xanthohumol and Neoplasms

Today, there is a growing interest nowadays in the use of herbal substances as cancer therapeutic agents. Over recent years, Xanthohumol (XTL) has been brought out as a prenylated chalcone that is found in hops (Humulus lupulus) and beer. XTL is being investigated for its potential properties, and it has been found to have various biological effects, including anti-microbial, anti-viral, and immunomodulatory. Other than these biological effects, it has also been found that XTL exerts anti-tumor effects. In the beginning, XTL, by modulating cell signaling pathways, including ERK, AKT, NF-κB, AMPK, Wnt/β-catenin, and Notch signaling in cancer cells, inhibits tumor cell functions. Moreover, XTL, by inducing apoptotic pathways, either intrinsic or extrinsic, promotes cancer cell death and arrests the cell cycle. Furthermore, XTL inhibits metastasis, angiogenesis, cancer stemness, drug resistance, cell respiration, etc., which results in tumor aggressiveness inhibition. XTL has low solubility in water, and it has been hypothesized that some modifications, including biotinylation, can improve its pharmacogenetic characteristics. Additionally, XTL derivates such as dihydroXTL and tetrahydroXTL can be helpful for more anti-tumor activities. Using XTL with other anti-tumor agents is another approach to overcome tumor cell resistance. XTL or its derivatives, it is believed, might provide novel chemotherapeutic methods in future cancer therapy.

Topics: Antineoplastic Agents; Flavonoids; Humulus; Neoplasms; Propiophenones

The overwhelming global burden of cancer has posed numerous challenges and opportunities for developing anti-cancer therapies. Phytochemicals have emerged as promising synergistic compounds with potential anti-cancer effects to supplement chemo- and immune-therapeutic regimens. Anti cancer synergistic effects have been investigated in the interaction between phytocompounds derived from flavonoids such as quercetin, apigenin, kaempferol, hesperidin, emodin, etc., and conventional drugs. Xanthohumol is one of the prenylated phytoflavonoid that has demonstrated key anti-cancer activities in in vitro (anti proliferation of cancer cell lines) and in vivo (animal models of xenograft tumours) studies, and has been explored from different dimensions for targeting cancer subtypes. In the last decade, xanthohumol has been investigated how it induces the anti- cancer effects at cellular and molecular levels. The different signalling cascades and targets of xanthohumol are summarized in this review. Overall, this review summarizes the current advances made in the field of natural compounds with special reference to xanthohumol and its promising anti-cancer effects to inhibit tumour progression. The present review has also discussedthe potential of xanthohumol transitioning into a leadingcandidate from nano-therapy viewpoint along with the challenges which need to be addressed for extensive preclinical and clinical anti-cancer studies.

Topics: Animals; Antineoplastic Agents, Phytogenic; Cell Proliferation; Flavonoids; Humans; Neoplasms; Neoplasms, Experimental; Phytochemicals; Propiophenones

Xanthohumol (XH) is an important prenylated flavonoid that is found within the inflorescence of

Topics: Animals; Antineoplastic Agents, Phytogenic; Female; Flavonoids; Humans; Humulus; Male; Neoplasms; Propiophenones

Cancer is a major public health concern due to high mortality and poor quality of life of patients. Despite the availability of advanced therapeutic interventions, most treatment modalities are not efficacious, very expensive, and cause several adverse side effects. The factors such as drug resistance, lack of specificity, and low efficacy of the cancer drugs necessitate developing alternative strategies for the prevention and treatment of this disease. Xanthohumol (XN), a prenylated chalcone present in Hop (Humulus lupulus), has been found to possess prominent activities against aging, diabetes, inflammation, microbial infection, and cancer. Thus, this manuscript thoroughly reviews the literature on the anti-cancer properties of XN and its various molecular targets. XN was found to exert its inhibitory effect on the growth and proliferation of cancer cells via modulation of multiple signaling pathways such as Akt, AMPK, ERK, IGFBP2, NF-κB, and STAT3, and also modulates various proteins such as Notch1, caspases, MMPs, Bcl-2, cyclin D1, oxidative stress markers, tumor-suppressor proteins, and miRNAs. Thus, these reports suggest that XN possesses enormous therapeutic potential against various cancers and could be potentially used as a multi-targeted anti-cancer agent with minimal adverse effects.

Topics: Antineoplastic Agents, Phytogenic; Bibliometrics; Female; Flavonoids; Humans; Humulus; Male; Neoplasms; Propiophenones; Signal Transduction

Conjugated α,β-unsaturated ketones are very useful compounds associated with diverse medicinal properties. This review outlines α,β-unsaturated ketones as candidate cytotoxic agents which affect mitochondrial function. Both naturally occurring compounds and synthetic chemicals have been discussed which exert their cytotoxic effects, at least in part, by acting on mitochondria. Biochemical differences between tumour mitochondria and this organelle in non-malignant cells have been exploited to investigate various compounds that can cause greater toxicity to neoplasms than normal cells. On a number of instances, correlations between the structures of various α,β-unsaturated ketones and cytotoxic potencies have been observed. The aspiration is that this review will assist drug designers to create compounds which are significantly more toxic to neoplasms than normal tissues.

Topics: Animals; Humans; Ketones; Mitochondria; Neoplasms

Angiogenesis, a process characterized by the formation of new blood vessels from pre-existing ones, is a crucial step in tumor growth and dissemination. Given the ability of tumors to interfere with multiple or different molecular pathways to promote angiogenesis, there is an increasing need to therapeutically block tumor progression by targeting multiple antiangiogenic pathways. Natural polyphenols present health-protective properties, which are likely attributed to their ability to activate multiple pathways involved in inflammation, carcinogenesis, and angiogenesis. Recently, increased attention has been addressed to the ability of flavonoids, the most abundant polyphenols in the diet, to prevent cancer by suppressing angiogenesis. Here we investigate the mechanisms by which xanthohumol (the major prenylated flavonoid of the hop plant Humulus lupulus L.) and nobiletin (flavonoid from red-orange Citrus sinensis) can modulate the effects of Tumor Necrosis Factor-α (TNF-α) on human umbilical vein endothelial cells (HUVEC). The results reported in this paper show that xanthohumol and nobiletin pretreatment of HUVEC inhibits the effects induced by TNF-α on cell migration, invasion capability, and colon cancer cell adhesion on the endothelial monolayer. Moreover, the pretreatment reduces metalloproteinases and adhesion molecules' expression. Finally, our results highlight that xanthohumol and nobiletin can counteract the effects of TNF-α on angiogenesis and invasiveness, mainly through Vascular Endothelial Growth Factor and NF-κB pathways. Since angiogenesis plays an important pathological role in the progression of several diseases, our findings may provide clues for developing xanthohumol and nobiletin as therapeutic agents against angiogenesis-associated diseases.

Topics: Flavonoids; Human Umbilical Vein Endothelial Cells; Humans; Neoplasms; NF-kappa B; Polyphenols; Signal Transduction; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A

Xanthohumol (XN), a simple prenylated chalcone, can be isolated from hops and has the potential to be a cancer chemopreventive agent against several human tumor cell lines. We previously identified valosin-containing protein (VCP) as a target of XN; VCP can also play crucial roles in cancer progression and prognosis. Therefore, we investigated the molecular mechanisms governing the contribution of VCP to the antitumor activity of XN. Several human tumor cell lines were treated with XN to investigate which human tumor cell lines are sensitive to XN. Several cell lines exhibited high sensitivity to XN both in vitro and in vivo. shRNA screening and bioinformatics analysis identified that the inhibition of the adenylate cyclase (AC) pathway synergistically facilitated apoptosis induced by VCP inhibition. These results suggest that there is crosstalk between the AC pathway and VCP function, and targeting both VCP and the AC pathway is a potential chemotherapeutic strategy for a subset of tumor cells.

Topics: A549 Cells; Adenosine Triphosphatases; Adenylyl Cyclases; Animals; Apoptosis; Blotting, Western; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cyclic AMP-Dependent Protein Kinases; Female; Flavonoids; HCT116 Cells; HeLa Cells; HT29 Cells; Humans; Inhibitor of Apoptosis Proteins; Intracellular Signaling Peptides and Proteins; MCF-7 Cells; Mice, Inbred BALB C; Mice, Nude; Neoplasms; Propiophenones; RNA Interference; Signal Transduction; Survivin; Valosin Containing Protein; Xenograft Model Antitumor Assays

Angiogenesis, a process characterized by the formation of new blood vessels from pre-existing ones, is a crucial step in tumor growth and dissemination. Recently, increased attention has been addressed to the ability of flavonoids to prevent cancer by suppressing angiogenesis, strategy that we named "angioprevention". Several natural compounds exert their anti-tumor properties by activating 5' adenosine monophosphate-activated protein kinase (AMPK), a key regulator of metabolism in cancer cells. Drugs with angiopreventive activities, in particular metformin, regulate AMPK in endothelial cells. Here we investigated the involvement of AMPK in the anti-angiogenic effects of xanthohumol (XN), the major prenylated flavonoid of the hop plant, and mechanisms of action. The anti-angiogenic activity of XN was more potent than epigallocatechin-3-gallate (EGCG). Treatment of endothelial cells with XN led to increased AMPK phosphorylation and activity. Functional studies using biochemical approaches confirmed that AMPK mediates XN anti-angiogenic activity. AMPK activation by XN was mediated by CAMMKβ, but not LKB1. Analysis of the downstream mechanisms showed that XN-induced AMPK activation reduced nitric oxide (NO) levels in endothelial cells by decreasing eNOS phosphorylation. Finally, AKT pathway was inactivated by XN as part of its anti-angiogenic activity, but independently from AMPK, suggesting that these two signaling pathways proceed autonomously. Our study dissects the molecular mechanism by which XN exerts its potent anti-angiogenic activity, pointing out AMPK as a crucial signal transducer.

Topics: AMP-Activated Protein Kinase Kinases; Angiogenesis Inhibitors; Apoptosis; Cell Proliferation; Endothelium, Vascular; Flavonoids; Human Umbilical Vein Endothelial Cells; Humans; Humulus; Neoplasms; Neovascularization, Pathologic; Nitric Oxide Synthase Type III; Phosphorylation; Prenylation; Propiophenones; Protein Kinases; Signal Transduction

Xanthohumol is a prenylflavonoid extracted from hops (Humulus lupulus). It possesses anti-cancer and anti-inflammatory activities in vitro and in vivo, and offers therapeutic benefits for treatment of metabolic syndromes. However, the precise mechanisms underlying its pharmacological effects remain to be elucidated, together with its cellular target. Here, we provide evidence that xanthohumol directly interacts with the mitochondrial electron transfer chain complex I (NADH dehydrogenase), inhibits the oxidative phosphorylation, triggers the production of reactive oxygen species, and induces apoptosis. In addition, we show that as a result of the inhibition of the mitochondrial oxidative phosphorylation, xanthohumol exposure causes a rapid decrease of mitochondrial transmembrane potential. Furthermore, we showed that xanthohumol up-regulates the glycolytic capacity in cells, and thus compensates cellular ATP generation. Dissection of the multiple steps of aerobic respiration by extracellular flux assays revealed that xanthohumol specifically inhibits the activity of mitochondrial complex I, but had little effect on that of complex II, III and IV. Inhibition of complex I by xanthohumol caused the overproduction of reactive oxygen species, which are responsible for the induction of apoptosis in cancer cells. We also found that isoxanthohumol, the structural isomer of xanthohumol, is inactive to cells, suggesting that the reactive 2-hydroxyl group of xanthohumol is crucial for its targeting to the mitochondrial complex I. Together, the remodeling of cell metabolism revealed here has therapeutic potential for the use of xanthohumol.

Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Cell Line, Tumor; Cell Survival; Electron Transport Complex I; Flavonoids; Flow Cytometry; Humans; Membrane Potential, Mitochondrial; Neoplasms; Propiophenones; Reactive Oxygen Species

Xanthohumol (1) and xanthohumol D (2) were isolated from spent hops. Isoxanthohumol (3) was obtained from xanthohumol by isomerisation in alkaline solution. Six metabolites were obtained as a result of transformation of xanthohumol (1) by selected fungal cultures. Their structures were established on the basis of their spectral data. One of them: 2″-(2'''-hydroxyisopropyl)-dihydrofurano-[4″,5″:3',4']-4',2-dihydroxy-6'-methoxy-α,β-dihydrochalcone (6) has not been previously reported in the literature. The antioxidant properties of hops flavonoids and xanthohumol derivatives were investigated using the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The effects of these compounds on proliferation of MCF-7, PC-3 and HT-29 human cancer cell lines were determined by the SRB assay. With the exception of one metabolite, all tested compounds showed antiproliferative activity against the tested human cancer lines. α,β-Dihydroxanthohumol (4), obtained through the biotransformation of xanthohumol, showed higher antiproliferative activity against MCF-7 human breast carcinoma cell line than cisplatin, a widely used anticancer therapeutic agent, and a comparably high activity against PC-3 human prostate cancer cell line.

Topics: Antineoplastic Agents; Antioxidants; Biotransformation; Cell Line, Tumor; Cell Proliferation; Flavonoids; Fungi; Humans; Humulus; Neoplasms; Propiophenones

Cancer metastasis is the main cause of death (90%), and only recently we have gained some insight into the mechanisms by which metastatic cells arise from primary tumors and target to specific organs. Cysteine X Cysteine (CXC) chemokine receptor 4 (CXCR4), initially linked with leukocyte trafficking, is overexpressed in various tumors and mediates homing of tumor cells to distant sites expressing its cognate ligand CXCL12. Therefore, identification of CXCR4 inhibitors has great potential to abrogate tumor metastasis. In this study, we demonstrated that xanthohumol (XN), a prenylflavonoid derived from the female flowers of the hops plant (Humulus lupulus. L), suppressed CXCR4 expression in various cancer cell types in a concentration- and time-dependent manner. Both proteasome and lysosomal inhibitors had no effect to prevent the XN-induced downregulation of CXCR4, suggesting that the inhibitory effect of XN was not due to proteolytic degradation but occurred at the transcriptional level. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay further confirmed that XN could block endogenous activation of nuclear factor kappa B, a key transcription factor regulates the expression of CXCR4 in cancer cells. Consistent with the above molecular basis, XN abolished cell invasion induced by CXCL12 in both breast and colon cancer cells. Interestingly, although co-exist in hops, XN is the only isoform that exhibited the inhibitory effect on the expression of CXCR4 compared with other isomers, isoxanthohumol and 8-prenylnaringenin. Together, our results suggested that XN, as a novel inhibitor of CXCR4, could be a promising therapeutic agent contributed to cancer treatment.

Topics: Antineoplastic Agents; Cell Line, Tumor; Chemokine CXCL12; Dose-Response Relationship, Drug; Down-Regulation; Flavonoids; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Invasiveness; Neoplasms; NF-kappa B; Promoter Regions, Genetic; Propiophenones; Receptors, CXCR4; Transcription, Genetic

Oxidative stress and increased release of reactive oxygen species (ROS) are associated with apoptosis induction. Here we report ROS-mediated induction of apoptosis by xanthohumol (XN) from hops. XN at concentrations of 1.6-25 microM induced an immediate and transient increase in superoxide anion radical (O(2)(-*)) formation in 3 human cancer cell lines (average+/-SD EC(50) of maximum O(2)(-*) induction=3.1+/-0.8 microM), murine macrophages (EC(50)=4.0+/-0.3 microM), and BPH-1 benign prostate hyperplasia cells (EC(50)=4.3+/-0.1 microM), as evidenced by the O(2)(-*)-specific indicator dihydroethidium. MitoSOX Red costaining and experiments using isolated mouse liver mitochondria (EC(50)=11.4+/-1.8 microM) confirmed mitochondria as the site of intracellular O(2)(-*) formation. Antimycin A served as positive control (EC(50)=12.4+/-0.9 microM). XN-mediated O(2)(-*) release was significantly reduced in BPH-1 rho(0) cells harboring nonfunctional mitochondria (EC(50)>25 microM) and by treatment of BPH-1 cells with vitamin C, N-acetylcysteine (NAC), or the superoxide dismutase mimetic MnTMPyP. In addition, we demonstrated a rapid 15% increase in oxidized glutathione and a dose-dependent overall thiol depletion within 6 h (IC(50)=24.3+/-11 microM). Respiratory chain complexes I-III were weakly inhibited by XN in bovine heart submitochondrial particles, but electron flux from complex I and II to complex III was significantly inhibited in BPH-1 cells, with IC(50) values of 28.1 +/- 2.4 and 24.4 +/- 5.2 microM, respectively. Within 15 min, intracellular ATP levels were significantly reduced by XN at 12.5 to 50 microM concentrations (IC(50)=26.7+/-3.7 microM). Concomitantly, XN treatment caused a rapid breakdown of the mitochondrial membrane potential and the release of cytochrome c, leading to apoptosis induction. Pre- or coincubation with 2 mM NAC and 50 microM MnTMPyP at various steps increased XN-mediated IC(50) values for cytotoxicity in BPH-1 cells from 6.7 +/- 0.2 to 12.2 +/- 0.1 and 41.4 +/- 7.6 microM, and it confirmed XN-induced O(2)(-*) as an essential trigger for apoptosis induction. In summary, we have identified mitochondria as a novel cellular target of XN action, resulting in increased O(2)(-*) production, disruption of cellular redox balance and mitochondrial integrity, and subsequent apoptosis.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cattle; Cell Line, Tumor; Electron Transport Chain Complex Proteins; Flavonoids; Glutathione; Humans; Mitochondria, Liver; Neoplasms; Propiophenones; Reactive Oxygen Species; Sulfhydryl Compounds; Superoxides

Characterization and use of effective cancer chemopreventive agents have become important issues in public health-related research. Aiming to identify novel potential chemopreventive agents, we have established an interrelated series of bioassay systems targeting molecular mechanisms relevant for the prevention of tumor development. We report anticarcinogenic properties of Xanthohumol (XN), a prenylated chalcone from hop (Humulus Iupulus L.) with an exceptional broad spectrum of inhibitory mechanisms at the initiation, promotion, and progression stage of carcinogenesis. Consistent with anti-initiating potential, XN potently modulates the activity of enzymes involved in carcinogen metabolism and detoxification. Moreover, XN is able to scavenge reactive oxygen species, including hydroxyl- and peroxyl radicals, and to inhibit superoxide anion radical and nitric oxide production. As potential antitumor-promoting mechanisms, it demonstrates anti-inflammatory properties by inhibition of cyclooxygenase-1 and cyclooxygenase-2 activity and is antiestrogenic without possessing intrinsic estrogenic potential. Antiproliferative mechanisms of XN to prevent carcinogenesis in the progression phase include inhibition of DNA synthesis and induction of cell cycle arrest in S phase, apoptosis, and cell differentiation. Importantly, XN at nanomolar concentrations prevents carcinogen-induced preneoplastic lesions in mouse mammary gland organ culture. Because XN is easily cyclized to the flavanone isoxanthohumol, activities of both compounds were compared throughout the study. Together, our data provide evidence for the potential application of XN as a novel, readily available chemopreventive agent, and clinical investigations are warranted once efficacy and safety in animal models have been established.

Topics: Animals; Anticarcinogenic Agents; Antioxidants; Apoptosis; Carcinogens; Cell Differentiation; Cell Division; Cyclooxygenase 1; Cyclooxygenase 2; Dose-Response Relationship, Drug; Flavonoids; Flow Cytometry; Humulus; Inhibitory Concentration 50; Isoenzymes; Kinetics; Membrane Proteins; Mice; Mice, Inbred BALB C; Models, Chemical; Neoplasms; Plant Extracts; Precancerous Conditions; Propiophenones; Prostaglandin-Endoperoxide Synthases; S Phase