Flavonoids as prospective compounds for anti-cancer therapy

Antioxidant, Antiproliferative and Apoptosis-Inducing Efficacy of Fractions from Cassia fistula L. Leaves

: Cassia fistula L. is a highly admirable traditional medicinal plant used for the treatment of various diseases and disorders. The present study was performed to divulge the antioxidant, antiproliferative, and apoptosis-inducing efficacy of fractions from C. fistula leaves. The hexane (CaLH fraction), chloroform (CaLC fraction), ethyl acetate (CaLE fraction), n-butanol (CaLB fraction), and aqueous (CaLA fraction) were sequentially fractionated from 80% methanolic (CaLM extract) of C. fistula leaves. The CaLE fraction was fractionated using column chromatography to yield a pure compound, which was characterized as Epiafzelechin (CFL1) based on 1H, 13C, and DEPT135 NMR. Among these fractions, CaLE and isolated CFL1 fractions exhibited an effective antioxidant potential in Ferric ion reducing power, (2,2'-azino-bis (3-ethylbenzothiazoline -6-sulfonic acid)) cation radical scavenging, and nitric oxide radical scavenging assays. Epiafzelechin was investigated for its antiproliferative effects against MG-63 (osteosarcoma), IMR-32 (neuroblastoma), and PC-3 (prostate adenocarcinoma), and was found to inhibit cell proliferation with a GI50 value of 8.73, 9.15, and 11.8 μM respectively. MG-63 cells underwent apoptotic cell death on treatment with Epiafzelechin as the cells showed the formation of apoptotic bodies, enhanced reactive oxygen species (ROS) generation, mitochondrial membrane depolarization along with an increase in early apoptotic cell population analyzed using Annexin V-FITC/PI double staining assay. Cells showed cell cycle arrest at the G0/G1 phase accompanied by a downregulation in the expression levels of p-Akt (Protein kinase B), p-GSK-3β (Glycogen synthase kinase-3 beta), and Bcl-xl (B-cell lymphoma-extra large) proteins. RT-PCR (Real time-polymerase chain reaction) analysis revealed downregulation in the gene expression level of β-catenin and CDK2 (cyclin-dependent kinases-2) while it upregulated the expression level of caspase-8 and p53 genes in MG-63 cells.

Genistein Represses HOTAIR/Chromatin Remodeling Pathways to Suppress Kidney Cancer

BACKGROUND/AIMS

Genistein, a soy isoflavone, has been shown to have anti-cancer effects in various cancers including renal cancer. Long non-coding RNA, HOX transcript antisense RNA (HOTAIR), is involved in cancer progression and metastasis, such as renal cancer. Our aim was to investigate the effects of genistein on HOTAIR chromatin remodeling functions.

METHODS

We used MTS assays and Transwell migration assays to study the effects of genistein on cell proliferation and migration respectively in human renal cell carcinoma (RCC) cell lines. We used Western blots to analyze SNAIL and ZO-1 expression. We performed chromatin immunoprecipitation (ChIP) assays to study recruitment of the polycomb repressive complex 2 (PRC2) to the ZO-1 promoter. We performed RNA immunoprecipitation (RIP) assays to study interaction between HOTAIR and PRC2, SMARCB1 or ARID1A. We also performed transfection experiments to overexpress EED, HOTAIR and knockdown SMARCB1.

RESULTS

Genistein reduced cell proliferation and migration of human renal cell carcinoma cell lines. ChIP assays indicated that genistein reduces recruitment of the PRC2 to the ZO-1 promoter and increased its expression. RIP assays showed that genistein inhibits HOTAIR interaction with PRC2, leading to tumor suppression. Immunoprecipitation also revealed that genistein reduced EED levels in PRC2, suggesting that decreased EED levels suppress HOTAIR interaction with PRC2. EED overexpression in the presence of genistein restored PRC2 interaction with HOTAIR and reduced ZO-1 transcription, suggesting genistein activates ZO-1 by inhibiting HOTAIR/PRC2 functions. RIP assays also showed that HOTAIR interacts with SMARCB1 and ARID1A, subunits of the human SWI/SNF chromatin remodeling complex and genistein reduces this interaction. Combination of HOTAIR overexpression and SMARCB1 knockdown in the presence of genistein revealed that genistein inhibits SNAIL transcription via the HOTAIR/SMARCB1 pathway.

CONCLUSION

Genistein suppresses EED levels in PRC2 and inhibits HOTAIR/PRC2 interaction. Genistein suppresses HOTAIR/PRC2 recruitment to the ZO-1 promoter and enhances ZO-1 transcription. Genistein also inhibits SNAIL transcription via reducing HOTAIR/SMARCB1 interaction. We demonstrate that the reduction of HOTAIR interaction with chromatin remodeling factors by genistein represses HOTAIR/chromatin remodeling pathways to suppress RCC malignancy.

Isoflavones Isolated from the Seeds of Millettia ferruginea Induced Apoptotic Cell Death in Human Ovarian Cancer Cells

The seeds of Millettia ferruginea are used in fishing, pesticides, and folk medicine in Ethiopia. Here, the anti-cancer effects of isoflavones isolated from M. ferruginea were evaluated in human ovarian cancer cells. We found that isoflavone ferrugone and 6,7-dimethoxy-3’,4’-methylenedioxy-8-(3,3-dimethylallyl)isoflavone (DMI) had potent cytotoxic effects on human ovarian cancer cell A2780 and SKOV3. Ferrugone and DMI treatment increased the sub-G1 cell population in a dose-dependent manner in A2780 cells. The cytotoxic activity of ferrugone and DMI was associated with the induction of apoptosis, as shown by an increase in annexin V-positive cells. Z-VAD-fmk, a broad-spectrum caspase inhibitor, and z-DEVD-fmk, a caspase-3 inhibitor, significantly reversed both the ferrugone and DMI-induced apoptosis, suggesting that cell death stimulated by the isoflavones is mediated by caspase-3-dependent apoptosis. Additionally, ferrugone-induced apoptosis was found to be caspase-8-dependent, while DMI-induced apoptosis was caspase-9-dependent. Notably, DMI, but not ferrugone, increased the intracellular levels of reactive oxygen species (ROS), and antioxidant N-acetyl-L-cysteine (NAC) attenuated the pro-apoptotic activity of DMI. These data suggest that DMI induced apoptotic cell death through the intrinsic pathway via ROS production, while ferrugone stimulated the extrinsic pathway in human ovarian cancer cells.

3D lanthanide-coordination frameworks constructed by a ternary mixed-ligand: crystal structure, luminescence and luminescence sensing

Highly stable 3D Ln-MOFs were constructed by a ternary mixed-ligand. The Sm/Dy-MOFs present dual-emission while the Tb/Eu-MOFs exhibit red/green MC emission. The detection of quercetin and Fe³⁺ion was realized based on the luminescence Eu-MOF under the excitation of 358 nm.

Effect of citrus peel extracts on the cellular quiescence of prostate cancer cells

The re-entry of quiescent cancer cells to the cell cycle plays a key role in cancer recurrence, which can pose a high risk after primary treatment. Citrus peel extracts (CPEs) contain compounds that can potentially impair tumour growth; however the mechanism of action and effects on cell cycle regulation remain unclear. In this study, the capacity of an ethyl acetate : hexane extract (CPE/hexane) and water extract (CPE/water) to modulate the cell cycle re-entry of quiescent (PC-3 and LNCaP) prostate cancer cells was tested in an in vitro culture system. Cell cycle analysis showed that the quiescent PC-3 and LNCaP cancer cells in the presence of CPE/water were impaired in their ability to enter the S phase where only 2-3% reduction of G0/G1 cells was noted compared to 12-18% reduction of control cells. In contrast, the CPE/hexane did not show any cell cycle inhibition activity in both cell lines. A low DNA synthesis rate and weak apoptosis were observed in quiescent cancer cells treated with CPEs. Hesperidin and narirutin, the predominant flavonoids found in citrus fruits, were not responsible for the observed biological activity, implicating alternative bioactive compounds. Notably, citric acid was identified as one of the compounds present in CPEs that acts as a cell cycle re-entry inhibitor. Citric acid exhibited a higher cell toxicity effect on PC-3 prostate cancer cells than non-cancerous RWPE-1 prostate cells, suggesting specific benefits for cancer treatment. In conclusion, CPE containing citric acid together with various bioactive compounds may be used as a chemopreventive agent for post-therapy cancer patients.

Genotoxicity, anti-melanoma and antioxidant activities of Hymenaea courbaril L. seed extract

Hymenaea courbaril has been used to treat different diseases, although its properties are yet to be scientifically validated. The objective of this study was to determine the cytotoxicity, genotoxicity, antigenotoxicity and antioxidant potentials of hydroethanolic extract from H. courbaril seeds. Therefore, for the cytotoxicity test an anti-melanoma assay was performed in B16F10 strain cells. The genotoxicity and antigenotoxicity was evaluated in bone marrow cells (Permit number: 002/2010) of mice, the antioxidant activity was determined by the DPPH test and the total flavonoid content was also determined. The hydroethanolic extract showed antigenotoxic effect and antioxidant activity. It was verified that total flavonoid content was 442.25±18.03 mg RE/g dry extract. HPLC-PAD chromatogram revealed presence of flavones as majority compound in evaluated extract. The results allowed us to also infer that the hydroethanolic extract from seeds shows cytotoxic activity against B16F10 melanoma cells line and it has dose-and-time-dependency.

Efficacy of N-Methyl-N-Nitrosourea Mutation on Physicochemical Properties, Phytochemicals, and Momilactones A and B in Rice

Attempts regarding the improvement and development of novel rice with better quality and higher productivity have been increasing. Among approaches, mutation is a direct alteration on the genome and considered as one of the most beneficial routes to acquire new beneficial traits in rice. An experiment was carried out to explore the effects of N-methyl-N-nitrosourea (MNU) mutation on the antioxidant activities, phytochemical compounds, and momilactones A (MA) and B (MB) in rice. Two rice cultivars, K1 (an original cultivar DT84) and K2 (mutated DT84), were examined. Antioxidant activities, phenolic compounds, and momilactones of the rice grain, husk, and straw portions were measured and quantified. Antioxidant activities were higher in grain and straw of K2, whereas K1 showed greater antioxidant activity in rice husk. Additionally, K2 displayed higher total phenolic contents (TPC) in grain and straw as well as lower of it in the husk, but these variations significantly differed only in the straw portion. An increase in total flavonoid contents (TFC) was observed in the husk of K1, while K2 significantly enhanced TFC in straw. Both MA and MB, two compounds obtaining antidiabetes, anticancer, antimicrobial, antigout, and antiobesity properties, were detected and quantified in grain, husk, and straw of K1 and K2 samples. Generally, the contents of MA were higher than MB in all tested portions of rice crop. MA and MB were higher in straw followed by those in husk and grain, respectively. K2 contained higher amounts of MA and MB in straw and husk, but lower contents in grain compared with those in K1. This study illustrates that MNU mutation can improve grain quality and enhance bioactive compounds in straw, husk, and grain of rice. This approach has the potential to develop functional foods from rice, and therefore help farmers in developing countries to improve value in rice production.

The synthetic flavanone 6-methoxy-2-(naphthalen-1-yl)chroman-4-one induces apoptosis and activation of the MAPK pathway in human U-937 leukaemia cells

Synthetic flavonoids containing a naphthalene ring have attracted attention as potential cytotoxic compounds. Here, we synthesized ten chalcones and their corresponding flavanones and evaluated their antiproliferative activity against the human tumour cell line U-937. This series of chalcone derivatives was characterized by the presence of a naphthalene ring which was kept unaltered- and attached to the β carbon of the 1-phenyl-2-propen-1-one framework. The structure-activity relationship of these chalcone derivatives and their corresponding cyclic compounds was investigated by the introduction of different substituents (methyl, methoxy, benzyloxy, chlorine) or by varying the position of the methoxy or benzyloxy groups on the A ring. The results revealed that both the chalcone containing the methoxy group at 5' position of the A ring as well as its corresponding flavanone [6-methoxy-2-(naphthalen-1-yl)chroman-4-one] were the most cytotoxic compounds, with IC₅₀ values of 2.8 ± 0.2 and 1.3 ± 0.2 μM, respectively, against U-937 cells. This synthetic flavanone was as cytotoxic as the antitumor etoposide in U-937 cells and displayed strong cytotoxicity against additional human leukaemia cell lines, including HL-60, MOLT-3 and NALM-6. Human peripheral blood mononuclear cells were more resistant than leukaemia cells to the cytotoxic effects of the flavanone. Treatment of U-937 cells with this compound induced G₂-M cell cycle arrest, an increase in sub-G₁ ratio and annexin-V positive cells, mitochondrial cytochrome c release, caspase activation and poly(ADP-ribose)polymerase processing. Apoptosis induction triggered by this flavonoid was blocked by overexpression of the anti-apoptotic protein Bcl-2. This flavanone induces phosphorylation of p38 mitogen-activated protein kinases, extracellular-signal regulated kinases and c-jun N-terminal kinases/stress-activated protein kinases (JNK/SAPK) following different kinetics. Moreover, cell death was attenuated by the inhibition of mitogen-activated extracellular kinases and JNK/SAPK and was independent of reactive oxygen species generation.

Metal complexes of flavonoids: their synthesis, characterization and enhanced antioxidant and anticancer activities

Flavonoids are polyphenolic compounds of natural origin. They are extensively studied within drug discovery programs due to their wide ranging biological activities such as antimicrobial, antioxidant, antitumor, neuroprotective and cardioprotective properties. The ability of flavonoids to coordinate with metal atoms has provided new leads for drug discovery programs, with better pharmacological activities and clinical profiles than the parent flavonoids. In this review, the enhanced antioxidant and anticancer activities of flavonoid metal complexes versus the parent flavonoids are discussed. Possible mechanisms of action for the metal complexes, such as DNA binding and apoptosis induction, are also presented alongside an overview of the synthesis of the metal complexes, and the different techniques used for their characterization.

Leaf Extracts from Dillenia philippinensis Rolfe Exhibit Cytotoxic Activity to both Drug-Sensitive and Multidrug-Resistant Cancer Cells

Background:

Cancer is one of the leading causes of illness and death worldwide. Only palliative therapeutic options are available for many types of cancers, and most anticancer drugs in clinical use exhibit significant side effects. It is therefore important to develop new anticancer drugs that are more effective and less toxic. In this study, we evaluate the bioactivity of a Philippine endemic plant, “katmon” or Dillenia philippinensis, and its potential use in cancer therapy.

Methods:

The cytotoxicity of the crude leaf extract, partitions, and isocratic column chromatography fractions of Dillenia philippinensis was determined in vitro by MTT assay against drug-sensitive cancer cell lines MCF7 (human breast adenocarcinoma) and HCT 116 (human colorectal carcinoma), as well as against moderately multidrug resistant (MDR) cancer cell line HCT-15 (human colorectal carcinoma) and its highly MDR subline HCT-15/Dox. The selectivity of the extract to cancer cells was determined by computing for the selectivity index (SI) with respect to normal mouse embryonic fibroblasts (NIH/3T3) cell line. To check for a possible mechanism for overcoming cancer multiple drug resistance, Calcein-AM assay was performed to assess the activity of the extract against P-glycoprotein-activated efflux pump.

Results:

Dillenia philippinensis (DP1) fraction from the hexane partition exhibited cytotoxicity (IC₅₀< 30 µg/ml) against MCF7, HCT 116, HCT-15, and HCT-15/Dox cells. DP1 also exhibited a moderate level of selectivity against cancer cells over normal cells as supported by the SI computed from the IC₅₀ value obtained for the normal cell line. DP1 was able to inhibit P-glycoprotein (P-gp) activity in a dose-dependent manner, suggesting its possible role in targeting cancer cells with overexpressed P-gp.

Conclusion:

The present findings thus demonstrate the potential chemotherapeutic properties of D. philippinensis which can be promising for future drug development against cancer.

Protective Effects of Flavone from Tamarix aphylla against CCl4-Induced Liver Injury in Mice Mediated by Suppression of Oxidative Stress, Apoptosis and Angiogenesis

The current study aimed to investigate, for the first time, the beneficial effects of 3,5-dihydroxy-4',7-dimethoxyflavone isolated from Tamarix aphylla L. against liver injury in mice. Liver injury was induced by intraperitoneal (i.p.) injection of carbon tetrachloride (CCl₄) at a dose of 0.4 mL/kg mixed in olive oil at ratio (1:4) twice a week for 6 consecutive weeks. The administration of CCl₄ caused significant histopathological changes in liver tissues while the pre-treatment with the flavone at dose of 10 and 25 mg/kg ameliorated the observed liver damages. Also, it markedly reduced hepatic malondialdehyde (MDA) level as well as increased the activities of liver superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (Gpx) compared with their recorded levels in CCl₄ model group. Moreover, the immunohistochemical analysis demonstrated the enhancement in the protein level of B-cell lymphoma-2 (Bcl-2) while the protein levels of cysteine-aspartic acid protease-3 (caspase-3), Bcl-2-associated x protein (Bax), transforming growth factor-β1 (TGF-β1) and CD31 were suppressed following the flavone treatement. These results suggest that the flavone can inhibit liver injury induced in mice owning to its impact on the oxidation, apoptotic and angiogenesis mechanisms. Further pharmacological investigations are essential to determine the effectiveness of the flavone in human.

LC-ESI-QTOF/MS Characterization of Phenolic Compounds in Palm Fruits (Jelly and Fishtail Palm) and Their Potential Antioxidant Activities

Palm fruits have gained growing attention for their nutrition values and health promotion perspectives. They have a diverse range of bioactive compounds including carotenoids, vitamins, dietary fibres and especially polyphenolic compounds. These polyphenolic compounds contribute to the putative health benefits of palm fruits. Nevertheless, the detailed information about these polyphenols in palm fruits is limited. The present work was conducted to comprehensively characterize polyphenols in two palm fruits, jelly palm (Butia ordorata) and fishtail palm (Caryota uren), using liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF/MS) and assess their antioxidant potential. The total phenolic content (TPC), total tannins content (TTC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant assay and 2,2′-azinobis-(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS) scavenging abilities and ferric reducing antioxidant power (FRAP) were higher in the jelly palm fruit while total flavonoid contents (TFC) were higher in the fishtail palm. The LC-ESI-QTOF/MS tentatively identified a total of 86 phenolic compounds in both jelly and fishtail palm fruits. Although both palm fruits exhibited different phenolic profiles, hydroxycinnamic acids and flavonols were the most common in both. In high performance liquid chromatography photodiode array (HPLC-PDA) quantification, 4-hydroxybenzoic acid (317.46 ± 4.68 µg/g) and catechin (4724.00 ± 32.39 µg/g) were the most abundant phenolic acid and flavonoid quantified in the jelly palm fruit, respectively. Quercetin (557.28 ± 7.81 µg/g) and kaempferol 3-O-glucoside (220.99 ± 2.06 µg/g) were the most abundant flavonoids quantified in the fishtail palm. Our study indicates that palm fruit is a good source of polyphenols and has strong antioxidant potential for health promotion. Furthermore, this study provides the scientific basis for an exploitation of jelly and fishtail palm fruits in the food, pharmaceutical and nutraceutical industries.

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.

Progress in Research on the Role of Flavonoids in Lung Cancer

Lung cancer is the leading cause of cancer deaths worldwide. Therefore, for the prevention, diagnosis, prognosis and treatment of lung cancer, efficient preventive strategies and new therapeutic strategies are needed to face these challenges. Natural bioactive compounds and particular flavonoids compounds have been proven to have an important role in lung cancer prevention and of particular interest is the dose used for these studies, to underline the molecular effects and mechanisms at a physiological concentration. The purpose of this review was to summarize the current state of knowledge regarding relevant molecular mechanisms involved in the pharmacological effects, with a special focus on the anti-cancer role, by regulating the coding and non-coding genes. Furthermore, this review focused on the most commonly altered and most clinically relevant oncogenes and tumor suppressor genes and microRNAs in lung cancer. Particular attention was given to the biological effect in tandem with conventional therapy, emphasizing the role in the regulation of drug resistance related mechanisms.

Systematic Diversity-Oriented Synthesis of Reduced Flavones from γ-Pyrones to Probe Biological Performance Diversity

Diversity-oriented synthesis (DOS) has historically focused on the development of small-molecule collections with considerable chemical diversity with the hypothesis that chemical diversity will lead to diverse biological activities. We took a systematic approach to DOS to develop a focused library of reduced flavones from γ-pyrones with diversity of appendage, stereochemistry, and chemical properties to determine which features of small molecules are most predictive of biological performance diversity. The effects of these systematic modifications on biodiversity were determined using Cell Painting and cytotoxicity assays to compare the results of multiple methods of assessment. We observed that a greater fraction of sp³ hybridized atoms (fsp³) does not always lead to enhanced biodiversity, that stereochemistry and appendage diversity both contribute to biodiversity, and that lipophilicity of the pyrone class of compounds correlates with biodiversity. These results will contribute to the development of a general algorithm to predict which chemical features should be considered during the synthesis of DOS libraries to create biological performance-diverse collections of small molecules for probe and drug discovery.

Nimbolide Represses the Proliferation, Migration, and Invasion of Bladder Carcinoma Cells via Chk2-Mediated G2/M Phase Cell Cycle Arrest, Altered Signaling Pathways, and Reduced Transcription Factors-Associated MMP-9 Expression

Nimbolide, an active chemical constituent of Azadirachta indica, reportedly has several physiological effects. Here, we assessed novel anticancer effects of nimbolide against bladder cancer EJ and 5637 cells. Nimbolide treatment inhibited the proliferation of both bladder cancer cell lines with an IC50 value of 3 μM. Treatment of cells with nimbolide induced G2/M phase cell cycle arrest via both Chk2-Cdc25C-Cdc2/cyclin B1-Wee1 pathway and Chk2-p21WAF1-Cdc2/cyclin B1-Wee1 pathway. Nimbolide increased JNK phosphorylation and decreased p38MAPK and AKT phosphorylation. Additionally, nimbolide impeded both wound healing migration and invasion abilities by suppressing matrix metalloproteinase-9 (MMP-9) activity. Finally, nimbolide repressed the binding activity of NF-κB, Sp-1, and AP-1 motifs, which are key transcription factors for MMP-9 activity regulation. Overall, our study indicates that nimbolide is a potential chemotherapeutic agent for bladder cancer.

The Application of Aqueous Two-phase System in the Extraction of Natural Products from Chinese Herbal Medicine: A Review

Background:

In the past decades, Chinese herbal medicine has attracted worldwide attention because they contain a variety of active ingredients which are beneficial to human health. As a result, there is a growing interest in the extraction of these substances. However, traditional extraction methods not only need a large amount of extractant, but are also time-consuming, moreover, the extraction efficiency is extremely poor and tedious purification steps are required to purify the crude extract. Thus, researchers hope to find an alternative method for the extraction of these components and the aqueous two-phase system (ATPS) seems to be one.

Objective:

This review focuses on introducing the properties of the aqueous two-phase system and summarizing the application of ATPS in the extraction of natural products. Meanwhile, this review also provided a guideline to researchers who wish to design a suitable ATPS for a specific target and how to amplify it to industrial-scale.

The relationship between antioxidant activity, first electrochemical oxidation potential, and spin population of flavonoid radicals

I have shown that by averaging antioxidant activity (AA) values measured by different methods it is possible to obtain an excellent correlation (R2=0.960) between the first electrochemical oxidation potential, Ep1, and AA. Separate correlations using the AA values obtained with each of the four methods [R2 were 0.561 for diphenyl-1-picrylhydrazyl (DPPH), 0.849 for Folin Ciocalteu reagent (FCR), 0.848 for the ferric-reducing ability of plasma (FRAP), and 0.668 for the Trolox equivalent antioxidant capacity (TEAC)] were all worse, and in some cases not useful at all, such as the one for DPPH. Also, the sum of atomic orbital spin populations on the carbon atoms in the skeleton of radicals ( s(C) Σ AOSPRad), calculated with the semi-empirical parameterisation method 6 (PM6) in water, was used to correlate both Ep1 and AA, yielding R2=0.926 and 0.950, respectively. This showed to be a much better variable for the estimation of Ep1 and AA than the bond dissociation energy (BDE), R2=0.854 and 0.901 for Ep1 and AA, respectively, and especially the ionisation potential (IP), R2=0.445 and 0.435 for Ep1 and AA, respectively.

Proanthocyanidins: A comprehensive review

Proanthocyanidins are condensed tannins with various pharmacological properties. These phytochemicals are considered as 'offense and defense molecules because of their human health benefits. The validation of their diverse health aspects, namely, antioxidant, anticancer, antidiabetic, neuroprotective, and antimicrobial has earned them repute in thermochemistry. Proanthocyanidins are oligo- or polymers of monomeric flavan-3-ols produced as an end product of flavonoid biosynthetic pathway. Agricultural wastes and food processing wastes contain immense amount of proanthocyanidins, exploitation of which can be a sustainable source of dietary supplements and functional ingredients. The current review article discusses recent developments in the health promoting properties of proanthocyanidins and the associated hurdles.

High dietary inflammatory index scores are associated with an elevated risk of hepatocellular carcinoma in a case-control study

Chronic inflammation and diet play crucial roles in the development of hepatocellular carcinoma (HCC); yet the association between dietary inflammatory potential and risk of HCC has rarely been investigated. This study aimed to examine whether a higher dietary inflammatory index (DII®) score (indicating a pro-inflammatory diet) is associated with an increased risk of HCC in a matched case-control study conducted between September 2013 and October 2017 in South China. A total of 659 cases with newly diagnosed, previously untreated HCC and 659 controls individually matched on age (±3 years) and sex were included in this study. DII scores were computed based on dietary intake information collected via a validated 79-item food frequency questionnaire (FFQ) during the one year prior to diagnosis (for the cases) or interview (for the controls). Logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) between the DII score and the risk of HCC, adjusted for age, energy intake, body mass index, physical activity, marital status, education, household income, smoking status, and hepatitis B virus (HBV) infection status. Compared with subjects in the lowest DII tertile, subjects in the highest tertile had an elevated risk of HCC (fully adjusted OR: 3.22, 95% CI: 1.30-7.98, P-trend = 0.009). In stratified analyses, a significantly positive association was observed only in men, individuals with lower education level, smokers and non-alcohol drinkers. In conclusion, a higher DII score, representing a more inflammatory diet, was associated with an increased risk of HCC, in men, individuals with lower education level, smokers and non-alcohol drinkers.

Immunomodulatory Effects of Flavonoids: Possible Induction of T CD4+ Regulatory Cells Through Suppression of mTOR Pathway Signaling Activity

The increasing rate of autoimmune disorders and cancer in recent years has been a controversial issue in all aspects of prevention, diagnosis, prognosis and treatment. Among dietary factors, flavonoids have specific immunomodulatory effects that might be of importance to several cancers. Over different types of immune cells, T lymphocytes play a critical role in protecting the immune system as well as in the pathogenesis of specific autoimmune diseases. One of the important mediators of metabolism and immune system is mTOR, especially in T lymphocytes. In the current review, we assessed the effects of flavonoids on the immune system and then their impact on the mTOR pathway. Flavonoids can suppress mTOR activity and are consequently able to induce the T regulatory subset.

6'-Benzyloxy-4-bromo-2'-hydroxychalcone is cytotoxic against human leukaemia cells and induces caspase-8- and reactive oxygen species-dependent apoptosis

In this study, we investigated the effects of synthetic 6'-benzyloxy-4-bromo-2'-hydroxychalcone on viabilities of seven human leukaemia cells. It was cytotoxic against U-937, HL-60, K-562, NALM-6, MOLT-3 cells, and also against Bcl-2-overexpressing U-937/Bcl-2 cells and P-glycoprotein-overexpressing K-562/ADR, but had no significant cytotoxic effects against quiescent or proliferating human peripheral blood mononuclear cells. This chalcone is a potent apoptotic inducer in human leukaemia U-937 cells. Cell death was (i) mediated by the activation and the cleavage of initiator and executioner caspases and poly(ADP-ribose) polymerase; (ii) prevented by the pan-caspase inhibitor z-VAD-fmk, and by the selective caspase-3/7, -6 and -8 inhibitors, and by a cathepsins B/L inhibitor; (iii) associated with the release of mitochondrial proteins, including cytochrome c and Smac/DIABLO; (iv) accompanied by dissipation of the mitochondrial membrane potential, (v) partially blocked by the inhibition of p38^MAPK and (vi) mostly abrogated by catalase. In conclusion, the synthetic chalcone is cytotoxic against several types of human leukaemia cell with apoptosis being induced by activation of the extrinsic pathway and the generation of reactive oxygen species.

Benzoflavone derivatives as potent antihyperuricemic agents

Two series of benzoflavone derivatives were rationally designed, synthesized and evaluated for their xanthine oxidase (XO) inhibitory potential. Among both series, eight compounds (NF-2, NF-4, NF-9, NF-12, NF-16, NF-25, NF-28, and NF-32) were found to exert significant XO inhibition with IC50 values lower than 10 μM. Enzyme kinetic studies revealed that the most potent benzoflavone derivatives (NF-4 and NF-28) are mixed type inhibitors of the XO enzyme. Molecular modeling studies were also performed to investigate the binding interactions of these molecules (NF-4 and NF-28) with the amino acid residues present in the active site of the enzyme. Docking results confirmed that their favorable binding conformations in the active site of XO can completely block the catalytic activity of the enzyme. Benzoflavone derivatives exhibiting potent XO enzyme inhibition also showed promising results in a hyperuricemic mice model when tested in vivo.

Flavonoids in Cancer and Apoptosis

Cancer is the second leading cause of death globally. Although, there are many different approaches to cancer treatment, they are often painful due to adverse side effects and are sometimes ineffective due to increasing resistance to classical anti-cancer drugs or radiation therapy. Targeting delayed/inhibited apoptosis is a major approach in cancer treatment and a highly active area of research. Plant derived natural compounds are of major interest due to their high bioavailability, safety, minimal side effects and, most importantly, cost effectiveness. Flavonoids have gained importance as anti-cancer agents and have shown great potential as cytotoxic anti-cancer agents promoting apoptosis in cancer cells. In this review, a summary of flavonoids and their effectiveness in cancer treatment targeting apoptosis has been discussed.

Interaction of Arylidenechromanone/Flavanone Derivatives with Biological Macromolecules Studied as Human Serum Albumin Binding, Cytotoxic Effect, Biocompatibility Towards Red Blood Cells

The aim of this study was to determine the cytotoxic effect of 3-arylidenechromanone (1) and 3-arylideneflavanone (2) on HL-60 and NALM-6 cell lines (two human leukemia cell lines) and a WM-115 melanoma cell line. Both compounds exhibited high cytotoxic activity with higher cytotoxicity exerted by compound 2, for which IC₅₀ values below 10 µM were found for each cell line. For compound 1, the IC₅₀ values were higher than 10 µM for HL-60 and WM-115 cell lines, but IC₅₀ < 10 µM was found for the NALM-6 cell line. Both compounds, at the concentrations close to IC₅₀ (concentration range: 5–24 µM/L for compound 1 and 6–10 µM/L for compound 2), are not toxic towards red blood cells. The synthesized compounds were characterized using spectroscopic methods ¹H- and ¹³C-NMR, IR, MS, elemental analysis, and X-ray diffraction. The lipophilicity of both synthesized compounds was determined using an RP-TLC method and the logP values found were compared with the theoretical ones taken from the Molinspiration Cheminformatics (miLogP) software package. The mode of binding of both compounds to human serum albumin was assessed using molecular docking methods.

Active compounds present inRosmarinus officinalis leaves andScutellaria baicalensis root evaluated as new therapeutic agents for endometriosis

RESEARCH QUESTION

Can carnosic acid, (CA) rosmarinic acid (RA) and wogonin (WG) inhibit the growth of cultured human endometrial stromal cells and endometriotic-like lesions induced in a BALB/c model of endometriosis?

DESIGN

Primary stromal cell cultures were established from endometrial biopsies from women with endometriosis and controls. The human endometrial stromal cell line T-HESC was also used for in-vitro experiments. Endometriosis was surgically induced in BALB/c mice, which were randomly assigned to CA 2 mg/kg/day (n = 11); CA 20 mg/kg/day (n = 10); RA 1 mg/kg/day (n = 11); RA 3 mg/kg/day (n = 10); WG 20 mg/kg/day (n = 12); intraperitoneal vehicle control (n = 8) or oral vehicle control (n = 11). After surgery, CA and RA were administered intraperitoneally on days 14-28. WG was administered orally by intragastric gavage on days 14-26.

RESULTS

CA, RA and WG significantly inhibited in-vitro cell proliferation in primary and T-HESC cell cultures (P < 0.05). CA and WG induced cell cycle arrest of T-HESC at the G2/M phase (P < 0.01). RA reduced intracellular ROS accumulation (P < 0.001), whereas WG increased it (P < 0.05). WG significantly inhibited oestrogen receptor alpha expression in T-HESC (P < 0.01). In-vivo, CA, RA and WG significantly reduced lesions size (P < 0.05). All compounds significantly decreased the percentage of cells in proliferation (P < 0.05) whereas RA and WG further increased the percentage of apoptotic cells (P < 0.05) in endometriotic-like lesions.

CONCLUSIONS

The results are promising; further investigation of these compounds as new therapeutics is needed.

De novo biosynthesis of myricetin, kaempferol and quercetin in Streptomyces albus and Streptomyces coelicolor

Flavonols are a flavonoid subfamily widely distributed in plants, including several ones of great importance in human and animal diet (apple, tomato, broccoli, onion, beans, tea). These polyphenolic nutraceuticals exert potent antimicrobial (membrane potential disruptors), antioxidant (free-radical scavengers), pharmacokinetic (CYP450 modulators), anti-inflammatory (lipoxygenase inhibitors), antiangiogenic (VEGF inhibitors) and antitumor (cyclin inhibitors) activities. Biotechnological production of these nutraceuticals, for example via heterologous biosynthesis in industrial actinomycetes, is favored since in plants these polyphenols appear as inactive glycosylated derivatives, in low concentrations or as part of complex mixtures with other polyphenolic compounds. In this work, we describe the de novo biosynthesis of three important flavonols, myricetin, kaempferol and quercetin, in the industrially relevant actinomycetes Streptomyces coelicolor and S. albus. De novo biosynthesis of kaempferol, myricetin and quercetin in actinomycetes has not been described before.

A novel rutin-fucoidan complex based phytotherapy for cervical cancer through achieving enhanced bioavailability and cancer cell apoptosis

Recent studies on flavonoids forming complexes with macromolecules attract researchers due to their enhanced bioavailability as well as chemo-preventive efficacy. In this study, a flavonoid rutin (Ru) is non-covalently complexed with fucoidan (Fu) using the functional groups to obtain a therapeutic polymeric complex overcoming the limitations of bioavailability of rutin. The prepared novel rutin-fucoidan (Ru-Fu) complex is characterized for spectroscopic features, particle size and distribution analysis by DLS. It is shown that the complex displayed the nanostructural features that are different from that of the usual rutin-fucoidan mixture. The studies on drug release profiles at different pH (5.5, 6.8 and 7.4) show that the sustained release of compounds from complex occurs preferentially at the desired endosomal pH (5.5). Further, the chemopreventive potential of Ru-Fu complex is investigated against HeLa cells by cellular apoptotic assays and flow cytometric analysis. It showed that the complex is able to disrupt cell cycle regulation and has the ability to induce cellular apoptosis via nuclear fragmentation, ROS generation and mitochondrial potential loss. In vitro cell viability assay with Ru-Fu complex shows that the complex is biocompatible on normal cells. The hemolysis assay also reveals that the complex does not release hemoglobin from human red blood cells (RBCs). Thus, the study is envisaged to open up interests for developing such formulations against cervical cancer and other cancers.

Computational screening of fatty acid synthase inhibitors against thioesterase domain

Thioesterase (TE) domain of fatty acid synthase (FAS) is an attractive therapeutic target for design and development of anticancer drugs. In this present work, we search for the potential FAS inhibitors of TE domain from the ZINC database based on similarity search using three natural compounds as templates, including flavonoids, terpenoids, and phenylpropanoids. Molecular docking was used to predict the interaction energy of each screened ligand compared to the reference compound, which is methyl γ-linolenylfluorophosphonate (MGLFP). Based on this computational technique, rosmarinic acid and its eight analogs were observed as a new series of potential FAS inhibitors, which showed a stronger binding affinity than MGLFP. Afterward, nine docked complexes were studied by molecular dynamics simulations for investigating protein-ligand interactions and binding free energies using MM-PB(GB)SA, MM-3DRISM-KH, and QM/MM-GBSA methods. The binding free energy calculation indicated that the ZINC85948835 (R34) displayed the strongest binding efficiency against the TE domain of FAS. There are eight residues (S2308, I2250, E2251, Y2347, Y2351, F2370, L2427, and E2431) mainly contributed for the R34 binding. Moreover, R34 could directly form hydrogen bonds with S2308, which is one of the catalytic triad of TE domain. Therefore, our finding suggested that R34 could be a potential candidate as a novel FAS-TE inhibitor for further drug design.

CuS@MOF-Based Well-Designed Quercetin Delivery System for Chemo-Photothermal Therapy

Quercetin (QT) is one promising candidate for the treatment of various cancers with virtually no toxic side effects. However, its anticancer effect is severely restricted by its poor bioavailability, low water solubility, and chemical instability in the neutral and alkaline medium. Herein, zeolitic imidazolate framework-8 (ZIF-8) is first reported as the multifunctional nanoplatform to the codelivery of quercetin as an anticancer agent and CuS nanoparticles as a photothermal therapy (PTT) agent for synergistic combination of chemotherapy and PTT as well as overcoming the drawbacks of quercetin. Moreover, folic acid-bovine serum albumin (FA-BSA) conjugates are applied to stabilize the CuS@ZIF-8-QT to promote the bioavailability of quercetin and realize active-targeting drug delivery. Near-infrared (NIR) fluorescent imaging demonstrated the highly increased drug accumulations of FA-BSA/CuS@ZIF-8-QT in tumors, resulting from efficient internalization via FA-receptors-mediated endocytosis. The results of in vivo and in vitro anticancer experiments demonstrate that quercetin and PTT agent can work together efficiently under NIR irradiation, thus remarkably improving the anticancer effect. Therefore, our newly designed FA-BSA/CuS@ZIF-8-QT multifunctional drug delivery system might be a promising nanoplatform for cancer treatment.

Quercetagetin and Patuletin: Antiproliferative, Necrotic and Apoptotic Activity in Tumor Cell Lines

Quercetagetin and patuletin were extracted by the same method from two different Tagetes species that have multiple uses in folk medicine in Mexico and around the globe, one of which is as an anticancer agent. Their biological activity (IC50 and necrotic, apoptotic and selective activities of these flavonols) was evaluated and compared to that of quercetin, examining specifically the effects of C6 substitution among quercetin, quercetagetin and patuletin. We find that the presence of a methoxyl group in C6 enhances their potency.

Synergistic Interaction of Rutin and Silibinin on Human Colon Cancer Cell Line

AIM OF THE STUDY

Rutin and Silibinin are active flavonoid compounds, well-known for possessing multiple biological activities. We have studied how Rutin and Silibinin in combination modulate wide range intracellular signaling cascades as evidenced by in-vitro research. Data obtained from preclinical studies provide evidence to be supportive to bridge basic and translational studies.

METHODS

In this study, cytotoxic effect of Rutin and Silibinin individually and in combination on the viability of colon cancer cell line (HT-29) was revealed using the MTT assay. Mechanism involved in the cytotoxic effect were then investigated in terms of apoptosis using comet assay, DNA fragmentation and fluorescent microscopy analyses. The apoptosis associated proteins viz; Caspase-3, 8, 9, Bax, Bcl-2, p53, inflammation associated proteins viz; NFκB, IKK-α IKK-β and MAPK pathway associated proteins viz; p38 and MK-2 were determined by western-blot and Real Time-PCR analysis.

RESULTS

Results suggest that Rutin and Silibinin produce anticancer effects via induction of apoptosis as well as regulating the expressions of genes related to apoptosis, inflammation and MAPK pathway proteins more effectively in combination than individually.

CONCLUSION

Our study supports the viability of developing Rutin and Silibinin in combination as a novel therapeutic prodrug for colon cancer treatment and may have a promising role in the development of new anticancer drugs in the future.

Controlled quercetin release from high-capacity-loading hyperbranched polyglycerol-functionalized graphene oxide

PURPOSE

An efficient drug-delivery system was prepared based on graphene oxide using a facile and one-step strategy for controlling the release of anticancer drugs.

METHODS

Fabrication of single-layer graphene oxide (GO) sheets was carried out by both modified and improved Hummers method. Biocompatible hyperbranched polyglycerol (HPG) was grafted on the surface of GO through the ring-opening hyperbranched polymerization of glycidol. Various ratios of GO and glycidol were used for polymer grafting. An anticancer drug, quercetin (Qu), was loaded into modified GO via noncovalent interactions.

RESULTS

Polymer grafting on the surface of GO sheets was confirmed by results obtained from Fourier-transform infrared and Raman spectroscopy, thermogravimetric analysis, energy-dispersive X-ray and X-ray spectroscopy, scanning electron microscopy, and atomic force microscopy. It was revealed that polymerization increased d-spacing between the basal planes. In addition, as a hydrophilic polymer, HPG improved the stability and dispersion of GO sheets in biological solutions and endowed extra drug-loading capacity for the sheets. The effect of hyperbranched structure on drug loading and release was investigated by comparing drug loading and release for HPG-modified GO and linear PPO-modified GO. Our experiments indicated high drug-loading capacity (up to 185%), and excellent encapsulation efficiency (up to 93%) for HPG-GO compared to linear PO-grafted GO. The release profile of Qu under various pH levels exhibited controlled and sustained drug release without an initial burst effect for HPG-GO, suggesting that an acidic solution could facilitate drug release. HPG-GO did not show any cytotoxicity on the MCF7 cell line in different concentrations during 72 hours' incubation. Uptake and entrance of HPG-GO into the cells were verified by determining the intracellular amount of Qu by high-performance liquid chromatography.

CONCLUSION

A combination of the unique properties of GO and the biodegradable polymer polyglycerol revealed high drug-loading capacity, pH-dependent drug release, and cytocompatibility with HPG-GO, thus introducing it as a promising nanocarrier for anticancer drug delivery.

Primula vulgaris extract induces cell cycle arrest and apoptosis in human cervix cancer cells

Primula vulgaris belongs to the genus Primula, members of which are frequently used in folk medicine. Various studies have investigated the cytotoxic effect of different Primula species, but there have been limited studies on the cytotoxic effect of P. vulgaris. The aim of this study was to investigate the cytotoxic effects, and possible mechanisms involved, of P. vulgaris flower extract on human cervical cancer (HeLa) cells. The cytotoxic effect of the extract on HeLa cells was revealed using the MTT assay. Mechanisms involved in the extract's cytotoxic effect were then investigated in terms of apoptosis, mitochondrial membrane potential, and the cell cycle, using fluorometric methods. P. vulgaris flower extract exhibited selective cytotoxic effects against HeLa cells by arresting their cell cycle at the S phase, and inducing the number of apoptotic cells compared to normal fibroblast cells by reducing mitochondrial membrane potential in a concentration-dependent manner. This is the first study to reveal the antiproliferative effect of P. vulgaris flower extract. Further studies are now needed to identify the cytotoxic molecules in the extract and their mechanisms.

Structure-Based Classification and Anti-Cancer Effects of Plant Metabolites

A variety of malignant cancers affect the global human population. Although a wide variety of approaches to cancer treatment have been studied and used clinically (surgery, radiotherapy, chemotherapy, and immunotherapy), the toxic side effects of cancer therapies have a negative impact on patients and impede progress in conquering cancer. Plant metabolites are emerging as new leads for anti-cancer drug development. This review summarizes these plant metabolites with regard to their structures and the types of cancer against which they show activity, organized by the organ or tissues in which each cancer forms. This information will be helpful for understanding the current state of knowledge of the anti-cancer effects of various plant metabolites against major types of cancer for the further development of novel anti-cancer drugs.

Quercetin and doxorubicin co-delivery using mesoporous silica nanoparticles enhance the efficacy of gastric carcinoma chemotherapy

BACKGROUND

Effective gastric carcinoma (GC) chemotherapy is subject to many in vitro and in vivo barriers, such as tumor microenvironment and multidrug resistance.

MATERIALS AND METHODS

Herein, we developed a hyaluronic acid (HA)-modified silica nanoparticle (HA-SiLN/QD) co-delivering quercetin and doxorubicin (DOX) to enhance the efficacy of GC therapy (HA-SiLN/QD). The HA modification was done to recognize overexpressed CD44 receptors on GC cells and mediate selective tumor targeting. In parallel, quercetin delivery decreased the expression of Wnt16 and P-glycoprotein, thus remodeling the tumor microenvironment and reversed multidrug resistance to facilitate DOX activity.

RESULTS

Experimental results demonstrated that HA-SiLN/QD was nanoscaled particles with preferable stability and sustained release property. In vitro cell experiments on SGC7901/ADR cells showed selective uptake and increased DOX retention as compared to the DOX mono-delivery system (HA-SiLN/D).

CONCLUSION

In vivo anticancer assays on the SGC7901/ADR tumor-bearing mice model also revealed significantly enhanced efficacy of HA-SiLN/QD than mono-delivery systems (HA-SiLN/Q and HA-SiLN/D).

Structure-activity relationship and pharmacokinetic studies of 3-O-substitutedflavonols as anti-prostate cancer agents

Thirty-eight 3-O-substituted-3',4'-dimethoxyflavonols and twenty-five 3-O-substituted-3',4',7-trimethoxyflavonols have been synthesized for systematic investigation on the structure-activity relationships of 3-O-substituted-3',4'-dimethoxyflavonols in three human prostate cancer cell models. Our findings indicate that incorporation of an appropriate amino group to 3-OH of 3',4'-dimethoxyflavonol and 3',4',7-trimethoxyflavonol through a 3- to 5-carbon linker can substantially improve the in vitro antiproliferative potency in three human prostate cancer cell models, but not in two non-neoplastic human epithelial cell models (MCF 10A and PWR-1E). 1-Methylpiperazine, pyrrolidine, and dibutylamine are optimal terminal amine groups that, in combination with a 3- to 5-carbon linker, are notably beneficial to the anti-proliferative potency of 3-O-substituted-3',4'-dimethoxyflavonols. It is worth noting that 3-O-(4-methylpiperazin-1-yl)propyl-3',4',7-trimethoxyflavonol (76) induces PC-3 cell death in a completely different way from 3-O-pyrrolidinopentyl-3',4',7-trimethoxyflavonol (81) even though they belong to 3-O-substituted-3',4',7-trimethoxyflavonols and exhibit similar potency in inhibiting PC-3 cell proliferation, suggesting that the mechanism of action for each specific 3-O-substitutedflavonol varies with different amino moiety. 3-O-(N,N-Dibutylamino)propyl-3',4'-dimethoxyflavonol (42) emerged as the most promising derivative due to its substantially improved potency in cell models, superior bioavailability in rats, and good selectivity of inhibiting prostate cancer cell proliferation over non-neoplastic human epithelial cell proliferation.

Cirsimarin, a flavone glucoside from the aerial part of Cirsium japonicum var. ussuriense (Regel) Kitam. ex Ohwi, suppresses the JAK/STAT and IRF-3 signaling pathway in LPS-stimulated RAW 264.7 macrophages

Cirsium japonicum var. ussuriense (Regel) Kitam. ex Ohwi (C. ussuriense) is known as "Dae-Gye" or "Korean milk thistle". C. ussuriense have long been used as a folk medicinal plant for inflammatory diseases such as hepatitis, nephritis, and mastitis in Korea, China, and Japan. To reveal the anti-inflammatory components of C. ussuriense, we isolated three flavone glycosides (linarin, cirsimarin, and hispidulin-7-O-neohesperidoside) from the aerial part of C. ussuriense and evaluated their inhibitory effects on LPS-induced pro-inflammatory mediators in macrophages. We also investigated the involving molecular mechanisms of cirsimarin. Among three flavone glycosides, cirsimarin showed vastly superior inhibitory potency in LPS-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production. Cirsimarin concentration-dependently inhibited LPS-induced inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein and mRNA levels in macrophages. Cirsimarin suppressed the production and mRNA expression of tumor necrosis factor- α (TNF-α) and interleukin (IL)-6 in LPS-stimulated RAW 264.7 and bone marrow-derived macrophages. Moreover, molecular data presented that cirsimarin down-regulated the phosphorylation of Janus kinase (JAK)/signal transducer and activator of transcriptions (STATs) and p38 mitogen-activated protein kinase (MAPK), and nuclear translocation of interferon regulatory factor (IRF)-3. Collectively, cirsimarin may be an active ingredient responsible for anti-inflammatory effects of C. ussuriense and it may act as a promising therapeutic against inflammatory diseases by suppressing the JAK/STAT and IRF-3 signaling pathway.

Self-reported dietary flavonoid intake and serum markers of inflammation: the multiethnic cohort

PURPOSE

To examine if dietary intake of foods rich in flavonoids, which have been shown to be inversely associated with chronic diseases, is associated with inflammatory processes.

METHODS

This analysis includes controls of case-control studies nested within the Multiethnic Cohort (MEC) who completed a validated food frequency questionnaire at cohort entry. Biomarkers were assessed in blood donated during follow-up (mean = 9.6 years). We used multivariate linear regression adjusted for potential confounders to estimate associations between intake of flavanones, flavonols, and isoflavones and levels of adiponectin, leptin, C-reactive protein, interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor-α.

RESULTS

Among the 1,287 participants, the respective median intakes of flavanones, flavonols, and isoflavones were 26.5, 12.4, and 1.3 mg/day at cohort entry. With the exception of flavanone intake, which was statistically significantly inversely associated with adiponectin (p = 0.01) and IL-6 concentrations (p = 0.01), none of the examined flavonoids was related with levels of adipokines or inflammatory markers. Heterogeneity by ethnicity was only observed for flavonol intake and IL-10 (pinteraction = 0.04) and may be the result of multiple testing. These null findings were confirmed in a subset of participants who completed a second dietary history within 2.6 years of blood draw.

CONCLUSION

The current results do not support a consistent association between dietary intake of flavonoids and markers of inflammatory processes.