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Effects of a nutrient mixture on infectious properties of the highly pathogenic strain of avian influenza virus A/H5N1
Abstract
Numerous outbreaks of avian influenza virus infection (A/H5N1) have occurred recently, infecting domestic birds, chicken and ducks. The possibility of the emergence of a new strain of influenza virus capable of causing a pandemic in humans is high and no vaccine effective against such a strain currently exists. A unique nutrient mixture (NM), containing lysine, proline, ascorbic acid, green tea extract, N-acetyl cysteine, selenium among other micro nutrients, has been shown to exert a wide range of biochemical and pharmacological effects, including an inhibitory effect on replication of influenza virus and HIV. This prompted us to investigate the potential anti-viral activity of a nutrient mixture (NM) and its components on avian influenza virus A/H5N1at viral dosages of 1.0, 0.1 and 0.01 TCID(50). Antiviral activity was studied in cultured cell lines PK, BHK-21, and Vero-E6. Virus lysing activity was determined by co-incubation of virus A/H5N1 with NM for 0-60 min, followed residual virulence titration in cultured SPEV or BHK-21 cells. NM demonstrated high antiviral activity evident even at prolonged periods after infection. NM antiviral properties were comparable to those of conventional drugs (amantadine and oseltamivir); however, NM had the advantage of affecting viral replication at the late stages of the infection process.
... Positive effects of green tea have been demonstrated in poultry diseases including coccidiosis (Jang et al. 2007) and avian influenza (Deryabin et al. 2008;Song et al. 2007). Seven species of Eimeria (an intracellular protozoan) belonging to the phylum Apicomplexa cause avian coccidiosis, which is an economically important disease in the poultry industry. ...
... The structureactivity data of catechin derivatives may usefully guide future research endeavours for applying green tea catechins as alternative anti-viral agents. Subsequently Deryabin et al. (2008) investigated the potential anti-viral activity of a unique nutrient mixture (NM) (containing green tea extract, lysine, proline, ascorbic acid, N-acetyl cysteine and selenium, amongst other micronutrients) and its components on A/H5N1 at viral dosages of 1.0, 0.1 and 0.01 TCID 50 . Antiviral activity was studied in cultured cell lines PK, BHK-21, and Vero-E6. ...
This review examined the use of green tea (Camellia sinensis) in the diets of poultry. Research findings were obtained from various recent studies, where much attention was focused on the role of green tea in the promotion of both animal and human health. The review involved some of the currently available information about green tea, pertaining to its chemical composition, anticoccidial and antimicrobial effect, effect on broiler and layer performance and on blood and egg yolk constituents. To the author's knowledge this is the first review paper on this topic. It will be helpful for poultry nutritionists and the poultry industry, although more detailed studies are still needed to elucidate the effects of green tea in poultry nutrition under various circumstances.
... Positive effects of green tea have been demonstrated in poultry diseases including coccidiosis (Jang et al. 2007) and avian influenza (Deryabin et al. 2008;Song et al. 2007). Seven species of Eimeria (an intracellular protozoan) belonging to the phylum Apicomplexa cause avian coccidiosis, which is an economically important disease in the poultry industry. ...
... The structureactivity data of catechin derivatives may usefully guide future research endeavours for applying green tea catechins as alternative anti-viral agents. Subsequently Deryabin et al. (2008) investigated the potential anti-viral activity of a unique nutrient mixture (NM) (containing green tea extract, lysine, proline, ascorbic acid, N-acetyl cysteine and selenium, amongst other micronutrients) and its components on A/H5N1 at viral dosages of 1.0, 0.1 and 0.01 TCID 50 . Antiviral activity was studied in cultured cell lines PK, BHK-21, and Vero-E6. ...
This review examined the use of green tea (Camellia sinensis) in the diets of poultry. Research findings were obtained from various recent studies, where much attention was focused on the role of green tea in the promotion of both animal and human health. The review involved some of the currently available information about green tea, pertaining to its chemical composition, anticoccidial and antimicrobial effect, effect on broiler and layer performance and on blood and egg yolk constituents. To the author's knowledge this is the first review paper on this topic. It will be helpful for poultry nutritionists and the poultry industry, although more detailed studies are still needed to elucidate the effects of green tea in poultry nutrition under various circumstances.
... GT and GT extracts have received much attention because of their diverse beneficial effects such as antimutagenic ( Krul et al. 2001), antioxidant ( Henning et al. 2004), anticancer (Sommer et al. 2010), antiosteoporotic (Shen et al. 2009), and above all, antihyperlipidemic ( Muramatsu et al. 1986;Suzuki et al. 1998;Yang and Koo 1997;Chan et al. 1999;Yang et al. 2001;Bose et al. 2008) properties as well as antibacterial, antitoxin, antiviral, and antifungal effects (Friedman 2007) in vivo or in vitro. Positive effects of GT have also been demonstrated in poultry diseases including avian influenza ( Deryabin et al. 2008;Song et al. 2007) and coccidiosis ( Jang et al. 2007). However, some reports show that GT may adversely affect nutrient absorption from the gastrointestinal tract of laboratory animals and humans (Frejnagel and Wroblewska 2010 ;Samman et al. 2001). ...
... Recently, positive effects of GT on poultry diseases have been evaluated. It has been demonstrated that a nutrient mixture containing GT has antiviral activity against a highly pathogenic strain of avian influenza virus (H5N1) in cultured cell lines, which is comparable to those of conventional drugs such as amantadine and oseltamivir (Deryabin et al. 2008). Moreover, semi-synthetic catechin derivatives have been shown to inhibit H2N2 and H9N2 avian influenza viruses in vitro and in ovo ( Song et al. 2007). ...
The aim of the present study was to investigate the putative effects of dietary supplementation with green tea powder on growth performance, D-xylose absorption as well as serum-selected parameters of broiler chickens. Forty 21-day-old chickens were randomly allocated into four groups and fed with diets supplemented with 0% (control), 1%, 2%, or 4% green tea powder for 2 weeks. At the end of the experiment, D-xylose absorption test was performed on all birds on a 45-min basis for 135 min, and PCV as well as serum total protein, total cholesterol, LDL-c, HDL-c, triglycerides, iron, calcium, and phosphorus concentrations were assayed. Body weight, feed intake, and feed conver-sion ratio (FCR) were also recorded during the experiment. No significant differences were observed in plasma D-xylose concentrations, PCV, or serum parameters among different groups (p>0.05). Differences in body weight, feed intake, and FCR were insignificant as well. In conclusion, dietary supplementation with green tea powder for 2 weeks has no adverse effect on PCV, intestinal absorption of D-xylose, serum total protein, lipid profile, and mineral concentrations as well as performance parameters of broiler chickens.
... Recently, beneficial effects of green tea or green tea catechins have also been demonstrated in avian species, for instance epigallocatechin gallate supplementation has improved antioxidant status in heat-stressed quails Tuzcu et al. (2008). Moreover, positive effects of green tea has been shown in poultry diseases such as avian influenza Song et al. (2007), Deryabin et al. (2008 and coccidiosis Jang et al. (2007). Although Jang et al. (2007 observed that dietary supplementation with 0.5% and 2% green tea powder for 2 weeks, does not significantly affect body weight gain in broiler chickens; however possible effect of higher doses or longer period of administration on performance parameters has not been clarified yet. ...
... Jang et al., 2007 observed that dietary supplementation with 0.5% and 2% green tea powder has positive effects on coccidiosis in chickens. Moreover, green tea or green tea derivatives have shown favorable effects on avian influenza viruses in vitro Deryabin et al. (2008) and Song et al. (2007). However, it should always be recognized that dietary components can affect performance parameters of the chickens by different mechanisms among them is alteration of the histological parameters of the small intestine, which subsequently can affect nutrient absorption. ...
Mosleh N, Shomali T, Hamedi S., The effects of green tea powder on performance parameters, D-xylose absorption and jejunum (histology) in broilers, Online J Vet Res., 15 (2): 147-154, 2011. Effects of green tea powder on performance parameters, D-xylose absorption and jejunal histological parameters of thirty 21-day old broiler chickens of both sexes were investigated. Birds in untreated controls gained significantly higher body weight than birds treated with green tea powder. No significant differences were observed in plasma D-xylose concentrations in any groups. Green tea consumption did not affect jejunum villus width, height/crypt depth ratio or epithelial cell area. However, villus height, area and crypt depth increased in treated birds. In conclusion, 1% green tea in diet appears to be able to lower body weight and increase FCR in broiler chickens at no apparent detriment to jejunal mucosa.
... Well-known effects of green tea on human health include anti-diabetic, hypocholesterolemic, antiinflammatory and anticarcinogenic activities, as well as antiviral properties. [1][2][3][4][5][6][7] In respect of its antiviral properties, a green tea extract has been shown to have inhibitory effects on the human immunodeficiency virus, influenza virus, Epstein-Barr virus, herpes virus, and human T-cell lymphotropic virus type 1, and many other viruses. This broad-spectrum antiviral activity is expected to be found among enveloped viruses in general. ...
... 11,12) The search for antiviral substances with high efficacy, low toxicity, and minor side effects must therefore be continued from both natural and synthetic resources. [3][4][5][6][7][13][14][15] In parallel with prevention and therapy using vaccines and antivirals, much simpler and probably lower-cost intervention would be possible for reducing the transmission of epidemic respiratory viruses among the public. Enhanced hygiene, including wearing face masks and keeping the hands clean continue to be proposed as the first-hand measures against the spread of respiratory viral infection, because influenza viruses are transmitted through both skin contact and through aerosol transfer. ...
Based on the broad-spectrum antiviral effect of green tea catechins, we established an experimental skin contact model for influenza virus transmission and evaluated the use of a green tea solution as a first-hand disinfectant. The infectivity of the virus on the skin cell layer became obsolete when washed with the green tea solution. The skin contact model could be applied to develop non-pharmaceutical intervention measures for reducing human transmission of the influenza virus.
... L'hypothèse principale est qu'une déficience en sélénium entraine une augmentation du stress oxydatif dans la cellule infectée, causant des dommages à l'ADN plus importants. (Deryabin et al., 2008;Fang et al., 2015;Sartori et al., 2016). Dans le cas du virus porcin PCV2 (Porcine Circovirus 2), une supplémentation en sélénium de cellules en culture inhibe la réplication virale. ...
Le sélénium et le zinc sont deux oligo-éléments indispensables à de nombreux processus physiologiques et cellulaires. De manière générale, les virus perturbent la balance des micronutriments des organismes qu’ils infectent, et c’est particulièrement le cas du virus de l’immunodéficience humaine (VIH), responsable du syndrome d’immunodéficience acquise (SIDA). De nombreuses études épidémiologiques ont mis en évidence des carences en sélénium et en zinc chez les patients, démontrant leur importance lors de cette infection virale. Malgré leurs similitudes, ces oligo-éléments ont des mécanismes d’action très différents chez l’Homme. Le sélénium entre dans la composition de seulement 25 protéines, nommées sélénoprotéines, grâce à son incorporation dans la chaine polypeptidique par le biais d’un acide aminé, la sélénocystéine. Les sélénoprotéines sont principalement impliquées dans le maintien de l’homéostasie redox de la cellule et la détoxification des espèces réactives de l’oxygène, des voies particulièrement importantes lors d’infections virales. Le zinc est quant à lui le cofacteur de près de 3000 protéines humaines, permettant, entre autres, la structuration de domaines protéiques nommés doigts de zinc. Ces protéines sont impliquées dans des fonctions très variées qui requièrent des interactions avec des molécules d’acides nucléiques. Parmi les protéines à doigt de zinc, on retrouve la nucléocapside du VIH, NCp7, une protéine de structure indispensable au virus. Le zinc possède 5 isotopes stables et des études montrent que lors de processus biologiques, certains isotopes sont favorisés au dépend des autres, c’est le fractionnement isotopique. Ce phénomène a plus particulièrement été mis en évidence dans des contextes physiologiques ou pathologiques tels que des cancers, mais jamais dans le cas d’infections virales. Ce projet s’articule donc autour de ces deux oligo-éléments essentiels dans le contexte de l’infection des lymphocytes T CD4+ par le VIH-1. La première partie de ce travail s’intéresse au rôle du sélénium et des sélénoprotéines. Nos résultats montrent que le niveau de sélénium, qui régule la production des sélénoprotéines, influence la réplication du VIH et que à l’inverse, l’infection modifie le profil d’expression cellulaire des sélénoprotéines. La seconde partie, à l’interface avec la géochimie, se concentre sur le fractionnement isotopique du zinc dans le contexte infectieux du VIH. Nos résultats montrent que les virus produits en modèle cellulaire sont enrichis en isotopes légers. De plus, les virus enrichis en isotopes légers du zinc ils sont plus infectieux que les virus enrichis en isotopes lourds. Nos travaux visent à mieux caractériser l’implication du zinc et du sélénium lors de l’infection des lymphocytes T CD4+ par le VIH-1 afin de comprendre les effets des carences en ces deux oligo-éléments, leur utilisation par l’organisme et la manière dont le virus les détourne.
... [72] The different nutrient mixtures of natural EGCG have an inhibitory effect on IV and has also been demonstrated by various investigators. [73][74][75] Some researchers have undertaken clinical trials of EGCG as an IAV restriction factor. [76] One research team discovered a link between IV infection and gargling tea catechin extract, demonstrating that GTCs dramatically reduced the influenza infection incidence in 124 elderly individuals aged 65 and up. ...
Green Tea Catechins (GTCs) - unarguably the wonder compounds with numerous medicinal properties and health benefits. And most importantly, these benefits include antiviral effects, so significant nowadays in our corona-hit world. The major catechins of green tea are four - epigallocatechin gallate (EGCG), epigallocatechin, epicatechin, and epicatechin-gallate. While each one of these has its own unique properties, EGCG, as per different studies, has been reported to be the most effective catechin showing significant antiviral activity against a broad spectrum of human and animal viruses. The antiviral properties of green tea extracts are manifold and target different areas. These include direct inactivation of the virus particles, prevention of entry into the target cell, inhibition of gene expression, inhibition of protein expression, inhibition of intestinal α-glycosidases that are important for processing glyco-conjugates of viruses, and lowering of proliferation of virus. Furtehrmore, a positive correlation between the antioxidant effects of catechins and their antiviral activities has been suggested. The growing concern about our health and the persistent fight while we are amidst the present coronavirus pandemic makes the inhibitory effect of GTCs a promising area of research. Due to their “relief and rectification” properties, these may be considered as a food supplement to ameliorate the harmful and deadly effects of the virus. The bioavailability of these polyphenols has been shown to be influenced by factors such as temperature, food processing methods, food matrix, and interaction with other compounds. Furthermore, the hydrophilic nature of EGCG molecule limits its bioavailability at the site of action. However, this limitation can be overcome and bioavailability of GTCs can be increased by chemical interventions, such as attachment of fatty acids. These ensure wide availability, and even wider use. The leading objective of this review is to collate, summarize and explain the information available on GTCs, and their effect on various pathogenic viruses in humans and animals. The GTCs surely promise to be an important weapon in our armour to fight corona and other pathogens.
... The activity of epigallocatechin gallate against adenovirus is demonstrated in different levels like direct inactivation of virus, protease adenine inhibition or intracellular growth inhibition. Epigallocatechin gallate is most potent antiviral molecule because of its structure having paragalloyl and galloyl moieties (Deryabin et al. 2008;Ishii et al. 2010). These groups are responsible factor for antiviral activity. ...
The food industry is generating huge amounts of by-products, about 1,890,000 tons, which should be better recycled into pharmaceuticals, cosmetics and functional foods, for instance, in order to save costs and avoid pollution. Here we review food by-products and methods of extraction. We present bioactive compounds from fruits, vegetable, tea, coffee, egg, nuts, meat and dairy products. Extracting methods include soxhlet, maceration, microwave, ultrasound, pressure.
... The activity of epigallocatechin gallate against adenovirus is demonstrated in different levels like direct inactivation of virus, protease adenine inhibition or intracellular growth inhibition. Epigallocatechin gallate is most potent antiviral molecule because of its structure having paragalloyl and galloyl moieties (Deryabin et al. 2008;Ishii et al. 2010). These groups are responsible factor for antiviral activity. ...
The food industry is generating huge amounts of by-products, about 1,890,000 tons, which should be better recycled into pharmaceuticals, cosmetics and functional foods, for instance, in order to save costs and avoid pollution. Here we review food by-products and methods of extraction. We present bioactive compounds from fruits, vegetable, tea, coffee, egg, nuts, meat and dairy products. Extracting methods include soxhlet, maceration, microwave, ultrasound, pressure.KeywordsFood by-productsBioactive moleculesNovel techniquesConventional techniquesGreen techniquesEnvironmental pollution
... Based on this study and our earlier findings [18,19,27], this combination of plant-derived compounds and micronutrients may constitute a new anti-SARS-CoV-2 strategy by simultaneously affecting multiple aspects of viral life cycle, including viral entry and replication. This strategy was also implemented in our earlier studies, including those of human influenza H1N1, bird flu H1N5, and others, which were based on selecting natural components that simultaneously affect key pathology mechanisms across a wide spectrum of infective agents [28][29][30][31]. ...
Despite vaccine availability, the global spread of COVID-19 continues, largely facilitated by emerging SARS-CoV-2 mutations. Our earlier research documented that a specific combination of plant-derived compounds can inhibit SARS-CoV-2 binding to its ACE2 receptor and controlling key cellular mechanisms of viral infectivity. In this study, we evaluated the efficacy of a defined mixture of plant extracts and micronutrients against original SARS-CoV-2 and its Alpha, Beta, Gamma, Delta, Kappa, and Mu variants. The composition containing vitamin C, N-acetylcysteine, resveratrol, theaflavin, curcumin, quercetin, naringenin, baicalin, and broccoli extract demonstrated a highest efficacy by inhibiting the receptor-binding domain (RBD) binding of SARS-CoV-2 to its cellular ACE2 receptor by 90%. In vitro exposure of test pseudo-typed variants to this formula for 1 h before or simultaneously administrated to human pulmonary cells resulted in up to 60% inhibition in their cellular entry. Additionally, this composition significantly inhibited other cellular mechanisms of viral infectivity, including the activity of viral RdRp, furin, and cathepsin L. These findings demonstrate the efficacy of natural compounds against SARS-CoV-2 including its mutated forms through pleiotropic mechanisms. Our results imply that simultaneous inhibition of multiple mechanisms of viral infection of host cells could be an effective strategy to prevent SARS-CoV-2 infection.
... Fatty acid monoester derivatives of EGCG, especially those with long alkyl chains, exhibited a sharply increased antiviral effect against IAV compared to natural EGCG [57]. The inhibitory effects of different nutrient mixtures of natural EGCG on influenza virus have also been demonstrated by different investigators [58,81,82]. Some researchers contributed to clinical trials of EGCG as an IAV restriction factor [59]. ...
Over the centuries, infectious diseases caused by viruses have seriously threatened human health globally. Viruses are responsible not only for acute infections but also many chronic infectious diseases. To prevent diseases caused by viruses, the discovery of effective antiviral drugs, in addition to vaccine development, is important. Green tea catechins (GTCs) are polyphenolic compounds from the leaves of Camellia sinensis. In recent decades, GTCs have been reported to provide various health benefits against numerous diseases. Studies have shown that GTCs, especially epigallocatechin-3-gallate (EGCG), have antiviral effects against diverse viruses. The aim of this review is to summarize the developments regarding the antiviral activities of GTCs, to discuss the mechanisms underlying these effects and to offer suggestions for future research directions and perspectives on the antiviral effects of EGCG.
... This processing produces glucuronide and sulfate conjugates or methyl epicatechins [4]. Lim et al. demonstrated that green tea flavonoids have anti-inflammatory and anti-enzymatic activities by reducing NLRP3 ral effects on influenza virus subtypes by inhibiting its replication, RNA synthesis and agglutination in cell culture [12]. ...
... The application of lyophilized green tea extracts (GTE) in feed or drinking water reduced the replication and excretion in H9N2 experimentally infected chickens (Lee et al., 2012). Moreover, GTE was effective as amantadine in protection of chicken embryos against an H7N3 AIV (Shaukat et al., 2011) or cell culture after infection with H5N1 virus (Deryabin et al., 2008). Interestingly, GTE was found to enhance the immune response of mice to influenza vaccines (Won et al., 2017;Zaman et al., 2019). ...
Highly pathogenic avian influenza virus (HPAIV) H5N1 is an endemic disease in Egypt and severe outbreaks have been reported even in vaccinated flocks. Several H5 vaccines have failed to protect birds against Egyptian H5N1 virus. In this study, the antiviral effect of green tea extract (GTE) in combination with inactivated H5N1 vaccine was evaluated. GTE found to be safe at high concentration on Vero cells and decrease the CPE on infected cells. In vivo, specific pathogen free chickens were allocated into four groups, 15 birds each. Negative control group, positive control group, vaccinated group, vaccinated group supplied by GTE in drinking water (5gm/L). Blood samples were collected weekly and tested using (HI) test. Lung tissue specimens collected for histopathology and immunohistochemistry. Interestingly, vaccinated non-treated birds exhibited severe post vaccinal reaction and deaths. GTE in combination with inactivated vaccine increased HI titer one-week post vaccination, and no deaths were recorded in this group. Moreover, treated chickens did not excrete virus in swab samples and minimal antigen and pathological changes were reported in its lungs. The addition of GTE prevent the shedding of the virus and achieve complete protection against HPAI.
... Fatty acid monoester derivatives of EGCG, especially those with long alkyl chains, exhibited a sharply increased antiviral effect against IAV compared to natural EGCG [57]. The inhibitory effects of different nutrient mixtures of natural EGCG on influenza virus have also been demonstrated by different investigators [58,81,82]. Some researchers contributed to clinical trials of EGCG as an IAV restriction factor [59]. ...
... Positive influence of Camellia sinensis was also observed against poultry infections including coccidiosis and influenza ( Jang et al., 2007). The leaves as well as by-products of Camellia sinensis can be provided to the broilers as a feed supplement in order to reduce mortality and improve performance (Deryabin et al., 2008;Uuganbayar et al., 2005). Yang et al. (2003) demonstrated that feeding of different levels of Camellia sinensis to animals declines the level of fatty acids and cholesterol in muscles and plasma and also improve the meat quality. ...
The agroprocessing industries are producing a large volumes of waste biomass that contains valuable nutrients which if recycled properly could save millions of dollars. This is the case for the tea industry which produces large amounts of biomass from the tea plant, Camellia sinensis. Here, we review bioactive compounds from tea leaves, flowers and fruits, and their applications in medicine. Compounds include vitamins, aromatic compounds, spermidine derivatives, polysaccharides, saponins, polysaccharides, fatty acids, flavanols, phenolic acids and methylxanthenes. Pharmacological properties include antioxidant, antimicrobial, anti-COVID, antiobesity, antidiabetic, antihypertensive and anticancer.Keywords
Camellia sinensis
PolyphenolsSpermidineFunctional molecules
SARS-CoV-2 pandemic remains a challenge to human health and economy worldwide. Previously we have shown that a combination of active plant-derived compounds and plant extracts can dose-dependently inhibit binding of RBD-spike protein SARS-CoV-2 to the ACE2 receptor and its expression on human alveolar epithelial cells. Here we use eGFP-luciferase-SARS-CoV-2 spike protein pseudo-virions and SARS-CoV-2-RdRp, to show if the antiviral effectiveness of this combination of plant-derived compounds and plant extracts expands to other important key mechanisms of SARS-CoV-2 infection. Or results revealed that this combination of five plant-derived compounds inhibited the attachment of the SARS-CoV-2 pseudo-typed particles with lung hACE2/A549 cells. In addition, it down-regulated the activity of key enzymes known to be crucial for the entry of the SARS-CoV-2 virus, such as TMPRSS2, furin and cathepsin L, but not their expression at protein level. This combination did not affect ACE2 binding to and ACE2 enzymatic activity, but modestly decrease cellular expression of neuropilin-1 molecule and significantly inhibited activity of viral RdRp. This study demonstrates inhibitory effects of this combination on key cellular mechanisms of SARS-CoV-2 infection. The findings further support the use of plant-derived compounds as effective health measures against SARS-CoV-2-caused infection.
Reactive oxygen species (ROS) are frequently produced during viral infections. Generation of these ROS can be both beneficial and detrimental for many cellular functions. When overwhelming the antioxidant defense system, the excess of ROS induces oxidative stress. Viral infections lead to diseases characterized by a broad spectrum of clinical symptoms, with oxidative stress being one of their hallmarks. In many cases, ROS can, in turn, enhance viral replication leading to an amplification loop. Another important parameter for viral replication and pathogenicity is the nutritional status of the host. Viral infection simultaneously increases the demand for micronutrients and causes their loss, which leads to a deficiency that can be compensated by micronutrient supplementation. Among the nutrients implicated in viral infection, selenium (Se) has an important role in antioxidant defense, redox signaling and redox homeostasis. Most of biological activities of selenium is performed through its incorporation as a rare amino acid selenocysteine in the essential family of selenoproteins. Selenium deficiency, which is the main regulator of selenoprotein expression, has been associated with the pathogenicity of several viruses. In addition, several selenoprotein members, including glutathione peroxidases (GPX), thioredoxin reductases (TXNRD) seemed important in different models of viral replication. Finally, the formal identification of viral selenoproteins in the genome of molluscum contagiosum and fowlpox viruses demonstrated the importance of selenoproteins in viral cycle.
Influenza infection is the principal cause of acute respiratory illnesses resulting in epidemic or pandemic worldwide. It also has major social and economic consequences for school and work, as well as significant treatment and hospitalization costs, hence proper management of influenza transmission is a global concern. Catechins are the major flavonoids and are reported to possess anti-oxidant, anti-cancer and anti-microbial activities. Recent experimental studies have revealed that green tea extracts including catechins prevent influenza infection, in vitro and in clinical settings. Along with the proven virucidal effect against influenza viruses, the beneficial effects of green tea components in reducing clinical symptoms of influenza infection, as demonstrated by gargling or ingesting supplement tablets, merit their use in influenza management in times of pandemic or in the annual influenza season. In this chapter, we discuss the biological anti-influenza viral activities of green tea catechins in vitro and in vivo .
Spathaspora passalidarum, a recently isolated native xylose-fermenting yeast, can ferment xylose faster than glucose, and can co-ferment glucose, xylose, and cellobiose. Studies on S. passalidarum have been reported in terms of fermentation conditions. However, to the best of our knowledge, the molecular modification of S. passalidarum has not been achieved. The lack of successful transformants may be attributed to the absence of an effective transformation method. In the current work, a genetic transformation protocol for S. passalidarum was established. S. passalidarum was transformed via the lithium acetate method with a plasmid containing the KmR as a selectable marker and the Saccharomyces cerevisiae 2μ replicon as a replication origin. Several important parameters affecting transformation efficiency were optimized; these parameters included the strain growth period, heat shock time, lithium acetate concentration, and the amount of plasmid DNA. The transformation efficiency reached 170 ± 30 transformants·μg−1 plasmid DNA with the optimized method. This novel transformation system will allow for the genetic analysis and metabolic engineering of S. passalidarum for industrial bioethanol production.This article is protected by copyright. All rights reserved
Highly pathogenic avian influenza virus (HPAIV) of subtype H5N1 causes a devastating disease in poultry but when it accidentally infects humans it can cause death. Therefore, decrease the incidence of H5N1 in humans needs to focus on prevention and control of poultry infections. Conventional control strategies in poultry based on surveillance, stamping out, movement restriction and enforcement of biosecurity measures did not prevent the virus spreading, particularly in developing countries. Several challenges limit efficiency of the vaccines to prevent outbreaks of HPAIV H5N1 in endemic countries. Alternative and complementary approaches to reduce the current burden of H5N1 epidemics in poultry should be encouraged. The use of antiviral chemotherapy and natural compounds, avian-cytokines, RNA interference, genetic breeding and/or development of transgenic poultry warrant further evaluation as integrated intervention strategies for control of HPAIV H5N1 in poultry.
We investigated the possible involvement of oxidative mechanisms in the pathogenesis of influenza A/PR8/34 virus infection in mice. As a biochemical marker of oxidative stress, we determined the endogenous concentrations of the antioxidants glutathione and vitamins C and E in their reduced and oxidized forms in the lungs, liver and blood plasma of control and infected animals. Following intranasal infection with 8 to 10 LD50, influenza virus was detected in the lungs, but not in the plasma, liver or other organs. Infection resulted in a decrease in the total concentration of glutathione and vitamins C and E, whereas no relevant change in the ratio of oxidized to total concentration of antioxidants was observed. Changes in the concentration of hepatic antioxidants were significant in the early stages of the infection. The results suggest that hepatic alterations may be caused indirectly by mechanisms related to the host response to virus infection. The observed general decrease in the antioxidant buffering capacity may reduce the ability of tissues to protect against potential oxidative stress. Such stress can occur during bacterial superinfections, which are common in influenza, thereby rendering the host more susceptible to the pathogenic effects of such agents. In addition, reactive oxygen species produced in the lung may inactivate protease inhibitors, resulting in increased protease activity. Using an in vitro system consisting of alpha 1-antiprotease, trypsin and HOCl as the oxidant, we have shown that the infectivity of influenza viruses can be increased up to 10,000-fold by proteolytic cleavage of haemagglutinin, leading to activation of the fusogenic properties of this protein.
Genetic and biologic observations suggest that pigs may serve as "mixing vessels" for the generation of human-avian influenza A virus reassortants, similar to those responsible for the 1957 and 1968 pandemics. Here we demonstrate a structural basis for this hypothesis. Cell surface receptors for both human and avian influenza viruses were identified in the pig trachea, providing a milieu conducive to viral replication and genetic reassortment. Surprisingly, with continued replication, some avian-like swine viruses acquired the ability to recognize human virus receptors, raising the possibility of their direct transmission to human populations. These findings help to explain the emergence of pandemic influenza viruses and support the need for continued surveillance of swine for viruses carrying avian virus genes.
We have extensively studied the effects of N-acetylcysteine (NAC), a cytoprotective drug that can prevent in vivo carcinogenesis. Here we review our findings NAC completely inhibits gelatinolytic activity of metalloproteases and chemotactic and invasive activities of tumor cells. In addition, NAC reduces the number of lung metastases when malignant murine melanoma cells are injected into nude mice. NAC treatment decreases the weight of primary tumors and produces a dose-related increase in tumor latency. Moreover, oral administration of NAC reduces the formation of spontaneous metastases. In experimental metastasis assays, we have found a synergistic reduction in the number of lung metastases after treatment with doxorubicin (DOX) and NAC in nude mice. In tumorigenicity and spontaneous metastasis assays, the combined administration of DOX and oral NAC again has shown synergistic effects on the frequency and weight of primary tumors and local recurrences and completely prevented the formation of lung metastases. The addition of NAC to endothelial cells strongly reduces their invasive activity in response to angiogenic stimuli. NAC inhibited the degradation and release of radiolabeled type IV collagen by activated endothelial cells, indicating that NAC blocks gelatinase activity. Oral administration of NAC reduces the angiogenic response induced by KS tumor cell products, confirming the ability of NAC to inhibit the invasive activity of endothelial cells in vivo and thereby blocking angiogenesis.
Selenium (Se) deficiency has previously been shown to induce myocarditis in mice infected with a benign strain of coxsackievirus. To determine if Se deficiency would also intensify an infection with influenza virus, Se-deficient and Se-adequate mice were infected with a mild strain of influenza, influenza A/Bangkok/1/79 (H3N2). Infected Se-deficient mice developed much more severe interstitial pneumonitis than did Se-adequate mice. This increase in pathology was associated with significant alterations in mRNA levels for cytokines and chemokines involved in pro-inflammatory responses. These results demonstrate that adequate nutrition is required for protection against viral infection and suggest that nutritional deprivation may be one of many factors that increase the susceptibility of individuals to influenza infection.
Reactive oxygen intermediates (ROI) and cytokines, particularly tumor necrosis factor (TNF) have been implicated in the pathogenesis of influenza. Using a murine model of influenza, we have studied the levels of TNF, interleukin 6 (IL-6) and of superoxide-generating xanthine oxidase (XO). Mice infected intranasally with influenza virus APR/8 had high levels of XO, TNF and IL-6 in the broncoalveolar lavage, as early as 3 d after infection. XO was elevated also in serum and lung tissue. Administration of the antioxidant N-acetylcysteine (NAC,1 g/kg per day, orally) significantly decreased the mortality in infected mice, indicating a role for RO1 in the lethality associated with influenza infection.
To study whether influenza virus receptors in chickens differ from those in other species, we compared the binding of lectins and influenza viruses with known receptor specificity to cell membranes and gangliosides from epithelial tissues of ducks, chickens, and African green monkeys. We found that chicken cells contained Neu5Ac alpha(2-6)Gal-terminated receptors recognized by Sambucus nigra lectin and by human viruses. This finding explains how some recent H9N2 viruses replicate in chickens despite their human virus-like receptor specificity. Duck virus bound to gangliosides with short sugar chains that were abundant in duck intestine. Human and chicken viruses did not bind to these gangliosides and bound more strongly than duck virus to gangliosides with long sugar chains that were found in chicken intestinal and monkey lung tissues. Chicken and duck viruses also differed by their ability to recognize the structure of the third sugar moiety in Sia2-3Gal-terminated receptors. Chicken viruses preferentially bound to Neu5Ac alpha(2-3)Gal beta(1-4)GlcNAc-containing synthetic sialylglycopolymer, whereas duck viruses displayed a higher affinity for Neu5Ac alpha(2-3)Gal beta(1-3)GalNAc-containing polymer. Our data indicate that sialyloligosaccharide receptors in different avian species are not identical and provide a potential explanation for the differences between the hemagglutinin and neuraminidase proteins of duck and chicken viruses.
Oxidative stress is implicated in the pathogenesis of pulmonary damage during viral infections. In a previous study we observed a significant improvement of survival of influenza-infected mice with NAC, 1g/kg divided in two daily administrations, for 8 days including a pretreatment on day 1 before infection. In order to test NAC in a more realistic model, we studied the effect of combined treatment with NAC and the antiviral drug, ribavirin. Since in the present work we wanted to test a possible synergistic effect by combination of NAC and ribavirin, we used a different NAC's treatment regimen (1 g/kg, once a day for 4 days) that, alone, did not significantly protect mice from death. Mice (12 per group) infected intranasally with a lethal dose of influenza A virus APR/8. NAC was given as a single daily dose of 1000 mg/kg starting from 4 h after infection and until day 4 after infection, in association with ribavirin (100 mg/kg, i.p.). End-point evaluation was 14-day survival. With this schedule survival in infected mice was 17%, it was not significantly changed by NAC (25%). Survival increased to 58% with ribavirin and to 92% (n=12) with a combined treatment with ribavirin and NAC. This suggest that antioxidant therapy can increase survival by either improving the defenses against virus or by protecting from the pathogenesis of lung inflammation.
Polyphenolic compound catechins ((-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin (EGC)) from green tea were evaluated for their ability to inhibit influenza virus replication in cell culture and for potentially direct virucidal effect. Among the test compounds, the EGCG and ECG were found to be potent inhibitors of influenza virus replication in MDCK cell culture and this effect was observed in all influenza virus subtypes tested, including A/H1N1, A/H3N2 and B virus. The 50% effective inhibition concentration (EC50) of EGCG, ECG, and EGC for influenza A virus were 22-28, 22-40 and 309-318 microM, respectively. EGCG and ECG exhibited hemagglutination inhibition activity, EGCG being more effective. However, the sensitivity in hemagglutination inhibition was widely different among three different subtypes of influenza viruses tested. Quantitative RT-PCR analysis revealed that, at high concentration, EGCG and ECG also suppressed viral RNA synthesis in MDCK cells whereas EGC failed to show similar effect. Similarly, EGCG and ECG inhibited the neuraminidase activity more effectively than the EGC. The results show that the 3-galloyl group of catechin skeleton plays an important role on the observed antiviral activity, whereas the 5'-OH at the trihydroxy benzyl moiety at 2-position plays a minor role. The results, along with the HA type-specific effect, suggest that the antiviral effect of catechins on influenza virus is mediated not only by specific interaction with HA, but altering the physical properties of viral membrane.
An updated literature survey identified 1,407 recognized species of human pathogen, 58% of which are zoonotic. Of the total, 177 are regarded as emerging or reemerging. Zoonotic pathogens are twice as likely to be in this category as are nonzoonotic pathogens. Emerging and reemerging pathogens are not strongly associated with particular types of nonhuman hosts, but they are most likely to have the broadest host ranges. Emerging and reemerging zoonoses are associated with a wide range of drivers, but changes in land use and agriculture and demographic and societal changes are most commonly cited. However, although zoonotic pathogens do represent the most likely source of emerging and reemerging infectious disease, only a small minority have proved capable of causing major epidemics in the human population.
Six strains of influenza AH5N1 virus were isolated, by using PS and MDCK continuous cell lines from poultry and wild birds, which were collected on July 28, 2005 in the samples taken from 5 examines species of wild birds in the Novosibirsk region during the epizootic outbreak with a high mortality. The strains were identified by means of HIT, RT-PCR, and microchip-based techniques. Two strains, A/Grebe/Novosibirsk/29/05 (H5N1) and A/Duck/Novosibirsk/56/05 (H5N1), were deposited to the Russian State Collection of Viruses (Registration Nos. 2372 and 2371, respectively) with the priority date 08.08.2005. Positive results in RT-PCR for influenza A/H5N1 virus detec- tion were obtained in 100% of the samples from dead and sick poultry; 93% from the clinically healthy poultry kept together with sick one; positive results ranged from 0 to 36%. Sequencing established the identity of genetic characteristics of strains isolated for wild birds and poultry as well as their affiliation to high pathogenic avian influenza (HPAI). Phylogenetic analysis revealed a high homology of hemagglutining of West-Siberian strains and strains isoolated from bar-headed gooses (Eulabeia indica) on the Qinghai Lake (Western China) in the 2005 spring.
Commercial drugs, such as rimantadine, amantadine, rivabirine, and arbidole, are effective in suppressing the in vitro reproduction of highly pathogenic avian influenza A/H5N1 viruses. The study has used a porcine embryonic renal cell line and the highly pathogenic A/Duck/Novosibirsk/56/05 (H5N1) strain from a sick domestic duck (Anas platyrhynchos domesticus) (Chany Lake environs, Novosibirsk Region).
The full-size genomes of 2 highly pathogenetic avian influenza (HPAI) virus strains isolated from a wild great-crested grebe (A/Grebe/Novosibirsk/29/05) and a domestic duck (A/Duck/Novosibirsk/56/05) in the tract of the Chany hollow, Barabino forest-steppe (Novosibirsk Region) during the epizootic outbreak in the summer of 2005. The reproductive properties of these strains successively increase in the series of cell lines BHK-2 --> LEH --> Vero-E6 --> MDCK --> PS. A/Grebe/Novosibirsk/29/05 and A/Duck/Novosibirsk/56/05 were shown to be genetically close in all genomic segments to both each other and a group of HPAI/H5N1 A/Qinghai 05 strains isolated from wild birds on the Kukunor Lake in the northwestern province of Tsinkhai, China, in May 2005. All the above strains have the HPAI/H5-specific amino acid sequence of a proteolytic cleavage site (PQGERRRKKRGLF) with Lys-627 in the protein PB2 (which is associated with increased virulence to mammalian cells), Glu-92 in the protein NS1 (that suppresses an antiviral response in the host), Ser-31 in M2 (that is a marker of rimantadine/amantadine sensitivity), 20-member amino acid deletion in the protein NA (positions 49-68) that is a marker of affiliation to the so-called genotype Z and of increased tropism to poultry.
Molecular virological studies of the field material collected in the epicenter of epizooty with high mortality among mute swans (Cygnus olor) in the area of the lower estuary of the Volga River (November 2005) could establish the etiological role of highly pathogenic influenza A (HPAI) virus of the subtype H5N1. Ten HPAI/H5N1 strains deposited at the State Collection of Viruses of the Russian Federation with the priority dated December 1, 2005 were isolated from the cloacal/tracheal swabs and viscera of sick and freshly died mute swans. Complete nucleotide sequences of all fragments of the genome of 6 strains have been deposited in the Gene Bank. The paper discusses the molecular genetic characteristics of isolated strains.
The authors investigated the effect of a nutrient mixture (NM) on lung metastasis by B16F0 melanoma cells in C57BL/6 female mice. Mice were divided into equal groups (1 to 6) and injected via tail vein with B16F0 cells (groups 1 to 4), B16FO cells pretreated with NM (group 5), or saline (group 6). Groups 1, 3, 4, 5, and 6 were fed the control diet and group 2 the 0.5% NM supplemented diet. Groups 3 and 4 received NM intraperitoneally (IP) and intravenously (IV), respectively. Two weeks later, pulmonary metastatic colonies were counted. Pulmonary colonization was reduced by 63% in mice supplemented with NM diet, by 86% in mice receiving NM by IP and IV injections, and completely inhibited in mice injected with melanoma cells pretreated with NM. These results show that NM is effective in inhibiting the metastasis of B16FO melanoma cells.
Virological and molecular genetic studies of the field material collected in the epicenter of epizooty with high mortality rates among the wild birds on the coast of the Ubsu-Nur lake (Republic of Tyva, 51 degrees NL, 93 degrees EL, June 2006) revealed the etiological role of highly pathogenic avian influenza (HPAI) H5N1. Seven HPAI/H5N1 strains were isolated from the tracheal/cloacal swabs of clinically healthy, ill and recently dead great-crested grebes (Podiceps cristatus), cormorants (Phalacrocorax carbo), balt-coots (Fulica atra), and common terns (Sterna hirundo) collected on June 24, 2006, and incorporated to the RF State Collection of Viruses (with the July 3, 2006 priority). Full-length genome nucleotide sequences were incorporated to the GenBank (with the July 23, 2006 priority) (DQ852600-DQ852607). Comparative analysis of molecular genetic characteristics showed their belonging to the Qinghai-Siberian genotype. The strains were sensitive to rimantadine.
The reproduction of highly pathogenic avian influenza (HPAI) A/tern/SA/61 H5N3 and A/ducklNovosibirsk/56/05 H5NI viruses was comparatively studied in 16 human and animal cell lines. The strain A/duck/Novosibirsk/56/05 was shown to have a wider range of hosts. The most sensitive transplanted cell lines were found to be feline fibroblasts (CC-81), primarily trypsin-treated cells of chick embryonic fibroblasts (CEF), the kidney of dogs (MDCK), pigs (SPEV), monkeys (Vero), the human conjunctiva (1-5C-4), and, to a lesser extent, the feline kidney (CRFK). Unlike the strain A/tern/South Africa/61, that A/duck/Novosibirsk/56105 replicated in the polecat brain cells (Mpf).
The proteolytic degradation of the extracellular matrix by the protease plasmin is a universal mechanism determining human health and disease. Under physiological conditions plasmin- induced proteolysis is involved in cell migration as well as organ remodeling. Under pathological conditions this mechanism is exacerbated leading to a sustained degradation of the extracellular matrix. Plasmin-induced proteolysis is an important pathomechanism, not only for the proliferation of cancer and viral processes but also for cardiovascular disease and most other diseases. The exacerbation of this mechanism is characterized by a chronic imbalance between activators and inhibitors of this proteolytic pathway. Optimum availability of endogenous and exogenous inhibitors of plasmin-induced proteolysis is an important physiologic and therapeutic aim. We recently proposed that apoprotein(a), apo(a), functions as an endogenous inhibitor of plasmin-induced proteolysis. We now propose that this function of apo(a) is also an important determinant for the evolutionary advantage of this molecule. This function of apo(a) can explain the unique structure of the apo(a) molecule and the selective advantage of the plasminogen kringle IV as compared to the other plasminogen kringles. We also proposed that the effectiveness of apo(a) as an inhibitor of plasmin-induced proteolysis depends on an optimum number of kringle repeats. This could explain not only the inverse relation of kringle repeats to the synthesis rate of apo(a) molecules but also the remarkably high genetic variation of individual plasma levels of lipoprotein (a), Lp(a). Exogenous inhibitors of plasmin-induced proteolysis include the essential amino acid L- lysine and synthetic lysine analogs such as tranexamic acid. Di-
Influenza, one of the oldest and most common infections, poses a serious health problem causing significant morbidity and mortality, and imposing substantial economic costs. The efficacy of current drugs is limited and improved therapies are needed. A unique nutrient mixture (NM), containing ascorbic acid, green tea extract, lysine, proline, N-acetyl cysteine, selenium among other micronutrients, has been shown to exert anti-carcinogenic and anti-atherogenic activity both in vitro and in vivo. Many of the constituents of NM have been shown to have an inhibitory effect on replication of influenza virus and HIV. This prompted us to study the effect of NM on influenza A virus multiplication in infected cells and neuraminidase activity (NA) in virus particles. Addition of NM to Vero or MDCK cells post infection resulted in dose-dependent inhibition of viral nucleoprotein (NP) production in infected cells. NM-mediated inhibition of viral NP was selective and not due to cytotoxicity towards host cells. This antiviral effect was enhanced by pretreatment of virus with the nutrient mixture. Individual components of NM, namely ascorbic acid and green tea extract, also blocked viral NP production, conferring enhanced inhibition when tested in combination. Incubation of cell-free virus with NM resulted in dose-dependent inhibition of associated NA enzyme activity. In conclusion, the nutrient mixture exerts an antiviral effect against influenza A virus by lowering viral protein production in infected cells and diminishing viral enzymatic activity in cell-free particles.
We have studied the action of ascorbate (vitamin C) on human immunodeficiency virus type 1 (HIV-1), the etiological agent clinically associated with AIDS. We report the suppression of virus production and cell fusion in HIV-infected T-lymphocytic cell lines grown in the presence of nontoxic concentrations of ascorbate. In chronically infected cells expressing HIV at peak levels, ascorbate reduced the levels of extracellular reverse transcriptase (RT) activity (by greater than 99%) and of p24 antigen (by 90%) in the culture supernatant. Under similar conditions, no detectable inhibitory effects on cell viability, host metabolic activity, and protein synthesis were observed. In freshly infected CD4+ cells, ascorbate inhibited the formation of giant-cell syncytia (by approximately 93%). Exposure of cell-free virus to ascorbate at 37 degrees C for 1 day had no effect on its RT activity or syncytium-forming ability. Prolonged exposure of virus (37 degrees C for 4 days) in the presence of ascorbate (100-150 micrograms/ml) resulted in the drop by a factor of 3-14 in RT activity as compared to a reduction by a factor of 25-172 in extracellular RT released from chronically infected cells. These results indicate that ascorbate mediates an anti-HIV effect by diminishing viral protein production in infected cells and RT stability in extracellular virions.
Among the molecular maneuvers that enable the influenza virus to survive are antigenic variation and functional alterations. Two kinds of minor antigenic variations, producing new strains within type A virus subtypes, have been discovered: antigenic drift, in which the amino acid sequences of the antigens are changed; and antigenic camouflage, in which the antigens are glycosylated. Both kinds of variation are caused by mutations in the viral genome. These mutations produce slightly changed antigens, which many existing antibodies cannot recognize. Major antigenic variations (so-called antigenic shift) are produced by gene reassortment. Two subtypes, coinfecting a host, can reassort their eight ribonucleoprotein gene segments into as many as 256 different combinations. Such recombinations can produce new viruses with the potential for transmission in humans, but whose surface antigens are completely unmatched by antibodies in the population, permitting a pandemic to occur. Functional changes, caused by mutations, alter the interactions between the virus and the host, including virus binding to host receptor sites and fusion of viral and host membranes. All these mechanisms allow the influenza virus to survive in humans, probably perpetually.
Four hundred fifty volunteers participated in a placebo-controlled, double-blind, randomized trial of the prophylactic effects of rimantadine and amantadine during an outbreak of influenza A. The subjects received drugs orally at a dose of 100 mg twice a day for six weeks. Influenza-like illness occurred in 41 per cent of the subjects receiving placebo but in only 14 per cent of those receiving rimantadine and 9 per cent of these receiving amantadine (P less than 0.001 for either drug vs. placebo). Laboratory-documented influenza occurred in 21 per cent of placebo recipients, 3 per cent of rimantadine recipients, and 2 per cent of amantadine recipients (P less than 0.001). These findings represent efficacy rates of 85 per cent for rimantadine and 91 per cent for amantadine, as compared with placebo. More recipients of amantadine (13 per cent) than recipients of rimantadine (6 per cent; P less than 0.05) or placebo (4 per cent; P less than 0.01) withdrew from the study because of central-nervous-system side effects. On the basis of this study, rimantadine appears to be the drug of choice for the prophylaxis of influenza A.
(-)Epigallocatechin gallate (EGCg) and theaflavin digallate (TF3) (1-10 microM) inhibited the infectivity of both influenza A virus and influenza B virus in Madin-Darby canine kidney (MDCK) cells in vitro. Study by electron microscope revealed that EGCg and TF3 (1 mM) agglutinated influenza viruses as well as did antibody, and that they prevented the viruses from adsorbing to MDCK cells. EGCg and TF3 more weakly inhibited adsorption of the viruses to MDCK cells. EGCg and TF3 (1-16 microM) also inhibited haemagglutination by influenza viruses. These findings suggest that tea polyphenols bind to the haemagglutinin of influenza virus, inhibit its adsorption to MDCK cells, and thus block its infectivity.
We investigated the effect of influenza A/Beijing/353/89 (H3N2) virus infection on the expression of type IV collagenase in two different types of epithelial cell. Depending on the cell line infected, the viral infection caused changes in the expression of type IV collagenase. The expression of matrix metalloproteinase-9 (MMP-9; 92 kDa) but not of matrix metalloproteinase-2 (MMP-2; 72 kDa) was stimulated in Vero cells. In MDCK cells, the MMP-2 production increased with the virus infection. According to the enzymatic activity revealed with zymography, the MMP-9 promoter activity rose by a factor of over 1788 in influenza A virus-infected Vero cells but not in MDCK cells. The tissue inhibitor of metalloproteinase, TIMP-1, had increased slightly (2.3-fold) in Vero cells 48 hours after the infection, but in MDCK cells, influenza A virus had no effect on the TIMP-1 expression. In conclusion, the MMP-9 and -2 expression by influenza A virus infection are modulated at transcriptional level, depending on the epithelial cell line.
Safe and effective antiviral agents are needed to prevent infection with influenza A and B virus. Oseltamivir (GS4104), which can be administered orally, is the prodrug of GS4071, a potent and selective inhibitor of influenzavirus neuraminidases. We studied the use of oseltamivir for long-term prophylaxis against influenza in two placebo-controlled, double-blind trials at different U.S. sites during the winter of 1997-1998.
We randomly assigned 1559 healthy, nonimmunized adults 18 to 65 years old to receive either oral oseltamivir (75 mg given once or twice daily, for a total daily dose of 75 or 150 mg) or placebo for six weeks during a peak period of local influenzavirus activity. The primary end point with respect to efficacy was laboratory-confirmed influenza-like illness (defined as a temperature of at least 37.2 degrees C accompanied by at least one respiratory and at least one systemic symptom).
In the two studies combined, the risk of influenza among subjects assigned to either once-daily or twice-daily oseltamivir (1.2 percent and 1.3 percent, respectively) was lower than that among subjects assigned to placebo (4.8 percent; P<0.001 and P=0.001 for the comparison with once-daily and twice-daily oseltamivir, respectively). The protective efficacy of oseltamivir in the two active-treatment groups combined was 74 percent (95 percent confidence interval, 53 to 88 percent) at all the sites combined and 82 percent (95 percent confidence interval, 60 to 93 percent) at sites in Virginia, where the rate of influenza infection was higher than the overall rate. For culture-proved influenza, the rate of protective efficacy in the two oseltamivir groups combined was 87 percent (95 percent confidence interval, 65 to 96 percent). The rate of laboratory-confirmed influenza infection was lower with oseltamivir than with placebo (5.3 percent vs. 10.6 percent, P<0.001). Oseltamivir was well tolerated but was associated with a greater frequency of nausea (12.1 percent and 14.6 percent in the once-daily and twice-daily groups, respectively) and vomiting (2.5 percent and 2.7 percent, respectively) than was placebo (nausea, 7.1 percent; vomiting, 0.8 percent). However, the frequency of premature discontinuation of drug or placebo was similar among the three groups (3.1 to 4.0 percent).
Oseltamivir administered daily for six weeks by the oral route is safe and effective for the prevention of influenza.
Selenium, an essential biological trace element, has been shown to reduce and prevent the incidence of cancer. Our previous
studies have shown that selenite is involved in the chemoprevention of cancer and induction of apoptosis of cancer cells.
In this study, we demonstrate that selenite also inhibits the invasion of tumor cells. Cancer cell invasion requires coordinated
processes, such as changes in cell-cell and cell-matrix adhesion, degradation of the extracellular matrix, and cell migration.
We found that selenite inhibited invasion of HT1080 human fibrosarcoma cells. Adhesion of HT1080 cells to the collagen matrix
was also inhibited by treatment with selenite, but cell-cell interaction and cell motility were not affected by selenite.
Moreover, selenite reduced expression of matrix metalloproteinase-2 and -9 and urokinase-type plasminogen activator, which
are involved in matrix degradation, but increased a tissue inhibitor of metalloproteinase-1. This inhibitory effect of selenite
on the protease expressions was mediated by the suppression of transcription factors, NF-κB and AP-1. However, selenate showed
no remarkable effect on all the steps of cancer cell invasion.
MMPs play a crucial role in the process of cancer invasion and metastasis.
The influence of NAC on invasion and MMP-9 production of human bladder cancer cell line T24 was investigated using an in vitro invasion assay, gelatin zymography, Western and Northern blot analyses and RT-PCR assays.
TPA increased the number of invading T24 cells through reconstituted basement membrane more than 10-fold compared to basal condition. NAC inhibited TPA-enhanced invasion dose-dependently. TPA increased the MMP-9 production by T24 cells without altering expression of TIMP-1 gene, while NAC suppressed TPA-enhanced production of MMP-9. Neither TPA nor NAC altered TIMP-1 mRNA level in T24 cells. In vitro experiments demonstrated that MMP-9 was directly inhibited by NAC but was not influenced by TPA.
NAC limits invasion of T24 human bladder cancer cells by inhibiting the MMP-9 production in addition to a direct inhibition of MMP-9 activity.
Epigallocatechin-3-gallate (EGCG), one of the components of green tea, has been suggested to have antiviral activity. To determine the effects of EGCG on HIV infection, peripheral blood lymphocytes were incubated with either LAI/IIIB or Bal HIV strains and increasing concentrations of EGCG. EGCG strongly inhibited the replication of both virus strains as determined by reverse transcriptase and p24 assays on the cell supernatants.
It has been previously reported that green-tea extract (GTE) inhibits the growth of influenza virus by preventing its adsorption. In this study, we further investigated whether GTE exerts an additional inhibitory effect on the acidification of intracellular compartments such as endosomes and lysosomes (referred to as ELS) and thereby inhibits the growth of influenza A and B viruses in Madin-Darby canine kidney cells. The vital fluorescence microscopic study showed that GTE inhibited acidification of ELS in a concentration-dependent manner. Moreover, the growth of influenza A and B viruses was equally inhibited when the cells were treated with GTE within as early as 5 to 15 min after infection, depending on the virus strains. The fact that (-)epigallocatechin (EGC), one of major catechin molecules in GTE, exerts the inhibitory effects on the acidification of ELS and virus growth in a manner similar to that of GTE strongly suggests that EGC is one of the active components in the extract.
Outbreaks of highly pathogenic H5N1 avian influenza have occurred in Hong Kong in chickens and other gallinaceous poultry in 1997, 2001, twice in 2002 and 2003. High mortality rates were seen in gallinaceous birds but not in domestic or wild waterfowl or other wild birds until late 2002 when highly pathogenic H5N1 avian influenza occurred in waterfowl (geese, ducks and swans), captive Greater Flamingo (Phoenicopterus ruber) and other wild birds (Little Egret Egretta garzetta) at two waterfowl parks and from two dead wild Grey Heron (Ardea cinerea) and a Black-headed Gull (Larus ridibundus) in Hong Kong. H5N1 avian influenza virus was also isolated from a dead feral pigeon (Columba livia) and a dead tree sparrow (Passer montanus) during the second outbreak. The first waterfowl outbreak was controlled by immediate strict quarantine and depopulation 1 week before the second outbreak commenced. Control measures implemented for the second outbreak included strict isolation, culling, increased sanitation and vaccination. Outbreaks in gallinaceous birds occurred in some live poultry markets concurrently with the second waterfowl outbreak, and infection on a chicken farm was detected 1 week after the second waterfowl park outbreak was detected, on the same day the second grey heron case was detected. Subsequent virus surveillance showed the outbreaks had been contained.
Degradation of extracellular matrix (ECM) is a hallmark of tumor invasion, metastasis and angiogenesis. Based on the Rath multitargeted approach to cancer using natural substances to control ECM stability and enhancing its strength, we developed a novel formulation (NM) of lysine, proline, ascorbic acid and green tea extract that has shown significant anti-cancer activity against a number of cancer cell lines. The aim of the present study was to determine whether NM exhibits anti-angiogenic and anti-metastatic effects using in vitro and in vivo experimental models. Angiogenesis was measured using a chorioallantoic membrane (CAM) assay in chick embryos and bFGF-induced vessel growth in C57BL/6J female mice. To determine the in vivo effect of NM on the tumor xenograft growth, male nude mice were inoculated with 3 x 10(6) MNNG-HOS cells. Control mice were fed a mouse chow diet, while the test group was fed a mouse chow diet supplemented with 0.5% NM for 4 weeks. In vitro studies on cell proliferation (MTT assay), MMP expression (zymography) and Matrigel invasion were conducted on human osteosarcoma U2OS, maintained in McCoy medium, supplemented with 10% FBS, penicillin and streptomycin in 24-well tissue culture plates and tested with NM at 0, 10, 50, 100, 500, and 1000 microg/ml in triplicate at each dose. NM at 250 microg/ml caused a significant (p<0.05) reduction in bFGF-induced angiogenesis in CAM. NM inhibited tumor growth of osteosarcoma MNNG-HOS cell xenografts in nude mice by 53%; furthermore, tumors in NM-treated mice were less vascular and expressed lower levels of VEGF and MMP-9 immunohistochemically than tumors in the control group. In addition, NM exhibited a dose-dependent inhibition of osteosarcoma U2OS cell proliferation (up to 60% at 1000 microg/ml), MMP-2 and -9 expression (with virtual total inhibition at 500 microg/ml NM), and invasion through Matrigel (with total inhibition at 100 microg/ml NM). Moreover, NM decreased U2OS cell expression of VEGF, angiopoietin-2, bFGF, PDGF and TGFbeta-1. These results together with our earlier findings suggest that NM is a relatively non-toxic formulation, which inhibits growth, invasion, metastasis, and angiogenesis of tumor cells.
Michael P.Clark, Mark W.Ledeboer, IoanaDavies, Randal A.Byrn, Steven M.Jones, EmanuelePerola, AliceTsai, MarcJacobs, KwameNti-Addae, Upul K.Bandarage, Michael J.Boyd, Randy S.Bethiel, John J.Court, HongboDeng, John P.Duffy, Warren A.Dorsch, Luc J.Farmer, HuaiGao, WenxinGu, KatrinaJackson, Dylan H.Jacobs, Joseph M.Kennedy, BrianLedford, JianglinLiang, FrançoisMaltais, MarkMurcko, TianshengWang, M. WoodsWannamaker, Hamilton B.Bennett, Joshua R.Leeman, ColleenMcNeil, William P.Taylor, ChristineMemmott, MinJiang, ReneRijnbrand, ChristopherBral, UrsulaGermann, AzinNezami, YuegangZhang, Francesco G.Salituro, Youssef L.Bennani, Paul S.Charifson. (2014) Discovery of a Novel, First-in-Class, Orally Bioavailable Azaindole Inhibitor (VX-787) of Influenza PB2. Journal of Medicinal Chemistry 57, 6668-6678
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Use of antivirals is recommended for the control of seasonal and pandemic influenza. Our aim was to review the evidence of efficacy, effectiveness, and safety of registered antivirals against naturally occurring influenza in healthy adults.
We searched various Databases to October, 2005, and contacted manufacturers and corresponding authors. We included randomised controlled trials comparing prophylactic (n=27) or treatment (n=27) efficacy against symptomatic or asymptomatic influenza. We did a meta-analysis and expressed prophylactic efficacy as a proportion (1-relative risk [RR]). For treatment trials, because of inconsistent and non-standardised reporting, we expressed continuous outcomes either as means or as hazard ratios.
We included 51 reports of 52 randomised controlled trials. Amantadine prevented 61% (95% CI 35-76) of influenza A cases and 25% (13-36) of cases of influenza-like illness, but caused nausea (OR 2.56, 1.37-4.79), insomnia and hallucinations (2.54, 1.50-4.31), and withdrawals because of adverse events (2.54, 1.60-4.06). There was no effect on asymptomatic cases (RR 0.85, 0.40-1.80). In treatment, amantadine significantly shortened duration of fever compared with placebo (by 0.99 days, -1.26 to -0.71), but had no effect on nasal shedding of influenza A viruses (0.93, 0.71-1.21). The fewer data for rimantadine showed comparable effects. In prophylaxis, compared with placebo, neuraminidase inhibitors have no effect against influenza-like illness (1.28, 0.45-3.66 for oral oseltamivir 75 mg daily, 1.51, 0.77-2.95 for inhaled zanamivir 10 mg daily). Higher doses appear to make no difference. The efficacy of oral oseltamivir 75 mg daily against symptomatic influenza is 61% (15-82), or 73% (33-89) at 150 mg daily. Inhaled zanamivir 10 mg daily is 62% efficacious (15-83). Neither neuraminidase inhibitor appeared effective against asymptomatic influenza. Oseltamivir induces nausea (OR 1.79, 1.10-2.93), especially at higher prophylactic doses (2.29, 1.34-3.92). Oseltamivir in a post-exposure prophylaxis role has a protective efficacy of 58.5% (15.6-79.6) for households and from 68% (34.9-84.2) to 89% (67-97) in contacts of index cases. In influenza cases, compared with placebo the hazard ratios for time to alleviation of symptoms were 1.33, 1.29-1.37 for zanamivir; 1.30, 1.13-1.50 for oseltamivir provided medication was started within 48 h of symptom onset. Viral nasal titres were significantly diminished by both drugs (weighted mean difference -0.62, -0.82 to -0.41). Oseltamivir at 150 mg daily was effective in preventing lower respiratory tract complications in influenza cases (OR 0.32, 0.18-0.57). We could find no credible data on the effects of oseltamivir on avian influenza.
The use of amantadine and rimantadine should be discouraged. Because of their low effectiveness, neuraminidase inhibitors should not be used in seasonal influenza control and should only be used in a serious epidemic or pandemic alongside other public-health measures.
Certain drastic behavioral modifications by arterial wall smooth muscle cells (SMC) have been considered key steps in the formation of atherosclerotic lesions: massive migration of SMC from the media to the intima layer of the vessel, dedifferentiation of SMC to proliferating phenotype, and increased secretion of inflammatory cytokines as a response to inflammatory stimuli. We investigated the anti-atherogenic effects of naturally occurring compounds (ascorbic acid, green tea extract, lysine, proline, arginine, and N-acetyl cysteine) using the model of cultured aortic SMC. Cell growth was measured by DNA synthesis, cell invasiveness was measured through Matrigel, matrix metalloproteinase-2 (MMP-2) secretion was measured by zymography, and SMC secretion of monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) was measured by immunochemistry. Fetal bovine serum-stimulated SMC growth was inhibited by the nutrient mixture (NM) with 85% inhibition at 100 microg/mL. A corresponding concentration of epigallocatechin gallate (EGCG; 15 microM), the most active tea phenolic, produced a significant effect but one lower than NM. NM inhibited aortic SMC Matrigel invasion in a dose-dependent manner and significantly decreased MMP-2 expression. Stimulation of SMC with tumor necrosis factor-alpha significantly increased production and secretion of such mediators of inflammation as IL-6 and MCP-1; addition of 100 microg/mL NM inhibited secretion of MCP-1 and IL-6 by 65% and 47%, respectively. These data suggest that the NM of ascorbic acid, tea phenolics, and selected amino acids has potential in blocking the development of atherosclerotic lesions by inhibiting atherogenic responses of vascular SMC to pathologic stimuli and warrants in vivo studies.
Evaluation of the efficacy of Epican Forte against avian flu virus
- E K Barbour
- E G Rayya
- H Shaib
- R G Hakim
- A Niedzwiecki
- A M A Nour
- S Harakeh
E.K. Barbour, E.G. Rayya, H. Shaib, R.G. El Hakim, A. Niedzwiecki, A.M.A. Nour and S. Harakeh, Rath M. Evaluation of the efficacy of Epican Forte against avian flu virus, Intern J Appl Res Vet Med 5(1) (2007), 9–16.
Cu(II) inhibition of the proton translocation machinery of the influenza A virus by gentian violet (GV) and GV-dyed cotton cloth, and bacteriological activities of these agents
- C S Ghandi
- K Shuck
- J D Lear
- G R Dieckmann
- W F De
- R A Grado
- Lamb
C.S. Ghandi, K. Shuck, J.D. Lear, G.R. Dieckmann, W.F. De Grado and R.A. Lamb, Cu(II) inhibition of the proton translocation machinery of the influenza A virus by gentian violet (GV) and GV-dyed cotton cloth, and bacteriological activities of these agents, J Infect Chemother 12 (1999), 73–79.
Serum markers of the liver, heart, and kidney and lipid profile and histopathology in ODS rats treated with nutrient synergy
- M W Roomi
- V Ivanov
- S P Netke
- A Niedzwiecki
- M Rath
M.W. Roomi, V. Ivanov, S.P. Netke, A. Niedzwiecki and M. Rath, Serum markers of the liver, heart, and kidney and lipid profile and histopathology in ODS rats treated with nutrient synergy, J Am Coll Nutr 22(5) (2003), 477, Abstract #86.
Rath M. Evaluation of the efficacy of Epican Forte against avian flu virus
- Barbour E.K.
Serum markers of the liver, heart, and kidney and lipid profile and histopathology in ODS rats treated with nutrient synergy
- Roomi M.W.
Cu(II) inhibition of the proton translocation machinery of the influenza A virus by gentian violet (GV) and GV‐dyed cotton cloth, and bacteriological activities of these agents
- Ghandi C.S.