Inhibitory Effects of Nobiletin on Hepatocellular Carcinoma In Vitro and In Vivo

Nobiletin as an inducer of programmed cell death in cancer: a review

Cancer resistance to therapy is a big issue in cancer therapy. Tumours may develop some mechanisms to reduce the induction of cell death, thus stimulating tumour growth. Cancer cells may show a low expression and activity of tumour suppressor genes and a low response to anti-tumour immunity. These mutations can increase the resistance of cancer cells to programmed cell death mechanisms such as apoptosis, ferroptosis, pyroptosis, autophagic cell death, and some others. The upregulation of some mediators and transcription factors such as Akt, nuclear factor of κB, signal transducer and activator of transcription 3, Bcl-2, and others can inhibit cell death in cancer cells. Using adjuvants to induce the killing of cancer cells is an interesting strategy in cancer therapy. Nobiletin (NOB) is a herbal-derived agent with fascinating anti-cancer properties. It has been shown to induce the generation of endogenous ROS by cancer cells, leading to damage to critical macromolecules and finally cell death. NOB may induce the activity of p53 and pro-apoptosis mediators, and also inhibit the expression and nuclear translocation of anti-apoptosis mediators. In addition, NOB may induce cancer cell killing by modulating other mechanisms that are involved in programmed cell death mechanisms. This review aims to discuss the cellular and molecular mechanisms of the programmed cell death in cancer by NOB via modulating different types of cell death in cancer.

Nobiletin as a chemopreventive natural product against cancer, a comprehensive review

As a leading cause of death, second only to heart disease, cancer has always been one of the burning topics in medical research. When targeting multiple signal pathways in tumorigenesis chemoprevention, using natural or synthetic anti-cancer drugs is a vital strategy to reduce cancer damage. However, toxic effects, multidrug resistance (MDR) as well as cancer stem cells (CSCs) all prominently limited the clinical application of conventional anticancer drugs. With low side effects, strong biological activity, unique mechanism, and wide range of targets, natural products derived from plants are considered significant sources for new drug development. Nobiletin is one of the most attractive compounds, a unique flavonoid primarily isolated from the peel of citrus fruits. Numerous studies in vitro and in vivo have suggested that nobiletin and its derivatives possess the eminent potential to become effective cancer chemoprevention agents through various cellular and molecular levels. This article aims to comprehensively review the anticancer efficacy and specific mechanisms of nobiletin, enhancing our understanding of its chemoprevention properties and providing the latest research findings. At the end of this review, we also give some discussion and future perspectives regarding the challenges and opportunities in nobiletin efficient exploitation.

Pharmacokinetics and Metabolites of 12 Bioactive Polymethoxyflavones in Rat Plasma

Polymethoxyflavones (PMFs) are a subgroup of flavonoids possessing various health benefits. 3,5,7,4'-Tetramethoxyflavone (1), 5,6,7,4'-tetramethylflavone (2), 3,7,3',4'-tetramethoxyflavone (3), 5,7,3',4'-tetramethoxyflavone (4), 5-hydroxy-3,7,2',4'-tetramethoxyflavone (5), 3,5,7,2',4'-pentamethoxyflavone (6), 5-hydroxy-3,7,3',4'-tetramethoxyflavone (7), 3-hydroxy-5,7,3',4'-tetramethylflavone (8), 3,5,7,3',4'-pentamethoxyflavone (9), 5-hydroxy-3,7,3',4',5'-pentamethoxyflavone (10), 3-hydroxy-5,7,3',4',5'-pentamethoxyflavone (11), and 3,5,7,3',4',5'-hexamethoxylflavone (12) were 12 bioactive and available PMFs. The aim of this study was to investigate the pharmacokinetic, metabolite, and antitumor activities as well as the structure-pharmacokinetic-antitumor activity relationships of these 12 PMFs to facilitate further studies of their medicinal potentials. The cytotoxicity of PMFs with a hydroxy group toward HeLa, A549, HepG2, and HCT116 cancer cell lines was generally significantly more potent than that of PMFs without a hydroxy group. Compounds 5, 7, 8, 10, and 11 were all undetectable in rat plasma, while compounds 1-4, 6, 9, and 12 were detectable. Both the number and position of hydroxy and methoxy groups played an important role in modulating PMF pharmacokinetics and metabolites.

The Application of Citrus folium in Breast Cancer and the Mechanism of Its Main Component Nobiletin: A Systematic Review

Citrus folium and its main ingredient nobiletin (NOB) have received widespread attention in recent years due to their antitumor effects. The antitumor effect of Citrus folium is related to the traditional use, mainly in its Chinese medicinal properties of soothing the liver and promoting qi, resolving phlegm, and dispelling stagnation. Some studies have proved that Citrus folium and NOB are more effective for triple-negative breast cancer (TNBC), which is related to the syndrome of stagnation of liver qi. From the perspective of modern biomedical research, NOB has anticancer effects. Its potential molecular mechanisms include inhibition of the cell cycle, induction of apoptosis, and inhibition of angiogenesis, invasion, and migration. Citrus folium and NOB can also reduce the side effects of chemotherapy drugs and reverse multidrug resistance (MDR). However, more research studies are needed to clarify the underlying mechanisms. The modern evidence of Citrus folium and NOB in breast cancer treatment has a strong connection with the traditional concepts and laws of applying Citrus folium in Chinese medicine (CM). As a low-toxic anticancer drug candidate, NOB and its structural changes, Citrus folium, and compound prescriptions will attract scientists to use advanced technologies such as genomics, proteomics, and metabolomics to study its potential anticancer effects and mechanisms. On the contrary, there are relatively few studies on the anticancer effects of Citrus folium and NOB in vivo. The clinical application of Citrus folium and NOB as new cancer treatment drugs requires in vivo verification and further anticancer mechanism research. This review aims to provide reference for the treatment of breast cancer by Chinese medicine.

Determining novel candidate anti-hepatocellular carcinoma drugs using interaction networks and molecular docking between drug targets and natural compounds of SiNiSan

BACKGROUND

SiNiSan (SNS) is an ancient traditional Chinese medicine (TCM) used to treat liver and spleen deficiencies. We studied the unique advantages of using SNS to treat hepatocellular carcinoma (HCC) with multiple components and targets to determine its potential mechanism of action.

METHODS

The active compounds from the individual herbs in the SNS formula and their targets were mined from Traditional Chinese Medicine Systems Pharmacology Database (TCMSP). HCC-associated targets were collected from the TCGA and GEO databases and samples were collected from patients with stage III hepatocellular carcinoma. A compound-disease target network was constructed, visualized, and analyzed using Cytoscape software. We built a protein-protein interaction (PPI) network using the String database. We enriched and analyzed key targets using GSEA, GO, and KEGG in order to explore their functions. Autodock software was used to simulate the process of SNS molecules acting on HCC targets.

RESULTS

A total of 113 candidate compounds were taken from SNS, and 64 of the same targets were chosen from HCC and SNS. The predominant targets genes were PTGS2, ESR1, CHEK1, CCNA2, NOS2 and AR; kaempferol and quercetin from SNS were the principal ingredients in HCC treatment. The compounds may work against HCC due to a cellular response to steroid hormones and histone phosphorylation. The P53 signaling pathway was significantly enriched in the gene set GSEA enrichment analysis and differential gene KEGG enrichment analysis.

CONCLUSIONS

Our results showed that the SNS component has a large number of stage III HCC targets. Among the targets, the sex hormone receptors, the AR and ESR1 genes, are the core targets of SNS component and the most active proteins in the PPI network. In addition, quercetin, which has the most targets, can act on the main targets (BAX, CDK1, CCNB1, SERPINE1, CHEK2, and IGFBP3) of the P53 pathway to treat HCC.

Systematically Deciphering the Pharmacological Mechanism of Fructus Aurantii via Network Pharmacology

Fructus Aurantii (FA) is a traditional herbal medicine that has been widely used for thousands of years in China and possesses a variety of pharmacological effects. However, the active ingredients in FA and the potential mechanisms of its therapeutic effects have not been fully explored. Here, we applied a network pharmacology approach to explore the potential mechanisms of FA. We identified 5 active compounds from FA and a total of 209 potential targets to construct a protein-protein interaction (PPI) network. Prostaglandin G/H synthase 2 (PTGS2), heat shock protein 90 (HSP90), cell division protein kinase 6 (CDK6), caspase 3 (CASP3), apoptosis regulator Bcl-2 (Bcl-2), and matrix metalloproteinase-9 (MMP9) were identified as key targets of FA in the treatment of multiple diseases. Gene ontology (GO) enrichment demonstrated that FA was highly related to transcription initiation from RNA polymerase II promoter, DNA-templated transcription, positive regulation of transcription, regulation of apoptosis process, and regulation of cell proliferation. Various signaling pathways involved in the treatment of FA were identified, including pathways in cancer and pathways specifically related to prostate cancer, colorectal cancer, PI3K-Akt, apoptosis, and non-small-cell lung cancer. TP53, AKT1, caspase 3, MAPK3, PTGS2, and BAX/BCL2 were related key targets in the identified enriched pathways and the PPI network. In addition, our molecular docking results showed that the bioactive compounds in FA can tightly bind to most target proteins. This article reveals via network pharmacology research the possible mechanism(s) by which FA exerts its activities in the treatment of various diseases and lays a foundation for further experiments and the development of a rational clinical application of FA.

Nobiletin selectively inhibits oral cancer cell growth by promoting apoptosis and DNA damage in vitro

OBJECTIVES

The aim of this study was to investigate whether nobiletin (NOB) can inhibit the proliferation of oral squamous cell carcinoma (OSCC) cells by promoting apoptosis, oxidative stress (reactive oxygen species [ROS]), and DNA damage.

STUDY DESIGN

OSCCs were treated with different concentrations of NOB (25, 50, and 100 µM) for different amounts of time (0, 24, 48, and 72 hours). The viability of NOB was assessed by using MTT-based cell viability assays. Flow cytometry was used to assess cell apoptosis, and the expressions of capase-3 and poly (adenosine diphosphate-ribose) polymerase (PARP) were assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analyses. The intensity of ROS fluorescence was measured by using a spectrophotometer. The expression of γH2AX and 8-Oxo-20-deoxyguanosine (8-oxodG) were assessed to determine the degree of DNA damage.

RESULTS

We observed that NOB decreased OSCC cell viability in a dose- and time-dependent manner but had little effect on primary normal human oral epithelial cells (H0 ECs). Moreover, with the increase in NOB concentration and treatment time, capase-3, PARP messenger RNA (mRNA), and protein levels gradually increased, as did annexin V- and 7 adducin (ADD)-mediated apoptosis. In addition, NOB also increased the levels of ROS and DNA damage in a concentration- and time-dependent manner.

CONCLUSIONS

NOB can inhibit OSCC cell by promoting apoptosis, ROS production, and DNA damage.

Network Pharmacology to Uncover the Molecular Mechanisms of Action of LeiGongTeng for the Treatment of Nasopharyngeal Carcinoma

Background

Nasopharyngeal carcinoma (NPC) is a common head and neck cancer epidemic in southern China and southeast Asia. LeiGongTeng has been widely used for the treatment of cancers. The purpose of this study was to determine the pharmacological mechanism of action of LeiGongTeng in the treatment of NPC using a network pharmacological approach.

Material/Methods

The traditional Chinese medicine systems pharmacology (TCMSP) database was used to identify active ingredients and associated target proteins for LeiGongTeng. Cytoscape was utilized to create a drug-disease network and topology analysis was conducted to analyze the degree of each ingredient. The Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) online tool was applied for the construction and analysis of the protein-protein interaction (PPI) network, while Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and Gene Ontology (GO) functional analyses were utilized to determine drug-disease common genes.

Results

22 active ingredients including kaempferol, nobiletin, and beta-sitosterol, and 30 drug-disease common genes including VEGFA, CASP3, ESR1, and RELA were identified. GO analysis indicated that 94 biological processes, including RNA polymerase II, apoptotic process, response to drug, cell adhesion, and response to hypoxia, were found to be associated with NPC. The KEGG enrichment analysis showed that 58 pathways, including the PI3K-Akt signaling pathway, microRNAs in cancer, tumor necrosis factor (TNF) signaling pathway and pathways in cancer were found to be associated with NPC.

Conclusions

LeiGongTeng exerts its therapeutic effect through various biological processes and signaling pathways since it acts on several target genes. Systematic pharmacology can be used to predict the underlying function of LeiGongTeng and its mechanism of action in NPC.

Nobiletin in Cancer Therapy: How This Plant Derived-Natural Compound Targets Various Oncogene and Onco-Suppressor Pathways

Cancer therapy is a growing field, and annually, a high number of research is performed to develop novel antitumor drugs. Attempts to find new antitumor drugs continue, since cancer cells are able to acquire resistance to conventional drugs. Natural chemicals can be considered as promising candidates in the field of cancer therapy due to their multiple-targeting capability. The nobiletin (NOB) is a ubiquitous flavone isolated from Citrus fruits. The NOB has a variety of pharmacological activities, such as antidiabetes, antioxidant, anti-inflammatory, hepatoprotective, and neuroprotective. Among them, the antitumor activity of NOB has been under attention over recent years. In this review, we comprehensively describe the efficacy of NOB in cancer therapy. NOB induces apoptosis and cell cycle arrest in cancer cells. It can suppress migration and invasion of cancer cells via the inhibition of epithelial-to-mesenchymal transition (EMT) and EMT-related factors such as TGF-β, ZEB, Slug, and Snail. Besides, NOB inhibits oncogene factors such as STAT3, NF-κB, Akt, PI3K, Wnt, and so on. Noteworthy, onco-suppressor factors such as microRNA-7 and -200b undergo upregulation by NOB in cancer therapy. These onco-suppressor and oncogene pathways and mechanisms are discussed in this review.

Polo-like kinase 1 as a promising diagnostic biomarker and potential therapeutic target for hepatocellular carcinoma

Hepatocellular carcinoma is a major cause of cancer mortality worldwide. The outcome of hepatocellular carcinoma depends mainly on its early diagnosis. To date, the performance of traditional biomarkers is unsatisfactory. Polo-like kinase 1 is a serine/threonine kinase that plays essential roles in cell cycle progression and deoxyribonucleic acid damage. Moreover, polo-like kinase 1 knockdown decreases the survival of hepatocellular carcinoma cells; therefore, polo-like kinase 1 is an attractive target for anticancer treatments. Nobiletin, a natural polymethoxy flavonoid, exhibits a potential antiproliferative effect against a wide variety of cancers. This study targets to identify a reliable diagnostic biomarker for hepatocellular carcinoma and provide a potential therapeutic target for its treatment. Polo-like kinase 1 levels were analyzed in 44 hepatocellular carcinoma patients, 33 non-hepatocellular carcinoma liver cirrhosis patients and 15 healthy controls using the enzyme-linked immunosorbent assay method. Receiver operating characteristics curve analysis was used to establish a predictive model for polo-like kinase 1 relative to α-fetoprotein in hepatocellular carcinoma diagnosis. Furthermore, in the in vitro study, gene expressions were assessed by quantitative polymerase chain reaction in two human hepatocellular carcinoma cell lines after treatment with doxorubicin and polo-like kinase 1 inhibitor volasertib (Vola) either alone or in combination with nobiletin. Cell viability was also determined using the crystal violet assay.: Serum polo-like kinase 1 levels in hepatocellular carcinoma patients were significantly higher than liver cirrhosis and control groups (p < 0.0001). Polo-like kinase 1 showed a reasonable sensitivity, specificity, positive predictive value, and negative predictive value in hepatocellular carcinoma diagnosis. Moreover, nobiletin improved inhibition of cell growth induced by Vola and doxorubicin. Regarding reverse transcription polymerase chain reaction results, nobiletin suppressed expressions of polo-like kinase 1 and proliferating cell nuclear antigen and elevated expressions of P53, poly (ADPribose) polymerase 1, and caspase-3. Nobiletin/doxorubicin and nobiletin/Vola showed a significant increase in caspase-3 activity indicating cell apoptosis. Polo-like kinase 1 may be a potential biomarker for hepatocellular carcinoma diagnosis and follow-up during treatment with chemotherapies. In addition, nobiletin synergistically potentiates the doxorubicin and Vola-mediated anticancer effect that may be attributed partly to suppression of polo-like kinase 1 and proliferating cell nuclear antigen expression and enhancement of chemotherapy-induced apoptosis.

Nobiletin and Derivatives: Functional Compounds from Citrus Fruit Peel for Colon Cancer Chemoprevention

The search for effective methods of cancer treatment and prevention has been a continuous effort since the disease was discovered. Recently, there has been increasing interest in exploring plants and fruits for molecules that may have potential as either adjuvants or as chemopreventive agents against cancer. One of the promising compounds under extensive research is nobiletin (NOB), a polymethoxyflavone (PMF) extracted exclusively from citrus peel. Not only does nobiletin itself exhibit anti-cancer properties, but its derivatives are also promising chemopreventive agents; examples of derivatives with anti-cancer activity include 3′-demethylnobiletin (3′-DMN), 4′-demethylnobiletin (4′-DMN), 3′,4′-didemethylnobiletin (3′,4′-DMN) and 5-demethylnobiletin (5-DMN). In vitro studies have demonstrated differential efficacies and mechanisms of NOB and its derivatives in inhibiting and killing of colon cancer cells. The chemopreventive potential of NOB has also been well demonstrated in several in vivo colon carcinogenesis animal models. NOB and its derivatives target multiple pathways in cancer progression and inhibit several of the hallmark features of colorectal cancer (CRC) pathophysiology, including arresting the cell cycle, inhibiting cell proliferation, inducing apoptosis, preventing tumour formation, reducing inflammatory effects and limiting angiogenesis. However, these substances have low oral bioavailability that limits their clinical utility, hence there have been numerous efforts exploring better drug delivery strategies for NOB and these are part of this review. We also reviewed data related to patents involving NOB to illustrate the extensiveness of each research area and its direction of commercialisation. Furthermore, this review also provides suggested directions for future research to advance NOB as the next promising candidate in CRC chemoprevention.

Inhibitory effects of nobiletin and its major metabolites on lung tumorigenesis

The present study demonstrated that the oral administration of nobiletin significantly inhibited lung carcinogenesis in mice, and these chemopreventive effects could be attributed to its metabolites that showed potent anti-cancer effects.

Clarifying of the potential mechanism of Sinisan formula for treatment of chronic hepatitis by systems pharmacology method

Chronic hepatitis is a general designation class of diseases, which results in different degrees of liver necrosis and inflammatory reaction, followed by liver fibrosis, may eventually develop into cirrhosis. However, the molecular pathogenesis of chronic hepatitis is too complex to elucidate. Herbal medicines, featured with multiple targets and compounds, have long displayed therapeutic effect in treating chronic hepatitis, though their molecular mechanisms of contribution remain indistinct. This research utilized the network pharmacology to confirm the molecular pathogenesis of chronic hepatitis through providing a comprehensive analysis of active chemicals, drug targets and pathways' interaction of Sinisan formula for treating chronic hepatitis. The outcomes showed that 80 active ingredients of Sinisan formula interacting with 91 therapeutic proteins were authenticated. Sinisan formula potentially participates in immune modulation, anti-inflammatory and antiviral activities, even has regulating effects on lipid metabolism. These mechanisms directly or indirectly are involved in curing chronic hepatitis by an interaction way. The network pharmacology based analysis demonstrated that Sinisan has multi-scale curative activity in regulating chronic hepatitis related biological processes, which provides a new potential way for modern medicine in the treatment of chronic diseases.

Nobiletin bioactivation in MDA-MB-468 breast cancer cells by cytochrome P450 CYP1 enzymes

Nobiletin is a fully methoxylated flavone that has demonstrated anticancer activity via multiple modes of action. In the present study, the metabolism and further antiproliferative activity of nobiletin was evaluated in the CYP1 expressing human breast cancer cell line MDA-MB-468 and the normal breast cell line MCF10A. Nobiletin was metabolized in MDA-MB-468 cells to a single-demethylated derivative assigned NP1. This metabolite was absent in MCF10A cells that did not express CYP1 enzymes. Nobiletin exhibited submicromolar IC50 (0.1 ± 0.04 μM) in MDA-MB-468 cells, whereas it was considerably less active in MCF10A cells (40 μM). In MDA-MB-468 cells that were coincubated with the CYP1 inhibitor acacetin, an approximately 300-fold increase was noted in the IC50 (30 ± 2.4 μM) of nobiletin. In the presence of the CYP1 inhibitor acacetin, the conversion of nobiletin to NP1 was significantly reduced in MDA-MB-468 cells. Furthermore, a significant increase was noted in the population of the cells at the G1 phase, following treatment with nobiletin (10 μM) for 24 h compared with the control cells treated with DMSO (0.1%) alone (55.9 ± 0.14 vs. 45.6 ± 1.96), whereas the cell cycle of MCF10A cells was not significantly altered under the same treatment conditions. Taken collectively, the results suggest that nobiletin is selectively bioactivated in MDA-MB-468 breast cancer cells via metabolism by the cytochrome P450 CYP1 family of enzymes.

Oxyresveratrol prevents murine H22 hepatocellular carcinoma growth and lymph node metastasis via inhibiting tumor angiogenesis and lymphangiogenesis

The purpose of this study was to investigate the effects and mechanisms of oxyresveratrol (Oxyres) on hepatocellular carcinoma (HCC) in vitro and in vivo. The MTT and Transwell assays were performed to investigate the effects of Oxyres on cell proliferation and migration of two HCC cell lines, QGY-7701 and SMMC-7721 cells. H22 cells were subcutaneously injected into hind foot pads of 70 male mice to establish a lymph node metastasis model. These mice were randomly divided into seven groups as follows, control group, HCC group, Oxyres 20 mg/kg group, Oxyres 40 mg/kg group, Oxyres 60 mg/kg group, Resveratrol (Res) group, and Adriamycin (ADM) group. Oxyres, Res, and ADM were intraperitoneally injected daily for consecutive 21 days. Tumors and popliteal lymph node were isolated and embedded for histology analysis. Expressions of CD31 and vascular endothelial growth factor receptor-3 (VEGFR3) in tumors were detected by immunohistocehmistry. Expressions of vascular endothelial growth factor C (VEGF-C) were measured by Western blot. Oxyres significantly inhibited the proliferation and migration of QGY-7701 and SMMC-7721 cells. Oxyres significantly inhibited tumor growth (p < 0.001) and metastasis to sentinel lymph nodes (70%) in a dose-dependent manner. Oxyres showed a similar inhibition rate as Res. Oxyres also significantly decreased micro-blood vessel density and micro-lymphatic vessel density in tumors (p < 0.05). Expressions of CD31, VEGFR3, and VEGF-C of tumors were also inhibited by Oxyres (p < 0.05). Oxyres exerts anti-tumor effects against HCC through inhibiting both angiogenesis and lymph node metastasis, which suggests Oxyres be a potential therapeutic agent.

Nobiletin inhibits human osteosarcoma cells metastasis by blocking ERK and JNK-mediated MMPs expression

Nobiletin, a polymethoxyflavone, has a few pharmacological activities, including anti-inflammation and anti-cancer effects. However, its effect on human osteosarcoma progression remains uninvestigated. Therefore, we examined the effectiveness of nobiletin against cellular metastasis of human osteosarcoma and the underlying mechanisms. Nobiletin, up to 100 μM without cytotoxicity, significantly decreased motility, migration and invasion as well as enzymatic activities, protein levels and mRNA expressions of matrix metalloproteinase (MMP)-2 and MMP-9 in U2OS and HOS cells. In addition to inhibition of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), the inhibitory effect of nobiletin on the DNA-binding activity of the transcription factor nuclear factor-kappa B (NF-κB), cAMP response element-binding protein (CREB), and specificity protein 1 (SP-1) in U2OS and HOS cells. Co-treatment with ERK and JNK inhibitors and nobiletin further reduced U2OS cells migration and invasion. These results indicated that nobiletin inhibits human osteosarcoma U2OS and HOS cells motility, migration and invasion by down-regulating MMP-2 and MMP-9 expressions via ERK and JNK pathways and through the inactivation of downstream NF-κB, CREB, and SP-1. Nobiletin has the potential to serve as an anti-metastatic agent for treating osteosarcoma.

The Multifunctional Effects of Nobiletin and Its Metabolites In Vivo and In Vitro

Nobiletin (NOB) chemically known as 5,6,7,8,3′,4′-hexamethoxyflavone is a dietary polymethoxylated flavonoid found in Citrus fruits. Recent evidences show that NOB is a multifunctional pharmaceutical agent. The various pharmacological activities of NOB include neuroprotection, cardiovascular protection, antimetabolic disorder, anticancer, anti-inflammation, and antioxidation. These events may be underpinned by modulation of signaling cascades, including PKA/ERK/MEK/CREB, NF-κB, MAPK, Ca²⁺/CaMKII, PI3K/Akt1/2, HIF-1α, and TGFβ signaling pathways. The metabolites may exhibit stronger beneficial effects than NOB on diseases pathogenesis. The biological activities of NOB have been clarified on many systems. This review aims to discuss the pharmacological effects of NOB with specific mechanisms of actions. NOB may become a promising candidate for potential drug development. However, further investigations of NOB on specific intracellular targets and clinical trials are still needed, especially for in vivo medical applications.

Herbal Medicine Offered as an Initiative Therapeutic Option for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common malignant cancer and is the third leading cause of death worldwide. Effective treatment of this disease is limited by the complicated molecular mechanism underlying HCC pathogenesis. Thus, therapeutic options for HCC management are urgently needed. Targeting the Wnt/β-catenin, Hedgehog, Notch, and Hippo-YAP signaling pathways in cancer stem cell development has been extensively investigated as an alternative treatment. Herbal medicine has emerged as an initiative therapeutic option for HCC management because of its multi-level, multi-target, and coordinated intervention effects. In this article, we summarized the recent progress and clinical benefits of targeting the above mentioned signaling pathways and using natural products such as herbal medicine formulas to treat HCC. Proving the clinical success of herbal medicine is expected to deepen the knowledge on herbal medicine efficiency and hasten the adoption of new therapies. Copyright © 2016 John Wiley & Sons, Ltd.

Preventive and Therapeutic Effects of Chinese Herbal Compounds against Hepatocellular Carcinoma

Traditional Chinese Medicines, unique biomedical and pharmaceutical resources, have been widely used for hepatocellular carcinoma (HCC) prevention and treatment. Accumulated Chinese herb-derived compounds with significant anti-cancer effects against HCC have been identified. Chinese herbal compounds are effective in preventing carcinogenesis, inhibiting cell proliferation, arresting cell cycle, inducing apoptosis, autophagy, cell senescence and anoikis, inhibiting epithelial-mesenchymal transition, metastasis and angiogenesis, regulating immune function, reversing drug resistance and enhancing the effects of chemotherapy in HCC. This paper comprehensively reviews these compounds and their effects on HCC. Finally, the perspectives and rational application of herbal compounds for HCC management are discussed.

Nobiletin enhances the efficacy of chemotherapeutic agents in ABCB1 overexpression cancer cells

Multidrug resistance (MDR) is the major obstacle to the successful chemotherapy treatment of many cancers. Here we found that nobiletin, a citrus methoxyflavone, significantly sensitized ABCB1 overexpressing cells A2780/T and A549/T to chemotherapeutic agents such as paclitaxel (a 433-fold reversal of MDR to PTX at 9 μM), doxorubicin (DOX), docetaxel and dounorubicin. Nobiletin profoundly inhibited ABCB1 transporter activity since it significantly increased the intracellular accumulation of DOX and Flutax-2 in A2780/T cells and decreased the efflux of ABCB1 substrates in Caco2 cells without altering the mRNA and protein expression of ABCB1. Moreover, nobiletin stimulated ATPase activity and inhibited verapamil-stimulated ATPase activity in a concentration-dependent manner, indicating a direct interaction with the transporter. Consistent with these findings, molecular docking analysis also identified favorable binding of nobiletin with the transmemberane region site 1 of homology modeled human ABCB1 transporter. Moreover, the Nrf2 protein expression and phosphorylation levels of AKT/ERK were suppressed by co-treated with nobiletin and PTX at the reversal concentrations, suggesting that inhibition of the AKT/ERK/Nrf2 pathway was associated with the sensitizing effect of nobiletin. These findings encourage further animal and clinical MDR studies with the combination therapy of nobiletin and chemotherapeutic drugs.

Nobiletin, a Polymethoxylated Flavone, Inhibits Glioma Cell Growth and Migration via Arresting Cell Cycle and Suppressing MAPK and Akt Pathways

Nobiletin, a bioactive polymethoxylated flavone (5,6,7,8,3(') ,4(') -hexamethoxyflavone), is abundant in citrus fruit peel. Although nobiletin exhibits antitumor activity against various cancer cells, the effect of nobiletin on glioma cells remains unclear. The aim of this study was to determine the effects of nobiletin on the human U87 and Hs683 glioma cell lines. Treating glioma cells with nobiletin (20-100 µm) reduced cell viability and arrested the cell cycle in the G0/G1 phase, as detected using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and propidium iodide (PI) staining, respectively; however, nobiletin did not induce cell apoptosis according to PI-annexin V double staining. Data from western blotting showed that nobiletin significantly attenuated the expression of cyclin D1, cyclin-dependent kinase 2, cyclin-dependent kinase 4, and E2 promoter-binding factor 1 (E2F1) and the phosphorylation of Akt/protein kinase B and mitogen-activated protein kinases, including p38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase. Our data also showed that nobiletin inhibited glioma cell migration, as detected by both functional wound healing and transwell migration assays. Altogether, the present results suggest that nobiletin inhibits mitogen-activated protein kinase and Akt/protein kinase B pathways and downregulates positive regulators of the cell cycle, leading to subsequent suppression of glioma cell proliferation and migration. Our findings evidence that nobiletin may have potential for treating glioblastoma multiforme.

Efficient delivery of ursolic acid by poly(N-vinylpyrrolidone)-block-poly (ε-caprolactone) nanoparticles for inhibiting the growth of hepatocellular carcinoma in vitro and in vivo

Previous reports have shown that ursolic acid (UA), a pentacyclic triterpenoid derived from Catharanthus trichophyllus roots, could inhibit the growth of a series of cancer cells. However, the potential for clinical application of UA is greatly hampered by its poor solubility, whereas the hydrophobicity of UA renders it a promising model drug for nanosized delivery systems. In the current study, we loaded UA into amphiphilic poly(N-vinylpyrrolidone)-block-poly (ε-caprolactone) nanoparticles and performed physiochemical characterization as well as analysis of the releasing capacity. In vitro experiments indicated that UA-NPs inhibited the growth of liver cancer cells and induced cellular apoptosis more efficiently than did free UA. Moreover, UA-NPs significantly delayed tumor growth and localized to the tumor site when compared with the equivalent dose of UA. In addition, both Western blotting and immunohistochemistry suggested that the possible mechanism of the superior efficiency of UA-NPs is mediation by the regulation of apoptosis-related proteins. Therefore, UA-NPs show potential as a promising nanosized drug system for liver cancer therapy.

Nobiletin inhibits invasion and migration of human nasopharyngeal carcinoma cell lines by involving ERK1/2 and transcriptional inhibition of MMP-2

OBJECTIVE

Nasopharyngeal carcinoma (NPC) is known for its high incidence of neck lymph node metastasis, which represents poor prognosis. Nobiletin is a citrus polymethoxyflavonoid that suppresses tumor growth and metastasis, both of which depend on angiogenesis in previous studies. However, the effect of Nobiletin on human NPC cells metastasis has not been clearly clarified.

RESEARCH DESIGN AND METHODS

In this study, we determine the effects of Nobiletin on the migration and invasion in NPC cells.

RESULTS

Nobiletin significantly inhibited migration/invasion capacities of HONE-1 and NPC-BM cell lines. The results of gelatin zymography and western blotting revealed that the activities and protein levels of the MMP-2 were inhibited by Nobiletin. Nobiletin also showed that inhibits phosphorylation of ERK1/2. Tests of the real-time PCR and promoter assays evaluated the inhibitory effects of Nobiletin on MMP-2 expression in human NPC cells. Nobiletin inhibits MMP-2 expression, up-regulating tissue inhibitor of metalloproteinase-2 and down-regulation of the transcription factors of NF-κB and activator protein 1 (AP-1) signaling pathways. Finally, an administration of Nobiletin effectively suppressed the tumor formation and metastasis in the NPC xenograft model in vivo.

CONCLUSIONS

Nobiletin may have potential use as a chemo-preventive agent against nasopharyngeal cancer metastasis.

Nobiletin suppresses the proliferation and induces apoptosis involving MAPKs and caspase-8/-9/-3 signals in human acute myeloid leukemia cells

Nobiletin, a compound isolated from citrus fruits, is a polymethoxylated flavone derivative that was shown to have anti-inflammatory and anticancer activities in various solid tumors. The anticancer effect of nobiletin on nonsolid tumor remains unclear. Herein, the molecular mechanisms by which nobiletin exerts its anticancer effects on acute myeloid leukemia (AML) cells were investigated. The results showed that nobiletin suppressed cell proliferation in various types of AML cell lines. Moreover, nobiletin induced cell-cycle arrest of HL-60 AML cells at the G0/G1 phase by suppressing extracellular signal-regulated kinase (ERK) activity. Furthermore, nobiletin effectively induced apoptosis of HL-60 cells through caspase-8, caspase-9, and caspases-3 activation concomitantly with a marked induction of p38 mitogen-activated protein kinase (MAPK) activation, but without affecting expression levels of Bcl-2, Bax, or Bid. Taken together, our results suggest that nobiletin inhibited HL-60 cell proliferation through inducing cell-cycle arrest and apoptosis and could serve as a potential additional chemotherapeutic agent for treating AML.

Nobiletin suppresses the proliferation and induces apoptosis involving MAPKs and caspase-8/-9/-3 signals in human acute myeloid leukemia cells

Nobiletin, a compound isolated from citrus fruits, is a polymethoxylated flavone derivative that was shown to have anti-inflammatory and anticancer activities in various solid tumors. The anticancer effect of nobiletin on nonsolid tumor remains unclear. Herein, the molecular mechanisms by which nobiletin exerts its anticancer effects on acute myeloid leukemia (AML) cells were investigated. The results showed that nobiletin suppressed cell proliferation in various types of AML cell lines. Moreover, nobiletin induced cell-cycle arrest of HL-60 AML cells at the G0/G1 phase by suppressing extracellular signal-regulated kinase (ERK) activity. Furthermore, nobiletin effectively induced apoptosis of HL-60 cells through caspase-8, caspase-9, and caspases-3 activation concomitantly with a marked induction of p38 mitogen-activated protein kinase (MAPK) activation, but without affecting expression levels of Bcl-2, Bax, or Bid. Taken together, our results suggest that nobiletin inhibited HL-60 cell proliferation through inducing cell-cycle arrest and apoptosis and could serve as a potential additional chemotherapeutic agent for treating AML.