Diosmetin inhibits the metastasis of hepatocellular carcinoma cells by downregulating the expression levels of MMP-2 and MMP-9

Diosmetin as a promising natural therapeutic agent: In vivo, in vitro mechanisms, and clinical studies

Diosmetin, a natural occurring flavonoid, is primarily found in citrus fruits, beans, and other plants. Diosmetin demonstrates a variety of pharmacological activities, including anticancer, antioxidant, anti-inflammatory, antibacterial, metabolic regulation, cardiovascular function improvement, estrogenic effects, and others. The process of literature search was done using PubMed, Web of Science and ClinicalTrials databases with search terms containing Diosmetin, content, anticancer, anti-inflammatory, antioxidant, pharmacological activity, pharmacokinetics, in vivo, and in vitro. The aim of this review is to summarize the in vivo, in vitro and clinical studies of Diosmetin over the last decade, focusing on studies related to its anticancer, anti-inflammatory, and antioxidant activities. It is found that DIO has significant therapeutic effects on skin and cardiovascular system diseases, and its research in pharmacokinetics and toxicology is summarized. It provides the latest information for researchers and points out the limitations of current research and areas that should be strengthened in future research, so as to facilitate the relevant scientific research and clinical application of DIO.

miR‑576‑3p/M‑phase phosphoprotein 8 axis regulates the malignant progression of hepatocellular carcinoma cells via the PI3K/Akt signaling pathway

Hepatocellular carcinoma (HCC) is a fatal digestive system cancer with unclear pathogenesis. M-phase phosphoprotein 8 (MPP8) has been shown to play a vital role in several cancer types, such as non-small cell lung cancer, gastric cancer and melanoma; however, there have been no studies into its role in HCC. The present study aimed to evaluate the role of MPP8 in regulating malignant phenotypes of liver cancer cells, and to further investigate the underlying mechanism. Bioinformatics analysis was performed to analyze related data from a public database, and to predict the potential microRNAs (miRNAs) that might target MPP8 mRNA; reverse transcription-quantitative PCR was used to measure the levels of mRNA and miRNA; western blotting was employed to detect protein levels; Cell Counting Kit-8 (CCK-8) and plate colony formation assays, wound healing assay and Transwell invasion assay were performed to evaluate the ability of cell proliferation, migration and invasion, respectively; dual-luciferase reporter gene assay was performed to identify the target association. The results showed that MPP8 was a risk factor for the survival of patients with HCC, and was up-regulated in HCC tissue samples and cell lines; MPP8 knockdown inhibited the proliferation, migration and invasion of liver cancer cells; MPP8 knockdown suppressed the PI3K/Akt pathway, and activation of this pathway reversed the inhibited liver cancer cell phenotypes by down-regulating MPP8; miR-576-3p, which was low in liver cancer cells, negatively regulated MPP8 expression by directly targeting its mRNA; up-regulating MPP8 expression reversed the inhibited signaling pathway and malignant phenotypes of liver cancer cells by miR-576-3p overexpression. In conclusion, the miR-576-3p/MPP8 axis regulates the proliferation, migration, and invasion of liver cancer cells through the PI3K/Akt signaling pathway. These findings lead novel insights into HCC progression, and propose MPP8 as a potential therapeutic target for HCC.

Diosmetin: A dietary flavone as modulator of signaling pathways in cancer progression

Flavonoids, constituting the most extensive category of polyphenols, founds in a variety of plants and comprise over 9000 compounds. Diosmetin, O-methylated flavone (3',5,7-trihydroxy-4'-methoxyflavone) of flavonoid aglycone diosmin have witnessed a significant surge in recent years. Many studies showed that flavonoids induced cytotoxicity in different organ specific cancer types. Thus, current review evaluates the anticancer potential of diosmetin and shed light on its mechanism of action such as cell cycle regulation, apoptosis via both intrinsic and extrinsic pathway, autophagy and tumour progression and metastasis. It also provides comprehensive analysis of different cancer targets and their role in breast, colon, hepatic, gliomas, leukemia, lung, prostate and skin cancer. Combination studies of diosmetin to improve drug sensitivity and reduce toxicity towards normal cells has been also discussed. Besides, in vitro studies, present review also discuss the anticancer potential of diosmetin on xenograft mice model. Different natural sources of diosmetin, limitations, pharmacokinetic analysis and toxicity study also summarized in current review. The emphasis on enhancing solubility and permeability for clinical utility has been thoroughly highlighted with particular attention given to the utilization of nano formulations to overcome existing barriers. At last, in-depth analysis of current challenges and a forward-looking perspective deliberated to address the existing gaps and position it as a promising lead compound for clinical applications in cancer treatment. This discussion is boosted by diosmetin's potential anticancer properties on different cancers, makes valuable candidates in the ongoing quest for effective therapeutic interventions against cancer.

Diosmetin suppresses the progression of ESCC by CDK2/Rb/E2F2/RRM2 pathway and synergies with cisplatin

Cisplatin (CDDP) is the first-line drug in the clinical treatment of esophageal squamous cell carcinoma (ESCC), which has severe nephrotoxicity. Diosmetin (DIOS) can protect kidney from oxidative damage, however, its function in ESCC is unknown. This study aims to explore the effect and mechanism of DIOS on ESCC and its combined effect with CDDP. Herein, we found that DIOS significantly inhibited the progression of ESCC in vitro and in vivo. Furthermore, the anti-tumor effect of DIOS was not statistically different from that of CDDP. Mechanically, transcriptomics revealed that DIOS inhibited the E2F2/RRM2 signaling pathway. The transcriptional regulation of RRM2 by E2F2 was verified by luciferase assay. Moreover, docking model, CETSA, pull-down assay and CDK2 inhibitor assay confirmed that DIOS directly targeted CDK2, leading to significant suppression of ESCC. Additionally, the patient-derived xenografts (PDX) model showed that the combination of DIOS and CDDP significantly inhibited the growth of ESCC. Importantly, the combined treatment with DIOS and CDDP significantly reduced the mRNA expression levels of kidney injury biomarkers KIM-1 and NGAL in renal tissue, as well as the levels of blood urea nitrogen, serum creatinine and blood uric acid compared to the single treatment with CDDP. In conclusion, DIOS could be an effective drug and a potential chemotherapeutic adjuvant for ESCC treatment. Furthermore, DIOS could reduce the nephrotoxicity of CDDP to some extent.

Effects of Flavonoids on Cancer, Cardiovascular and Neurodegenerative Diseases: Role of NF-κB Signaling Pathway

Flavonoids are polyphenolic phytochemical compounds found in many plants, fruits, vegetables, and leaves. They have a multitude of medicinal applications due to their anti-inflammatory, antioxidative, antiviral, and anticarcinogenic properties. Furthermore, they also have neuroprotective and cardioprotective effects. Their biological properties depend on the chemical structure of flavonoids, their mechanism of action, and their bioavailability. The beneficial effects of flavonoids have been proven for a variety of diseases. In the last few years, it is demonstrated that the effects of flavonoids are mediated by inhibiting the NF-κB (Nuclear Factor-κB) pathway. In this review, we have summarized the effects of some flavonoids on the most common diseases, such as cancer, cardiovascular, and human neurodegenerative diseases. Here, we collected all recent studies describing the protective and prevention role of flavonoids derived from plants by specifically focusing their action on the NF-κB signaling pathway.

Plant-derived natural products and combination therapy in liver cancer

Liver cancer is one of the malignant cancers globally and seriously endangers human health because of its high morbidity and mortality. Plant-derived natural products have been evaluated as potential anticancer drugs due to low side effects and high anti-tumor efficacy. However, plant-derived natural products also have defects of poor solubility and cumbersome extraction process. In recent years, a growing numbers of plant derived natural products have been used in combination therapy of liver cancer with conventional chemotherapeutic agents, which has improved clinical efficacy through multiple mechanisms, including inhibition of tumor growth, induction of apoptosis, suppression of angiogenesis, enhancement of immunity, reversal of multiple drug resistance and reduction of side effects. The therapeutic effects and mechanisms of plant-derived natural products and combination therapy on liver cancer are reviewed to provide references for developing anti-liver-cancer strategies with high efficacy and low side effects.

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

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

ASIC1α up-regulates MMP-2/9 expression to enhance mobility and proliferation of liver cancer cells via the PI3K/AKT/mTOR pathway

A major challenge in the treatment of liver cancer is that a large proportion of patients fail to achieve long-term disease control, with death from liver cancer cell migration and invasion. Acid-sensitive ion channel 1α (ASIC1α) is involved in the migration, invasion, and proliferation of liver cancer cells. Therefore, we explored the mechanism of ASIC1α-mediated liver cancer cell migration and invasion. We determined the levels of ASIC1α by western blotting and immunofluorescence in HepG2 and SK-Hep1 cells cultured in various acidic conditions. In addition, wound healing assay, transwell invasion assay, and MTT assay were conducted to assess the migration, invasion, and proliferation abilities of liver cancer cells. Western blotting was conducted to determine the levels of MMP2, MMP9, ASIC1α, p-PI3Kp85, t-PI3Kp85, p-AKT(Ser473), t-AKT, p-mTOR (Ser2448), t-mTOR. We first found that the levels of ASIC1α in the HepG2 and SK-Hep1 cells in acidic conditions (pH 6.5) were significantly increased. Inhibition and knockdown of ASIC1α down-regulated MMP-2/9 expression and inhibited the migration, invasion, and proliferation of HepG2 and SK-Hep1 cells; overexpression of ASIC1α had the opposite effect. We further demonstrated that ASIC1α up-regulates MMP-2/9 via activation of the PI3K/AKT/mTOR pathway, thereby promoting migration, invasion, and proliferation of liver cancer cells. Overexpression of MMP-2/9 and activation of AKT reversed these effects on liver cancer cells caused by inhibition of ASIC1α. We conclude that ASIC1α can regulate migration, invasion, and proliferation of liver cancer cells through the MMP-2/9/PI3K/AKT/mTOR pathway. These observations may provide a new reference for liver cancer chemotherapy.

Tubeimoside-1: A review of its antitumor effects, pharmacokinetics, toxicity, and targeting preparations

Tubeimoside-1 (TBMS-1), a natural triterpenoid saponin found in traditional Chinese herbal medicine Bolbostemmatis Rhizoma, is present in numerous Chinese medicine preparations. This review aims to comprehensively describe the pharmacology, pharmacokinetics, toxicity and targeting preparations of TBMS-1, as well the therapeutic potential for cancer treatement. Information concerning TBMS-1 was systematically collected from the authoritative internet database of PubMed, Web of Science, and China National Knowledge Infrastructure applying a combination of keywords involving “tumor,” “pharmacokinetics,” “toxicology,” and targeting preparations. New evidence shows that TBMS-1 possesses a remarkable inhibitory effect on the tumors of the respiratory system, digestive system, nervous system, genital system as well as other systems in vivo and in vitro. Pharmacokinetic studies reveal that TBMS-1 is extensively distributed in various tissues and prone to degradation by the gastrointestinal tract after oral administration, causing a decrease in bioavailability. Meanwhile, several lines of evidence have shown that TBMS-1 may cause adverse and toxic effects at high doses. The development of liver-targeting and lung-targeting preparations can reduce the toxic effect of TBMS-1 and increase its efficacy. In summary, TBMS-1 can effectively control tumor treatment. However, additional research is necessary to investigate in vivo antitumor effects and the pharmacokinetics of TBMS-1. In addition, to reduce the toxicity of TBMS-1, future research should aim to modify its structure, formulate targeting preparations or combinations with other drugs.

Enabled homolog (ENAH) regulated by RNA binding protein splicing factor 3b subunit 4 (SF3B4) exacerbates the proliferation, invasion and migration of hepatocellular carcinoma cells via Notch signaling pathway

Enabled homolog (ENAH) is an actin-binding protein that implicated in multiple malignant tumors. High ENAH expression has been verified to be associated with poor prognosis in hepatocellular carcinoma (HCC). We aimed to reveal the role of ENAH in HCC and the potential mechanism. ENAH expression in HCC tissues and the prognostic correlation were analyzed by GEPIA2 database. RT-qPCR and Western blot were used to test ENAH expression in HCC cells. Following ENAH silencing, cell proliferation was estimated by CCK-8 and colony formation assays. Transwell and wound healing assays were to assess cell invasion and migration. ENCORI database was to analyze the correlation between ENAH and splicing factor 3b subunit 4 (SF3B4) in HCC tissues, which was then verified by RIP and actinomycin D assay. Then, the expression of Notch signaling-related proteins was detected by Western blotting after ENAH knockdown. Afterward, Notch1 was overexpressed to validate whether ENAH impacted the biological events of HCC cells through mediating Notch signaling. Results revealed that ENAH expression was elevated in HCC tissues and cells and associated with poor prognosis. ENAH deficiency mitigated proliferation, invasion and migration of HCC cells. Mechanistically, ENAH was positively correlated with SF3B4 in HCC tissues. SF3B4 could bind to ENAH mRNA and stabilized ENAH. Besides, ENAH activated Notch signaling. Notch1 up-regulation reversed the influence of ENAH knockdown on biological events of HCC cells. Collectively, ENAH regulated by SF3B4 promoted the development of HCC through activating Notch signaling, which identified ENAH as a potent molecular target for HCC therapy and prognosis.

Exosomal microRNA-15a from mesenchymal stem cells impedes hepatocellular carcinoma progression via downregulation of SALL4

Hepatocellular carcinoma (HCC) is a heterogeneous tumor with an increased incidence worldwide accompanied by high mortality and dismal prognosis. Emerging evidence indicates that mesenchymal stem cells (MSCs)-derived exosomes possess protective effects against various human diseases by transporting microRNAs (miRNAs or miRs). We aimed to explore the role of exosomal miR-15a derived from MSCs and its related mechanisms in HCC. Exosomes were isolated from transduced MSCs and co-incubated with Hep3B and Huh7 cells. miR-15a expression was examined by RT-qPCR in HCC cells, MSCs, and secreted exosomes. CCK-8, transwell, and flow cytometry were used to detect the effects of miR-15a or spalt-like transcription factor 4 (SALL4) on cell proliferative, migrating, invasive, and apoptotic properties. A dual-luciferase reporter gene assay was performed to validate the predicted targeting relationship of miR-15a with SALL4. Finally, in vivo experiments in nude mice were implemented to assess the impact of exosome-delivered miR-15a on HCC. The exosomes from MSCs restrained HCC cell proliferative, migrating, and invasive potentials, and accelerated their apoptosis. miR-15a was expressed at low levels in HCC cells and could bind to SALL4, thus curtailing the proliferative, migrating, and invasive abilities of HCC cells. Exosomes successfully delivered miR-15a to HCC cells. Exosomal miR-15a depressed tumorigenicity and metastasis of HCC tumors in vivo. Overall, exosomal miR-15a from MSCs can downregulate SALL4 expression and thereby retard HCC development.

Heparan sulfate proteoglycans and their modification as promising anticancer targets in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of primary liver cancer. Despite advancements in the treatment strategies of HCC, there is an urgent requirement to identify and develop novel therapeutic drugs that do not lead to resistance. These novel agents should have the potential to influence the primary mechanisms participating in the pathogenesis of HCC. Heparan sulfate proteoglycans (HSPGs) are major elements of the extracellular matrix that perform structural and signaling functions. HSPGs protect against invasion of tumor cells by preventing cell infiltration and intercellular adhesion. Several enzymes, such as heparanase, matrix metalloproteinase-9 and sulfatase-2, have been reported to affect HSPGs, leading to their degradation and thus enhancing tumor invasion. In addition, some compounds that are produced from the degradation of HSPGs, including glypican-3 and syndecan-1, enhance tumor progression. Thus, the identification of enzymes that affect HSPGs or their degradation products in HCC may lead to the development of novel therapeutic targets. The present review discusses the main enzymes and compounds associated with HSPGs, and their involvement with the pathogenicity of HCC.

Diosmetin Induces Apoptosis by Downregulating AKT Phosphorylation via P53 Activation in Human Renal Carcinoma ACHN Cells

Background:

Diosmetin (DIOS) is the aglycone of the flavonoid glycoside, diosmin, derived naturally from the leaves of the legume, Olea europaea, and Acacia farnesiana. It has potent anticancer activity against multiple forms of cancers. However, the role of DIOS in renal carcinoma and its mechanism of action remain unclear.

Objective:

The purpose of this study is to investigate the effect of DIOS on cell viability and apoptosis in renal carcinoma cells and explore the possible mechanism of action.

Methods:

Cell viability, cytotoxicity, caspase activity, apoptosis, and expression of apoptotic related proteins were analyzed in renal carcinoma ACHN cells.

Results:

The results showed that DIOS inhibited the cell viability, and induced cytotoxicity and apoptosis in ACHN cells. Furthermore, DIOS increased expression of p53 mRNA and proteins, and downregulated phosphorylation of the phosphoinositide 3-kinase and protein B kinase (PI3K/AKT). In addition, it was observed that the anticancer effect of DIOS was significantly enhanced by the p53 activator, but inhibited by the p53 inhibitor.

Conclusion:

Our data suggested that DIOS induced apoptosis in renal carcinoma ACHN cells by reducing AKT phosphorylation through p53 upregulation.

Diosmetin enhances the sensitivity of radiotherapy by suppressing homologous recombination in endometrial cancer

Radiotherapy is an essential treatment for endometrial cancer (EC), especially in advanced, metastatic, and recurrent cases. Combining radiotherapy, which mainly causes DNA double-strand breaks (DSBs), with small molecules targeting aberrantly activated homologous recombination (HR) repair pathways holds great potential for treating ECs in advanced stages. Here, we demonstrate that diosmetin (DIO), a natural flavonoid, suppresses HR, therefore inhibiting cell proliferation and enhancing the sensitivity of EC to radiotherapy. Clonogenic experiments revealed that combining DIO and X-ray significantly inhibited the viability of EC cells compared to cells treated with diosmetin or X-ray alone. The survival fraction of EC cells decreased to 40% when combining 0.4 Gy X-ray and 4 μM DIO; however, each treatment alone only caused death in approximately 15% and 22% of cancer cells, respectively. Further mechanistic studies showed that diosmetin inhibited the recruitment of RPA2 and RAD51, two critical factors involved in the HR repair pathway, upon the occurrence of DSBs. Thus, we propose that a combination of diosmetin and irradiation is a promising therapeutic strategy for treating endometrial cancer.

Catechol inhibits epidermal growth factor-induced epithelial-to-mesenchymal transition and stem cell-like properties in hepatocellular carcinoma cells

Epithelial-mesenchymal transition (EMT) is a major cellular process in which epithelial cells lose cell polarity and cell-cell adhesion and become motility and invasiveness by transforming into mesenchymal cells. Catechol is one of the natural compounds present in fruits and vegetables and has various pharmacological and physiological activities including anti-carcinogenic effects. However, the effects of catechol on EMT has not been reported. Epidermal growth factor (EGF) is one of the growth factors and is known to play a role in inducing EMT. The present study showed that catechol suppressed not only the morphological changes to the mesenchymal phenotype of epithelial HCC cells, but also the reduction of E-cadherin and the increment of Vimentin, which are typical hallmark of EMT. In addition, catechol suppressed EMT-related steps such as migration, invasion, anoikis resistance acquisition, and stem cell-like characterization through the EGFR-AKT-ERK signaling pathway during liver cancer metastasis. Therefore, these results suggest that catechol may be able to regulate the early metastasis of liver cancer in vitro.

Inhibitory effect of diosmetin on inflammation and lipolysis in coculture of adipocytes and macrophages

The interaction between adipocytes and macrophages in obese tissues plays a critical role in the onset of metabolic syndromes. This study aimed to evaluate the modulatory effect of diosmetin on anti-inflammatory and anti-lipolytic activities in the coculture of macrophages and adipocytes. The secretion of inflammatory mediators increased in a coculture medium, however, diosmetin significantly reduced the levels of these inflammatory mediators such as nitric oxide (NO), tumor necrosis factor-α, and monocyte chemoattractant protein. Diosmetin down-regulated the protein expression of inducible NO synthase in cocultured macrophages and adipocytes, and inhibited the phosphorylation of mitogen-activated protein kinases and the translocation of p65 and p50 to the nucleus. Moreover, it suppressed the phosphorylation of hormone-sensitive lipase and the production of fatty acid-binding protein 4, and increased the mRNA expression of adiponectin in cocultured adipocytes by 18%-35%. These results indicate that diosmetin inhibited inflammation and lipolysis in the crosstalk between adipocytes and macrophages; diosmetin-containing foods could be used in dietary therapy for the prevention of obesity-related metabolic syndromes. PRACTICAL APPLICATIONS: Diosmetin occurs naturally in citrus fruits that have a high inhibitory effect on inflammation in cocultured adipocytes and macrophages via the inactivation of the MAPKs/NF-kB pathway. Diosmetin also inhibited lipolysis via the reduction of FFA and free glycerol. The present study suggests that treatment of diosmetin may be useful for the prevention of obesity and inflammation-related metabolic syndromes.

FOXP3 promotes colorectal carcinoma liver metastases by evaluating MMP9 expression via regulating S-adenosylmethionine metabolism

Background

Growing evidence has proved that Forkhead box protein 3 (FOXP3), which is a master regulatory gene in the development and function of regulatory T-cells, is expressed in human cancer cells. This expression indicates the crucial role FOXP3 takes up as the disease progresses. However, its role in colorectal cancer (CRC) liver metastasis is still mostly unknown. This study set out to explore the molecular characteristics of FOXP3 in driving the liver metastasis within CRC.

Methods

We downloaded the RNA-seq data from the GSE50760. Weighted gene co-expression network analysis (WGCNA)WGCNA and RNA-Seq analysis were applied to find the key gene network associated with colorectal cancer liver metastasis. Then we performed pathway enrichment analysis on liver metastasis-associated gene set. Immunohistochemistry, in vitro and in vivo studies were conducted to test expression and function of FOXP3 in CRC tissues and liver metastasis tissues. Non-targeted metabolomics analysis was performed to identify the alteration of FOXP3 expression in metabolites of colorectal cancer liver metastasis. Western blot was performed to confirm changes of matrix metalloproteinase 9MMP9 expression were downstream events of S-adenosyl-methionine (SAM).

Results

We found that FOXP3 and MMP9 exhibited co-expression relationships and affected liver metastasis in CRC. Upregulation of FOXP3 promotes cell migration and invasion in CRC, which suggests a pro-cancer effect. Moreover, metabolomics analysis showed that knockdown of FOXP3 significantly reduced SAM levels, and changes of MMP9 expression were downstream events of SAM, which is concentration-dependent. Besides, The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Western blot analysis confirmed that overexpression of FOXP3 activates the Wnt pathway to promote colon cancer metastasis.

Conclusions

Our results altogether suggested that FOXP3 expression inhibited the SAM cycle to reduce SAMe levels, resulting in altered MMP9 expression and helped CRC liver metastasis.

Citrus Flavones: An Update on Sources, Biological Functions, and Health Promoting Properties

Citrus spp. are among the most widespread plants cultivated worldwide and every year millions of tons of fruit, juices, or processed compounds are produced and consumed, representing one of the main sources of nutrients in human diet. Among these, the flavonoids play a key role in providing a wide range of health beneficial effects. Apigenin, diosmetin, luteolin, acacetin, chrysoeriol, and their respective glycosides, that occur in concentrations up to 60 mg/L, are the most common flavones found in Citrus fruits and juices. The unique characteristics of their basic skeleton and the nature and position of the substituents have attracted and stimulated vigorous investigations as a consequence of an enormous biological potential, that manifests itself as (among other properties) antioxidant, anti-inflammatory, antiviral, antimicrobial, and anticancer activities. This review analyzes the biochemical, pharmacological, and biological properties of Citrus flavones, emphasizing their occurrence in Citrus spp. fruits and juices, on their bioavailability, and their ability to modulate signal cascades and key metabolic enzymes both in vitro and in vivo. Electronic databases including PubMed, Scopus, Web of Science, and SciFinder were used to investigate recent published articles on Citrus spp. in terms of components and bioactivity potentials.

Interference with SMO increases chemotherapy drug sensitivity of A2780/DDP cells by inhibiting the Hh/Gli signaling pathway

Aberrant activation of the Hedgehog (Hh)/Gli pathway contributes to the tumorigenesis of several human cancers, including ovarian cancers. We investigated the function of SMO on cell growth, drug resistance, and invasive ability in A2780/DDP cells. Moreover, we also tested the levels of the downstream target genes of the Hh/Gli pathway in SMO short hairpin RNA (shRNA) lentivirus-infected A2780/DDP cells. Western blot analysis results revealed that the Hh/Gli pathway was activated in cisplatin-resistant A2780/DDP cells. After infection by SMO shRNA lentivirus, the colony formation rate and invasive rate of cisplatin-resistant A2780/DDP cells were decreased. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that upon transfection with SMO shRNA, cell growth was decreased and drug sensitivity to cisplatin was upregulated. Moreover, interference with SMO decreased the expression of MMP-2, MMP-9, VEGF, and Snail in cisplatin-resistant cells. Thus, the Hh/Gli signaling pathway was aberrantly activated in A2780/DDP cells. The colony formation rate and invasive rate were decreased in SMO shRNA lentivirus-infected A2780/DDP cells. All results showed that inhibiting Hh/Gli signaling may negatively regulate the proliferation, invasion, and metastasis of cisplatin-resistant A2780/DDP cells, as well as increase the sensitivity of A2780/DDP to the chemotherapeutic drug of cisplatin.

Diosmetin exhibits anti-proliferative and anti-inflammatory effects on TNF-α-stimulated human rheumatoid arthritis fibroblast-like synoviocytes through regulating the Akt and NF-κB signaling pathways

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by inflammation and proliferation of synovial tissues. Diosmetin is a bioflavonoid possessing an anti-inflammatory property. Herein, we aimed to study the effects of diosmetin on the inflammation and proliferation of RA fibroblast-like synoviocytes MH7A cells. MH7A cell proliferation was measured using cell counting kit-8 assay. Cell apoptosis was examined using flow cytometry. The production of inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-8, and matrix metalloproteinase-1 (MMP-1) was measured using enzyme-linked immunosorbent assay (ELISA). Results showed that diosmetin inhibited tumor necrosis factor-α (TNF-α)-induced proliferation increase in MH7A cells in a dose-dependent manner. Diosmetin treatment resulted in an increase in apoptotic rates and a reduction in TNF-α-induced production of IL-1β, IL-6, IL-8, and MMP-1 in MH7A cells. Furthermore, diosmetin inhibited TNF-α-induced activation of protein kinase B (Akt) and nuclear factor-κB (NF-κB) pathways in MH7A cells. Suppression of Akt or NF-κB promoted apoptosis and inhibited TNF-α-induced proliferation increase and production of IL-1β, IL-6, IL-8, and MMP-1 in MH7A cells, and diosmetin treatment enhanced these effects. Taken together, these findings suggested that diosmetin exhibited anti-proliferative and anti-inflammatory effects via inhibiting the Akt and NF-κB pathways in MH7A cells.

Traditional Chinese Medicine in Oncotherapy: The Research Status

In China, Traditional Chinese Medicine (TCM) plays a vital role in the comprehensive treatment of cancer. As an auxiliary and supplement of major treatment modalities for cancer such as surgery, chemotherapy, and radiotherapy, both clinical observations and biomolecular research have confirmed the therapeutic efficacy of TCM in cancer.

Structural Insight into the In Vitro Anti-Intravasative Properties of Flavonoids

We investigated the effect of 21 flavonoids in a three-dimensional in vitro system for their ability to inhibit gap formation by MCF-7 breast cancer spheroids in monolayers of lymphendothelial cells. Different representatives of the classes of flavones, flavonols, and flavanones were tested in the circular chemorepellent-induced defects (CCID)-assay. Bay11-7082, a known inhibitor of CCID formation served as the positive control. This study provides the first comparison of the potential of flavonoids to suppress features influencing the intravasation of MCF-7 breast cancer cells aggregates through the lymph endothelial barrier. The most significant effects were seen after incubation with the flavones luteolin, chrysin, and apigenin. Additional hydroxylation or methoxylation in positions 6 or 8, as expected, resulted in decreased activity. The tested flavanones remained without or low efficacy.

Clock-Bmal1 mediates MMP9 induction in acrolein-promoted atherosclerosis associated with gut microbiota regulation

Circadian rhythm is believed to play important roles in atherosclerosis. The gut microbiota is found to be closely related to atherogenesis, and shows compositional and functional circadian oscillation. However, it's still unclarified whether circadian clock and intestinal microbiota are involved in the progression of atherosclerosis induced by environmental pollutant acrolein. Herein, patients with atherosclerosis showed higher MMP9, a promising biomarker for atherosclerosis, and lower Bmal1 and Clock expression in the plasma. Interestingly, acrolein exposure contributed to the increased MMP9, decreased Clock and Bmal1, and activated MAPK pathways in human umbilical vein endothelial cells (HUVECs). We found that knockdown of Clock or Bmal1 lead to upregulation of MMP9 in HUVECs, and that Clock and Bmal1 expression was elevated while MAPK pathways were blocked. Atherosclerotic apolipoproteinE-deficient mice consumed a high-fat diet were used and treated with acrolein (3 mg/kg/day) in the drinking water for 12 weeks. Upregulation of MMP9, and downregulation of Clock and Bmal1 were also observed in plasma of the mice. Besides, acrolein feeding altered gut microbiota composition at a phylum level especially for an increased Firmicutes and a decreased Bacteroidetes. Additionally, gut microbiota showed correlation with atherosclerotic plaque, MMP9 and Bmal1 levels. Therefore, our findings indicated that acrolein increased the expression of MMP9 through MAPK regulating circadian clock, which was associated with gut microbiota regulation in atherosclerosis. Circadian rhythms and gut microbiota might be promising targets in the prevention of cardiovascular disease caused by environmental pollutants.

Evaluation of Anti-Tumorigenic Effects of Diosmetin against Human Colon Cancer Xenografts in Athymic Nude Mice

Colon cancer is the third most common type of cancer in the world. Diosmetin (Dis), a natural O-methylated flavone, has been reported to have anti-cancer effects against different types of cancer. Although the mechanisms of action of Dis against several cancer cell lines are well reported, in vivo anti-tumorigenesis properties of this compound are still obscure. Therefore, this study aimed to investigate the anti-tumorigenesis properties of Dis against HCT-116 colon cancer xenografts in nude mice. HCT-116 colon cancer cells were injected in NCr nu/nu nude mice and treatment with Dis was initiated after the tumor volumes reached 100 mm³ and continued for four weeks. On the sacrificing date nude mice treated with 100 mg/kg of Dis showed significant lower tumor volume (264 ± 238.3 mm³) as compared to the untreated group (1428.8 ± 459.6 mm³). Anti-apoptotic Bcl-2 protein was significantly downregulated, while apoptotic protein (Bax) was significantly overexpressed in nude mice treated with 100 mg/kg Dis as compared to untreated mice. In conclusion, our in vivo results indicate that Dis significantly reduces tumor growth rate of HCT-116 colon cancer cells in nude mice at a dose of 100 mg/kg, and has no toxic effects in ICR mice up to 2000 mg/kg.

Anti-Proliferation and Pro-Apoptotic Effects of Diosmetin via Modulating Cell Cycle Arrest and Mitochondria-Mediated Intrinsic Apoptotic Pathway in MDA-MB-231 Cells

Background

Breast cancer is one of the most malignant tumors worldwide. The natural flavonoid diosmetin has been reported to exhibit various pharmacological activities, including anti-cancer effects. This study aimed to investigate the anti-breast cancer effects of diosmetin on MDA-MB-231 cells and to explore the underlying molecular mechanisms of cell apoptosis.

Material/Methods

The MDA-MB-231 cells were incubated with diosmetin for 24 h. Then, cell viability and lactate dehydrogenase (LDH) leakage were detected using CCK-8 and LDH assay kits, respectively. Inverted fluorescence microscopy and flow cytometry were used to measure the mitochondrial membrane potential (MMP) and intracellular reactive oxygen species (ROS). Cell apoptosis and cell cycle were determined by flow cytometry. The expressions of apoptosis and cell cycle-related genes were determined by Western blotting and qRT-PCR.

Results

The results revealed that diosmetin exerts significant cytotoxic effects on MDA-MB-231 cells, as indicated by decreased cell viability, increased intracellular ROS accumulation and LDH release, as well as cell cycle arrest in G0/G1 phase, inducing mitochondrial dysfunction and apoptosis. Moreover, diosmetin treatment significantly downregulated the expression levels of Bcl-2 and Cyclin D1, and upregulated that of p53, Bax, caspase 3, cleaved caspase 9, and cleaved caspase 3.

Conclusions

These findings demonstrate that diosmetin has anti-proliferative and pro-apoptotic activities against MDA-MB-231 cells via cell cycle arrest and the mitochondria-mediated intrinsic apoptotic pathway. Our results extend the understanding of the anti-tumor mechanism of diosmetin and suggest that it may be of use as an active natural agent for the prevention or treatment of human breast cancer.

Investigation into the Molecular Mechanisms underlying the Anti-proliferative and Anti-tumorigenesis activities of Diosmetin against HCT-116 Human Colorectal Cancer

Diosmetin (Dis) is a bioflavonoid with cytotoxicity properties against variety of cancer cells including hepatocarcinoma, breast and colorectal (CRC) cancer. The exact mechanism by which Dis acts against CRC however, still remains unclear, hence in this study, we investigated the possible molecular mechanisms of Dis in CRC cell line, HCT-116. Here, we monitored the viability of HCT-116 cells in the presence of Dis and investigated the underlying mechanism of Dis against HCT-116 cells at the gene and protein levels using NanoString and proteome profiler array technologies. Findings demonstrated that Dis exhibits greater cytotoxic effects towards HCT-116 CRC cells (IC50 = 3.58 ± 0.58 µg/ml) as compared to the normal colon CCD-841 cells (IC50 = 51.95 ± 0.11 µg/ml). Arrests of the cells in G2/M phase confirms the occurrence of mitotic disruption via Dis. Activation of apoptosis factors such as Fas and Bax at the gene and protein levels along with the release of Cytochrome C from mitochondria and cleavage of Caspase cascades indicate the presence of turbulence as a result of apoptosis induction in Dis-treated cells. Moreover, NF-ƙB translocation was inhibited in Dis-treated cells. Our results indicate that Dis can target HCT-116 cells through the mitotic disruption and apoptosis induction.

Tanshinol inhibits the growth, migration and invasion of hepatocellular carcinoma cells via regulating the PI3K-AKT signaling pathway

Background

Tanshinol is an active constituent of Salvia miltiorrhiza and possess anti-inflammatory, antioxidant, and anti-bacterial activity. Herein, we explored the role of tanshinol on the growth and aggressiveness of hepatocellular carcinoma (HCC) cells in vitro and in vivo.

Materials and methods

The proliferation of a panel of HCC cell lines was measured using MTT assay. The expressions of phosphatidylinositol 3 kinase (PI3K) and protein kinase B (AKT) were detected by immunofluorescence staining and immunohistochemical assay. The levels of Bcl-2 and Bax were determined using immunoblotting assay. The secretions of matrix metalloproteinase-2 (MMP-2) and MMP-9 were detected by ELISA. The migration and invasion abilities of HepG2 cell were determined using wound healing and Transwell invasion assays. The apoptosis of HepG2 cell induced by tanshinol was analyzed by Annexin V/propidium iodide staining. A xenograft model was constructed to investigate the inhibitory effect of tanshinol on HepG2 cell growth in vivo. To further investigate the role of tanshinol on the metastasis of HepG2 cell in vivo, an experimental metastasis assay was performed.

Results

Tanshinol inhibited the growth and colony formation of HCC cell in vitro. Tanshinol also induced the apoptosis of HepG2 cell and inhibited the migration and invasion of HepG2 cell. In in vivo experiments, tanshinol suppressed the tumor growth and metastasis of HepG2 cell. Furthermore, the phosphorylation of PI3K and AKT was decreased by tanshinol in vitro and in vivo.

Conclusion

Tanshinol exerts its anti-cancer effects via regulating the PI3K-AKT signaling pathway in HCC.

Circ5379-6, a circular form of tumor suppressor PPARα, participates in the inhibition of hepatocellular carcinoma tumorigenesis and metastasis

This study aimed to investigate the role of circRNAs encoded by PPARα in regulating the pathogenesis processes of hepatocellular carcinoma (HCC). Comprehensive analysis of 3 circular RNA databases revealed multiple circular RNAs within the PPARα gene. The candidate circRNAs were first structurally validated via specific convergent and divergent primer amplification, RNase R treatment, and Sanger sequencing. According to a further validation of the cell viability assay, cell cycle and apoptosis, and transwell assays, the circRNAs correlated to PPARα were obtained. Their functions in tumorigenesis were further validated via the subcutaneous tumor model and the migration model in nude mice. We showed that the overexpression of circ5379-6 decreased cell proliferation, inhibited cell migration and invasion, and induced cell apoptosis in the HCC cell lines. Consistently, in vivo studies in nude mice confirmed that the overexpression of circ5379-6 effectively inhibited the tumorigenesis and metastasis of HCC. We conclude that circ5379-6 plays a role similar to its linear counterpart PPARα to inhibit HCC tumorigenesis and progression.

Quercetin Inhibits the Migration and Invasion of HCCLM3 Cells by Suppressing the Expression of p-Akt1, Matrix Metalloproteinase (MMP) MMP-2, and MMP-9

Background

Quercetin is a natural bioactive flavonoid that is present in a wide variety of vegetables and fruits and exhibits a promising anti-metastasis property in various human cancer cells. However, the effect of quercetin on human HCCLM3 cells is unclear.

Material/Methods

In the current study, a wound-healing assay was performed using quercetin-treated HCCLM3 cells to further explore whether quercetin affects the motility of human HCCLM3 cells. Transwell assay was used to explore the potential effect of quercetin in HCCLM3 cells on cell migration and cell invasion. Western blotting analysis was used to explore the expression of p-Akt1, MMP-2, and MMP-9 in quercetin-treated HCCLM3 cells.

Results

The wound-healing time was delayed in quercetin-treated HCCLM3 cells, and the ability to migrate and invade was inhibited in quercetin-treated human HCCLM3 cells. Moreover, the protein levels of p-Akt1, MMP-2, and MMP-9 were down-regulated in quercetin-treated HCCLM3 cells, as detected by Western blotting.

Conclusions

Our data show that quercetin attenuated cell migration and invasion by suppressing the protein levels of p-Akt1, MMP-2, and MMP-9 in HCCLM3 cells.

YAP Is Decreased in Preeclampsia and Regulates Invasion and Apoptosis of HTR-8/SVneo

Preeclampsia (PE) is a gestational disorder with hypertension and proteinuria leading to maternal and fetal morbidity and mortality. Yes-associated protein (YAP), a transcription coactivator of Hippo pathway, was identified as an oncoprotein participated in tumorigenesis. However, the effect of YAP on trophoblast has not been investigated. In our study, YAP expression levels in first-trimester, full-term, and PE placentas were detected using quantitative real-time polymerase chain reaction (PCR), Western blot assays, and immunohistochemistry. Yes-associated protein expression was also detected in BeWo and HTR-8/SVneo. Overexpression plasmid and YAP small interfering RNA were introduced into trophoblast cells. Furthermore, we utilized a Transwell invasion assay, flow cytometry, and Cell Counting Kit-8 analysis to examine the role of YAP in the invasion, apoptosis, and proliferation of HTR-8/SVneo trophoblast cells. The result showed that both YAP messenger RNA (mRNA) and protein expression levels were less in preeclamptic placentas. Yes-associated protein mRNA and protein expression levels were more highly expressed in BeWo. Yes-associated protein enhanced cell invasion, reduced the cellular apoptotic response, and had no effect on proliferation. In addition, the overexpression of YAP activated the expression of caudal-related homeobox transcription factor 2 (CDX2), whereas reduced expression of YAP inhibited the expression of CDX2. Our results demonstrate that decreased YAP levels may contribute to the development of PE by regulating trophoblast invasion and apoptosis involving regulation of CDX2. Collectively, we proposed decreased YAP may contribute to trophoblast dysfunction, which suggests it might represent a prognostic biomarker and therapeutic target for PE.

Chelerythrine Inhibits Human Hepatocellular Carcinoma Metastasis in Vitro

Chelerythrine (CHE) is a type of benzophenanthridine alkaloid found in many herbs and is also the main alkaloid constituent of Toddalia asiatica (L.) LAM. It has been proven to have various activities including antitumor, antifungal, anti-inflammatory and anti-parasitic effects. We have previously demonstrated that CHE can inhibit proliferation and promote apoptosis in human hepatocellular carcinoma (HCC) cells. However, the effect of CHE on the metastasis of HCC and its related molecular mechanisms have yet to be validated. In this study, we investigated the effects of CHE on the migration and invasion of the HCC cell line Hep3B. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wounding healing, transwell migration and invasion assays and cytoskeleton staining demonstrated that CHE could inhibit the migration and invasion of Hep3B cells in a dose-dependent manner with change of cell structure. RNA interference studies made a knockdown of matrix metalloproteinase (MMP)-2/9 respectively in Hep3B cells. And the results of wounding healing and transwell invasion assay with the treatment of small interfering RNA (siRNA) investigated that MMP-2/9 are positively associated with Hep3B cell metastasis. The results of enzyme-linked immunosorbent assay (ELISA), Western blotting and quantitative RT-PCR showed that CHE suppressed the expression of MMP-2/9 at both mRNA and protein levels. CHE also exhibited an inhibitory effect on the phosphorylation of Focal adhesion kinase (FAK), phosphatidylinositol 3-kinase (PI3K), Akt, mammalian target of rapamycin (mTOR), c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases (ERK) and p38. In summary, on Hep3B cells, CHE could change the cell cytoskeletal structures through reducing the expression of p-FAK and inhibit the metastasis of Hep3B cells by downregulating the expression of MMP-2/9 mainly through PI3K/Akt/mTOR signaling pathway.

Inhibition of MMP-2 Expression Enhances the Antitumor Effect of Sorafenib in Hepatocellular Carcinoma by Suppressing the PI3K/AKT/mTOR Pathway

Sorafenib has been globally approved as the standard treatment for patients with advanced hepatocellular carcinoma (HCC). However, the response rate of HCC patients to sorafenib is limited because of tumor recurrence and metastasis. Therefore, seeking combined therapeutic strategies with sorafenib is necessary to improve the antitumor efficiency. Here we demonstrated that expression of MMP-2 is positively correlated with the migration ability of HCC cells. Cells with a higher MMP-2 expression (SK-HEP-1 cells) were less sensitive to sorafenib than those with lower MMP-2 expression (HepG2 cells). Cotreatment of cells with SB-3CT and sorafenib more strongly inhibited migration ability than with sorafenib treatment alone in both HCC cells with high and low expression of MMP-2. In vivo cell metastasis experiments confirmed the synergistic effects of sorafenib and SB-3CT in reducing lung metastasis of SK-HEP-1 cells. Mechanistically, we showed that the synergistic antitumor effect may be attributed to inhibition of the PI3K/AKT/mTOR signaling pathway, but not the RAF/MEK/ERK signaling pathway. With these results taken together, the current study demonstrates that inhibiting MMP-2 expression can enhance the antitumor effect of sorafenib in HCC cells with a high MMP-2 expression, which may provide a novel strategy to improve therapeutic efficiency in HCC.

Diosmetin protects against ischemia/reperfusion-induced acute kidney injury in mice

BACKGROUND

Renal ischemia/reperfusion (I/R)-induced acute kidney injury remains to be a troublesome condition in clinical practice. Although the exact molecular mechanisms underlying renal I/R injury are incompletely understood, the deleterious progress of renal I/R injury involves inflammation, apoptosis, and oxidative stress. Diosmetin is a member of the flavonoid glycosides family, which suppresses the inflammatory response and cellular apoptosis and enhances antioxidant activity. The purpose of this study was to investigate the protective effect of diosmetin on I/R-induced renal injury in mice.

METHODS

Thirty BALB/c mice were randomly divided into five groups. Four groups of mice received diosmetin (0.25, 0.5, and 1 mg/kg) or vehicle (I/R group) before ischemia. Another group received vehicle without ischemia to serve as a negative control (sham-operated group). Twenty-four hours after reperfusion, serum and renal tissues were harvested to evaluate renal function and histopathologic features. In addition, the expression of inflammation-related proteins, apoptotic molecules, and antioxidant enzymes was analyzed.

RESULTS

Compared with sham mice, the I/R group significantly exacerbated renal function and renal tube architecture and increased the inflammatory response and renal tubule apoptosis. Nevertheless, pretreatment with diosmetin reversed these changes. In addition, diosmetin treatment resulted in a marked increase in antioxidant protein expression compared with I/R mice.

CONCLUSIONS

The renoprotective effects of diosmetin involved suppression of the nuclear factor-κB and mitochondrial apoptosis pathways, as well as activation of the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway. Diosmetin has significant potential as a therapeutic intervention to ameliorate renal injury after renal I/R.

Glycosylation patterns and PHA-E-associated glycoprotein profiling associated with early hepatic encephalopathy in Chinese hepatocellular carcinoma patients

Hepatic encephalopathy (HE) as a severe neuropsychiatric complication is commonly present in the end stage of Hepatocellular Carcinoma (HCC). However, widely accepted biomarkers for diagnosing early HE are still absent. Here, we screened glycosylation patterns of serum proteins from Chinese HCC patients with or without early HE by lectin microarray. Then, phaseolus vulgaris erythroagglutinin (PHA-E) as a lectin binding with bisecting GlcNAc structure which was significantly decreased in sera from Chinese HCC patients with early HE, was chosen to perform lectin affinity chromatography, following by in-gel digestion, Mass Spectrometry (MS) analysis and bioinformatics analysis. Here we found, 13 lectins showed statistically significant reduction suggesting GalNAc, terminal α-1,3 Man, bisecting GlcNAc, (GlcNAc)n, O-GlcNAc, Neu5Ac, tetra-antennary complex-type N-glycan and GalNAc α/β1-3/6 Gal were decreased in serum glycoproteins from Chinese HCC patients with early HE. Furthermore, a total of 141 PHA-E-associated glycoproteins were identified in MS, of which 12 serum glycoproteins only in Chinese HCC patients without early HE and 26 serum glycoproteins only in Chinese HCC patients with early HE. In addition, bioinformatics analysis revealed the PHA-E-associated serum glycoproteins only in Chinese HCC patients with early HE might be related to early HE occurrence through p38 MAPK signaling pathway and MAPK/ERK signaling pathway. Collectively, this was the first glycomics study of serum proteins in HCC patients with early HE and it could provide a database for discovering and developing serum biomarkers to identify and predict early HE in HCC patients.