Isoquercitrin inhibits the progression of pancreatic cancer in vivo and in vitro by regulating opioid receptors and the mitogen-activated protein kinase signalling pathway

Phytochemical composition, antimicrobial, antioxidant, and wound healing activities of Thermopsis turcica

The antioxidant, antimicrobial, anticarcinogenic, wound healing activities and phenolic substance profile of aqueous extracts prepared using branch, leaf, flower parts and above-ground parts of Thermopsis turcica were determined in the study. The analyses indicate that the total phenolic substance contents and total antioxidant status are higher in the mix, flower, and leaf extracts. The extracts reduced cell viability in HGF cells more than in A549 cells. It shows that the extract has low anticarcinogenic activity in A549 cells. Flower extract had the highest wound closure rate. Quinic acid, cyranoside and luteolin were found in high concentrations in all extracts with LC/ESI-MS/LC analysis. It has been determined that the flower extract of the species is the most critical part showing antioxidant, antimicrobial, cytotoxic and wound healing properties. While the leaf and mix extracts stand out with their antioxidative and antimicrobial properties, the branch extract is effective in wound healing.

Flavonoids as modulators of miRNA expression in pancreatic cancer: Pathways, Mechanisms, And Therapeutic Potential

Pancreatic cancer (PC) is a complex malignancy, distinguished by its aggressive characteristics and unfavorable prognosis. Recent developments in understanding the molecular foundations of this disease have brought attention to the noteworthy involvement of microRNAs (miRNAs) in disease development, advancement, and treatment resistance. The anticancer capabilities of flavonoids, which are a wide range of phytochemicals present in fruits and vegetables, have attracted considerable interest because of their ability to regulate miRNA expression. This review provides the effects of flavonoids on miRNA expression in PC, explains the underlying processes, and explores the possible therapeutic benefits of flavonoid-based therapies. Flavonoids inhibit PC cell proliferation, induce apoptosis, and enhance chemosensitivity via the modulation of miRNAs involved in carcinogenesis. Additionally, this review emphasizes the significance of certain miRNAs as targets of flavonoid action. These miRNAs have a role in regulating important signaling pathways such as the phosphoinositide-3-kinase-protein kinase B/Protein kinase B (Akt), mitogen activated protein kinase (MAPK), Janus kinase/signal transducers and activators of transcription (JAK/STAT), and Wnt/β-catenin pathways. This review aims to consolidate current knowledge on the interaction between flavonoids and miRNAs in PC, providing a comprehensive analysis of how flavonoid-mediated modulation of miRNA expression could influence cancer progression and therapy. It highlights the use of flavonoid nanoformulations to enhance stability, increase absorption, and maximize anti-PC activity, improving patient outcomes. The review calls for further research to optimize the use of flavonoid nanoformulations in clinical trials, leading to innovative treatment strategies and more effective approaches for PC.

A Network Pharmacology and Molecular-Docking-Based Approach to Identify the Probable Targets of Short-Chain Fatty-Acid-Producing Microbial Metabolites against Kidney Cancer and Inflammation

(1) Background: A large and diverse microbial population exists in the human intestinal tract, which supports gut homeostasis and the health of the host. Short-chain fatty acid (SCFA)-secreting microbes also generate several metabolites with favorable regulatory effects on various malignancies and immunological inflammations. The involvement of intestinal SCFAs in kidney diseases, such as various kidney malignancies and inflammations, has emerged as a fascinating area of study in recent years. However, the mechanisms of SCFAs and other metabolites produced by SCFA-producing bacteria against kidney cancer and inflammation have not yet been investigated. (2) Methods: We considered 177 different SCFA-producing microbial species and 114 metabolites from the gutMgene database. Further, we used different online-based database platforms to predict 1890 gene targets associated with metabolites. Moreover, DisGeNET, OMIM, and Genecard databases were used to consider 13,104 disease-related gene targets. We used a Venn diagram and various protein-protein interactions (PPIs), KEGG pathways, and GO analyses for the functional analysis of gene targets. Moreover, the subnetwork of protein-protein interactions (through string and cytoscape platforms) was used to select the top 20% of gene targets through degree centrality, betweenness centrality, and closeness centrality. To screen the possible candidate compounds, we performed an analysis of the ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties of metabolites and then found the best binding affinity using molecular docking simulation. (3) Results: Finally, we found the key gene targets that interact with suitable compounds and function against kidney cancer and inflammation, such as MTOR (with glycocholic acid), PIK3CA (with 11-methoxycurvularin, glycocholic acid, and isoquercitrin), IL6 (with isoquercitrin), PTGS2 (with isoquercitrin), and IGF1R (with 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine, isoquercitrin), showed a lower binding affinity. (4) Conclusions: This study provides evidence to support the positive effects of SCFA-producing microbial metabolites that function against kidney cancer and inflammation and makes integrative research proposals that may be used to guide future studies.

A potential Chinese medicine monomer against influenza A virus and influenza B virus: isoquercitrin

BACKGROUND

Influenza viruses, especially Influenza A virus and Influenza B virus, are respiratory pathogens and can cause seasonal epidemics and pandemics. Severe influenza viruses infection induces strong host-defense response and excessive inflammatory response, resulting in acute lung damage, multiple organ failure and high mortality. Isoquercitrin is a Chinese medicine monomer, which was reported to have multiple biological activities, including antiviral activity against HSV, IAV, SARS-CoV-2 and so on. Aims of this study were to assess the in vitro anti-IAV and anti-IBV activity, evaluate the in vivo protective efficacy against lethal infection of the influenza virus and searched for the more optimal method of drug administration of isoquercitrin.

METHODS

In vitro infection model (MDCK and A549 cells) and mouse lethal infection model of Influenza A virus and Influenza B virus were used to evaluate the antiviral activity of isoquercitrin.

RESULTS

Isoquercitrin could significantly suppress the replication in vitro and in vivo and reduced the mortality of mouse lethal infection models. Compared with virus infection group, isoquercitrin mitigated lung and multiple organ damage. Moreover, isoquercitrin blocked hyperproduction of cytokines induced by virus infection via inactivating NF-κB signaling. Among these routes of isoquercitrin administration, intramuscular injection is a better drug delivery method.

CONCLUSION

Isoquercitrin is a potential Chinese medicine monomer Against Influenza A Virus and Influenza B Virus infection.

Antiangiogenic, Anti-Inflammatory and Antioxidant Properties of Bidens tripartite Herb, Galium verum Herb and Rumex hydrolapathum Root

Plants are commonly used in folk medicine. Research indicates that the mechanisms of biological activity of plant extracts may be essential in the treatment of various diseases. In this respect, we decided to test the ethanolic extracts of Bidens tripartita herb (BTH), Galium verum herb (GVH), and Rumicis hydrolapathum root (RHR) on angiogenic, anti-inflammatory, and antioxidant properties and their total polyphenols content. In vitro studies using endothelial cells were used to see tested extracts' angiogenic/angiostatic and anti-inflammatory properties. The DPPH assay and FRAP analysis were used to detect antioxidant properties of extracts. The Folin-Ciocalteu analysis was used to determine the content of total polyphenols. The results of gas chromatography-mass spectrometry analysis was also presented. In vitro study demonstrated that BTH, GVH, and RHR ethanolic extracts significantly increased cell invasiveness, compared with the control group. Increased endothelial proangiogenic invasiveness was accompanied by reduced metalloproteinase inhibitor 1 (TIMP-1) and raised in metalloproteinase 9 (MMP-9). Only BTH and GVH significantly reduced cell proliferation, while BTH and RHR facilitated migration. Additionally, tested extracts reduced the production of proangiogenic platelet-derived growth factor (PDGF) and hepatocyte growth factor (HGF). The most potent anti-inflammatory capacity showed BTH and GVH, reducing proinflammatory interleukin 8 (CXCL8) and interleukin 6 (Il-6), compared to RHR extract that has slightly less inhibited CXCL8 production without affecting IL-6 production. Moreover, we confirmed the antioxidant properties of all examined extracts. The highest activity was characterized by RHR, which has been correlated with the high content of polyphenols. In conclusion, the modifying influence of examined extracts can be promising in disorders with pathogenesis related to angiogenesis, inflammation and free radicals formation. BTH is the best choice among the three tested extracts with its antiangiogenic and anti-inflammatory properties.

Cefotetan-bound human RKIP involves in Ras/Raf1/MEK/ERK signaling pathway

Cefotetan is widely used to treat bacterial infections in the clinic owing to its broad spectrum of antibacterial activity. In the present study, we demonstrate that cefotetan can bind to the conserved ligand-binding pocket of human Raf1 kinase inhibitory protein (hRKIP), which acts as a negative regulator of the Ras/Raf1/MEK/ERK signaling pathway. The cefotetan-bound hRKIP adopts a rigid structure with insufficient space for binding Raf1 kinase, thereby reliving the inhibitory activity of hRKIP in the Ras/Raf1/MEK/ERK signaling pathway and enhancing the phosphorylation level of ERK. Both NMR titration and molecular docking approaches show that several residues (P74, Y81, W84, P111, P112, K113, S142, G143, D144, W173, P178, Y181 and L184) play crucial roles in hRKIP binding cefotetan. NMR dynamics analysis reveals that the binding of cefotetan with hRKIP promotes ps-ns internal motion but reduces μs-ms conformational exchange for residues in the cefotetan-binding pocket of hRKIP. Our results not only disclose the structural basis of cefotetan upregulating the Ras/Raf1/MEK/ERK signaling pathway but also benefit developing novel drugs against diseases caused by the impaired Ras/Raf1/MEK/ERK pathway.

Comparative Metabolomic Profiling Reveals Key Secondary Metabolites Associated with High Quality and Nutritional Value in Broad Bean (Vicia faba L.)

High quality and nutritional benefits are ultimately the desirable features that influence the commercial value and market share of broad bean (Vicia faba L.). Different cultivars vary greatly in taste, flavor, and nutrition. However, the molecular basis of these traits remains largely unknown. Here, the grain metabolites of the superior Chinese landrace Cixidabaican (CX) were detected by a widely targeted metabolomics approach and compared with the main cultivar Lingxiyicun (LX) from Japan. The analyses of global metabolic variations revealed a total of 149 differentially abundant metabolites (DAMs) were identified between these two genotypes. Among them, 84 and 65 were up- and down-regulated in CX compared with LX. Most of the DAMs were closely related to healthy eating substances known for their antioxidant and anti-cancer properties, and some others were involved in the taste formation. The KEGG-based classification further revealed that these DAMs were significantly enriched in 21 metabolic pathways, particularly in flavone and flavonol biosynthesis. The differences in key secondary metabolites, including flavonoids, terpenoids, amino acid derivates, and alkaloids, may lead to more nutritional value in a healthy diet and better adaptability for the seed germination of CX. The present results provide important insights into the taste/quality-forming mechanisms and contributes to the conservation and utilization of germplasm resources for breeding broad bean with superior eating quality.

Chemopreventive effects and anti-tumorigenic mechanisms of Actinidia arguta, known as sarunashi in Japan toward 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)- induced lung tumorigenesis in a/J mouse

BACKGROUND

Previously, we reported the inhibitory effect of Actinidia arguta juice, known as sarunashi juice (sar-j) in Japan, on mutagenesis, inflammation, and mouse skin tumorigenesis. The components of A. arguta responsible for the anti-mutagenic effects were identified to be water-soluble, heat-labile phenolic compounds. We proposed isoquercetin (isoQ) as a candidate anticarcinogenic component. In this study, we sought to investigate the chemopreventive effects of A. arguta juice and isoQ on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in A/J mice, and identify the possible mechanisms underlying the anti-tumorigenic effects of A. arguta.

RESULTS

The number of tumor nodules per mouse lung in the group injected with NNK and administered A. arguta juice orally was significantly lower than that in the group injected with NNK only. Oral administration of isoQ also reduced the number of nodules in the mouse lungs. As expected, the mutagenicity of NNK and 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) detected using S. typhimurium TA1535 decreased in the presence of sar-j. However, NNK and MNNG mutagenicity detected using S. typhimurium YG7108, a strain lacking the O⁶-methylguanine DNA methyltransferases (ogt_ST and ada_ST) did not decrease in the presence of sar-j suggesting that sar-j may mediate its antimutagenic effect by enhancing the DNA damage repair by ogt_ST and ada_ST. Phosphorylation of Akt, with or without epidermal growth factor stimulation, in A549 cells was significantly decreased following sar-j and isoQ treatment, indicating that components in sar-j including isoQ suppressed the PI3K/AKT signaling pathways.

CONCLUSIONS

Sar-j and isoQ reduced NNK-induced lung tumorigenesis. Sar-j targets both the initiation and growth/progression steps during carcinogenesis, specifically via anti-mutagenesis, stimulation of alkyl DNA adduct repair, and suppression of Akt-mediated growth signaling. IsoQ might contribute in part to the biological effects of sar-j via suppression of Akt phosphorylation, but it may not be the main active ingredient.

Drug repurposing-an emerging strategy in cancer therapeutics

Cancer is a complex disease affecting millions of people around the world. Despite advances in surgical and radiation therapy, chemotherapy continues to be an important therapeutic option for the treatment of cancer. The current treatment is expensive and has several side effects. Also, over time, cancer cells develop resistance to chemotherapy, due to which there is a demand for new drugs. Drug repurposing is a novel approach that focuses on finding new applications for the old clinically approved drugs. Current advances in the high-dimensional multiomics landscape, especially proteomics, genomics, and computational omics-data analysis, have facilitated drug repurposing. The drug repurposing approach provides cheaper, effective, and safe drugs with fewer side effects and fastens the process of drug development. The review further delineates each repurposed drug's original indication and mechanism of action in cancer. Along with this, the article also provides insight upon artificial intelligence and its application in drug repurposing. Clinical trials are vital for determining medication safety and effectiveness, and hence the clinical studies for each repurposed medicine in cancer, including their stages, status, and National Clinical Trial (NCT) identification, are reported in this review article. Various emerging evidences imply that repurposing drugs is critical for the faster and more affordable discovery of anti-cancerous drugs, and the advent of artificial intelligence-based computational tools can accelerate the translational cancer-targeting pipeline.

Pharmacological Interaction of Quercetin Derivatives of Tilia americana and Clinical Drugs in Experimental Fibromyalgia

Fibromyalgia (FM) is a pain syndrome characterized by chronic widespread pain and CNS comorbidities. Tilia americana var. mexicana is a medicinal species used to treat anxiety, insomnia, and acute or chronic pain. However, its spectrum of analgesic efficacy for dysfunctional pain is unknown. To investigate a possible therapeutic alternative for FM-type pain, an aqueous Tilia extract (TE) and its flavonoid fraction (FF) containing rutin and isoquercitrin were evaluated alone and/or combined with clinical drugs (tramadol—TRA and pramipexol—PRA) using the reserpine-induced FM model in rats. Chromatographic analysis allowed the characterization of flavonoids, while a histological analysis confirmed their presence in the brain. TE (10–100 mg/kg, i.p.) and FF (10–300 mg/kg, i.p.) produced significant and dose-dependent antihyperalgesic and antiallodynic effects equivalent to TRA (3–10 mg/kg, i.p.) or PRA (0.01–1 mg/kg, s.c.). Nevertheless, the combination of FF + TRA or FF + PRA resulted in an antagonistic interaction by possible competitive action on the serotonin transporter or µ-opioid and D₂ receptors, respectively, according to the in silico analysis. Flavonoids were identified in cerebral regions because of their self-epifluorescence. In conclusion, Tilia possesses potential properties to relieve FM-type pain. However, the consumption of this plant or flavonoids such as quercetin derivatives in combination with analgesic drugs might reduce their individual benefits.

Identification and Quantification of Flavonoids in Okra (Abelmoschus esculentus L. Moench) and Antiproliferative Activity In Vitro of Four Main Components Identified

Okra is a kind of flavonoid-rich food which was reported to have a variety of health functions. Flavonoids are the major polyphenolic compounds in okra and are thought to play a role in reducing the risk of disease. The aim of this study was to isolate and identify the flavonoids composition in okra pods and explore the activity of the main flavonoids components identified on inhibiting tumor cell proliferation in vitro. Six individual flavonoids were identified by HPLC-MS/MS: quercetin-3-gentiobioside (Q3G), quercetin-3-sambubioside (Q3S), rutin, quercetin-7-glucoside (Q7G), isoquercitrin (ISO) and quercetin-3-malonylglucoside (Q3M), which were all separated well within 30 min. The analytical method was validated by the recovery of spiked samples and so on. Moreover, four main flavonoids components, namely Q3G, Q3S, ISO and Q3M, exhibited significant (p < 0.05) inhibition of NCI-N87, A375, A549 cells proliferation (25−100 μmol/L) and of HFLS-RA (200−300 μmol/L) in different levels, according to MTT method, respectively. It is demonstrated that the flavonoids components of okra exhibited a noteworthy development prospect as a possible nutraceutical dietary supplement.

Application of Quality by Design Approach to the Pharmaceutical Development of Anticancer Crude Extracts of Crocus sativus Perianth

The application of the Quality by Design (QbD) concept to extracts obtained from Crocus sativus perianth with potential anticancer activity will ensure the safety, efficiency, and quality control of the entire technological process, as well as determine the critical factors affecting the quality of extracts. Potentially critical points of the production of the plant extracts, including the cultivation and processing of the plant materials, the extraction process, and the choice of solvents, were identified using the Ishikawa diagram and FMEA risk assessment methods as well as the corrective actions proposed. The Herbal Chemical Marker Ranking System (HerbMars) approach was used to justify the Q-markers choice of Crocus, which takes into account bioavailability, pharmacological activity, and the presence of the selected standard. An experimental design (DoE) was used to assess the influence of potentially critical factors on the efficiency of the compound extraction from raw materials with water or ethanol. The presence of 16 compounds in Crocus perianth was determined by HPLC and their quantitative assessment was established. Selected compounds (ferulic acid, mangiferin, crocin, rutin, isoquercitrin) can be used for the quality control of Crocus perianth. In addition, the stigmas from the Volyn region met the requirements of ISO 3632 for saffron as a spice (category I). The cytotoxic activity against melanoma (IGR39) and triple-negative breast cancer (MDA-MB-231) cell lines of the hydroethanolic extract of C. sativus perianth was significantly more pronounced than the water extract, probably due to the chemical composition of the constituent components. The results show that the QbD approach is a powerful tool for process development for the production of quality herbal drugs.

A highly versatile fungal glucosyltransferase for specific production of quercetin-7-O-β-D-glucoside and quercetin-3-O-β-D-glucoside in different hosts

Glycosylation is an effective way to improve the water solubility of natural products. In this work, a novel glycosyltransferase gene (BbGT) was discovered from Beauveria bassiana ATCC 7159 and heterologously expressed in Escherichia coli. The purified enzyme was functionally characterized through in vitro enzymatic reactions as a UDP-glucosyltransferase, converting quercetin to five monoglucosylated and one diglucosylated products. The optimal pH and temperature for BbGT are 35 ℃ and 8.0, respectively. The activity of BbGT was stimulated by Ca²⁺, Mg²⁺, and Mn²⁺, but inhibited by Zn²⁺. BbGT enzyme is flexible and can glycosylate a variety of substrates such as curcumin, resveratrol, and zearalenone. The enzyme was also expressed in other microbial hosts including Saccharomyces cerevisiae, Pseudomonas putida, and Pichia pastoris. Interestingly, the major glycosylation product of quercetin in E. coli, P. putida, and P. pastoris was quercetin-7-O-β-D-glucoside, while the enzyme dominantly produced quercetin-3-O-β-D-glucoside in S. cerevisiae. The BbGT-harboring E. coli and S. cerevisiae strains were used as whole-cell biocatalysts to specifically produce the two valuable quercetin glucosides, respectively. The titer of quercetin-7-O-β-D-glucosides was 0.34 ± 0.02 mM from 0.83 mM quercetin in 24 h by BbGT-harboring E. coli. The yield of quercetin-3-O-β-D-glucoside was 0.22 ± 0.02 mM from 0.41 mM quercetin in 12 h by BbGT-harboring S. cerevisiae. This work thus provides an efficient way to produce two valuable quercetin glucosides through the expression of a versatile glucosyltransferase in different hosts. KEY POINTS: • A highly versatile glucosyltransferase was identified from B. bassiana ATCC 7159. • BbGT converts quercetin to five mono- and one di-glucosylated derivatives in vitro. • Different quercetin glucosides were produced by BbGT in E. coli and S. cerevisiae.

A pharmacognostic approach for mitigating pancreatic cancer: emphasis on herbal extracts and phytoconstituents

Background

Pancreatic cancer is studied as one of the most lethal cancers with currently no control of its lethality, mainly due to its late diagnosis and lack of foolproof treatment processes. Despite continuous efforts being made in looking for therapies to deal with cancer, it keeps on being a labyrinth for the researchers. Efforts like discovering new treatment options, repurposing existing drugs, are continuously made to deal with this cancer.

Main body

With the urge to get answers and the fact that nature has all roots of therapeutics, efforts are made in the direction of finding those answers for providing ministrations for pancreatic cancer from plant products. Plant products are used as treatment options either directly in the form of extracts or an alternative to them is individual phytochemicals that are either isolated from the plants or are commercially synthesized for various purposes. In this review, we put forward such pharmacognostic initiatives made in combating pancreatic cancer, focusing mainly on plant extracts and various phytochemicals; along with the mechanisms which they triggered to fulfill the need for cytotoxicity to pancreatic cancer cells (in vitro and in vivo).

Conclusion

This study will thus provide insights into new combination therapy that can be used and also give a clue on which plant product and phytoconstituent can be used in dealing with pancreatic cancer.

Graphical abstract

Antioxidative effect of dietary flavonoid isoquercitrin on human ovarian granulosa cells HGL5 in vitro

This study aimed to examine the effect of dietary flavonoid isoquercitrin on ovarian granulosa cells using the immortalized human cell line HGL5. Cell viability, survival, apoptosis, release of steroid hormones 17beta-estradiol and progesterone, and human transforming growth factor-beta2 (TGF-beta2) and TGF-beta2 receptor as well as intracellular reactive oxygen species (ROS) generation were investigated after isoquercitrin treatment at the concentration range of 5-100 microg.ml-1. It did not cause any significant change (p>0.05) in cell viability as studied by AlamarBlue assay in comparison to control. No significant change was observed (p>0.05) in the proportion of live, dead and apoptotic cells as revealed by apoptotic assay using flow cytometry. Similarly, the release of 17beta-estradiol, progesterone, TGF-beta2 and its receptor were not affected significantly (p>0.05) by isoquercitrin as detected by ELISA, in comparison to control. Except for the highest concentration of 100 microg.ml-1, which led to oxidative stress, isoquercitrin exhibited antioxidative activity at lower concentration used in the study (5, 10, 25, and 50 microg.ml-1) by hampering the production of intracellular ROS, in comparison to control, as detected by chemiluminescence assay (p<0.05). Findings of the present study indicate an existence of the antioxidative pathway that involves inhibition of intracellular ROS generation by isoquercitrin in human ovarian granulosa cells.

Anticancer Effects of the Corchorus olitorius Aqueous Extract and Its Bioactive Compounds on Human Cancer Cell Lines

Corchorus olitorius is a common, leafy vegetable locally known as “Saluyot” in the Philippines. Several studies have reported on its various pharmacological properties, such as antioxidant, anti-inflammatory, analgesic, and anticancer properties. However, little is known about its effects on angiogenesis. This study aimed to evaluate the anticancer properties, such as the antiproliferative, anti-angiogenic, and antitumor activities, of the C. olitorius aqueous extract (CO) and its bioactive compounds, chlorogenic acid (CGA) and isoquercetin (IQ), against human melanoma (A-375), gastric cancer (AGS), and pancreatic cancer (SUIT-2), using in vitro and in ovo biological assays. The detection and quantification of CGA and IQ in CO were achieved using LC-MS/MS analysis. The antiproliferative, anti-angiogenic, and antitumor activities of CO, CGA, and IQ against A-375, AGS, and SUIT-2 cancer cell lines were evaluated using MTT and CAM assays. CGA and IQ were confirmed to be present in CO. CO, CGA, and IQ significantly inhibited the proliferation of A-375, AGS, and SUIT-2 cancer cells in a dose-dependent manner after 48 h of treatment. Tumor angiogenesis (hemoglobin levels) of A-375 and AGS tumors was significantly inhibited by CO, CGA, IQ, and a CGA–IQ combination. The growth of implanted A-375 and AGS tumors was significantly reduced by CO, CGA, IQ, and a CGA–IQ combination, as measured in tumor weight. Our investigation provides new evidence to show that CO has promising anticancer effects on various types of human cancer cells. CO and its compounds are potential nutraceutical products that could be used for cancer treatment.

Suramin Targets the Conserved Ligand-Binding Pocket of Human Raf1 Kinase Inhibitory Protein

Suramin was initially used to treat African sleeping sickness and has been clinically tested to treat human cancers and HIV infection in the recent years. However, the therapeutic index is low with numerous clinical side-effects, attributed to its diverse interactions with multiple biological macromolecules. Here, we report a novel binding target of suramin, human Raf1 kinase inhibitory protein (hRKIP), which is an important regulatory protein involved in the Ras/Raf1/MEK/ERK (MAPK) signal pathway. Biolayer interference technology showed that suramin had an intermediate affinity for binding hRKIP with a dissociation constant of 23.8 µM. Both nuclear magnetic resonance technology and molecular docking analysis revealed that suramin bound to the conserved ligand-binding pocket of hRKIP, and that residues K113, W173, and Y181 play crucial roles in hRKIP binding suramin. Furthermore, suramin treatment at 160 µM could profoundly increase the ERK phosphorylation level by around 3 times. Our results indicate that suramin binds to hRKIP and prevents hRKIP from binding with hRaf1, thus promoting the MAPK pathway. This work is beneficial to both mechanistically understanding the side-effects of suramin and efficiently improving the clinical applications of suramin.

Isoquercitrin Ameliorates Cisplatin-Induced Nephrotoxicity Via the Inhibition of Apoptosis, Inflammation, and Oxidative Stress

Cisplatin is extensively used and is highly effective in clinical oncology; nevertheless, nephrotoxicity has severely limited its widespread utility. Isoquercitrin (IQC), a natural flavonoid widely found in herbage, is well known and recognized for its antioxidant, anti-inflammatory, and anti-apoptotic properties. However, the potential effects and mechanism of IQC in cisplatin-induced acute kidney diseases remain unknown. In this study, we postulated the potential effects and mechanism of IQC upon cisplatin exposure in vivo and in vitro. For the in vivo study, C57BL/6J mice were pretreated with IQC or saline (50 mg/kg/day) by gavage for 3 days before cisplatin single injection (25 mg/kg). Renal function, apoptosis, inflammation, oxidative stress and p-ERK were measured to evaluate kidney injury. In vitro, mouse proximal tubular cells (mPTCs) and human proximal tubule epithelial cell line (HK2) were pretreated with or without IQC (80 μM for mPTCs and 120 μM for HK2) for 2 h and then co-administrated with cisplatin for another 24 h. Apoptosis, inflammation, ROS and p-ERK of cells were also measured. In vivo, IQC administration strikingly reduced cisplatin-induced nephrotoxicity as evidenced by the improvement in renal function (serum creatinine and blood urea nitrogen), kidney histology (PAS staining), apoptotic molecules (cleaved caspase-3, caspase-8, Bax and Bcl-2), inflammatory cytokines (IL-1β, IL-6, TNF-α, and COX-2), oxidative stress (MDA and total glutathione) and p-ERK. In line with in vivo findings, IQC markedly protected against cisplatin-induced cell injury in mPTCs and HK2 cells. Collectively, these findings demonstrated that IQC administration could significantly protect against cisplatin nephrotoxicity possibly through ameliorating apoptosis, inflammation and oxidative stress accompanied by cross talk with p-ERK. Furthermore, IQC may have potential therapeutic uses in the treatment of cisplatin-induced acute kidney injury.

Survival features, prognostic factors, and determinants of diagnosis and treatment among Iranian patients with pancreatic cancer, a prospective study

OBJECTIVES

Investigating the survival features, and determinants of treatment and stage at presentation in Iran.

METHODS

461 patients with pancreatic ductal adenocarcinoma (PC) were prospectively enrolled from Shariati hospital, Tehran, Iran, between 2011-2018. All patients underwent endoscopic ultrasonography, computed tomography scanning, and physical examination. Validated questionnaire was completed for the participants and all were actively followed on monthly basis.

RESULTS

Median survival time was 6.5 months, and 1-, and 5-year survival rates were 26.2%, and 1.5%. Patients who were older (p<0.001), illiterate (p = 0.004), unmarried (p = 0.003), rural inhabitant (p = 0.013), opium user (p = 0.039), and had lower body mass index (BMI) (p = 0.002) had lower overall survival. Tumors located in the head of pancreas were more commonly diagnosed at lower stages (p<0.001). Only 10.4% of patients underwent surgery who were more commonly educated (p<0.001), married (p = 0.005), had a tumor located in the head of pancreas (p = 0.016), and were diagnosed at lower stages (p<0.001). After adjustment for potential confounders and risk factors, rural inhabitance (HR: 1.33 (95% CI: 1.01-1.74)), having more symptoms (HR for each increasing symptom: 1.06 (1.02-1.11)), using opium (HR: 1.51 (1.04-2.20)), having a tumor located in the body of pancreas (HR: 1.33 (1.02-1.75)), and having an advanced tumor stage (HR: 2.07 (1.34-3.19)) remained significantly associated with increased risk of mortality. After the adjusting for potential confounders, we did not find significant relationships between smoking, alcohol intake, and BMI with the risk of death among patients with pancreatic cancer.

CONCLUSIONS

Iranian patients with PC have very poor long-term survival. Besides tumor's stage and location, socioeconomic disparities could affect the probabilities of receiving treatment and/or survival in these patients. Opium use is an independent risk factor for mortality among PC patients in Iran.

The Flavonol Isoquercitrin Promotes Mitochondrial-Dependent Apoptosis in SK-Mel-2 Melanoma Cell via the PI3K/AKT/mTOR Pathway

Isoquercitrin (IQ), a major flavonol present in Prunus mume fruit, has gained much attention in recent studies because of its superior bioavailability and physiological effects. In this study, the anti-cancer mechanism of IQ against human melanoma, particularly its effect on the mitochondria-mediated apoptosis, was investigated. Treatment with IQ at 25 μM concentration effectively inhibited the proliferation of SK-MEL-2 skin cancer cells while the same concentration did not exhibit cytotoxicity against human keratinocytes HaCaT. Morphological analysis and clonogenic assay also showed that IQ can alter the growth and long-term survival of SK-MEL-2 cells. IQ also induced apoptosis in the melanoma cells as manifested in the nuclear morphology changes, DNA fragmentation, increase in the apoptosis rate (17.69% at 25 μM) and accumulation of sub-G1 cell cycle phase population (19.55% at 25 μM). Western blot analysis revealed the involvement of the mitochondrial apoptosis signaling pathway in the anti-cancer property of IQ. Treatment with IQ resulted in the decrease in the levels of procaspase-8 and -9, and Bcl-2 protein, and an increase in the expression of cleaved PARP and Bax. Moreover, AIF and Endo G protein expression increased, indicating a caspase-independent mitochondrial-mediated apoptosis. The anti-proliferative activity of IQ against SK-MEL-2 can also be attributed to the downregulation of the PI3K/AktmTOR signaling pathway. These findings showed that IQ can be developed into a chemopreventive therapeutic agent against the melanoma cells.

Profiling Anticancer and Antioxidant Activities of Phenolic Compounds Present in Black Walnuts (Juglans nigra) Using a High-Throughput Screening Approach

Our recent studies have demonstrated multiple health-promoting benefits from black walnut kernels. These biological functions of black walnuts are likely associated with their bioactive constituents. Characterization of phenolic compounds found in black walnut could point out underexplored bioactive activities of black walnut extracts and promote the development of novel applications of black walnut and its by-products. In the present study, we assessed bioactivity profiles of phenolic compounds identified in the kernels of black walnuts using a high-throughput screening (HTS) approach. Black walnut phenolic compounds were evaluated in terms of their total antioxidant capacity, antioxidant response element (ARE) induction, and anticancer activities. The anticancer activities were identified by evaluating the effects of the phenolic compounds on the growth of the tumorigenic alveolar epithelial cells (A549) and non-tumorigenic lung fibroblast cells (MRC-5). Out of 16 phenolic compounds tested, several compounds (penta-O-galloyl-β-d-glucose, epicatechin gallate, quercetin, (–)-epicatechin, rutin, quercetin 3-β-d-glucoside, gallic acid, (+)-catechin, ferulic acid, syringic acid) exerted antioxidant activities that were significantly higher compared to Trolox, which was used as a control. Two phenolic compounds, penta-O-galloyl-β-d-glucose and quercetin 3-β-d-glucoside, exhibited antiproliferative activities against both the tumorigenic alveolar epithelial cells (A549) and non-tumorigenic lung fibroblast cells (MRC-5). The antioxidant activity of black walnut is likely driven not only by penta-O-galloyl-β-d-glucose but also by a combination of multiple phenolic compounds. Our findings suggested that black walnut extracts possibly possess anticancer activities and supported that penta-O-galloyl-β-d-glucose could be a potential bioactive agent for the cosmetic and pharmaceutical industries.

Traditional Chinese medicine may be further explored as candidate drugs for pancreatic cancer: A review

Pancreatic cancer is a disease with a high mortality rate. Although survival rates for different types of cancers have improved in recent years, the five-year survival rate of pancreatic cancer stands at 8%. Moreover, the current first-line therapy, gemcitabine, results in low remission rates and is associated with drug resistance problems. Alternative treatments for pancreatic cancer such as surgery, chemotherapy and radiation therapy provide marginal remission and survival rates. This calls for the search of more effective drugs or treatments. Traditional Chinese medicine contains numerous bioactive ingredients some of which show activity against pancreatic cancer. In this review, we summarize the mechanisms of five types of traditional Chinese medicine monomers. In so-doing, we provide new potential drug candidates for the treatment of pancreatic cancer.

The paradoxical role of methionine enkephalin in tumor responses

Methionine enkephalin (MENK) is an opioid peptide composed of five amino acids with multiple biological activities. Since its discovery, MENK has become prominent in neuroregulation and immunoregulation. Tumors have increasingly been a spotlight because of their terrible trends and refractory characteristic. The therapeutic potential of MENK was investigated on a large scale, and there are numerous evidences that MENK exerts anti-tumor effects via two mechanisms. The first mechanism explains the enhanced anti-tumor immune effects of MENK. The second mechanism shows that MENK directly inhibits tumor cell proliferation. However, numerous reports have clarified the pro-tumor role of MENK by inhibiting T and B cell proliferation, promoting tumor cell growth by binding to opioid receptors, leading to desensitization of lymphocytes, and inducing tolerance. It is particularly intriguing that dual reactions are triggered when MENK combines with its opioid receptors; thus, anti-tumor response of the whole body is influenced. This review will expound the dual roles of MENK in tumor responses based on immune cells, cytokines, and tumor cells to provide better suggestions for its application in tumor treatment.

Anticancer and cytotoxic effects of troxerutin on HeLa cell line: an in-vitro model of cervical cancer

Cervical cancer is one of the grave uterine tumors which leads to death in women worldwide. Troxerutin (TRX) as a bioflavonoid compound has many pharmacological effects such as anti-neoplastic, radioprotective, and anti-cancer. The present study was designed to examine the cytotoxic effect of TRX on human HeLa tumor cells. Human HeLa cells were cultured and treated with different doses of TRX (20-640 mg/ml) to evaluate the effective half-maximal inhibitory concentration (IC₅₀) after 24 h. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test was used for cell proliferation assay. Also, the Bax, Bcl-2, cleaved caspase-3, and tumor necrosis factor-α (TNF-α) protein expression levels were detected with immunoblotting analysis. The malondialdehyde (MDA) concentration, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity levels were measured via their commercial kits. Data were analyzed using one-way ANOVA. The result showed that TRX at 320 mg/ml concentration (IC₅₀) has a growth inhibitory effect against HeLa cells at 24 h treatment (P ˂ 0.01). Moreover, it increased the MDA concentration and also decreased the GPx and SOD activity levels at 320 mg/ml concentration versus control (P < 0.001). Also, TRX significantly up-regulated the Bax, cleaved caspase-3 and TNF-α proteins expression levels (P  <  0.01) and down-regulated the Bcl-2 protein expression in HeLa tumor cells at 320 mg/ml concentration compared to control (P < 0.05). Our study showed that 24 h of treatment with TRX (320 mg/ml) has apoptotic and growth inhibitory effects against HeLa cells. It can induce inflammation (at least via up-regulating the TNF-α protein expression) and oxidative stress in human HeLa cells.

Isolation and characterization of a glycosyltransferase with specific catalytic activity towards flavonoids from Tripterygium wilfordii

Flavonoids are important secondary metabolites that exist in many medicinal plants. Flavonoid glycosyltransferases can transfer sugar moieties to their parent rings, producing various flavonoid glycosides with significant pharmacological activities. Here, we report the molecular cloning of the O-glycosyltransferase TwUGT2 from Tripterygium wilfordii and its catalytic activity was explored by heterologous expression in E. coli. The results showed that TwUGT2 has specific glycosyltransferase activity towards C-3 and 7 hydroxyl groups of flavonoids, thereby converting quercetin and pinocembrin into isoquercitrin and pinocembrin 7-O-beta-D-glucoside, respectively. The identification of TwUGT2 will provide a useful molecular tool for synthetic biology and contribute to drug discovery.[Formula: see text].

Antiviral Activities of Quercetin and Isoquercitrin Against Human Herpesviruses

We previously reported that the ethyl acetate (EtOAc) fraction of a 70% ethanol extract of Elaeocarpus sylvestris (ESE) inhibits varicella-zoster virus (VZV) and human cytomegalovirus (HCMV) replication in vitro. PGG (1,2,3,4,6-penta-O-galloyl-ß-D-glucose) is a major chemical constituent of the EtOAc fraction of ESE that inhibits VZV but not HCMV replication. In this study, we comprehensively screened the chemical compounds identified in the EtOAc fraction of ESE for potential antiviral properties. Among the examined compounds, quercetin and isoquercitrin displayed potent antiviral activities against both VZV and HCMV with no significant cytotoxic effects. Both compounds strongly suppressed the expression of VZV and HCMV immediate–early (IE) genes. Our collective results indicated that, in addition to PGG, quercetin and isoquercitrin are bioactive compounds in the EtOAc fraction of ESE that effectively inhibit human herpesvirus replication.

Medicinal Plants Used in Traditional Management of Cancer in Uganda: A Review of Ethnobotanical Surveys, Phytochemistry, and Anticancer Studies

The burden of neoplastic diseases is a significant global health challenge accounting for thousands of deaths. In Uganda, about 32,617 cancer cases were reported in 2018, accompanied by 21,829 deaths. In a view to identify some potential anticancer plant candidates for possible drug development, the current study was designed to compile the inventory of plants with reported anticancer activity used in rural Uganda and the evidences supporting their use in cancer therapy. An electronic survey in multidisciplinary databases revealed that 29 plant species belonging to 28 genera distributed among 24 families have been reported to be used in the management of cancer in Uganda. Anticancer plants were majorly from the families Bignoniaceae (7%), Caricaceae (7%), Fabaceae (7%), Moraceae (7%), and Rutaceae (7%). Most species occur in the wild (52%), though some are cultivated (48%). The growth habit of the plants is as trees (55%) or herbs (45%). Anticancer extracts are usually prepared from leaves (29%), bark (24%), roots (21%), and fruits (13%) through decoctions (53%), as food spices (23%) or pounded to produce ointments that are applied topically (10%). Prunus africana (Hook.f.) Kalkman, Opuntia species, Albizia coriaria (Welw. ex Oliver), Daucus carota L., Cyperus alatus (Nees) F. Muell., Markhamia lutea (Benth.) K. Schum., and Oxalis corniculata L. were the most frequently encountered species. As per global reports, Allium sativum L., Annona muricata L., Carica papaya L., Moringa oleifera Lam., Opuntia species, Prunus africana (Hook.f.) Kalkman, and Catharanthus roseus (L.) G. Don. are the most studied species, with the latter having vincristine and vinblastine anticancer drugs developed from it. Prostate, cervical, breast, and skin cancers are the top traditionally treated malignancies. There is a need to isolate and evaluate the anticancer potential of the bioactive compounds in the unstudied claimed plants, such as Cyperus alatus (Nees) F. Muell., Ficus dawei Hutch., Ficus natalensis Hochst., and Lovoa trichilioides Harms, and elucidate their mechanism of anticancer activity.

Investigating the Catalytic Activity of Glycosyltransferase on Quercetin from Tripterygium wilfordii

Flavonoid glycosides have shown many pharmacological activities in clinical studies. However, the main way to obtain flavonoid glycosides is to extract and separate them from plants, which wastes both time and resources. Here, we identified the O-glycosyltransferase (UGTs) TwUGT3 from Tripterygium wilfordii and analyzed its bioinformatics. First, the enzyme was found to utilize phloretin and uridine diphosphate glucose (UDPG) as substrates to produce an acid-tolerant glucoside. Then, it also can use quercetin and UDPG as substrates to produce the corresponding O-glucoside. In addition, we further explored the substrate specificity of TwUGT3, which suggested that it also accepts luteolin, pinocembrin, and genistein to produce the corresponding O-glucosides. Subsequently, the optimum pH, reaction time, reaction temperature, and enzymatic kinetic parameters of TwUGT3 were determined.

Antitumor Effects of Quercetin in Hepatocarcinoma In Vitro and In Vivo Models: A Systematic Review

Quercetin is a flavonoid present in fruits, vegetables and plants with antioxidant, anti-inflammatory and anticancer properties. Its beneficial activities have been demonstrated in different human pathologies, including hepatoprotective effects against liver disorders. High mortality and late diagnosis of the primary liver tumor hepatocarcinoma (HCC) makes this cancer an interesting target for the study of quercetin effects. Our aim was to systematically review antitumor activities of quercetin in HCC preclinical studies employing single, encapsulated, combined or derived quercetin forms. Literature search was conducted in PubMed, Scopus and Web of Science (WOS), and 39 studies were finally included. We found that 17 articles evaluated quercetin effects alone, six used encapsulated strategy, 10 combined this flavonoid, two decided to co-encapsulate it and only four studied effects of quercetin derivatives, highlighting that only nine included in vivo models. Results evidence the quercetin antiproliferative and proapoptotic properties against HCC either alone and with the mentioned strategies; nevertheless, few investigations assessed specific activities on different processes related with cancer progression. Overall, further studies including animal models are needed to deeper investigate the precise mechanisms of action of quercetin as antitumor agent, as well as the potential of novel strategies aimed to improve quercetin effects in HCC.

The Effect of Okra (Abelmoschus esculentus (L.) Moench) Seed Extract on Human Cancer Cell Lines Delivered in Its Native Form and Loaded in Polymeric Micelles

Cancer is a noncommunicable disease with a high worldwide incidence and mortality rate. The National Cancer Institute of Thailand reports increasing cumulative incidence of breast, colorectal, liver, lung, and cervical cancers, accounting for more than 60% of all cancers in the kingdom. In this current work, we attempt to elucidate the phytochemical composition of the okra (Abelmoschus esculentus (L.) Moench) seed extract (OSE) and study its anticancer activity, delivered in its native form as well as in the form of polymeric micelles with enhanced solubility, in three carcinoma cell lines (MCF-7, HeLa, and HepG2). The presence of flavonoid compounds in the OSE was successfully confirmed, and direct delivery had the highest cytotoxic effect on the breast cancer cell line (MCF-7), followed by the hepatocellular carcinoma (HepG2) and cervical carcinoma (HeLa) cell lines in that order, while its delivery in polymeric micelles further increased this effect only in the HepG2 cell line. The OSE’s observed cytotoxic effects on cancer cell lines demonstrated a dose and time-dependent cell proliferation and migration inhibition plausibly due to VEGF production inhibition, leading to apoptosis and cell death, conceivably due to the four flavonoid compounds noted in the current study, one of which was isoquercitrin. However, in view of the latter compound’s isolated effects being inferior to those observed by the OSE, we hypothesize that either isoquercitrin requires the biological synergy of any one or all of the observed flavonoids or any of the three in isolation or all in concert are responsible. Further studies are required to elucidate the nature of the three unknown compounds. Furthermore, as we encountered significant problems in dissolving the okra seed extract and creating the polymeric micelles, further studies are needed to devise a clinically beneficial delivery and targeting system.

The Effect of Okra (Abelmoschus esculentus (L.) Moench) Seed Extract on Human Cancer Cell Lines Delivered in Its Native Form and Loaded in Polymeric Micelles

Cancer is a noncommunicable disease with a high worldwide incidence and mortality rate. The National Cancer Institute of Thailand reports increasing cumulative incidence of breast, colorectal, liver, lung, and cervical cancers, accounting for more than 60% of all cancers in the kingdom. In this current work, we attempt to elucidate the phytochemical composition of the okra (Abelmoschus esculentus (L.) Moench) seed extract (OSE) and study its anticancer activity, delivered in its native form as well as in the form of polymeric micelles with enhanced solubility, in three carcinoma cell lines (MCF-7, HeLa, and HepG2). The presence of flavonoid compounds in the OSE was successfully confirmed, and direct delivery had the highest cytotoxic effect on the breast cancer cell line (MCF-7), followed by the hepatocellular carcinoma (HepG2) and cervical carcinoma (HeLa) cell lines in that order, while its delivery in polymeric micelles further increased this effect only in the HepG2 cell line. The OSE's observed cytotoxic effects on cancer cell lines demonstrated a dose and time-dependent cell proliferation and migration inhibition plausibly due to VEGF production inhibition, leading to apoptosis and cell death, conceivably due to the four flavonoid compounds noted in the current study, one of which was isoquercitrin. However, in view of the latter compound's isolated effects being inferior to those observed by the OSE, we hypothesize that either isoquercitrin requires the biological synergy of any one or all of the observed flavonoids or any of the three in isolation or all in concert are responsible. Further studies are required to elucidate the nature of the three unknown compounds. Furthermore, as we encountered significant problems in dissolving the okra seed extract and creating the polymeric micelles, further studies are needed to devise a clinically beneficial delivery and targeting system.

In vitro response of human ovarian cancer cells to dietary bioflavonoid isoquercitrin

Isoquercitrin is a dietary bioflavonoid used as a food supplement. We studied the mechanism underlying its effect in human ovarian cancer cells using OVCAR-3 cell line. Viability, survival, apoptosis, release of human transforming growth factor-β1 (TGF-β1) and TGF-β1 receptor, and intracellular reactive oxygen species (ROS) generation by OVCAR-3 cells were examined after isoquercitrin treatment at concentrations 5, 10, 25, 50, and 100 μg mL^-1. AlamarBlue assay revealed that isoquercitrin did not cause any significant change (P > 0.05) in cell viability as compared to control. Apoptotic assay using flow cytometry did not find any significant change (P > 0.05) in the proportion of live, dead and apoptotic cells as compared to control. ELISA also showed that the release of human TGF-β1 and TGF-β1 receptor were not significantly (P > 0.05) affected by isoquercitrin as compared to control. Chemiluminescence assay demonstrated that lower concentrations (5, 10, and 25 μg mL^-1) were able to exhibit beneficial effects by inhibiting the generation of intracellular ROS. In contrast, elevated concentrations of 50 and 100 μg mL^-1 led to oxidative stress (P < 0.05). We concluded that the beneficial effect of isoquercitrin on ovarian cancer cells may be mediated by an antioxidative pathway that involves inhibition of intracellular ROS generation, thereby limiting oxidative stress.

Isoquercitrin promotes the osteogenic differentiation of osteoblasts and BMSCs via the RUNX2 or BMP pathway

AIM

Isoquercitrin is widely present in fruits, vegetables and medicinal herbs. As a natural phytoestrogen, isoquercitrin has been considered a possible osteoporosis prevention option to avoid the risk of hormone therapy.

MATERIALS AND METHODS

The cell proliferation of osteoblasts and bone mesenchymal stem cells (BMSCs) was examined by cell counting kit-8 (CCK-8). The osteogenic differentiation was evaluated by real-time qPCR, ALP staining and Alizarin Red S staining. Small interfering RNA (siRNA) was used to knockdown the expression of runt-related transcription factor 2 (RUNX2).

RESULTS

The cell proliferation of osteoblasts and BMSCs was promoted by isoquercitrin at low concentrations. High concentrations of isoquercitrin promoted the osteogenic differentiation via RUNX2 expression in osteoblasts and via the bone morphogenetic protein (BMP) pathway in BMSCs. Inhibition of RUNX2 expression in osteoblasts by siRNA or addition of noggin to the culture medium of BMSCs reduced the effects of osteogenic differentiation induced by isoquercitrin.

CONCLUSIONS

These data suggest that isoquercitrin is a natural potential osteoinductive compound and might be valuable for the prevention/treatment of bone disorders.

Anti-leprosy drug Clofazimine binds to human Raf1 kinase inhibitory protein and enhances ERK phosphorylation

Human Raf1 kinase inhibitory protein (hRKIP) is an important modulator of the Ras/Raf1/MEK/ERK signaling pathway. Here, we demonstrated that anti-leprosy drug Clofazimine can bind to hRKIP with a significantly stronger affinity than the endogenous substrate phosphatidylethanolamine (PE) by using Biolayer interference technology. Moreover, we identified that residues P74, S75, K80, P111, P112, V177, and P178 play crucial roles in the binding of hRKIP to Clofazimine by using a combination of Nuclear Magnetic Resonance spectroscopy and molecular docking approach. These residues are located at the conserved ligand-binding pocket of hRKIP. Furthermore, we found that 3.2 μM Clofazimine could significantly increase the ERK phosphorylation level by about 37%. Our results indicate that Clofazimine can enhance Ras/Raf1/MEK/ERK signaling transduction pathway via binding to hRKIP. This work provides valuable hints for exploiting Clofazimine as a potential lead compound to efficiently treat the diseases related to RKIP or the Ras/Raf/MEK/ERK pathway.

Isoquercitrin, ingredients in Tetrastigma hemsleyanum Diels et Gilg, inhibits hepatocyte growth factor/scatter factor-induced tumor cell migration and invasion

Aberrant activation of hepatocyte growth factor/scatter factor (HGF/SF) and its receptor, Met, is involved in the development and progression of many human cancers. In the screening assay of extracts from the root tuber of Tetrastigma hemsleyanum Diels et Gilg, isoquercitrin inhibited HGF/SF-Met signaling as indicated by its inhibitory activity on HGF/SF-induced cell scattering. Further analysis revealed that isoquercitrin specifically inhibited HGF/SF-induced tyrosine phosphorylation of Met. We also found that isoquercitrin decreased HGF-induced migration and invasion by parental or HGF/SF-transfected bladder carcinoma cell line NBT-II cells. Furthermore, isoquercitrin inhibited HGF/SF-induced epithelial mesenchymal transition in vitro and the invasion/metastasis of HGF/SF-transfected NBT-II cells in vivo. Our data suggest the possible use of isoquercitrin in human cancers associated with dysregulated HGF/SF-Met signaling.

Apoptosis triggered by isoquercitrin in bladder cancer cells by activating the AMPK-activated protein kinase pathway

Cancer cells are well known to require a constant supply of protein, lipid, RNA, and DNA via altered metabolism for accelerated cell proliferation. Targeting metabolic pathways is, therefore, a promising therapeutic strategy for cancers. Isoquercitrin (ISO) is widely distributed in dietary and medicinal plants and displays selective cytotoxicity to cancer cells, primarily by inducing apoptosis and cell cycle arrest. The aims of this study were to find out whether ISO could stabilize in a bladder-like acidic environment and inhibit bladder cancer cell proliferation by affecting their metabolism, and to investigate its molecular mechanism. In this study, the exposure of T24 bladder cancer cells to ISO (20-80 μM) decreased cell viability by causing ROS overproduction. This ROS change regulated the AMPK signaling pathway, and caused Caspase-dependent apoptosis as well as metabolism dysfunction. Metabolic alterations elevated metabolic pathway variation, which in turn destabilized lipid synthesis and altered anaerobic glycolysis. This linkage was proved by immunoblotting assay, and metabolomics as identified by UHPLC-QTOF-MS. Our findings provide comprehensive evidence that ISO influenced T24 bladder cancer cell metabolism, and that this process was mainly involved in activating the AMPK pathway. This study could lead to an understanding of how ISO suppresses bladder cancer cell growth, and whether the affected cancer metabolism is a common mechanism by which nutritional compounds suppress cancers.

microRNA-874 suppresses tumor proliferation and metastasis in hepatocellular carcinoma by targeting the DOR/EGFR/ERK pathway

The δ opioid receptor (DOR) is involved in the regulation of malignant transformation and tumor progression of hepatocellular carcinoma (HCC). However, regulation of the DOR in HCC remains poorly defined. We found that miR-874 was identified as a negative regulator of the DOR, which is a direct and functional target of miR-874 via its 3' untranslated region (UTR). Moreover, miR-874 was downregulated in HCC and its expression was inversely correlated with DOR expression. Downregulation of miR-874 was also associated with larger tumor size, more vascular invasion, a poor TNM stage, poor tumor differentiation, and inferior patient outcomes. Functionally, overexpression of miR-874 in the HCC cell line SK-hep-1 inhibited cell growth, migration, in vitro invasion, and in vivo tumorigenicity. Furthermore, miR-874 overexpression suppressed the DOR, resulting in a downregulated epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase (ERK) phosphorylation. The EGFR activator-epidermal growth factor (EGF)-can rescue the proliferation and migration suppression induced by miR-874 overexpression, and the rescue effects of the EGF were blocked by an ERK inhibitor. Our study results suggest that miRNA-874 is a negative regulator of the DOR that can suppress tumor proliferation and metastasis in HCC by targeting the DOR/EGFR/ERK pathway, which may be a potential target for HCC treatment.

Isoquercitrin protects against pulmonary hypertension via inhibiting PASMCs proliferation

Pulmonary vascular remodelling is a common feature among the heterogeneous disorders that cause pulmonary arterial hypertension (PAH), and pulmonary arterial smooth muscle cells (PASMCs) proliferation impact the long-term prognosis of the patient. Isoquercitrin (IQC) is a flavonoid with anti-oxidative, anti-inflammatory and anti-proliferative activations. This study aimed to investigate whether IQC could prevent PASMCs proliferation and vascular remodelling in monocrotaline (MCT) induced PAH. Male Wistar rats were administered with Vehicle or 0.1% IQC maintain feed after MCT (40 mg/kg) injection. Haemodynamic changes, right ventricular hypertrophy and lung morphological features were assessed 3 weeks later. MCT-induced PAH, pulmonary vascular remodelling and PASMCs proliferation in Vehicle-treated rats. IQC reduced the right ventricle systolic pressure (RVSP), the ratio of RV/LV+S and the RV hypertrophy. IQC significantly alleviated the expression of proliferating cell nuclear antigen (PCNA), smooth muscle α-actin (α-SMA), and the percentage of fully muscularized small arterioles. In vitro studies, PASMCs were pretreated with IQC and stimulated with platelet-derived growth factor (PDGF)-BB (20 ng/mL). IQC suppressed PDGF-BB-induced PASMCs proliferation and caused G0/G1 phase cell cycle arrest. IQC downregulated the expression of Cyclin D1 and CDK4 as well as inhibited p27Kip1 degradation. Meanwhile, IQC negatively modulated PDGF-BB-induced phosphorylation of PDGF-Rβ, Akt/GSK3β and ERK1/2. IQC ameliorated MCT-induced pulmonary vascular remodelling via suppressing PASMCs proliferation and blocking PDGF-Rβ signalling pathway.

3-O-Glucosylation of quercetin enhances inhibitory effects on the adipocyte differentiation and lipogenesis

Glycosylation of natural flavonoids with various sugar moieties can affect their physicochemical and pharmacological properties. In this study, the plant flavonoids quercetin aglycon (Quer) and quercetin 3-O-glucoside (Q3G) were evaluated and compared for their potential anti-obesity effects. The Q3G dose-dependently reduced the TG contents and lipid accumulation in 3T3-L1 adipocyte cells, by 52% and 60% at 20μM, respectively, compared to differentiated control (100%), which were 1.6-fold and 2.4-fold higher reduction than Quer. The Q3G (20μM) also more significantly reduced the expression of adipogenic markers such as C/EBP-β, C/EBP-α, PPAR-γ, and aP2 than Quer, indicating that the Q3G suppresses both adipocyte differentiation and lipogenesis more effectively than Quer in vitro. Comparing to those in the high-fat diet (HFD) fed mice control group for 10 weeks, both the body and liver weights and the size of adipocytes in epididymal adipose tissues were significantly reduced in HFD mice fed with Q3G for another 6 weeks (30mg/kg body weight by oral administration), accompanied by the reductions of TG, total cholesterol, and HDL-cholesterol in serum. The Q3G also reduced the levels of the lipid metabolism-associated proteins, PPAR-γ, SREBP-1c, and FAS in the liver tissues. These results clearly demonstrated that Q3G exhibits a stronger anti-obesity effect than Quer and its anti-obesity effect is mediated via inhibition of adipocyte differentiation and lipogenesis, decreasing serum lipid levels by altering hepatic lipid metabolism, and reducing body weight gain. The results of this study suggest that the Q3G, but not Quer, can be a potent functional ingredient of beneficial health foods or a therapeutic agent to prevent or treat obesity.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Isoquercitrin inhibits bladder cancer progression in vivo and in vitro by regulating the PI3K/Akt and PKC signaling pathways

Bladder cancer is the most common malignancy of the urinary system and is also one of the 10 most common cancers of the human body. Currently, clinical treatment of bladder cancer mainly utilizes partial or total cystectomy, supplemented by conventional chemotherapy. However, such treatment has not fully improved the prognosis of patients and is associated with various side effects. Studies have found that flavonoids extracted from plants can be used in radiotherapy and chemotherapy for the prevention of postoperative recurrence and metastasis but also alone for the treatment of advanced tumors. Both applications can ameliorate clinical symptoms, improve the quality of life, and prolong the survival of patients. Based on the above information, the present study investigated the effect of isoquercitrin, a type of flavonoid found in Bidens pilosa L. extracts, on bladder cancer progression, with the goal of understanding the biological characteristics of isoquercitrin by which it participates in bladder cancer progression. Using in vitro experiments, we found that therapeutic doses of isoquercitrin significantly inhibited cell proliferation and induced apoptosis in human bladder cancer cells and that the cell cycle was arrested in the G1 phase. Isoquercitrin inhibited phosphatidylinositol 3-kinase (PI3K) and Akt phosphorylation expression levels, thus inhibiting proliferation and inducing apoptosis in the cancer cells. In addition, we found that isoquercitrin reduced protein kinase C (PKC) protein expression levels in the human bladder cancer cell lines. We also showed via in vivo experiments that isoquercitrin inhibited xenograft tumor growth in nude mice. In conclusion, our study confirmed that isoquercitrin inhibits bladder cancer progression in vivo and demonstrated that the molecular mechanism of this inhibition may be closely associated with the PI3K/Akt and PKC signaling pathways.