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Kocyigit E, Kocaadam-Bozkurt B, Bozkurt O, Ağagündüz D, Capasso R. Plant Toxic Proteins: Their Biological Activities, Mechanism of Action and Removal Strategies. Toxins (Basel) 2023; 15:356. [PMID: 37368657 PMCID: PMC10303728 DOI: 10.3390/toxins15060356] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/11/2023] [Accepted: 05/19/2023] [Indexed: 06/29/2023] Open
Abstract
Plants evolve to synthesize various natural metabolites to protect themselves against threats, such as insects, predators, microorganisms, and environmental conditions (such as temperature, pH, humidity, salt, and drought). Plant-derived toxic proteins are often secondary metabolites generated by plants. These proteins, including ribosome-inactivating proteins, lectins, protease inhibitors, α-amylase inhibitors, canatoxin-like proteins and ureases, arcelins, antimicrobial peptides, and pore-forming toxins, are found in different plant parts, such as the roots, tubers, stems, fruits, buds, and foliage. Several investigations have been conducted to explore the potential applications of these plant proteins by analyzing their toxic effects and modes of action. In biomedical applications, such as crop protection, drug development, cancer therapy, and genetic engineering, toxic plant proteins have been utilized as potentially useful instruments due to their biological activities. However, these noxious metabolites can be detrimental to human health and cause problems when consumed in high amounts. This review focuses on different plant toxic proteins, their biological activities, and their mechanisms of action. Furthermore, possible usage and removal strategies for these proteins are discussed.
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Affiliation(s)
- Emine Kocyigit
- Department of Nutrition and Dietetics, Ordu University, Cumhuriyet Yerleşkesi, 52200 Ordu, Turkey;
| | - Betul Kocaadam-Bozkurt
- Department of Nutrition and Dietetics, Erzurum Technical University, Yakutiye, 25100 Erzurum, Turkey; (B.K.-B.); (O.B.)
| | - Osman Bozkurt
- Department of Nutrition and Dietetics, Erzurum Technical University, Yakutiye, 25100 Erzurum, Turkey; (B.K.-B.); (O.B.)
| | - Duygu Ağagündüz
- Department of Nutrition and Dietetics, Gazi University, Faculty of Health Sciences, Emek, 06490 Ankara, Turkey;
| | - Raffaele Capasso
- Department of Agricultural Sciences, University of Naples Federico II, 80055 Portici, Italy
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Targeting the Inside of Cells with Biologicals: Toxin Routes in a Therapeutic Context. BioDrugs 2023; 37:181-203. [PMID: 36729328 PMCID: PMC9893211 DOI: 10.1007/s40259-023-00580-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2023] [Indexed: 02/03/2023]
Abstract
Numerous toxins translocate to the cytosol in order to fulfil their function. This demonstrates the existence of routes for proteins from the extracellular space to the cytosol. Understanding these routes is relevant to multiple aspects related to therapeutic applications. These include the development of anti-toxin treatments, the potential use of toxins as shuttles for delivering macromolecular cargo to the cytosol or the use of drugs based on toxins. Compared with other strategies for delivery, such as chemicals as carriers for macromolecular delivery or physical methods like electroporation, toxin routes present paths into the cell that potentially cause less damage and can be specifically targeted. The efficiency of delivery via toxin routes is limited. However, low-delivery efficiencies can be entirely sufficient, if delivered cargoes possess an amplification effect or if very few molecules are sufficient for inducing the desired effects. This is known for example from RNA-based vaccines that have been developed during the coronavirus disease 2019 pandemic as well as for other approved RNA-based drugs, which elicited the desired effect despite their typically low delivery efficiencies. The different mechanisms by which toxins enter cells may have implications for their technological utility. We review the mechanistic principles of the translocation pathway of toxins from the extracellular space to the cytosol, the delivery efficiencies, and therapeutic strategies or applications that exploit toxin routes for intracellular delivery.
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Citores L, Iglesias R, Ferreras JM. Antiviral Activity of Ribosome-Inactivating Proteins. Toxins (Basel) 2021; 13:80. [PMID: 33499086 PMCID: PMC7912582 DOI: 10.3390/toxins13020080] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/14/2021] [Accepted: 01/20/2021] [Indexed: 12/13/2022] Open
Abstract
Ribosome-inactivating proteins (RIPs) are rRNA N-glycosylases from plants (EC 3.2.2.22) that inactivate ribosomes thus inhibiting protein synthesis. The antiviral properties of RIPs have been investigated for more than four decades. However, interest in these proteins is rising due to the emergence of infectious diseases caused by new viruses and the difficulty in treating viral infections. On the other hand, there is a growing need to control crop diseases without resorting to the use of phytosanitary products which are very harmful to the environment and in this respect, RIPs have been shown as a promising tool that can be used to obtain transgenic plants resistant to viruses. The way in which RIPs exert their antiviral effect continues to be the subject of intense research and several mechanisms of action have been proposed. The purpose of this review is to examine the research studies that deal with this matter, placing special emphasis on the most recent findings.
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Affiliation(s)
| | | | - José M. Ferreras
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain; (L.C.); (R.I.)
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Neller KCM, Diaz CA, Platts AE, Hudak KA. De novo Assembly of the Pokeweed Genome Provides Insight Into Pokeweed Antiviral Protein (PAP) Gene Expression. FRONTIERS IN PLANT SCIENCE 2019; 10:1002. [PMID: 31447869 PMCID: PMC6691146 DOI: 10.3389/fpls.2019.01002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 07/17/2019] [Indexed: 05/21/2023]
Abstract
Ribosome-inactivating proteins (RIPs) are RNA glycosidases thought to function in defense against pathogens. These enzymes remove purine bases from RNAs, including rRNA; the latter activity decreases protein synthesis in vitro, which is hypothesized to limit pathogen proliferation by causing host cell death. Pokeweed antiviral protein (PAP) is a RIP synthesized by the American pokeweed plant (Phytolacca americana). PAP inhibits virus infection when expressed in crop plants, yet little is known about the function of PAP in pokeweed due to a lack of genomic tools for this non-model species. In this work, we de novo assembled the pokeweed genome and annotated protein-coding genes. Sequencing comprised paired-end reads from a short-insert library of 83X coverage, and our draft assembly (N50 = 42.5 Kb) accounted for 74% of the measured pokeweed genome size of 1.3 Gb. We obtained 29,773 genes, 73% of which contained known protein domains, and identified several PAP isoforms. Within the gene models of each PAP isoform, a long 5' UTR intron was discovered, which was validated by RT-PCR and sequencing. Presence of the intron stimulated reporter gene expression in tobacco. To gain further understanding of PAP regulation, we complemented this genomic resource with expression profiles of pokeweed plants subjected to stress treatments [jasmonic acid (JA), salicylic acid, polyethylene glycol, and wounding]. Cluster analysis of the top differentially expressed genes indicated that some PAP isoforms shared expression patterns with genes involved in terpenoid biosynthesis, JA-mediated signaling, and metabolism of amino acids and carbohydrates. The newly sequenced promoters of all PAP isoforms contained cis-regulatory elements associated with diverse biotic and abiotic stresses. These elements mediated response to JA in tobacco, based on reporter constructs containing promoter truncations of PAP-I, the most abundant isoform. Taken together, this first genomic resource for the Phytolaccaceae plant family provides new insight into the regulation and function of PAP in pokeweed.
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Affiliation(s)
| | | | - Adrian E. Platts
- Department of Biology, Center for Genomics and Systems Biology, New York University, New York, NY, United States
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Gholizadeh A. Purification of a ribosome-inactivating protein with antioxidation and root developer potencies from Celosia plumosa. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2019; 25:243-251. [PMID: 30804646 PMCID: PMC6352530 DOI: 10.1007/s12298-018-0577-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 05/08/2018] [Accepted: 06/29/2018] [Indexed: 06/09/2023]
Abstract
Considering Celosia plumosa as a potent antiviral plant, the attempt was made to determine, purify and characterize its proteinaceous antiviral elements against tobacco mosaic virus hypersensitive response on Nicotiana glutinosa. By using 60% ammonium sulphate-precipitation, FPLC-based anion and cation-exchange chromatography in 10 and 50 mM NaCl, size-exclusion chromatography in 50 mM NaCl and SDS-PAGE 10%, a 25 kD antiviral protein with ribosome-inactivating/28S rRNase ability was purified from the leaves of C. plumosa at vegetative growth stage. The purified protein showed FRAP-based antioxidant activity in vitro and caused 1.7-fold and 1.4-fold increases in the growth rate of root system upon carborundum-based application on the root growth medium of N. glutinosa. The present work reports an antiviral protein with ribosome-inactivating, antioxidation and root developer potencies in C. plumosa as an edible or ornamental plant that may be useful in health and agricultural biotechnology in the future.
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Affiliation(s)
- Ashraf Gholizadeh
- Iran National Science Foundation (INSF), Tehran, Iran
- Department of Biology, Research Institute for Fundamental Sciences (RIFS), University of Tabriz, Tabriz, Iran
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Hassan Y, Ogg S, Ge H. Expression of novel fusion antiviral proteins ricin a chain-pokeweed antiviral proteins (RTA-PAPs) in Escherichia coli and their inhibition of protein synthesis and of hepatitis B virus in vitro. BMC Biotechnol 2018; 18:47. [PMID: 30081895 PMCID: PMC6080542 DOI: 10.1186/s12896-018-0458-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/26/2018] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Ricin A chain (RTA) and Pokeweed antiviral proteins (PAPs) are plant-derived N-glycosidase ribosomal-inactivating proteins (RIPs) isolated from Ricinus communis and Phytolacca Americana respectively. This study was to investigate the potential production amenability and sub-toxic antiviral value of novel fusion proteins between RTA and PAPs (RTA-PAPs). In brief, RTA-Pokeweed antiviral protein isoform 1 from seeds (RTA-PAPS1) was produced in an E. coli in vivo expression system, purified from inclusion bodies using gel filtration chromatography and protein synthesis inhibitory activity assayed by comparison to the production of a control protein Luciferase. The antiviral activity of the RTA-PAPS1 against Hepatitis B virus (HBV) in HepAD38 cells was then determined using a dose response assay by quantifying supernatant HBV DNA compared to control virus infected HepAD38 cells. The cytotoxicity in HepAD38 cells was determined by measuring cell viability using a tetrazolium dye uptake assay. The fusion protein was further optimized using in silico tools, produced in an E. coli in vivo expression system, purified by a three-step process from soluble lysate and confirmed in a protein synthesis inhibition activity assay. RESULTS Results showed that RTA-PAPS1 could effectively be recovered and purified from inclusion bodies. The refolded protein was bioactive with a 50% protein synthesis inhibitory concentration (IC50) of 0.06 nM (3.63 ng/ml). The results also showed that RTA-PAPS1 had a synergetic activity against HBV with a half-maximal response concentration value (EC50) of 0.03 nM (1.82 ng/ml) and a therapeutic index of > 21,818 with noticeable steric hindrance. Results also showed that the optimized protein ricin A chain mutant-Pokeweed antiviral protein isoform 1 from leaves (RTAM-PAP1) could be recovered and purified from soluble lysates with gain of function on protein synthesis inhibition activity, with an IC50 of 0.03 nM (1.82 ng/ml), and with minimal, if any, steric hindrance. CONCLUSIONS Collectively, our results demonstrate that RTA-PAPs are amenable to effective production and purification in native form, possess significant gain of function on protein synthesis inhibition and anti-HBV activities in vitro with a high therapeutic index and, thus, merit further development as potential potent antiviral agents against chronic HBV infection to be used as a standalone or in combination with existent therapies.
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Affiliation(s)
- Yasser Hassan
- Ophiuchus Medicine Inc., 1800 - 510 West Georgia Street, Vancouver, BC V6B 0M3 Canada
| | - Sherry Ogg
- Johns Hopkins University, AAP, Baltimore, MD 21218 USA
| | - Hui Ge
- AscentGene Inc., Gaithersburg, MD 20878 USA
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Zhang Y, Yu X, Wang Z, Yin M, Zhao Z, Li Y, Li W. Pokeweed antiviral protein attenuates liver fibrosis in mice through regulating Wnt/Jnk mediated glucose metabolism. Saudi J Gastroenterol 2018; 24:157-164. [PMID: 29652027 PMCID: PMC5985634 DOI: 10.4103/sjg.sjg_470_17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND/AIMS Pokeweed antiviral protein (PAP) has been reported to downregulate Wnt/Jnk pathway and attenuate liver fibrosis. This study was designed to intensively explore the mechanism of anti-fibrosis effect of PAP. MATERIALS AND METHODS Hepatic stellate cell (HSC) activation was induced by high concentration of glucose. Cell viability was detected at different time points after PAP treatment. Meanwhile, hepatic fibrosis models in mice were induced by CCl4 injection. In the end, liver pathology was observed and contents of alanine transaminase, aspartate transaminase, lactic dehydrogenase, hyaluronic acid (HA), and laminin (LN) in serum together with hydroxyproline (Hyp) in liver were measured. The mRNA and protein expressions of HK2, PFKP, PCK1, and FBP1 as well as Jnk expression in HSC-T6 cells and liver tissue were detected by qPCR and western-blot, respectively. RESULTS Compared with high glucose, PAP reduced viability and expressions of HK2, PFKP, α-SMA, and Col1A1, where as enhanced the expressions of PCK1 and FBP1 in HSC-T6 cells (P < 0.05) respectively. PAP attenuated liver pathology, improved liver function, and reduced collagen deposition in liver tissue compared with the model group (P < 0.05) respectively. Moreover, PAP reduced expressions of HK2, PFKP, α-SMA, and Col1A1 where as increased the expression of PCK1 and FBP1 in the liver of mice compared with the model group (P < 0.05) respectively. Most importantly, PAP reduced the phosphorylation of Jnk both in cells and liver tissue compared with the model group (P < 0.05) respectively. CONCLUSIONS Our results demonstrated that PAP attenuated liver fibrosis by regulating Wnt/Jnk-mediated glucose metabolism. It provided us a new target for the treatment of liver fibrosis.
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Affiliation(s)
- Yonghong Zhang
- Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xiaolan Yu
- Department of Ear-Nose-Throat, The First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Zheng Wang
- Department of Respiratory and Critical Medicine, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Ming Yin
- Infectious Diseases, Anhui Provincial Hospital, The First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Zonghao Zhao
- Infectious Diseases, Anhui Provincial Hospital, The First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Yi Li
- Infectious Diseases, Anhui Provincial Hospital, The First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Wenting Li
- Infectious Diseases, Anhui Provincial Hospital, The First Affiliated Hospital of University of Science and Technology of China, Hefei, China,Address for correspondence: Dr. Wenting Li, 3rd Liver Unit, Department of Infectious Disease, Anhui Provincial Hospital, The First Affiliated Hospital of University of Science and Technology of China, Hefei - 230001, China. E-mail:
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Biological and antipathogenic activities of ribosome-inactivating proteins from Phytolacca dioica L. Biochim Biophys Acta Gen Subj 2016; 1860:1256-64. [DOI: 10.1016/j.bbagen.2016.03.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/16/2016] [Accepted: 03/07/2016] [Indexed: 12/30/2022]
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Neller KCM, Klenov A, Hudak KA. The Pokeweed Leaf mRNA Transcriptome and Its Regulation by Jasmonic Acid. FRONTIERS IN PLANT SCIENCE 2016; 7:283. [PMID: 27014307 PMCID: PMC4792876 DOI: 10.3389/fpls.2016.00283] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/22/2016] [Indexed: 05/16/2023]
Abstract
The American pokeweed plant, Phytolacca americana, is recognized for synthesizing pokeweed antiviral protein (PAP), a ribosome inactivating protein (RIP) that inhibits the replication of several plant and animal viruses. The plant is also a heavy metal accumulator with applications in soil remediation. However, little is known about pokeweed stress responses, as large-scale sequencing projects have not been performed for this species. Here, we sequenced the mRNA transcriptome of pokeweed in the presence and absence of jasmonic acid (JA), a hormone mediating plant defense. Trinity-based de novo assembly of mRNA from leaf tissue and BLASTx homology searches against public sequence databases resulted in the annotation of 59 096 transcripts. Differential expression analysis identified JA-responsive genes that may be involved in defense against pathogen infection and herbivory. We confirmed the existence of several PAP isoforms and cloned a potentially novel isoform of PAP. Expression analysis indicated that PAP isoforms are differentially responsive to JA, perhaps indicating specialized roles within the plant. Finally, we identified 52 305 natural antisense transcript pairs, four of which comprised PAP isoforms, suggesting a novel form of RIP gene regulation. This transcriptome-wide study of a Phytolaccaceae family member provides a source of new genes that may be involved in stress tolerance in this plant. The sequences generated in our study have been deposited in the SRA database under project # SRP069141.
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Ishag HZ, Li C, Huang L, Sun MX, Ni B, Guo CX, Mao X. Inhibition of Japanese encephalitis virus infection in vitro and in vivo by pokeweed antiviral protein. Virus Res 2013; 171:89-96. [DOI: 10.1016/j.virusres.2012.10.032] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Revised: 10/31/2012] [Accepted: 10/31/2012] [Indexed: 11/29/2022]
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Zhang H, Qi Y, Ding Y, Wang J, Li Q, Zhang J, Jiang Y, Chi X, Li J, Niu J. Synthesis, characterization and biological activity of a niobium-substituted-heteropolytungstate on hepatitis B virus. Bioorg Med Chem Lett 2012; 22:1664-9. [PMID: 22264474 PMCID: PMC7127507 DOI: 10.1016/j.bmcl.2011.12.115] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 12/05/2011] [Accepted: 12/24/2011] [Indexed: 01/02/2023]
Abstract
To synthesise and characterize the polyoxometalate Cs2K4Na[SiW9Nb3O40]·H2O 1 for its anti-hepatitis B virus (HBV) properties by using the HepG2.2.15 cell. The methylthiazol tetrazolium assay was used to evaluate the growth inhibitory effect of Compound 1 on HepG2.2.15 cell. By using ELISA and real-time PCR, respectively, the presence of extracellular hepatitis B surface antigen (HBsAg), e antigen (HBeAg), and HBV DNA were measured. The levels of intracellular HBV DNA and mRNA were determined by using Southern blot or reverse-transcription-PCR, respectively. Intracellular distribution of antigen were measured by Western blot. A 1995 μmol/L concentration of the commercially-available hepatitis B drug, adefovir dipivoxil (ADV), was required to achieve 50% cytotoxicity against cultured cells (CC50) by day nine; in contrast, only 1747 μmol/L of Compound 1 was required for the same result. Treatment of HepG2.2.15 cells with Compound 1 effectively suppress the secretion of HBV antigens and HBV DNA in a dose-dependent and time-dependent manner. IC50 values were determined to be 80 μmol/L for HBsAg, 75 μmol/L for HBeAg and 3.72 μmol/L for supernatant HBV DNA at day nine post-exposure, as opposed to 266, 296, 30.09 μmol/L, respectively, for ADV. Intracellular HBV DNA, mRNA and antigen were also found to be decreased by Compound 1. The same dose of ADV yielded a significantly less robust inhibitory effect. Compound 1 can clear HBV from hepatic cells and may represent a therapeutic agent to treat HBV infection.
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Affiliation(s)
- Hong Zhang
- Department of Hepatology, First Hospital, Jilin University, Changchun, PR China
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Zheng L, Wang Q, Yang X, Guo X, Chen L, Tao L, Dong L, Li Y, An H, Yu X, Wang Q, Chang J. Antiviral activity of FNC, 2′-deoxy-2′-β-fluoro-4′-azidocytidine, against human and duck HBV replication. Antivir Ther 2012; 17:679-87. [DOI: 10.3851/imp2094] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2011] [Indexed: 10/28/2022]
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Goktepe I, Maness L, Hardy B, Yu J, Ahmedna M. Antiproliferative and Apoptotic Effects of Phytolacca americana Extracts and their Fractions on Breast and Colon Cancer Cells. ACTA ACUST UNITED AC 2012. [DOI: 10.3923/rjmp.2012.17.26] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Ribosome inactivating proteins from plants inhibiting viruses. Virol Sin 2011; 26:357-65. [PMID: 22160935 DOI: 10.1007/s12250-011-3223-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 10/26/2011] [Indexed: 10/14/2022] Open
Abstract
Many plants contain ribosome inactivating proteins (RIPs) with N-glycosidase activity, which depurinate large ribosomal RNA and arrest protein synthesis. RIPs so far tested inhibit replication of mRNA as well as DNA viruses and these proteins, isolated from plants, are found to be effective against a broad range of viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV). Most of the research work related to RIPs has been focused on antiviral activity against HIV; however, the exact mechanism of antiviral activity is still not clear. The mechanism of antiviral activity was thought to follow inactivation of the host cell ribosome, leading to inhibition of viral protein translation and host cell death. Enzymatic activity of RIPs is not limited to depurination of the large rRNA, in addition they can depurinate viral DNA as well as RNA. Recently, Phase I/II clinical trials have demonstrated the potential use of RIPs for treating patients with HIV disease. The aim of this review is to focus on various RIPs from plants associated with anti-HIV activity.
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Qi YF, Zhang H, Wang J, Jiang Y, Li J, Yuan Y, Zhang S, Xu K, Li Y, Li J, Niu J, Wang E. In vitro anti-hepatitis B and SARS virus activities of a titanium-substituted-heteropolytungstate. Antiviral Res 2011; 93:118-25. [PMID: 22127069 PMCID: PMC7114352 DOI: 10.1016/j.antiviral.2011.11.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 10/01/2011] [Accepted: 11/07/2011] [Indexed: 12/31/2022]
Abstract
A structural determined heteropolytungstate, [K4(H2O)8Cl][K4(H2O)4PTi2W10O40]·NH2OH 1, has been synthesized and evaluated for in vitro antiviral activities against hepatitis B (HBV) and SARS virus. The identity and high purity of compound 1 were confirmed by elemental analysis, NMR, IR analysis and single-crystal X-ray diffraction. The compound 1, evaluated in HepG 2.2.15 cells expressing permanently HBV, significantly reduced the levels of HBV antigens and HBV DNA in a dose-dependent and time-dependent manner. EC50 values were determined to be 54 μM for HBeAg, 61 μM for HBsAg and 2.66 μM for supernatant HBV DNA, as compared to 1671, 1570, 169 μM, respectively, for the commercially-available hepatitis B drug adefovir dipivoxil (ADV). Intracellular cccDNA, pgRNA and HBcAg were also found to be decreased by compound 1 in a concentration-dependent manner. Cytotoxicity results showed that compound 1 has low toxicity in HepG 2 cells with CC50 value of 515.20 μM. The results indicate that compound 1 can efficiently inhibit HBV replication in HepG 2.2.15 cells line in vitro. Additionally, compound 1 also shows high anti-SARS activity at an EC50 of 7.08 μM and toxicity with a CC50 of 118.6 μM against MDCK cells.
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Affiliation(s)
- Yan-fei Qi
- School of Public Health, Jilin University, Changchun, Jilin 130021, PR China
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Pokeweed antiviral protein down-regulates Wnt/β-catenin signalling to attenuate liver fibrogenesis in vitro and in vivo. Dig Liver Dis 2011; 43:559-66. [PMID: 21444256 DOI: 10.1016/j.dld.2011.02.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Revised: 01/30/2011] [Accepted: 02/19/2011] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND AIM Pokeweed antiviral protein (PAP) has been regarded as a strong negative regulator of Wnt/β-catenin signalling, which promotes tissue fibrogenesis. Whether PAP inhibits hepatic fibrosis remains unknown. Here, the inhibitory effects of PAP on hepatic fibrosis induced by CCl4 in rats were monitored. METHODS Plasmid pXF3H-PAP was transduced into liver in vivo and hepatic stellate cell (HSC-T6) in vitro. Changes in liver pathology were examined by haematoxylin and eosin (H&E) and Masson's trichrome staining. Hepatic function and the levels of hyaluronic acid (HA) and laminin (LN) in serum and hydroxyproline (Hyp) in liver were measured. We also observed the expressions and distribution of α-SMA, TIMP-1, smad3 and β-catenin in HSCs and liver, together with the viability of HSC-T6 cells. RESULTS PAP obviously attenuated the histological changes, decreased the content of Hyp in liver and improved liver function in rats (P<0.05). PAP significantly reduced the expressions and distribution of α-SMA and β-catenin in vivo (0.0125 ± 0.002 vs. 0.0374 ± 0.003, 0.0135 ± 0.003 vs. 0.0382 ± 0.004; P<0.05, respectively) and in vitro as well as the cell viability (P<0.05). CONCLUSIONS Our results revealed that PAP attenuated liver fibrogenesis through down-regulating the Wnt/β-catenin pathway. It provides us an alternative new strategy for the treatment of hepatic fibrosis.
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