Didymin reverses phthalate ester-associated breast cancer aggravation in the breast cancer tumor microenvironment

Didymin ameliorates ulcerative colitis-associated secondary liver damage by facilitating Notch1 degradation

BACKGROUND

Didymin is a dietary flavonoid originally discovered by our group as a potent anti-ulcerative colitis (UC) agent. However, whether didymin plays a protective role in UC-associated inflammatory liver injury is still unclear.

PURPOSE

This study aimed to evaluate the therapeutic potential of didymin on UC-associated inflammatory liver injury and explore the underlying mechanism.

STUDY DESIGN AND METHODS

Colitis model was established in C57BL/6 mice by exposure to DSS, and didymin was administrated intragastrically for consecutive 10 days. The inflammatory liver injury was assessed by levels of alanine aminotransferase (ALT) and aspartate transaminase (AST) in serum and histopathological damage in the liver. In vitro Kupffer cells and RAW264.7 cells challenged with lipopolysaccharides (LPS) were used to explore the modulatory activity of didymin on pro-inflammatory cytokines secretion and Notch1 signaling pathway activation.

RESULTS

Didymin significantly mitigated liver coefficiency, ALT and AST levels in serum, and the hepatic histopathological damage caused by DSS-induced acute and chronic colitis. The mRNA expressions of pro-inflammatory factors including Tnf, Il1, and Il6 in liver tissues, Kupffer cells, and RAW264.7 cells stimulated by the influx of LPS was significantly deprived after didymin treatment. Mechanistically, didymin obstructed the protein expression, nuclear translocation of notch intracellular domain 1 (Notch1-ICD) and mRNA expression of hairy and enhancer of split 1 (Hes1). Further, the inhibitory mechanism of the Notch1-Hes1 pathway was dependent on c-Cbl-mediated Notch1-ICD lysosomal degradation.

CONCLUSION

Our study verified for the first time that didymin could prevent UC-associated diseases, such as inflammatory liver injury, and the mechanism was related to facilitating Notch1 lysosomal degradation rather than proteasome degradation via promoting protein expression of c-Cbl in macrophages. Our findings that the inhibition of Notch1 signaling transduction helps to alleviate UC-associated liver injury provides possible therapeutics for the treatment of colitis and also furnishes a research paradigm for the study of flavonoids with similar structures.

Didymin alleviates metabolic dysfunction-associated fatty liver disease (MAFLD) via the stimulation of Sirt1-mediated lipophagy and mitochondrial biogenesis

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is one of the most prevalent metabolic syndromes worldwide. However, no approved pharmacological treatments are available for MAFLD. Chenpi, one kind of dried peel of citrus fruits, has traditionally been utilized as a medicinal herb for liver diseases. Didymin is a newly identified oral bioactive dietary flavonoid glycoside derived from Chenpi. In this study, we investigated the therapeutic potential of Didymin as an anti-MAFLD drug and elucidated its underlying mechanisms.

METHODS

High-fat diet (HFD)-induced MAFLD mice and alpha mouse liver 12 (AML12) cells were utilized to evaluate the effects and mechanisms of Didymin in the treatment of MAFLD. Liver weight, serum biochemical parameters, and liver morphology were examined to demonstrate the therapeutic efficacy of Didymin in MAFLD treatment. RNA-seq analysis was performed to identify potential pathways that could be affected by Didymin. The impact of Didymin on Sirt1 was corroborated through western blot, molecular docking analysis, microscale thermophoresis (MST), and deacetylase activity assay. Then, a Sirt1 inhibitor (EX-527) was utilized to confirm that Didymin alleviates MAFLD via Sirt1. Western blot and additional assays were used to investigate the underlying mechanisms.

RESULTS

Our results suggested that Didymin may possess therapeutic potential against MAFLD in vitro and in vivo. By promoting Sirt1 expression as well as directly binding to and activating Sirt1, Didymin triggers downstream pathways that enhance mitochondrial biogenesis and function while reducing apoptosis and enhancing lipophagy.

CONCLUSIONS

These suggest that Didymin could be a promising medication for MAFLD treatment. Furthermore, its therapeutic effects are mediated by Sirt1.

Di(2-ethylhexyl) phthalate mediates IL-33 production via aryl hydrocarbon receptor and is associated with childhood allergy development

Background

Few studies assess cord blood biomarkers to predict prenatal exposure to di(2-ethylhexyl) phthalate (DEHP) on the development of allergic diseases later in childhood. IL-33 has been indicated to play an important role in allergic diseases. We evaluated the association of prenatal DEHP exposure and IL-33 in cord blood on the development of allergic diseases. We also investigated the mechanism of DEHP in human lung epithelial cells and asthma animal models.

Methods

66 pregnant women were recruited, and their children followed when they were aged 3 years. Maternal urinary DEHP metabolites were determined using liquid chromatography-electrospray-ionization-tandem mass spectrometry. The effect of DEHP on IL-33 production was investigated in human lung epithelial cells and club cell-specific aryl hydrocarbon receptor (AhR) deficiency mice. ELISA and RT-PCR, respectively, measured the IL-33 cytokine concentration and mRNA expression.

Results

The concentrations of maternal urinary DEHP metabolites and serum IL-33 in cord blood with childhood allergy were significantly higher than those in the non-childhood allergy group. DEHP and MEHP could induce IL-33 production and reverse by AhR antagonist and flavonoids in vitro. Enhanced ovalbumin-induced IL-4 and IL-33 production in bronchoalveolar lavage fluid (BALF) by DEHP exposure and suppressed in club cell-specific AhR null mice. Kaempferol has significantly reversed the DEHP effect in the asthma animal model.

Conclusions

Cord blood IL-33 level was correlated to childhood allergy and associated with maternal DEHP exposure. IL-33 might be a potential target to assess the development of DEHP-related childhood allergic disease. Flavonoids might be the natural antidotes for DEHP.

Antioxidants from different citrus peels provide protection against cancer

Cancer is one of the leading causes of death. Despite significant advancements in the discovery of medications for the treatment of cancer, these drugs are hindered by applicability and efficacy issues and frequently exhibit major side effects that can further impair patients 'quality of life. Therefore, the development of therapeutically sound anti-cancer medicines derived from natural products has gained prominence in the field of functional foods. Some of these compounds have shown efficacy in the prevention and treatment of cancer as well as low toxicity. Additionally, many recent studies have explored the recycling of agro-industrial waste to create bioactive chemicals. Citrus peels are produced in vast quantities in the food processing sector; due to their abundance of flavonoids, they may be inexpensive sources of protection against several cancers. Citrus is a common type of fruit that contains a variety of nutrients. In particular, the antioxidant chemicals found in citrus peel have been identified as potential cancer-fighting agents. Antioxidant substances such as flavonoids prevent the development of cancer by inhibiting the metastatic cascade, decreasing the mobility of cancer cells in the circulatory system, promoting apoptosis, and suppressing angiogenesis. To explore the most effective uses of citrus peel-derived antioxidants, this review presents background information, an overview of the role of citrus antioxidants in cancer therapy, and a discussion of the key underlying molecular mechanisms.

Mediterranean Diet as a Shield against Male Infertility and Cancer Risk Induced by Environmental Pollutants: A Focus on Flavonoids

The role of environmental factors in influencing health status is well documented. Heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, dioxins, pesticides, ultrafine particles, produced by human activities put a strain on the body’s entire defense system. Therefore, together with public health measures, evidence-based individual resilience measures are necessary to mitigate cancer risk under environmental stress and to prevent reproductive dysfunction and non-communicable diseases; this is especially relevant for workers occupationally exposed to pollutants and/or populations residing in highly polluted areas. The Mediterranean diet is characterized by a high intake of fruits and vegetables rich in flavonoids, that can promote the elimination of pollutants in tissues and fluids and/or mitigate their effects through different mechanisms. In this review, we collected evidence from pre-clinical and clinical studies showing that the impairment of male fertility and gonadal development, as well as cancers of reproductive system, due to the exposure of organic and inorganic pollutants, may be counteracted by flavonoids.

An Overview of Bioactive Flavonoids from Citrus Fruits

Citrus species are one of the world’s popular fruit crops, cultivated all over the world for their economic and nutritional values. Citrus, like other fruits and vegetables, are an important source of several antioxidant molecules (polyphenols, ascorbic acid, and carotenoids) that can inhibit the harmful effects of free radicals on the human body; due to their functional values and health-promoting properties, Citrus species are considered valuable fruits not only in agri-food industry, but also in pharmaceutical industry. Flavonoids are among the major constituents of polyphenols found in different parts of Citrus fruits (skin, peels, seed, pulp membrane, and juice). Flavonoids have different biological properties (antiviral, antifungal, and antibacterial activities). Several studies have also shown the health-related properties of Citrus flavonoids, especially antioxidant, anticancer, anti-inflammation, anti-aging, and cardiovascular protection activities. In the present review, attempts are made to discuss the current trends of research on flavonoids in different Citrus species.

Chiral Flavonoids as Antitumor Agents

Flavonoids are a group of natural products with a great structural diversity, widely distributed in plant kingdom. They play an important role in plant growth, development and defense against aggressors. Flavonoids show a huge variety of biological activities such as antioxidant, anti-inflammatory, anti-mutagenic, antimicrobial and antitumor, being able to modulate a large diversity of cellular enzymatic activities. Among natural flavonoids, some classes comprise chiral molecules including flavanones, flavan-3-ols, isoflavanones, and rotenoids, which have one or more stereogenic centers. Interestingly, in some cases, individual compounds of enantiomeric pairs have shown different antitumor activity. In nature, these compounds are mainly biosynthesized as pure enantiomers. Nevertheless, they are often isolated as racemates, being necessary to carry out their chiral separation to perform enantioselectivity studies. Synthetic chiral flavonoids with promising antitumor activity have also been obtained using diverse synthetic approaches. In fact, several new chiral bioactive flavonoids have been synthesized by enantioselective synthesis. Particularly, flavopiridol was the first cyclin-dependent kinase (CDK) inhibitor which entered clinical trials. The chiral pool approaches using amino acid as chiral building blocks have also been reported to achieve small libraries of chrysin derivatives with more potent in vitro growth inhibitory effect than chrysin, reinforcing the importance of the introduction of chiral moieties to improve antitumor activity. In this work, a literature review of natural and synthetic chiral flavonoids with antitumor activity is reported for the first time.

DEHP mediates drug resistance by directly targeting AhR in human breast cancer

Resistance to chemotherapy and hormonal therapy is a major clinical problem in breast cancer medicine, especially for cancer metastasis and recurrence. Di(2-ethylhexyl)phthalate (DEHP) affects drug resistance by an unknown mechanism of action. Here we analyzed breast cancer patients (N = 457) and found that Σ₄MEHP (the sum of MEHP, MEHHP, MECPP and MEOHP concentrations) in urine was significantly higher (P = 0.018) in the recurrent breast cancer group compared with non-recurrent patients. Σ₄MEHP-High was positively and significantly correlated with tumor stage (P = 0.005), lymph node status (P = 0.001), estrogen receptor status (P = 0.010), Her2/Neu status (P = 0.004), recurrence (P = 0.000) and tumor size (P = 0.002), as well as an independent prognostic marker (OR = 1.868; 95% CI = 1.424-2.451; P < 0.000) associated with poor survival rates based on a positive Her2/Neu status (P = 0.035). In addition, we found that DEHP inhibited paclitaxel and doxorubicin effects in breast cancer cell lines MCF-7 and MDA-MB-231 and in zebrafish and mouse tumor initiation models. DEHP induced trefoil factor 3 (TFF3) expression through the vinculin/aryl hydrocarbon receptor (AhR)/ERK signaling pathway and induced CYP2D6, CYP2C8 and CYP3A4 expression through the AhR genomic pathway to increase the epithelial-mesenchymal transition (EMT) and doxorubicin metabolism, respectably. DEHP mediated AhR-related alterations in estrogen receptor expression through the ubiquitination system, which decreased tamoxifen effects in AhR knockout mice. These findings suggest a novel therapeutic avenue by targeting AhR in drug-resistant and recurrent breast cancer.

Didymin switches M1-like toward M2-like macrophage to ameliorate ulcerative colitis via fatty acid oxidation

Inflammatory response by different polarized macrophages has a critical role in a variety of immunological pathophysiology, such as ulcerative colitis (UC). Herein, targeting the paradigm of macrophage phenotypes by small molecular modulators may influence the disease status. In the present study, we firstly demonstrated that didymin, one of the most abundant flavonoid constituents present in the citrus fruits such as oranges and lemons, remarkably attenuated the clinical symptoms of acute and chronic colitis in mice. Mechanistic studies showed that didymin converted pro-inflammatory M1-like to anti-inflammatory M2-like macrophage phenotype, but did not alter the polarization of M2-like macrophages. Metabolic tracing studies revealed that didymin strengthened fatty acid oxidation rather than glycolysis by inducing Hadhb expression. More importantly, in vivo studies verified that promotion of Hadhb expression resulted in the conversion of M1- toward M2-like macrophages and eventually alleviated colitis. Our data highlights the potential of macrophage paradigm in UC inflammation and put forth the stage for considering didymin as a metabolism regulator in reprogramming macrophage polarization, which may serve as a promising therapeutic approach for treatment of inflammation-associated disorders.

Dibutyl phthalate contamination accelerates the uptake and metabolism of sugars by microbes in black soil

Dibutyl phthalate (DBP) is widely used as plasticizer and has been detected in the environment, posing a threat to animal health. However, the effects of DBP on agricultural microbiomes are not known. In this study, DBP levels in black soil were evaluated, and the impact of DBP contamination on the uptake and metabolism of sugars in microbes was assessed by glucose absorption tests, metaproteomics, metabolomics, enzyme activity assays and computational simulation analysis. The results indicated that DBP contamination accelerated glucose consumption and upregulated the expression of porins and periplasmic monosaccharide ATP-binding cassette (ABC) transporter solute-binding proteins (SBPs). DBP and its metabolic intermediates (carboxymuconate and butanol) may form a stable complex with sugar transporters and enhance the rigidity and stability of these proteins. Sugar metabolism resulting in the generation of ATP and reducing agent (NADPH), as well as the expression of some key enzymes (dehydrogenases) were also upregulated by DBP treatment. Moreover, a diverse bacterial community appears to utilize sugar, suggesting that there are widespread effects of DBP contamination on soil microbial ecosystems. The results of this study provide a theoretical basis for investigating the toxicological effects of DBP on microbes in black soil.

Combined effect of silver nanoparticles and aluminium chloride, butylparaben or diethylphthalate on the malignancy of MDA-MB-231 breast cancer cells and tumor-specific immune responses of human macrophages and monocyte-derived dendritic cells

The aim of this study was to assess whether silver nanoparticles (AgNP) or selected cosmetic ingredients may modify functions of various immunocompetent cell populations. To this end, the effect of two AgNP (size of 15 nm or 45 nm), alone and in combination with aluminium chloride, butyl paraben, di-n-butyl phthalate or diethyl phthalate was assessed on: (1) migration and invasion of MDA-MB-231 human breast cancer cells; (2) M1/M2 polarization of phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages (M0) and (3) activation/maturation of monocyte-derived dendritic cells (DCs). The results of this study showed that neither any of the test chemicals alone nor the mixtures significantly changed the migration or invasion ability of MDA-MB-231 cells following, both 72-h and 21-day exposure. Analysis of the expression of marker genes for both M1 (IL-1B, CXCL9, TNF) and M2 (DCSIGN, MRC1) polarization revealed that the chemicals/mixtures did not activate M1/M2 differentiation of the M0 macrophages. In addition, no significant changes were observed in the expression of CD86, HLA-DR and CD54 surface markers and phagocytic activity of DCs following 48-h exposure to AgNP alone or in combination with test compounds. Our study suggests that AgNP alone or in combination with tested cosmetic ingredients do not alter function of immunocompetent cells studied.

Didymin, a dietary citrus flavonoid exhibits anti-diabetic complications and promotes glucose uptake through the activation of PI3K/Akt signaling pathway in insulin-resistant HepG2 cells

Didymin is a naturally occurring orally active flavonoid glycoside (isosakuranetin 7-O-rutinoside) found in various citrus fruits, which has been previously reported to possess a wide variety of pharmacological activities including anticancer, antioxidant, antinociceptive, neuroprotective, hepatoprotective, inflammatory, and cardiovascular. However, there have not been any reports concerning its anti-diabetic potential until now. Therefore, we evaluated the anti-diabetic potential of didymin via inhibition of α-glucosidase, protein tyrosine phosphatase 1B (PTP1B), rat lens aldose reductase (RLAR), human recombinant AR (HRAR), and advanced glycation end-product (AGE) formation inhibitory assays. Didymin strongly inhibited PTP1B, α-glucosidase, HRAR, RLAR, and AGE in the corresponding assays. Kinetic study revealed that didymin exhibited a mixed type inhibition against α-glucosidase and HRAR, while it competitively inhibited PTP1B and RLAR. Docking simulations of didymin demonstrated negative binding energies and close proximity to residues in the binding pocket of HRAR, RLAR, PTP1B and α-glucosidase, indicating that didymin have high affinity and tight binding capacity towards the active site of these enzymes. Furthermore, we also examined the molecular mechanisms underlying the anti-diabetic effects of didymin in insulin-resistant HepG2 cells which significantly increased glucose uptake and decreased the expression of PTP1B in insulin-resistant HepG2 cells. In addition, didymin activated insulin receptor substrate (IRS)-1 by increasing phosphorylation at tyrosine 895 and enhanced the phosphorylations of phosphoinositide 3-kinase (PI3K), Akt, and glycogen synthasekinase-3(GSK-3). Interestingly, didymin reduced the expression of phosphoenolpyruvate carboxykinase and glucose 6-phosphatase, two key enzymes involved in the gluconeogenesis and leading to a diminished glucose production. The results of the present study clearly demonstrated that didymin will be useful for developing multiple target-oriented therapeutic modalities for treatment of diabetes, and diabetes-associated complications.

Didymin by suppressing NF-κB activation prevents VEGF-induced angiogenesis in vitro and in vivo

Although didymin, a dietary flavonoid glycoside from citrus fruits, known to be a potent antioxidant with anti-cancer activities, its role in angiogenesis is not known. In this study, we examined the effect of didymin on VEGF-induced angiogenesis in vitro and in vivo models. Our results suggest that treatment of human umbilical vein endothelial cell (HUVECs) with didymin significantly prevented the VEGF-induced cell proliferation, migration, and invasion. Further, didymin significantly prevented the VEGF-induced endothelial tube formation in culture. Didymin also attenuated the VEGF-induced generation of ROS, activation of NF-κB and the expression of adhesion molecules such as VCAM-1, ICAM-1, and E-selectin in HUVECs. Further, didymin also prevented the VEGF-induced microvessel sprouting in ex vivo mouse aortic rings. Most importantly, didymin significantly prevented the invasion of endothelial cells and formation of blood capillary-like structures in Matrigel plug model of angiogenesis in mice. Thus, our results suggest a novel antiangiogenic efficacy of didymin in addition to its reported anti-cancer properties, which warrant further development of this agent for cancer therapy.

Recent Trends in Potential Therapeutic Applications of the Dietary Flavonoid Didymin

Didymin (isosakuranetin 7-O-rutinoside) is an orally bioactive dietary flavonoid glycoside first found in citrus fruits. Traditionally, this flavonoid has long been used in Asian countries as a dietary antioxidant. Recent studies have provided newer insights into this pleiotropic compound, which could regulate multiple biological activities of many important signaling molecules in health and disease. Emerging data also presented the potential therapeutic application of dietary flavonoid glycoside didymin against cancer, neurological diseases, liver diseases, cardiovascular diseases, and other diseases. In this review, we briefly introduce the source and extraction methods of didymin, and summarize its potential therapeutic application in the treatment of various diseases, with an emphasis on molecular targets and mechanism that contributes to the observed therapeutic effects. The dietary flavonoid didymin can be used to affect health and disease with multiple therapeutic targets, and it is anticipated that this review will stimulate the future development of this potential dietary medicine.

Didymin prevents hyperglycemia-induced human umbilical endothelial cells dysfunction and death

Although didymin, a flavonoid-O-glycosides compound naturally found in the citrus fruits, has been reported to be a potent anticancer agent in the prevention of various cancers, its role in the prevention of cardiovascular complications is unclear. Most importantly, its effect in the prevention of endothelial dysfunction, a pathological process involved in the atherogenesis, is unknown. We have examined the efficacy of didymin in preventing the high glucose (HG; 25 mM)-induced human umbilical vein endothelial cells (HUVECs) dysfunction. Our results indicate that incubation of HUVECs with HG resulted in the loss of cell viability, and pre-incubation of didymin prevented it. Further, didymin prevented the HG-induced generation of reactive oxygen species (ROS) as well as lipid peroxidation product, malondialdehyde. Pretreatment of HUVECs with didymin also prevented the HG-induced decrease in eNOS and increase in iNOS expressions. Further, didymin prevented the HG-induced monocytes cell adhesion to endothelial cells, expressions of ICAM-1 and VCAM-1 and activation of NF-κB. Didymin also prevented the release of various inflammatory cytokines and chemokines in HG-treated HUVECs. In conclusion, our results demonstrate that didymin with its anti-oxidative and anti-inflammatory actions prevents hyperglycemia-induced endothelial dysfunction and death. Thus, it could be developed as a potential natural therapeutic agent for the prevention of cardiovascular complications in diabetes.

Didymin: an orally active citrus flavonoid for targeting neuroblastoma

Neuroblastoma, a rapidly growing yet treatment responsive cancer, is the third most common cancer of children and the most common solid tumor in infants. Unfortunately, neuroblastoma that has lost p53 function often has a highly treatment-resistant phenotype leading to tragic outcomes. In the context of neuroblastoma, the functions of p53 and MYCN (which is amplified in ~25% of neuroblastomas) are integrally linked because they are mutually transcriptionally regulated, and because they together regulate the catalytic activity of RNA polymerases. Didymin is a citrus-derived natural compound that kills p53 wild-type as well as drug-resistant p53-mutant neuroblastoma cells in culture. In addition, orally administered didymin causes regression of neuroblastoma xenografts in mouse models, without toxicity to non-malignant cells, neural tissues, or neural stem cells. RKIP is a Raf-inhibitory protein that regulates MYCN activation, is transcriptionally upregulated by didymin, and appears to play a key role in the anti-neuroblastoma actions of didymin. In this review, we discuss how didymin overcomes drug-resistance in p53-mutant neuroblastoma through RKIP-mediated inhibition of MYCN and its effects on GRK2, PKCs, Let-7 micro-RNA, and clathrin-dependent endocytosis by Raf-dependent and -independent mechanisms. In addition, we will discuss studies supporting potential clinical impact and translation of didymin as a low cost, safe, and effective oral agent that could change the current treatment paradigm for refractory neuroblastoma.

A systematic review on the adverse health effects of di-2-ethylhexyl phthalate

Di (ethylhexyl) phthalate (DEHP) is a global environmental pollutant. This study aims to systematically review the literature on health effects of exposure to DEHP including effects on reproductive health, carcinogenesis, pregnancy outcome, and respiratory system. The literature search was done through Scopus, ISI Web of Science, Google Scholar, PubMed, Medline, and the reference lists of previous review articles to identify relevant articles published to June 2016 in each subject area. The inclusion criteria were as follows: original research, cross-sectional studies, case-control studies, cohort studies, interventional studies, and review articles. Both human and animal studies were included. The search was limited to English language papers. Conference papers, editorials, and letters were not included. The systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Overall, 152 of the 407 papers met the inclusion criteria. We provided an up-to-date comprehensive and critical assessment of both human and animal studies undertaken to explore the effects of DEHP. It revealed that in experimental studies, exposure to DEHP mainly targeted the reproductive, neurodevelopment, and respiratory systems. Human studies reported that exposure to this contaminant had carcinogenic effects and influenced neurodevelopment in early life. This systematic review underscored the adverse health effects of DEHP for pregnant women and the pediatric age group. It summarizes different response of humans and experimental animals to DEHP exposure, and some suggested underlying mechanisms.

Chemopreventive Agents and Inhibitors of Cancer Hallmarks: May Citrus Offer New Perspectives?

Fruits and vegetables have long been recognized as potentially important in the prevention of cancer risk. Thus, scientific interest in nutrition and cancer has grown over time, as shown by increasing number of experimental studies about the relationship between diet and cancer development. This review attempts to provide an insight into the anti-cancer effects of Citrus fruits, with a focus on their bioactive compounds, elucidating the main cellular and molecular mechanisms through which they may protect against cancer. Scientific literature was selected for this review with the aim of collecting the relevant experimental evidence for the anti-cancer effects of Citrus fruits and their flavonoids. The findings discussed in this review strongly support their potential as anti-cancer agents, and may represent a scientific basis to develop nutraceuticals, food supplements, or complementary and alternative drugs in a context of a multi-target pharmacological strategy in the oncology.