphoid cell lines were more sensitive to polyphenol treatment compared to myeloid cell lines, however the most resistant myeloid (KG-1a and K562) cell lines were still found to respond to emodin and quercetin treatment at low micromolar levels. Non-tumor cells were less sensitive to all polyphenols compared to the leukemia cells.

CONCLUSIONS

These findings suggest that polyphenols have anti-tumor activity against leukemia cells with differential effects. Importantly, the differential sensitivity of emodin, quercetin, and cis-stilbene between leukemia and normal cells suggests that polyphenols are potential therapeutic agents for leukemia.