Article

Antiviral efficacy and mechanisms of action of oregano essential oil and its primary component carvacrol against murine norovirus

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Abstract

To investigate the antiviral efficacy of oregano oil and its primary active component, carvacrol, against the nonenveloped murine norovirus (MNV), a human norovirus surrogate. Along with an observed loss in cell culture infectivity, the antiviral mechanisms of action were determined in side-by-side experiments including a cell-binding assay, an RNase I protection assay and transmission electron microscopy (TEM). Both antimicrobials produced statistically significant reductions (P ≤ 0·05) in virus infectivity within 15 min of exposure (c. 1·0-log10 ). Despite this, the MNV infectivity remained stable with increasing time exposure to oregano oil (1·07-log10 after 24 h), while carvacrol was far more effective, producing up to 3·87-log10 reductions within 1 h. Based on the RNase I protection assay, both antimicrobials appeared to act directly upon the virus capsid and subsequently the RNA. Under TEM, the capsids enlarged from ≤35 nm in diameter to up to 75 nm following treatment with oregano oil and up to 800 nm with carvacrol; with greater expansion, capsid disintegration could be observed. Virus adsorption to host cells did not appear to be affected by either antimicrobial. Our results demonstrate that carvacrol is effective in inactivating MNV within 1 h of exposure by acting directly on the viral capsid and subsequently the RNA. This study provides novel findings on the antiviral properties of oregano oil and carvacrol against MNV and demonstrates the potential of carvacrol as a natural food and surface (fomite) sanitizer to control human norovirus.

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... NoV is highly resistant to chemicals such as alcohol and quaternary ammonium compounds (Donaldson et al. 2008). It is important to notice that nonenveloped viruses such as NoV are resistant to many antimicrobials under various environmental conditions (Gilling et al. 2014b). This contributes into viral spread of NoV during transmission. ...
... This compound is found in many spices like oregano, savory and thyme (Alinkina, Misharina, and Fatkullina 2013) and has been recognized as a natural and economic preservative (Lu and Wu 2010). It was observed by Gilling et al. (2014b) that carvacrol can also inhibit MNV by acting on the capsid first and subsequently on the viral RNA. S anchez, Aznar, and S anchez (2015) tested the efficiency of 0.25, 0.50 and 1% carvacrol against FCV, MNV and Hepatitis A in quantities of 6-7 log TCID 50 /mL during 2 hours at 37 C. Carvacrol at a concentration of 0.5% (w/w) completely inactivated the two NoVs surrogates (FCV and MNV) and carvacrol at a concentration of 1.0% completely inactivated HAV (Table 2). ...
... A complete elimination of FCV at a concentration of 6-7 log TCID 50 / mL was observed when carvacrol 0.5% (w/w) was added on inoculated lettuce. According to Gilling et al. (2014b), the efficiency of carvacrol against MNV-1 can be effective at concentrations < 0.5% (Table 2). After only 15 minutes of treatment with carvacrol at a concentration of 0.25% and 0.5%, a decrease of the viral titer by 1.03 and 1.28 log 10 was respectively observed. ...
Article
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Fresh foods like fruits, vegetables and shellfish are potential sources for viral infections such as human norovirus (NoV). Chemical treatment like chlorination is a well-known process for food pathogens and virus elimination. However, with the increase of the consumer demand for less toxic treatment, the use of natural antimicrobials like essential oils from spice or plants, fruit extracts, and cold pasteurization treatments (fermentation, irradiation, ozonation and high pressure) could be considered. The aim of this review is to discuss these technologies and their efficacy to eliminate NoV on the surface of fresh food.
... Murine norovirus type 1 MNV-1 infects mice and is virulent, especially in immunocompromised mice. MNV-1 is used as a surrogate to study the biological and physiological behavior of noroviruses [138][139][140]. In three different in vitro experiments, oregano oil, carvacrol [138], allspice oil, lemongrass oil-1, and citral [139] as well as Artemisia oil-2 (s. ...
... MNV-1 is used as a surrogate to study the biological and physiological behavior of noroviruses [138][139][140]. In three different in vitro experiments, oregano oil, carvacrol [138], allspice oil, lemongrass oil-1, and citral [139] as well as Artemisia oil-2 (s. Table 4S, Supporting Information) and α-thujone [140] were evaluated for their anti-MNV-1 effects in RAW 264.7 cells. ...
... RNase I protection assays and TEM analyses showed that carvacrol acted directly on the virion capsid and the RNA. Interestingly, after carvacrol treatment, the protein capsids enlarged from about 35 nm in diameter to 800 nm [138]. ...
Article
Essential oils and isolated essential oil compounds are known to exert various pharmacological effects, such as antibacterial, antifungal, antiviral, anti-inflammatory, anti-immunomodulatory, antioxidant, and wound healing effects. Based on selected articles, this review deals with the potential antiviral and virucidal activities of essential oils and essential oil compounds together with their mechanism of action as well as in silico studies involving viral and host cell-specific target molecules that are indispensable for virus cell adsorption, penetration, and replication. The reported in vitro and in vivo studies highlight the baseline data about the latest findings of essential oils and essential oil compounds antiviral and virucidal effects on enveloped and non-enveloped viruses, taking into account available biochemical and molecular biological tests. The results of many in vitro studies revealed that several essential oils and essential oil compounds from different medicinal and aromatic plants are potent antiviral and virucidal agents that inhibit viral progeny by blocking different steps of the viral infection/replication cycle of DNA and RNA viruses in various host cell lines. Studies in mice infected with viruses causing respiratory diseases showed that different essential oils and essential oil compounds were able to prolong the life of infected animals, reduce virus titers in brain and lung tissues, and significantly inhibit the synthesis of proinflammatory cytokines and chemokines. In addition, some in vitro studies on hydrophilic nano-delivery systems encapsulating essential oils/essential oil compounds exhibited a promising way to improve the chemical stability and enhance the water solubility, bioavailabilty, and antiviral efficacy of essential oils and essential oil compounds.
... The strong and rapid bacteriostatic and bactericidal activity of oregano essential oil (EO) against Gram-negative and Gram-positive bacteria and in particular E. coli (activity within 1 min) is now well-established both by direct addition into diffusion plates inoculated with bacteria culture [3,4] but also by addition to diffusion plates as re-emulsified spray dried powder [5]. Later studies have also demonstrated antiviral activity of EO against a range of human/animal viruses: Gilling et al. [6] and Sánchez et al. [7] demonstrated that EO inactivated murine norovirus (MNV) and other enteric viruses such as the picornaviruses, caliciviruses, astroviruses, and hepatitis by acting directly on the viral capsid; Pilau et al. [8] demonstrated the activity of EO against bovine viral diarrhea virus (BVDV); Choi et al. [9] showed activity against anti-enterovirus. Gaur et al. demonstrated the anti-parasitic action of EO against Cryptosporidium parvum, which is the second leading cause of persistent diarrhea among children in low-resource settings [10]. ...
... At the same time, the feed rate was reduced to increase drying efficiency. From the mass of powder collected at the receiving end, the vessel relative yield (%) was calculated from Equation (6). ...
... Weight of collected powder Weight of dispersed phase in feed emulsion (6) Additionally, oil retention (RT%) was determined as previously described [5] from the expression: % 100 . The particle size and shape of the spray-dried products were analyzed with optical microscopy as described above for emulsion droplet size. ...
Article
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Oregano essential oil (EO) enteric release powder was formulated by spray drying feed emulsions stabilized with polysaccharides (PSC) and Eudragit® L100 (PLM). Different modified starches were used in the PSC component. Spray-dried powders were evaluated for particle size and morphology, dynamic packing, flowability, chemical interactions, reconstitution, and gastric protection. Feed emulsions were stable, indicating the good emulsification ability of the PLM/PSC combination. The presence of polymer in the encapsulating wall neutralized electrostatic charges indicating physical attraction, and FTIR spectra showed peaks of both PLM and PSC without significant shifting. Furthermore, the presence of polymer influenced spray drying, resulting in the elimination of surface cavities and the improvement of powder packing and flowability, which was best when the surface-active, low-viscosity sodium octenyl succinate starch was used (angle of repose 42°). When a PLM/PSC ratio of 80/20 was used in the encapsulating wall, the spray-dried product showed negligible re-emulsification and less than 15% release in pH 1.2 medium for 2 h, confirming gastric protection, whereas at pH 6.8, it provided complete re-emulsification and release. In conclusion, (1) polymer–PSC physical interaction promoted the formation of a smoother particle surface and product with improved technological properties, which is important for further processing, and (2) the gastro protective function of Eudragit® L100 was not impaired due to the absence of significant chemical interactions.
... Essential oils (EOs) (esp. herb-based essential oils), which are enriched in plant-derived volatile aromatic compounds, have potential as natural agents for food preservation because of their antibacterial, antifungal, and antioxidative activities and have long been applied as flavoring agents in food (Gilling et al. 2014). EOs play an important role in food processing due to the abovementioned myriad of characteristics. ...
... For example, carvacrol and thymol methyl ether from Zataria multiflora Boiss were suggested to inhibit norovirus via an inactivation mechanism. Meanwhile, carvacrol from oregano oil could bind to the virus and inhibit virus adsorption to host cells (Gilling et al. 2014). Meanwhile, lemongrass essential oil has been suggested to inhibit norovirus by reducing the virus's replication (Kim et al. 2017). ...
... For instance, cranberry juice and proanthocyanidins, which contain polyphenols were found to damage the capsid of feline calicivirus (Su et al. 2010). In addition, a visible capsid disintegration of murine norovirus was found in the essential oil-treated samples (Gilling et al. 2014). ...
Article
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Food-borne viruses and contaminants, as an important global food safety problem, are caused by chemical, microbiological, zoonotic, and other risk factors that represent a health hazard. Natural bioactive substances, originating from plants, animals, or microorganisms, might offer the possibility of preventing and controlling food-borne diseases. In this contribution, the common bioactive substances such as polyphenols, essential oils, proteins, and polysaccharides which are effective in the prevention and treatment of food-borne viruses and contaminants are discussed. Meanwhile, the preventive effects of natural bioactive substances and the possible mechanisms involved in food protection are discussed and detailed. The application and potential effects of natural bioactive substances in the adjuvant treatment for food-borne diseases is also described. Graphical abstract
... isatidis granula have been proposed for use against COVID-19 in the PRC (Zhang et al. 2020a)-the latter two herbal drugs had also been used during the SARS outbreak in 2003 with effective results as anti-viral, and antiinflammatory compounds, as well as being an immune regulator (Cui et al., 2020;Huang et al., 2020aHuang et al., , 2020b. Table 2 summarizes all the potential herbal oils that may serve as a treatment for COVID-19 (Becker, 2020;Burja et al., 2019;Carson et al., 2006;Chambial et al., 2013;Cherayil, 2011;Gilling et al., 2014;Hemilä and Chalker, 2020;Marshall, 2018;Roller et al., 2009;United States Food and Drug Administration, 2020;Wińska et al., 2019). ...
... Eucalyptus oil has been shown in laboratory studies to inhibit certain viruses, including HSV-1, influenza A (H1N1), and the mumps virus (Gilling et al., 2014). Inhaling eucalyptus oil vapors is a common home remedy for colds and sinus infections. ...
... Lavender oil has been shown in laboratory studies to inhibit bacteria known to cause respiratory infections, and the virus HSV-1. However, there are no clinical studies showing lavender oil to prevent or treat respiratory infections (Carson et al., 2006;Gilling et al., 2014). Oregano oil has been shown in laboratory studies to have antibacterial and antiviral effects (Becker, 2020). ...
Article
Background In late December 2019, the outbreak of COVID-19 caused by the coronavirus severe acute respiratory syndrome-CoV-2, originated in Wuhan Province, the People’s Republic of China (PRC). The rapid and highly infectious virus quickly spread around the country and has become a global pandemic. Thousands of people have been infected, and have died. Scientists around the world are working on the vaccine; however, an effective cure is yet to be developed. Aims Search to be made on some alternative antiviral components from the rich sources of traditional herbal medicine in India as well as in the PRC. Here we discuss them with references. Methods The knowledge gained from the literature search of antiviral known herbal products or Ayurvedic medicines that used to be applied against any viral or bacterial infections in the past, may be considered for deployment against COVID-19, and may be rewarded. Results Many medicinal compounds are extracted from plants and have led to drug discovery. Similarly, plant products and their analogues have been employed as an early line of defense against COVID-19. Conclusion Research into ethnobotany, phytochemistry, plant physiology and ecology may be important in protecting the global population from current and future pandemics.
... The mechanism of action and anti-viral activities of carvacrol derived from oregano oil has been explored against murine norovirus (MNV), a non-enveloped virus. Carvacrol was found to help deactivate MNV, a human NoV surrogate, within 1 h of exposure, directly affecting the viral capsid and thereafter RNA (Gilling et al., 2014). Carvacrol inhibits MNV binding to host cells via hiding the capsid, however, there was no altered structural morphology of the virus reported (Gilling et al., 2014). ...
... Carvacrol was found to help deactivate MNV, a human NoV surrogate, within 1 h of exposure, directly affecting the viral capsid and thereafter RNA (Gilling et al., 2014). Carvacrol inhibits MNV binding to host cells via hiding the capsid, however, there was no altered structural morphology of the virus reported (Gilling et al., 2014). ...
Article
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The recent outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) started in December 2019, resulting in the coronavirus disease-19 (COVID-19) pandemic. Coronaviruses are solely accountable for rising mortality and socioeconomic saddles. Presently, there are few repurposed drugs such as remdesivir or favipiravir approved for the treatment of COVID-19, although vaccines and plasma therapy is also subject to emergency approval. However, some potential natural treatments and cures have also been proposed. Molecules of natural origin showed therapeutic importance such as antiviral, anti-inflammatory, and antioxidant activity, and could be useful drug candidates for treating COVID-19. In recent years, essential oils have shown promising therapeutic effects against many viral diseases. Carvacrol is one of the monoterpene phenol with abundant presence in essential oils of many aromatic plants, including thyme and oregano. It is being used as food flavoring, additive, and preservatives. Carvacrol is also used as a fragrance in cosmetic products. A number of research studies have shown biological actions of carvacrol with its therapeutic potential is of clinical significance. The in vitro and in vivo studies have shown multiple pharmacological properties such as anticancer, anti-fungal, anti-bacterial, anti-oxidant, anti-inflammatory, vasorelaxant, hepatoprotective, and spasmolytic. This review highlights the various biological and pharmacological properties of carvacrol within the scope of COVID-19.
... Carvacrol (2-Methyl-5-(propan-2-yl)phenol) is a monoterpenoid phenol, possesses a wide range of strong antimicrobial and antiviral activity (Gilling et al., 2014;Kamalabadi et al., 2018;Marinelli et al., 2019). It is a major constituent of essential oil of plants of Labiatate family including oregano and thyme, and has been emerged as active molecule for therapeutic purpose (Hyldgaard et al., 2012). ...
... confirms the present study results. From a biological point of view, reported phytochemicals, carvacrol, oleanolic acid and ursolic acid which are proposed as potential inhibitors of the M pro having a significant antiviral activity with evident to bibliographical research and performed invitro studies (Gilling et al., 2014;Jesus et al., 2015;Kamalabadi et al., 2018;Khwaza et al., 2018;Marinelli et al., 2019;Tohm e et al., 2019). ...
Article
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Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel corona virus that causes corona virus disease 2019 (COVID-19). The COVID-19 rapidly spread across the nations with high mortality rate even as very little is known to contain the virus at present. In the current study, we report novel natural metabolites namely, ursolic acid, carvacrol and oleanolic acid as the potential inhibitors against main protease (Mpro) of COVID-19 by using integrated molecular modeling approaches. From a combination of molecular docking and molecular dynamic (MD) simulations, we found three ligands bound to protease during 50 ns of MD simulations. Furthermore, the molecular mechanic/generalized/Born/Poisson-Boltzmann surface area (MM/G/P/BSA) free energy calculations showed that these chemical molecules have stable and favourable energies causing strong binding with binding site of Mpro protein. All these three molecules, namely, ursolic acid, carvacrol and oleanolic acid, have passed the ADME (Absorption, Distribution, Metabolism, and Excretion) property as well as Lipinski’s rule of five. The study provides a basic foundation and suggests that the three phytochemicals, viz. ursolic acid, carvacrol and oleanolic acid could serve as potential inhibitors in regulating the Mpro protein's function and controlling viral replication.
... Both molecules enrich various therapeutic properties such as antibacterial, antiviral, anticancer, antioxidant and tantimycotic activity (Jesus et al., 2015). Previous in vitro studies reported that these molecules exhibit antiviral activity against rotavirus, HIV, the in uenza virus, hepatitis B and C viruses (Tohmé et Carvacrol (2-Methyl-5-(propan-2-yl)phenol) is a monoterpenoid phenol, possesses a wide range of strong antimicrobial and antiviral activity (Gilling et al., 2014;Kamalabadi et al., 2018;Marinelli et al., 2019). It is a major constituent of essential oil of plants of Labiatate family including oregano and thyme, and has been emerged as active molecule for therapeutic purpose (Hyldgaard et al., 2012). ...
... con rms the present study results. From a biological point of view, reported phytochemicals, carvacrol, oleanolic acid and ursolic acid which are proposed as potential inhibitors of the M pro having a signi cant antiviral activity with evident to bibliographical research and performed in-vitro studies(Gilling et al., 2014;Jesus et al., 2015; Khwaza et al., 2018; Kamalabadi et al., 2018; Tohmé et al., 2019; Marinelli et al., 2019). ...
Preprint
Full-text available
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel corona virus that causes corona virus disease 2019 (COVID-19). The COVID-19 rapidly spread across the nations with high mortality rate even as very little is known to contain the virus at present. In the current study, we report novel natural metabolites namely, ursolic acid, carvacrol and oleanolic acid as the potential inhibitors against main protease (M pro ) of COVID-19 by using integrated molecular modeling approaches. From a combination of molecular docking and molecular dynamic (MD) simulations, we found three ligands bound to protease during 50 ns of MD simulations. Furthermore, the molecular mechanic/generalized/Born/Poisson-Boltzmann surface area (MM/G/P/BSA) free energy calculations showed that these chemical molecules have stable and favourable energies causing strong binding with binding site of M pro protein. All these three molecules, namely, ursolic acid, carvacrol and oleanolic acid, have passed the ADME (Absorption, Distribution, Metabolism, and Excretion) property as well as Lipinski’s rule of five. The study provides a basic foundation and suggests that the three phytochemicals, viz. ursolic acid, carvacrol and oleanolic acid could serve as potential inhibitors in regulating the M pro protein's function and controlling viral replication.
... Fortunately, transmission electron microscopy (TEM) imaging was used to visualize structural changes of the virus. With the aid of TEM, Gilling et al. [21] found that murine norovirus (a non-enveloped virus) exposed to 4% oregano EO expanded in size from 20-35 nm to 40-75 nm in diameter but appeared intact in morphology. Meanwhile, 0.5% carvacrol treated murine norovirus expanded from normal to ~900 nm in diameter, resulting in capsid disintegration. ...
... Moreover, Eucalyptus bicostata and Dysphania ambrosioides EOs also exhibited high anti-Coxsackie activities [42,44]. The oregano EO and its primary component carvacrol were able to strongly inhibit human rotavirus and murine norovirus [21,33]. These studies indicated potential antiviral activities of EOs against non-enveloped viruses. ...
Article
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The presence of resistance to available antivirals calls for the development of novel therapeutic agents. Plant-derived essential oils may serve as alternative sources of virus-induced disease therapy. Previous studies have demonstrated essential oils to be excellent candidates to treat antiviral-resistant infection associated with their chemical complexity which confers broad-spectrum mechanisms of action and non-specific antiviral properties. However, almost no comprehensive reviews are updated to generalize knowledge in this regard and disclose the interplay between the components and their antiviral activities. This review provides an up-to-date overview of the antiviral efficacy of essential oils from a wide range of plant species and their characteristic components, as well as their overall mechanisms of action, focusing on the last decade. The roles of individual components relative to the overall antiviral efficacy of essential oils, together with the antiviral activity of essential oils in comparison with commercial drugs are also discussed. Lastly, the inadequacies in current research and future research are put forward. This review will provide references in the design of new drug prototypes and improve our understanding of the proper applications of essential oils in the future.
... Oregano (Origanum vulgare L.): Oregano is a popular herb (Family Lamiaceae) with impressive medicinal qualities owing to the presence of carvacrol, is a potential candidate for antiviral therapy. In vitro studies demonstrated thatthe activity of murine norovirus (MNV: highly contagious being responsible to cause of human stomach flu) has been reduced by the application of oregano oil with carvacrol (Gilling, et al, 2014).MNV shows a molecular similarity to human noro-virus and has been used as alternate models to reportits mechanism of action and molecular structures because human norovirus is extremely difficult to culture in laboratories (www.cdc.gov). Oregano oil is of immense medicinal value and its active constituent, carvacrol is reported to exhibit antiviral activity against herpes simplex virus type-1 (HSV-1); rotavirus (a common causal organism of diarrhoea in infants and children); and respiratory syncytial virus (RSV), which causes respiratory infections (Pilau et al., 2011;Sharifi-Rad et al, 2017). ...
... These two compounds are powerful antibacterial and antifungal in mode of action. Carvacrol reduces infections from several viruses, as well as allergies, tumors, parasitic infections and has been an ant-inflammatory photochemical (Gilling et al, 2014). ...
Chapter
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A Curtain Raiser on Natural Supplements Being Targeted Choice of Surveillance As Potential Anti-Viral Drugs : Neutraceutical Supplementations Vis-à-Vis Immune Boosters
... Oregano belongs to the herb of mint family and has antiviral and medicinal activity due to the presence of eatable carvacrol and other bioactive compounds. Gilling et al. (2014) demonstrated the antiviral activity of carvacrol that was active against murine norovirus (NMV), so it can be used in foods as preservative and as antiviral agent for preventing infections. Another study was based on the investigation of antiviral action of Mexican oregano, and it was found that it has antiviral effects against human respiratory syncytial virus (HRSV) [292][293][294]. ...
... Gilling et al. (2014) demonstrated the antiviral activity of carvacrol that was active against murine norovirus (NMV), so it can be used in foods as preservative and as antiviral agent for preventing infections. Another study was based on the investigation of antiviral action of Mexican oregano, and it was found that it has antiviral effects against human respiratory syncytial virus (HRSV) [292][293][294]. ...
Article
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To date, the leading causes of mortality and morbidity worldwide include viral infections , such as Ebola, influenza virus, acquired immunodeficiency syndrome (AIDS), severe acute respiratory syndrome (SARS) and recently COVID-19 disease, caused by the SARS-CoV-2 virus. Currently, we can count on a narrow range of antiviral drugs, especially older generation ones like ribavirin and interferon which are effective against viruses in vitro but can often be ineffective in patients. In addition to these, we have antiviral agents for the treatment of herpes virus, influenza virus, HIV and hepatitis virus. Recently, drugs used in the past especially against ebolavirus, such as remdesivir and favipiravir, have been considered for the treatment of COVID-19 disease. However, even if these drugs represent important tools against viral diseases, they are certainly not sufficient to defend us from the multitude of viruses present in the environment. This represents a huge problem, especially considering the unprecedented global threat due to the advancement of COVID-19, which represents a potential risk to the health and life of millions of people. The demand, therefore, for new and effective antiviral drugs is very high. This review fo-cuses on three fundamental points: (1) presents the main threats to human health, reviewing the most widespread viral diseases in the world, thus describing the scenario caused by the disease in question each time and evaluating the specific therapeutic remedies currently available. (2) It comprehensively describes main phytochemical classes, in particular from plant foods, with proven antiviral activities, the viruses potentially treated with the described phytochemicals. (3) Consideration of the various applications of drug delivery systems in order to improve the bioa-vailability of these compounds or extracts. A PRISMA flow diagram was used for the inclusion of the works. Taking into consideration the recent dramatic events caused by COVID-19 pandemic, the cry of alarm that denounces critical need for new antiviral drugs is extremely strong. For these Citation: Behl, T.; Rocchetti, G.; Chadha, S.; Zengin, G.; Bungau, S.; Kumar, A.; Mehta, V.; Uddin, M.S.; Khullar, G.; Setia, D.; et al. Phyto-chemicals from Plant Foods as Po
... The potential relationships between the novel coronavirus and "acerola", 27 "andrographis", 28 "astragalus", 29 "cinchona", 30 "echinacea", 31 "elderberry", 32 "goldenseal", 33 "mullein", 34 and "oregano oil" 35 are summarized in Table 2. Although, in general, the antiviral, anti-inflammatory, and immunomodulatory effects of these plants have been described in the literature, 29,35,36 a limited number of studies have investigated the protective effects of these herbs & herbal supplements against COVID-19, and any protective role these plants may have is currently hypothetical. ...
Article
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Abstract Object The aim of this retrospective infodemiological study was to evaluate people’s interests in biologically-based (B-B) complementary and alternative medicine (CAM) therapies such as herbs, foods, and supplements during the coronavirus pandemic via analysis of Google search engine statistics. Design & settings The category, period, and regions selected in the Google Trends were “health,” “15 January–15 May 2020,” in the United States of America (USA), the United Kingdom (UK), Germany, Italy, and France, respectively. The most commonly searched herbs, foods and supplements (n = 32) during the pandemic were determined from a pool of keywords (n = 1286) based on the terms’ relative search volumes (RSVs) within the last five years. Correlation analyses were conducted to investigate associations between coronavirus-related parameters with each keyword’s RSV for each country. Selected keywords (n = 25) were analyzed using the gtrendsR package in the R programming language; the ggplot2 package was used to visualize the data, the Prophet package was used to estimate the time series, and the dplyr package was used to create the data frame. Results Significantly strong positive correlations were identified between daily RSVs of the terms “black seed,” “vitamin C,” “zinc,” and “quercetin,” and search queries for “coronavirus” and “COVID-19” in the USA (Spearman’s correlation coefficient > 0.8, p < 0.05), and between the RSVs of the terms “vitamin C” and “zinc,” and daily search queries for “coronavirus” and/or “COVID-19” in the UK (Spearman’s correlation coefficient > 0.8, p < 0.05). Conclusion Google Trends can be a beneficial tool for following public interest in identifying outbreak-related misinformation, and scientific studies and statements from authorities and the media play a potential role in driving internet searches.
... [46][47][48][49] Pure REO was the individual component with significant AMS, this could be due to the presence of a-pinene, eucalyptol, and camphor as the major compounds present in REO as reported as the responsible for its antimicrobial activity. [50][51][52] On the other hand, there are several works report that NE and nanostructured systems owed their improved functional properties to their very small size and the almost null resistances for diffusive processes even in front of the cell wall, [47,53,54] for this reason, non-loaded ACK NE (NE W/O F) were tested as blank samples in order to assure that AMS was caused by the integral system. Figure 5 showed that NE30F, NE20F, and NE10F displayed significant lower AMS than their correspondent NE W/O loaded with ACK extract in the disperse phase, and the effect observed for these treatments did not change (p < .05) ...
Article
Ardisia compressa K. (ACK) fruits are a potential source of antioxidant compounds like phenolics and anthocyanins. ACK extracts made with aqueous ethanol (E75) yielded the highest total phenolic content (TPC) and antioxidant activity (AA) by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assays. Water-in-oil nanoemulsions (NEW/O) were produced by spontaneous emulsification, in order to provide longer stability to functional activities from ACK extract, and formulated using ACK extract (10–30%wt.), rosemary essential oil (REO), and Tween 80:Span 80 (10–30% wt.). Resultant NEW/O were placed in a pseudo-ternary phase diagram and classified based on their visual performance, like phase separation, opacity, or translucent-stable systems. The latter displayed smaller hydrodynamic droplet sizes and better stability and were selected for physicochemical characterization. Physical stability through the hydrodynamic diameter, turbidity, and color attributes was monitored until 93 d at 25 °C under light exposure (LE) and dark. A first-order model was used for the first two variables, with rate kinetic constants (k) from 10⁻⁶ to 10⁻⁸ s⁻¹. Color index (CI) showed higher reduction when NEW/O were stored under LE, whereas total color difference (TCD) values were higher than 5.5, indicating marked differences in visual color compared to fresh NEW/O (t =0 d). Chemical stability from NEW/O made with 30% w/w of ACK extract (NE30) displayed the best stability against pH changes, and TPC and AA during storage time, exhibiting also good antimicrobial susceptibility (AMS) against Gram-positive and Gram-negative bacteria with a synergistic effect of enhanced AMS than that observed in their respective individual components, even after storage time.
... In in-vitro studies, it has been stated that oleanolic acid and its analogs show antiviral effects against HIV, influenza and hepatitis viruses (Khwaza et al., 2018). Carvacrol is a natural monoterpenoid phenol derivative and has antiviral and antimicrobial effects (Gilling et al., 2014). It is an important component of Labiatae family plants and is a molecule used for therapeutic purposes (Hyldgaard et al., 2012). ...
... The essential oil from oregano (Origanum vulgare) decreased FCV-F9 and MNV-1 replication in a dose-dependent manner. Besides, it has been shown that oregano essential oil and its primary component carvacrol caused the loss of viral capsid integrity of MNV-1 virions as determined by transmission electron microscopy experiments [140]. Persimmon (Diospyros kaki) extracts containing persimmon tannin was found to reduce noroviral genome replication with no cytotoxicity effect [141]. ...
Article
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Viral infections are responsible for several chronic and acute diseases in both humans and animals. Despite the incredible progress in human medicine, several viral diseases, such as acquired immunodeficiency syndrome, respiratory syndromes, and hepatitis, are still associated with high morbidity and mortality rates in humans. Natural products from plants or other organisms are a rich source of structurally novel chemical compounds including antivirals. Indeed, in traditional medicine, many pathological conditions have been treated using plant-derived medicines. Thus, the identification of novel alternative antiviral agents is of critical importance. In this review, we summarize novel phytochemicals with antiviral activity against human viruses and their potential application in treating or preventing viral disease.
... This underlines the efficacy of carvacrol as a natural surface disinfectant and as a food preservative to control human norovirus, which are the most frequent cause of food-borne viral diseases in humans, causing non-bacterial gastroenteritis. [83]. ...
Article
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Essential oils (EOs) are a complex mixture of hydrophobic and volatile compounds synthesized from aromatic plants, most of them commonly used in the human diet. In recent years, many studies have analyzed their antimicrobial, antioxidant, anti-inflammatory, immunomodulatory and anticancer properties in vitro and on experimentally induced animal models of colitis and colorectal cancer. However, there are still few clinical studies aimed to understand their role in the modulation of the intestinal pathophysiology. Many EOs and some of their molecules have demonstrated their efficacy in inhibiting bacterial, fungi and virus replication and in modulating the inflammatory and oxidative processes that take place in experimental colitis. In addition to this, their antitumor activity against colorectal cancer models makes them extremely interesting compounds for the modulation of the pathophysiology of the large bowel. The characterization of these EOs is made difficult by their complexity and by the different compositions present in the same oil having different geographical origins. This review tries to shift the focus from the EOs to their individual compounds, to expand their possible applications in modulating colon pathophysiology.
... However, the authors have not established a relation between the binding of the antimicrobial agent to the viral envelope and the envelope dissolution itself. Using oregano essential oil (4%), Gilling et al. (2014) reported a reduction in the murine norovirus titer. After 1 hour of exposure the titer reduced by 0.98 ± 0.17 log10, and after 6 hours it reduced by 1.10 ± 0.12 log10. ...
Article
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The search for natural resources with antiviral potential, as an alternative to synthetic drugs, has been growing and, in this sense, oregano presents itself as a potential candidate. However, the antiviral studies with oregano are still poorly explored. BoHV-1 stands out among veterinary pathogens, for its economic impact on cattle production. In this study, the antiviral and virucidal activity of polar extracts of Origanum vulgare was evaluated against BoHV-1. Infusion (INF10), decoction (DEC), and hydroalcoholic (HAE) extracts were tested to cytotoxic and antiviral assays on MDBK cells. Cytotoxic effects were analyzed through MTT assay and the antiviral activity was expressed as a percentage of inhibition (PI). BoHV-1 was incubated with O. vulgare extracts as virucidal assay. Concentrations ≤3.12 mg/ml (INF10) and ≤1.56 mg/ml (DEC/HAE) preserved the cell viability above 60%, and all extracts were safe (>96%) between 0.78 and 0.39 mg/ml. Regarding the antiviral activity, pre-treatment of all extracts highlighted in comparison to the post-treatment. The pre-treatment of infusion at 2 mg/ml highlighted due to the high cell viability (84.69%) and the elimination of the viral load. All extracts inactivated BoHV-1 from 2 hours of incubation (20 mg/ml), showing virucidal activity. These findings may be related to 4-hydroxybenzoic acid as prevalent in all extracts. These findings showed the in vitro antiviral and virucidal activity of oregano polar extracts against BoHV-1 and may be promising for the therapeutic use against herpesviruses infections.
... Furthermore, the effectiveness of the chemical components in combating pathogenic microorganisms has been amply demonstrated (Fisher and Phillips 2008;Ozogul et al. 2015;Piątkowska and Rusiecka-Ziółkowska 2016). Yet, few oils have been tested for these properties in food sector applications, and data on the efficacy of EOs against foodborne viruses are scarce (Kovac et al. 2012;Elizaquível et al. 2013;Gilling et al. 2014;Kim et al. 2017) particularly for HAV . Here, we investigated the efficacy of four EOs to reduce viral loads of HAV in soft fruits and assessed their potential use to reduce or eliminate viral contamination in fresh fruit production. ...
... Lipid encapsulation is mentioned for a specific reason. A major basis behind the effects of monolaurin and oregano has been postulated to be their ability to destroy the protective lipid encapsulation of organisms (1)(2)(3)(4)(5)(6)(7)(8)(9). Accordingly, because of the long-term safety records of these natural products, they seem to be reasonable agents to consider therapeutically in the absence of effective drugs. ...
... MNV is a very infectio us and is catched easily and it causes stomach flu. Its strain is very much familiar with novovir us which cannot be isolated in laboratory [9]. Therefore Oregano Oil and its compound carvacrol is effectively inhibit the viral activities in humans and animals as well. ...
Preprint
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Corona Virus disease 2019 (COVID-19) is a new strain of coronavirus that causes respiratory illnesses with a start of flu like symptoms. This disease is fatal and is spread all over the world. The Scientist are working day and night to find vaccine or a cure. World Health Organisation has declared COVID-19 as pandemic [1]. In the view of the pandemic many treatments are being tried on the patients and various treatment modalities are being followed, the traditional medicine has shown a major role to manage this disease. The traditional medicines include the use of herbs, nutrition and spices that are freely available in Asian countries. These are used in day to day life by Asian population [2]. In this paper we have compiled and reviewed the role of various herbs and spices such as Oregano, Ashwagandha, Ginseng, Basil, Sage, Curcumin, Fenugreek, Ginger and Garlic in building immunity and also in curing pathogenic invasions based on evidence based researches. As there is no cure available for COVID-19 till now so supportive therapy is playing a major role for the patients to fight with this pandemic. The AYUSH ministry has also promoted the use of above herbs for a patient suffering from this disease. The corona virus is present in respiratory system as shown by different studies and it has different strains. The guidelines laid by the ICMR and WHO shows that use of herbs, spices and nutrients can be helpful to manage this virus by increasing the immunity in patients. Hence we are not claiming any cures but the herbs and spices used in day to day life are very much effective in management of COVID-19. World Health Organisation (WHO) has recognised the use of alternative and traditional medicine in the management of COVID-19 but the herbs should be used in prescribed amounts and overdose of them can be harmful for health [1,3]. Therefore the present article will enlighten the readers about the role of herbs, spices and nutrients in improving the conditions in COVID-19.
... Both pure carvacerol extracts and oregano oil have also proven effective against Herpes Simplex Virus type 1 (HSV-1), rotavirus and Respiratory Syncytial Virus (RSV). Thus, its inclusion in regular diet may prove beneficial [48]. ...
Article
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Plants are one of the most important sources of human nutrition and they also act as store house of important pharmaceuticals. Plant-derived bioactive compounds have long been used to treat diseases in traditional medicine. Plant biotechnology provides a blooming opportunity for improving the bioactive compounds in our food. This coupled with the emergence of concepts like nutritional therapy and phytotherapy makes us curious about understanding the health benefits of the bioactive compounds in our food. Plant secondary metabolites have long played an important role as anti-inflammatory substances. Some functional metabolites help in curing chronic diseases, while phenolic compounds are well-known antioxidants which improve our overall heath. Long used in folk medicines, some bioactive compounds have antiviral, cardio-tonic and immune-stimulatory properties. Some again have a neuro-protective role, while some may even display anti-cancer properties. Coupling nutritional research with genomics may help us to improve our diet and prevent diseases. Use of animal models helps to study the immune responses to different plant-derived bioactive compounds, and the useful ones may be incorporated in our diet. This review addresses all the health benefits with special emphasis on immune-boosting ability of plant bioactive compounds in view of their role in nutritional therapy.
... Many studies have been exploring the additive effects of herb materials such as oregano, rosemary, thyme, sage, basil, and mint as growth promoters, antimicrobial agents, or natural antioxidants in poultry production (N.A. BOTSOGLOU & al [4], F.C. GUO & al [5]). Due to their antibacterial, antifungal, antiviral and antioxidant properties, several authors (D.H. GILLING & al [6]) showed that the use of phytogenic additives has many advantages over the antibiotics commonly used in animal feeding as growth promotors. S.L. CUPPETT & HALL [7] consider that plant extracts, such as the oregano essential oil, have strong antioxidant effects due to their large amounts of monoterpenes timol and carvacrol. ...
Article
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The purpose of the study was to assess the effect of dietary oregano (Origanum vulgare) oil and powder on the performance, development of internal organs and balance of intestinal microflora in broilers (14-42 days) reared on the floor. A number of 150 chicks of Cobb 500 broilers hybrid, aged 14 days were assigned to three groups (C, E1 and E2) housed in an experimental hall under controlled microclimate conditions. Diet C was conventional, with corn, gluten and soybean meal, while diets E1 and E2 were supplemented with 0.01% oregano oil (E1), and concomitant with 0.005% oregano oil and 1% oregano powder (E2). Six broilers per group were slaughtered at the end of the feeding trial and measurements were performed on the carcass and internal organs, while the intestinal content was sampled for subsequent bacteriological determinations. The overall (14-42 days) performance shows that both experimental groups (E1 and E2) had a significantly (P≤0.05) higher daily weight gain compared to C group, while the daily feed intake was not significantly different between the three groups. The Enterobacteriaceae and Escherichia coli count was significantly (P ≤ 0.05) lower in the intestine of the experimental groups than in group C, while the Lactobacillus spp. count was significantly (P≤ 0.05) higher in the intestine of the experimental groups than in group C.
... (Amaro y Iparraguirre, 2018;Kelawy et al., 2018;Xie, 2019). El aceite esencial de Origanum vulgare "orégano" (Lamiaceae), efectivo antimicrobiano y antiviral; justifica su consumo tradicional en sopas y aderezos (Rivera et al., 2019); propiedades fundamentadas por investigaciones fitoquimicas de Téllez y Nolazco (2017), quienes demuestran que la presencia de monoterpenos, fenoles, terpineno-4-ol, timol y carvacrol son efectivos para inactivar virus, al incidir en la cápside y posteriormente en el ARN (Gilling et al., 2014). Citrus limon "limón'', Citrus aurantium " naranja '', Citrus aurantiifolia "lima''; ya considerada fuente natural de antioxidantes, por su alto contenido de polifenoles, flavonoides, terpenos y vitamina C en cáscara y semillas; tal como fue confirmada por De la rosa et al. (2016), quien demostró la acción antiviral de los polifenoles y flavonoides al inhibir la replicación viral. ...
Article
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The "cold plants" and "hot plants" were determined as resources for the prevention and / or treatment of COVID-19, by showing that they would be related to alkaline and acidic pHs, to help solve this pandemic. A total of 83 species of medicinal plants between "cold" and "hot" are registered for the north of Peru, as potential resources in the prevention and / or treatment of COVID-19; Of these, 64 species are "cold plants" and 19 species are "hot plants".
... Other studies focusing on the therapeutic properties of LOLE using in vivo models did not report any negative effects of the extract on the health of the animals [27]. Gilling et al. [28] reported significant reductions of MNV with application of essential oils from oregano, clove and Zataria. The reductions in that study appeared to be temperature-dependent. ...
Article
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Noroviruses are the leading cause of acute gastroenteritis and food poisoning worldwide. In this study, we investigated the anti-noroviral activity of Lindera obtusiloba leaf extract (LOLE) using murine norovirus (MNV-1), a surrogate of human norovirus. Preincubation of MNV-1 with LOLE at 4, 8, or 12 mg/mL for 1 h at 25 °C significantly reduced viral infectivity, by 51.8%, 64.1%, and 71.2%, respectively. Among LOLE single compounds, β-pinene (49.7%), α-phellandrene (26.2%), and (+)-limonene (17.0%) demonstrated significant inhibitory effects on viral infectivity after pretreatment with MNV-1, suggesting that the anti-noroviral effects of LOLE may be due to the synergetic activity of several compounds, with β-pinene as a key molecule. The inhibitory effect of LOLE was tested on the edible surfaces of lettuce, cabbage, and oysters, as well as on stainless steel. After one hour of incubation at 25°C, LOLE (12 mg/mL) pretreatment significantly reduced MNV-1 plaque formation on lettuce (76.4%), cabbage (60.0%), oyster (38.2%), and stainless-steel (62.8%). These results suggest that LOLE effectively inhibits norovirus on food and metal surfaces. In summary, LOLE, including β-pinene, may inactivate norovirus and could be used as a natural agent promoting food safety and hygiene.
... Lemongrass oil, citral, allspice oil showed effectiveness against murine norovirus and also indicated their potential as natural food and surface sanitizers to control norovirus [46]. Oregano containing carvacrol as the main constituent showed effectiveness in inactivating murine norovirus by directly acting on viral capsid and RNA [47]. Melissa officinalis was found to inhibit the influenza virus replication process by directly interacting with the virus [48]. ...
Article
Background Coronavirus has become a life- threatening disease and it is caused by severe acute respiratory syndrome (SARS). This new strain of coronavirus is not completely understood and to date, there is no treatment of coronavirus. Traditional ayurvedic medicines mainly essential oils and Chinese herbs have always played a vital role in the prevention and treatment of several epidemics and pandemics. In the meantime, guidelines of the ministry of AYUSH (Ayurveda, yoga, unani, siddha and homoepathy) include a traditional medicinal treatment for flu and fever and also recommended to boost immunity to prevent the spread of coronavirus. It is not possible to find which essential oil will offer the best level of protection. However, it is likely to assume that some essential oils are likely to offer a measurable level of defense in the same way they do with many other known viruses. Methods Literature relevant to various essential oils having antiviral activity has been collected and compiled. Various nanocarriers of essential oils have also been stated. The database was collected using various search engines such as jgate, google scholar, scihub, pubmed, sciencedirect etc. Results Essential oils contain active constituents such as phenolics compounds, terpenoids, alkaloids, phenyl propanoids etc., which are responsible for their biological properties such as antiviral, antibacterial, antimicrobial, antioxidant activities and many more. But the use of essential oils has always been limited due to poor solubility, solvent toxicity, volatility and low solubility. Many nanotechnology based carriers especially, liposomes, dendrimers, nanoparticles, nanoemulsion and microemulsion etc. have been evidenced to overcome limitations associated with essential oils. Conclusion Several essential oils possess potent antiviral activity and are characterized by fewer side effects and are safe to human use. The nanocarrier systems of these oils have proved the potential to treat viral and bacterial infections.
... It is mainly found in the region of Central America and Mexico. Oregano contains an essential oil named Carvacrol (Pilau et al., 2011) which has antiviral properties as shown in various studies e.g. against Respiratory Syncytial Virus (RSV) (Chidgey & Broadley, 2005), Murine Norovirus (MNV) responsible for stomach flu (Gilling et al., 2014) and various other RNA and DNA viruses (Ball & Knipe, 2007;Pilau et al., 2011). So, it could be a very good option as a natural home remedy during this COVID-19 pandemic. ...
Article
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Corona virus disease 2019 (COVID-19) is primarily caused by Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). The infection begins with flu like symptoms with respiratory problems but in severe cases it affects cardiovascular system and excretory systems. On March 11, 2020 World Health organization (WHO) announced this disease as pandemic. Researchers are working continuously to find a proper treatment in the form of an effective vaccine or drugs/medicines but till date these are not available in the market and mainly symptomatic treatment is provided to COVID-19 patients. Under these circumstances, Ministry of Health and AYUSH, India has released advisory to people to use natural home remedies as potential alternative treatment. Home remedies are easily available at home in the form of spices and herbs e.g. citrus fruits, garlic, ginger, turmeric, ashwagandha, mulethi, tulsi, oregano, ginseng etc and have immunomodulatory effects as evidenced by ayurvedic literature and scientific publications. As per WHO guidelines the use of herbs within permissible limit would be helpful to manage COVID-19 but its overuse may have harmful effects. In the present article authors attempted to draw the attention of readers about the easy availability and affordability of home remedies to boost immunity and general well being of our body to fight against COVID-19.
... A large number of herbs and aromatic plants are frequently used for treating human skin diseases, especially from the family of Lamiaceae including origanum, satureja, thymus, and coridothymus species [12]. Carvacrol, a monoterpene phenol that is also known as 2methyl-5-(1-methyl ethyl)-phenol, is one of the significant components of oregano essential oils, and presents a wide diversity of biological activities, such as antiviral [13][14][15], anticancer [12], antimicrobial [16], antioxidant and anti-inflammatory [17,18]. Besides, carvacrol also has been identified as a natural, economical food preservative. ...
Article
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Background Carvacrol, as the major components of aromatic plants used for treating human skin diseases including origanum, Satureja, thymus, and coridothymus species, presented a kind of antiviral activity. To explore the mechanisms of carvacrol against herpes simplex virus (HSV) in vitro. Method The BSC-1 cells model of HSV infection was established, and from the two aspects of viral replication level and cell death pathway, the antiviral effects of carvacrol on HSV infected cells were also evaluated by plaque assay under the three modes including prevention, treatment, and direct inactivation. Results In the three ways, the half-maximal effective concentration (EC50) of 2% true carvacrol solution on HSV-2 infected cells were severally 0.43, 0.19 and 0.51 mmol/L, and the corresponding therapeutic index (TI) were 4.02, 9.11 and 3.39, respectively. It’s the opposite of the increased levels caused by HSV-2 infection, that both the expressions at the transcription genes and protein levels of virus own replication key factors (including ICP4, ICP27, VP16, gB, and UL30) and cytokines (including RIP3, TNF-α, and MLKL) of infected cells treated with carvacrol were dose-dependently inhibited. Besides, HSV-2 infection can cause the decrease of intracellular protein ubiquitination level, and carvacrol can reverse the ubiquitination decrease level caused by HSV-2 infection. Conclusion Carvacrol exhibits significant antiviral activity by inhibiting the HSV-2 proliferation process and HSV-2-induced TNF-α increasing levels, decreasing RIP3 and MLKL protein expressions through the intracellular RIP3-mediated programmed cell necrosis pathway. In addition, carvacrol also may exhibit anti-HSV-2 activity by reversing the ubiquitination decrease level caused by HSV-2 infection on the ubiquitin-proteasome system, which provides insights into the molecular mechanism.
... The virus was successfully propagates in RAW264.7 cell culture. And the size and morphological characteristics of this virus were similar to norovirus described previously by other investigators (35,36). In general, different MNV isolates show different pathogenicity. ...
Article
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Murine Norovirus (MNV) is one of the most known viruses among viruses in mice. Because of the high prevalence of MNV in frequently used laboratory animals in biomedical researches, there is a significant impact of MNV. There may be different prevalence degrees and molecular characteristics of MNV in different regions around the world. Here, we reported an MNV strain “designated HBTS-1806” isolation from commercial mice's feces that caused a detectable cytopathic effect (CPE) in RAW264.7 cells. According to electron microscopy, the virus was 50–70 nm in diameter. The complete genome of HBTS-1806 is 7383 nucleotides with a structure similar to that of MNV reference strains. According to phylogenetic analysis on the basis of the whole genome, HBTS-1806 shared nucleotide sequence identities of 90.2–95.4% with other Chinese isolates reported. Analysis of amino acid sequence on the basis of ORF1 and ORF2 suggested that the isolated strain may be derived from recombination. Although no gross lesions or histopathological changes were found from mice infected with 5 × 10 ⁵ TCLD 50 of MNV by oral gavage inoculation, the intestinal virus loads lasted 12 weeks, suggesting a persistent infection strain of MNV isolate in China.
... In an in vitro analysis, oregano oil and isolated carvacrol both decreased murine norovirus activity within 15 min of exposure. 152 'Lippia graveolens' (Mexican oregano oil) and carvacrol also demonstrated antiviral activity against herpes simplex virus type 1, viral gastroenteritis due to rotavirus infection, and RSV. [153][154] Salvia rosmarinus (rosemary) herb is mostly used in cooking; however, it also has therapeutic applications due to its multiple plant compounds, including oleanolic acid. ...
Coronavirus disease 2019 (COVID-19) is a recently emerged pandemic caused by a novel virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This disease is communicable and mainly affects the respiratory tract. The outbreak of this disease has greatly influenced human health and economic activities worldwide. The absence of any medication for this infection highlights the urgent need for the development of alternative methods for managing the spread of the disease. Our immune system operates based on a complex array of cells, processes, and chemicals that continuously protect our body from invading pathogens, including viruses, toxins, and bacteria. The present study was conducted to perform a comprehensive review of all dietary treatments for boosting immunity against viral infections. No study was found to explicitly support the use of any healthy foods or supplements to protect against COVID-19. However, this study offers details on well-researched functional foods and supplements that typically improve the immune response, which could be helpful against this newly emerged pandemic. Altern Ther Health Med. 2020 Dec 29; AT6564. Online ahead of print
... Not reported [20,80,93] 7. Capsid protein disintegration. [96][97][98] 9. Inhibits herpes virus replication, inhibits HIV-1 LTR-directed gene expression, and inhibits transcription of HPV-18. ...
Article
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All the plants and their secondary metabolites used in the present study were obtained from Ayurveda, with historical roots in the Indian subcontinent. The selected secondary metabolites have been experimentally validated and reported as potent antiviral agents against genetically-close human viruses. The plants have also been used as a folk medicine to treat cold, cough, asthma, bronchitis, and severe acute respiratory syndrome in India and across the globe since time immemorial. The present study aimed to assess the repurposing possibility of potent antiviral compounds with SARS-CoV-2 target proteins and also with host-specific receptor and activator protease that facilitates the viral entry into the host body. Molecular docking (MDc) was performed to study molecular affinities of antiviral compounds with aforesaid target proteins. The top-scoring conformations identified through docking analysis were further validated by 100 ns molecular dynamic (MD) simulation run. The stability of the conformation was studied in detail by investigating the binding free energy using MM-PBSA method. Finally, the binding affinities of all the compounds were also compared with a reference ligand, remdesivir, against the target protein RdRp. Additionally, pharmacophore features, 3D structure alignment of potent compounds and Bayesian machine learning model were also used to support the MDc and MD simulation. Overall, the study emphasized that curcumin possesses a strong binding ability with host-specific receptors, furin and ACE2. In contrast, gingerol has shown strong interactions with spike protein, and RdRp and quercetin with main protease (Mpro) of SARS-CoV-2. In fact, all these target proteins play an essential role in mediating viral replication, and therefore, compounds targeting aforesaid target proteins are expected to block the viral replication and transcription. Overall, gingerol, curcumin and quercetin own multitarget binding ability that can be used alone or in combination to enhance therapeutic efficacy against COVID-19. The obtained results encourage further in vitro and in vivo investigations and also support the traditional use of antiviral plants preventively.
... The polymer chitosan which is created from the exoskeleton of crustaceans by deacetylation, more specifically reduced infectivity of FCV but showed no effect on MNV [22]. Oregano essential oil (4.0 %) and its primary component carvacrol reduced MNV by 0.95 log10 after treatment for 15 min [36]. ...
Thesis
Human norovirus is the dominating+ cause of outbreaks of viral gastroenteritis across all age groups, with an estimated 684 million cases worldwide and 219,000 deaths per year. Outbreaks of human norovirus frequently occur in enclosed settings (e.g. cruise ships, hospitals, nursing homes). This is economically relevant, as it is estimated to cost 4.2 billion USD in direct health system and 60.3 billion USD in social costs. Although symptoms are self-limited to two to three days, the illness can be severe in young children, elderly, or immunocompromised people. The complete lack of treatment or vaccination limits counter measurements to easing symptoms. Additionally, spreading is limited by preventative measures, such as isolating infected individuals. An adequate treatment for patients as well as a possible early treatment (before symptoms appear) for people in the near environment of a beginning outbreak, including nurses and other staff, could prevent outbreaks from spreading. Therefore, inexpensive treatments with a minimum of side effects that can be delivered to patients and people in their surrounding are urgently needed. For more than four decades, antiviral research was hampered by the lack of cell culture systems for human norovirus propagation. Therefore, surrogate systems, such as murine norovirus and feline calicivirus, were used. Human noroviruses typically require histo-blood group antigens (HBGAs) as co-factors for viral infection. Thus, the HBGA pocket is the main target region on the viral capsid for the development of antivirals. In this thesis, a panel of synthetic antivirals and natural extracts, including a set of 31 different honeys, were screened using various techniques (X-ray crystallography, ELISA, DLS, and EM) to identify potential norovirus capsid inhibitors. Several Nanobodies (Fab fragments of camelid derived heavy chain only antibodies) directed specifically against genotype GI.1 of human norovirus inhibited virus like particles (VLPs) in surrogate attachment inhibition ELISAs. However, inhibition by these Nanobodies was specifically directed against their respective genotype and showed limited cross-reactivity. The high specificity of the Nanobodies limits their use as broadly reactive antivirals. Of the Natural extracts, date syrup, wine, barley malt, coconut blossom syrup, apple sweetener, different types of honey and propolis inhibited the binding of VLPs to HBGAs. Treatment of VLPs with these compounds resulted in the disruption of VLP integrity and particle aggregation. Most natural extracts showed broad reactivity against VLPs of several genotypes. Preliminary structural analysis revealed the presence of small, unidentified ligand(s) for date syrup, coconut blossom syrup, apple sweetener, and honey. The strongest inhibition was observed with date syrup, wine, and propolis. Three flavonols, common to these natural extracts, were identified as inhibiting compounds. To address if a combinatorial approach could improve the performance of the individual inhibitors, special combinatorial ELISAs were designed to assess the interaction between two inhibitors. These assays revealed combinations of Nanobodies with the HMO 2’FL or natural extracts to have additive or synergistic inhibition. This demonstrated a combinatorial approach with natural extracts and Nanobodies could be a comparatively easy, safe, and affordable treatment that could be administered to people suffering from norovirus disease and healthy people in the surrounding of a beginning outbreak.
... Treatment of RSV with 1053 µg ml -1 reduced infectivity by 36 % after 2 h and almost completely after 24 h (Fig. 1C). Furthermore, if the capsid integrity is affected, viral genomes can be damaged as observed for the norovirus, a RNA-virus (Gilling et al. 2014). This hypothesis is supported by the much higher sensitivity of the three RNA viruses to the HMP in comparison to the DNA virus AV, as RNA in general is less stable than DNA. ...
Article
Full-text available
Background : The herbal medicinal product (HMP) ELOM-080 has a proven efficacy in the treatment of acute respiratory tract (ART) infections, which typically are of viral etiology. However, whether the HMP exerts an antiviral activity against viral pathogens was unknown and therefore tested in this in vitro study. Purpose : This study was performed in order to test antiviral effects of the HMP against four viral pathogens of ART infections: Influenza A (FluA), Rhinovirus (RV), Respiratory Syncytial Virus (RSV), and Adenovirus (AV). Methods : Infectivity of the viruses was tested after their 2 or 24 h incubation with HMP at final concentrations between 89 and 2673 µg ml⁻¹ in order to investigate virucidal activity. Virostatic effects were assessed by application of physiologically tolerated concentrations up to 268 µg ml⁻¹ in cell cultures 1 h after infection with each virus and quantification of plaque formation or cytopathogenic effect. Results : HMP inhibited infectivity of FluA, RV and RSV by more than 50 %, and of AV by about 20 %. In the virostatic tests, mean half maximal effective concentrations (EC50) for RNA viruses were almost 15 times lower compared to virucidal results, AV was not significantly affected. Discussions : The in vitro antiviral effects of ELOM-080 on the enveloped viruses FluA and RSV suggest that this HMP exerts permanent and/or transient viral envelope changes, thereby potentially lowering the attachment to the host cell membrane. Furthermore, the rather high sensitivity of RNA viruses for the HMP suggests an effect on integrity and functionality of viral RNA which may interfere with viral replication causing the observed virostatic effects.
... In an in vitro analysis, oregano oil and isolated carvacrol both decreased murine norovirus activity within 15 min of exposure. 152 'Lippia graveolens' (Mexican oregano oil) and carvacrol also demonstrated antiviral activity against herpes simplex virus type 1, viral gastroenteritis due to rotavirus infection, and RSV. [153][154] Salvia rosmarinus (rosemary) herb is mostly used in cooking; however, it also has therapeutic applications due to its multiple plant compounds, including oleanolic acid. ...
Coronavirus disease 2019 (COVID-19) is a recently emerged pandemic caused by a novel virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This disease is communicable and mainly affects the respiratory tract. The outbreak of this disease has greatly influenced human health and economic activities worldwide. The absence of any medication for this infection highlights the urgent need for the development of alternative methods for managing the spread of the disease. Our immune system operates based on a complex array of cells, processes, and chemicals that continuously protect our body from invading pathogens, including viruses, toxins, and bacteria. The present study was conducted to perform a comprehensive review of all dietary treatments for boosting immunity against viral infections. No study was found to explicitly support the use of any healthy foods or supplements to protect against COVID-19. However, this study offers details on well-researched functional foods and supplements that typically improve the immune response, which could be helpful against this newly emerged pandemic.
... Carvacrol has been reported to be active against HSV-1 by direct inhibition of virus particle. This compound possessed anti-murine norovirus activity too [46,47]. The a and b-pinene detected are naturally found in black cumin and clove, respectively. ...
Article
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Background Viruses cause many life threatening human diseases. Recently, COVID-19 pandemic has challenged the health care systems worldwide. As a disease preventive approach and to bring relief to the severity of the symptoms, a infusion termed as Bhabha Anti-Viral Infusion-23 (‘BhAVI-23’) was conceptualized and formulated which comprised of 23 selected spices and herbals. Objective The present study was conducted to assess the in vitro antiviral potential of the formulation, BhaAVI-23. Material and Methods The in-vitro anti-viral potential of BhAVI-23 was assessed through inhibition of HIV1 reverse transcriptase (RT) as well as through a novel P1 (virulent) bacteriphage based screening assay system. Anti-diabetic potential was assessed by non-enzymatic glycosylation of haemoglobin and the bioactive volatile components were detected through headspace gas chromatography followed by molecular docking analysis. Results The infusion displayed prominent anti-viral activity as evident from significant (57%) inhibition of the HIV1-RT as well as through reduction in the infectivity of P1 (virulent) bacteriophage. The infusion also exerted profound protection (∼64%) to non-enzymatic glycosylation of haemoglobin. Headspace gas chromatography and mass spectrometric analysis confirmed the presence of at least 47 major compounds. Docking analysis indicated possible interaction of α-pinene and eugenol with SARS-CoV spike protein. Conclusion This ‘BhAVI-23’ infusion displayed prominent in-vitro anti-viral and anti-diabetic potential in different model systems. These attributes have relevance as diabetic patients are more prone to COVID-19 morbidity. ‘BhAVI-23’ opens the avenue for its potential inclusion as a supportive health care system upon due regulatory approval during the current pandemic.
... Çalışma sonucunda; bileşiklerin büyük çoğunluğunun güçlü antioksidan ve antiviral aktivite gösterdiği tespit edilmiştir (78) (79). Origanum uçucu yağı ile saf karvakrol (>%98) bileşiğinin insan MNV (nonenveloped murine norovirus) virüsüne karşı antiviral aktivitesinin araştırıldığı çalışma sonucunda, kekik yağı ve ana bileşeni olan karvakrolün MNV virüsüne karşı antiviral özellik gösterdiği ve karvakrolün gıda ve yüzeyler için doğal bir dezenfektan olabileceğini göstermiştir (80). ...
... It kills the virus by the direct attack to the capsid and then subsequently destroys the RNA. This study provided a strong supportive framework regarding the antiviral properties of these two active components (oregano oil and carvacrol) against MNV and illustrated the considerable potency of carvacrol to control human norovirus as a natural food and surface (fomite) sanitizer (Gilling et al., 2014). ...
Article
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This chapter focuses on the effect of natural antimicrobial systems on spoilage and pathogenic microflora during storage. The antimicrobial effect during storage will depend on the concentration of the compound, storage temperatures, pH changes, water activity (aw) levels, oxygen levels, enzyme activity, interaction with food components and additives, microbial interactions, and the sensitivity and growth phase of the target bacteria. Lactic acid bacteria and their associated antimicrobial metabolites, yeasts, antimicrobial compounds from plants, chelating agents such as transferrins, enzymes, and bacteriophages could all be used to extend the shelf life of food products. Their main use would be as part of hurdle technology when they could be used in combination with traditional preservatives and storage methods.
Chapter
This chapter begins with a discussion of household sources of pathogens that can enter the home via air, food or water. Pathogens can also be introduced into a home via humans themselves who acquire an infection outside of the home prior to entry into the home. Once inside the home, pathogens can be transferred either via person-person contact, or via person-fomite-person. In this chapter are identified household and indoor sources of pathogens, and their fate and transport within the indoor environment, with particular emphasis on the occurrence and persistence of pathogens on fomites. Finally, the potential for transfer of pathogens via fomites and hand-to-hand contact is discussed.
Chapter
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Chapter
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Chapter
The indoor environments including home, schools, workplaces, and hospitals act as reservoirs of human pathogens. This chapter provides an overview of the household and indoor sources of pathogens, their fate, and transport within the indoor environment. Household sources of pathogens include air, food, water, and fomites. Microbial airborne pathogens can occur as bioaerosols and include bacteria, viruses, molds, and spores. Infectious pathogens—such as viruses and bacteria—can also be found in household air such as influenza, cold, and even chickenpox and tuberculosis are transmitted within households. The food products that contain pathogens—such as Salmonella—can result in human infections within households via two mechanisms: contamination of human hands and fomites and direct consumption of raw or undercooked foodstuffs. Legionella pneumophila and Acanthamoeba spp. are the pathogens commonly associated with waterborne illness. Enteric, respiratory, and dermal pathogens have the greatest potential to be spread by fomites. Higher bacterial transfer rates from a fomite to the hand have been observed with hard, nonporous surfaces (phone receiver, or faucet) than with porous surfaces (clothings or sponges).
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Oregano and clove oils were diluted and examined for their activity against enveloped and non-enveloped RNA and DNA viruses. An innocuous oil such as olive oil was also included in this study as a control. Viruses were incubated with oil dilutions and enumerated by plaque assay. Antiviral activity of oregano and clove oils was demonstrated on two enveloped viruses of both the DNA and RNA types and the disintegration of virus envelope was visualised by negative staining using transmission electron microscopy.
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Essential oils (EOs) have long been applied as flavoring agents in foods, and due to their content in antimicrobial compounds, they have potential as natural agents for food preservation. In this study the effect of three EOs, clove, oregano and zataria, was evaluated on the infectivity of norovirus surrogates, i.e. feline calicivirus (FCV) and murine norovirus (MNV).Different concentrations of EOs were individually mixed with each virus at titers of ca. 7–8 log TCID50/ml and incubated for 2 h at 4 °C and 37 °C. The infectivity of the recovered viruses after triplicate treatments was evaluated by cell-culture assays. 2% of oregano EO at 37 °C decreased the FCV titers by 3.75 log TCID50/ml, with decreasing effects at lower concentrations, and also decreased MNV titers by 1.04–1.62 log TCID50/ml, with respect to the concentration used. Clove and zataria EO effects on FCV showed similar trends in titer reductions to those obtained with oregano EO, achieving the maximum titer reduction when FCV was treated at 37 °C with 0.1% of zataria EO. These results represent a step forward in the understanding of EOs as antimicrobials and their possible application in the food industry as alternative natural compounds to reduce viral contamination and, therefore enhancing food safety.
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This study examined the anti-herpes simplex virus type I activity of the major constituents of several essential oils. Plaque reduction assays were performed to evaluate anti-herpes simplex virus type I activity. Thymol and carvacrol both possessed significant antiviral activity with an IC50 of 7 µM, and herpes simplex virus type I was 90 % inactivated within 1 hr. The mode of antiviral action was shown to affect the virion directly. Evidence was also observed by electron microscopy. Evaluation of the structural requirements for antiviral activity of thymol-related monoterpenoids revealed that aliphatic side chains had a minor effect, while a hydrophilic group on the benzene ring was sufficient for activity. Our results suggest that thymol and carvacrol are potential candidates for topical therapeutic application to reduce herpes simplex virus transmission.
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Viruses are probably the most common cause of infectious disease acquired within indoor environments and have considerable impact on human health, ranging from severe life-threatening illnesses to relatively mild and self-limiting or asymptomatic diseases. In particular, viruses causing gastrointestinal and respiratory diseases spread rapidly in the community and cause considerable morbidity. Increasing numbers of people who have impaired immunity, for whom the consequences of infection can be much more serious, are now cared for in "out of hospital" settings. This review examines the dispersal, persistence and control of some common viruses in the domestic home and in community facilities. There is growing evidence that person-to-person transmission via the hands and contaminated fomites plays a key role in the spread of viral infections and there is a need for wider understanding of the potential for contaminated surfaces to act as unidentified vectors of pathogens in the transmission cycle. Intervention studies have shown that improved standards of education, personal hygiene (particularly handwashing) and targeted environmental hygiene have considerable impact in the control and prevention of infectious organisms.
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Pomegranate juice (PJ) and pomegranate polyphenolic extracts (PP) have antiviral effects against HIV-1, influenza, herpes, and poxviruses, and we recently demonstrated their effect against human noroviral surrogates. In the present study, the time-dependent effects of two commercial brands of PJ and PP at two concentrations (2 and 4 mg/mL) on the infectivity of foodborne viral surrogates (feline calicivirus FCV-F9, murine norovirus MNV-1, and MS2 bacteriophage) at room temperature for up to 1 h were evaluated. Each virus at ∼5 log(10) plaque-forming units (PFU)/mL was mixed with equal volumes of PJ, or PP at 4 or 8 mg/mL, and incubated for 0, 10, 20, 30, 45, and 60 min at room temperature. Viral titers after each treatment were determined by standardized plaque assays and compared with untreated controls. Virus titer reduction by PJ and PP was found to be a rather rapid process, with ≥50% of titer reduction occurring within the first 20 min of treatment for all three tested viruses. Within the first 20 min, titer reductions of 3.12, 0.79, and 0.23 log(10) PFU/mL for FCV-F9, MNV-1, and MS2, respectively, were obtained using PJ. FCV-F9, MNV-1, and MS2 titers were reduced by 4.02, 0.68, and 0.18 log(10) PFU/mL with 2 mg/mL PP and 5.09, 1.14, and 0.19 log(10) PFU/mL with 4 mg/mL PP, respectively, after 20 min. The mechanism of viral reduction by PJ and PP needs to be elucidated and clinical trials should be undertaken before recommending for therapeutic or preventive purposes.
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Unlabelled: Campylobacter jejuni is the leading cause of bacterial diarrheal illness worldwide. Many strains are now becoming multidrug resistant. Apple-based edible films containing carvacrol and cinnamaldehyde were evaluated for bactericidal activity against antibiotic resistant and susceptible C. jejuni strains on chicken. Retail chicken breast samples inoculated with D28a and H2a (resistant strains) and A24a (a sensitive strain) were wrapped in apple films containing cinnamaldehyde or carvacrol at 0.5%, 1.5%, and 3% concentrations, and then incubated at 4 or 23 °C for 72 h. Immediately after wrapping and at 72 h, samples were plated for enumeration of viable C. jejuni. The antimicrobial films exhibited dose- and temperature-dependent bactericidal activity against all strains. Films with ≥1.5% cinnamaldehyde reduced populations of all strains to below detection at 23 °C at 72 h. At 4 °C with cinnamaldehyde, reductions were variable for all strains, ranging from 0.2 to 2.5 logs and 1.8 to 6.0 logs at 1.5% and 3.0%, respectively. Films with 3% carvacrol reduced populations of A24a and H2a to below detection, and D28a by 2.4 logs at 23 °C and 72 h. A 0.5-log reduction was observed for both A24a and D28a, and 0.9 logs for H2a at 4 °C at 3% carvacrol. Reductions ranged from 1.1 to 1.9 logs and 0.4 to 1.2 logs with 1.5% and 0.5% carvacrol at 23 °C, respectively. The films with cinnamaldehyde were more effective than carvacrol films. Reductions at 23 °C were greater than those at 4 °C. Our results showed that antimicrobial apple films have the potential to reduce C. jejuni on chicken and therefore, the risk of campylobacteriosis. Possible mechanisms of antimicrobial effects are discussed. Practical application: Apple antimicrobial films could potentially be used in retail food packaging to reduce C. jejuni commonly present on food.
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The bactericidal effect of 3 natural agents (carvacrol, thymol, and eugenol) was evaluated as well as their binary and ternary mixtures on Listeria innocua inactivation in liquid model systems. Minimal bactericidal concentrations (MBC) of these agents were determined, and then binary and ternary mixtures were evaluated. Culture media were inoculated with L. innocua and incubated for 72 h at 35 °C. Turbidity of studied systems were determined every 24 h. The most effective individual antimicrobial agent was carvacrol, followed by thymol and then eugenol with MBCs of 150, 250, and 450 mg kg(-1), respectively. It was observed that the most effective binary mixture was 75 mg kg(-1) carvacrol and 62.5 mg kg(-1) thymol. Furthermore, the ternary mixture carvacrol-thymol-eugenol in concentrations of 75, 31.25, and 56.25 mg kg(-1), correspondingly, was the most effective for L. innocua inactivation. Several binary and ternary mixtures of these 3 natural antimicrobial agents worked adequately to inactivate L. innocua.
Article
Grape seed extract (GSE) is reported to have many pharmacological benefits, including antioxidant, anti-inflammatory, anticarcinogenic, and antimicrobial properties. However, the effect of this inexpensive rich source of natural phenolic compounds on human enteric viruses has not been well documented. In the present study, the effect of commercial GSE, Gravinol-S, on the infectivity of human enteric virus surrogates (feline calicivirus, FCV-F9; murine norovirus, MNV-1; and bacteriophage MS2) and hepatitis A virus (HAV; strain HM175) was evaluated. GSE at concentrations of 0.5, 1, and 2 mg/ml was individually mixed with equal volumes of each virus at titers of ∼7 log10 PFU/ml or ∼5 log10 PFU/ml and incubated for 2 h at room temperature or 37°C. The infectivity of the recovered viruses after triplicate treatments was evaluated by standardized plaque assays. At high titers (∼7 log10 PFU/ml), FCV-F9 was significantly reduced by 3.64, 4.10, and 4.61 log10 PFU/ml; MNV-1 by 0.82, 1.35, and 1.73 log10 PFU/ml; MS2 by 1.13, 1.43, and 1.60 log10 PFU/ml; and HAV by 1.81, 2.66, and 3.20 log10 PFU/ml after treatment at 37°C with 0.25, 0.50, and 1 mg/ml GSE, respectively (P < 0.05) in a dose-dependent manner. GSE treatment of low titers (∼5 log10 PFU/ml) at 37°C also showed viral reductions. Room-temperature treatments with GSE caused significant reduction of the four viruses, with higher reduction for low-titer FCV-F9, MNV-1, and HAV compared to high titers. Our results indicate that GSE shows promise for application in the food industry as an inexpensive novel natural alternative to reduce viral contamination and enhance food safety.
Article
Our previous study demonstrated that Melaleuca alternifolia (tea tree) oil (TTO) had an interesting antiviral activity against Influenza A in MDCK cells. In fact, when we tested TTO and some of its components, we found that TTO had an inhibitory effect on influenza virus replication at doses below the cytotoxic dose; terpinen-4-ol, terpinolene, and alfa-terpineol were the main active components. The aim of this study was to investigate the mechanism of action of TTO and its active components against Influenza A/PR/8 virus subtype H1N1 in MDCK cells. None of the test compounds showed virucidal activity nor any protective action for the MDCK cells. Thus, the effect of TTO and its active components on different steps of the replicative cycle of influenza virus was studied by adding the test compounds at various times after infection. These experiments revealed that viral replication was significantly inhibited if TTO was added within 2h of infection, indicating an interference with an early step of the viral replicative cycle of influenza virus. The influence of the compound on the virus adsorption step, studied by the infective center assay, indicated that TTO did not interfere with cellular attachment of the virus. TTO did not inhibit influenza virus neuraminidase activity, as shown by the experiment measuring the amount of 4-methylumbelliferone, cleaved by the influenza virus neuraminidase from the fluorogenic substrate 2'-O-(4-methylumbelliferyl)-N-acetylneuraminic acid. The effect of TTO on acidification of cellular lysosomes was studied by vital staining with acridine orange using bafilomycin A1 as positive control. The treatment of cells with 0.01% (v/v) of TTO at 37°C for 4h before staining inhibited the acridine orange accumulation in acid cytoplasmic vesicles, indicating that TTO could inhibit viral uncoating by an interference with acidification of intralysosomal compartment.
Article
The effect of high hydrostatic pressure (HPP) was evaluated for inactivation of murine norovirus (MNV), a propagable norovirus (NoV), and human NoV genogroup II.4. Inactivation of MNV was assessed by viral culturing (50% tissue culture infectious dose [TCID(50)]) and real-time reverse-transcription-polymerase chain reaction (RT-qPCR), whereas NoV survival was determined only by RT-qPCR. A treatment of 450 MPa for 15 min at 45°C was sufficient to inactivate 6.5 log(10) of infectious MNV in culture medium as determined by TCID(50). Further, the inactivation of MNV was enhanced when pressure was applied at an initial temperature of 25°C. On the other hand, a baroprotective effect was observed when MNV suspensions were supplemented with 10 mM of CaCl(2). A 400 MPa treatment at 45°C inactivated >5 log(10) of infectious MNV, whereas the addition of CaCl(2) increased the pressure resistance of MNV, with <0.5 log(10) reduction observed. MNV decay as determined by TCID(50) was generally greater than that determined by RT-qPCR; for instance, MNV genomes were detected even after 15 min treatment at 450 MPa, with <0.5 log(10) reduction. Experiments with NoV suspensions showed that all tested HPP treatments reduced the numbers of NoV by <0.5 log(10) units as determined by RT-qPCR. Additionally, RNA of human NoV was more resistant to certain HPP treatments than the RNA of MNV.
Article
The essential oils of seven aromatic plants from central west Argentina were isolated by steam distillation and analyzed by a gas chromatography/mass spectrometry technique. The oils were screened for cytotoxicity and in vitro inhibitory activity against herpes simplex virus type 1 (HSV-1), dengue virus type 2 (DENV-2) and Junin virus (JUNV). The oils showed a variable virucidal action according to the virus. JUNV was the least susceptible virus in comparison with HSV-1 and DENV-2. The better relationship between cytotoxicity and inhibitory activity was observed for the essential oil of Lantana grisebachiii (Seckt.) var. grisebachii against DENV-2 and HSV-1 with IC50 (inhibitory concentration 50%) values of 21.1 and 26.1 ppm, respectively. This effect was specific since the selectivity indices (ratio cytotoxicity/virucidal activity) were > 23.7 and > 19.1 for DENV-2 and HSV-1, respectively. Furthermore, the oil from L. grisebachii was also an effective inhibitor of HSV-2 and acyclovir resistant variants of herpes virus. This study demonstrates the effective and selective inhibitory activity of the essential oil from Lantana grisebachii against HSV and DENV by direct virus inactivation.
Article
Cranberry juice (CJ) and cranberry proanthocyanidins (PAC) are widely known for their antibacterial, antiviral, and pharmacological activities. The effect of CJ and cranberry PAC on the infectivity of foodborne viral surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), MS2 (ssRNA) bacteriophage, and ϕX-174 (ssDNA) bacteriophage after 0 min to 1h at room temperature was evaluated. Viruses at titers of ∼5log(10)PFU/ml were mixed with equal volumes of CJ at pH 2.6, CJ at pH 7.0, 0.30 mg/ml CJ PAC, 0.60mg/ml PAC, or water and incubated for 0, 10, 20, 30, 40, 50 min, and 1h at room temperature. Infectivity was determined using standard plaque assays. The viral reduction rates of the four tested viruses were found to vary considerably. Among the tested viruses, FCV-F9 titers were decreased the most by ∼5log(10)PFU/ml within 30 min. MS2 titers were decreased the least by only ∼1log(10)PFU/ml after 1h with CJ at pH 2.6 and 0.30 mg/ml PAC, and ∼0.5log(10)PFU/ml with CJ at pH 7.0 and 0.15 mg/ml PAC. MNV-1 and ϕ-X174 showed comparable titer reductions which was between that of FCV-F9 and MS2. In most cases, viral reduction within the first 10 min of treatment accounted for ≥50% of the total reduction. Transmission electron microscopy on FCV-F9 treated with CJ and PAC revealed structural changes. This study shows potential of using natural bioactive compounds for controlling foodborne viral diseases. Further studies are necessary to elucidate the mechanism of action of CJ components and to understand the differences in viral titer reduction profiles.
Article
Murine norovirus (MNV) is a viral agent newly identified in laboratory mice and a large number of genetically diverse MNV strains have been reported to date. A broadly reactive TaqMan-based real-time reverse transcription (RT)-polymerase chain reaction (PCR) assay was developed for MNVs. Novel primers and a TaqMan MGB probe were designed targeting highly conserved sequences among MNV strains, which are located in the open reading frames 1 (ORF1)-ORF2 junction region. The quantitative range of this assay was determined as 1.0 × 10(2)-1.0 × 10(8)copies/PCR tube based on a 10-fold serial dilution of plasmid DNA containing the target sequences. Viral RNA in eight murine stool specimens positive by nested RT-PCR assay was measured, and the highest viral RNA load was calculated at 4.7 × 10(6)copies/g-stool. MNV was inoculated into RAW 264.7 cells, and the viral RNA was monitored to validate assay sensitivity. MNV-RNA in the supernatant was detected during in vitro replication, which increased substantially from 5 to 30 h post-infection (hpi) and reached more than 1.0 × 10(10)copies/mL at 96 hpi. This real-time RT-PCR assay is a useful tool to detect and quantify MNV-RNA in in vivo and in vitro studies.
Article
The effect of cranberry juice (CJ) and cranberry proanthocyanidins (PAC) on the infectivity of human enteric virus surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), MS2(ssRNA) bacteriophage, and phiX-174(ssDNA) bacteriophage was studied. Viruses at high (approximately 7 log(10) PFU/ml) or low (approximately 5 log(10) PFU/ml) titers were mixed with equal volumes of CJ, 0.30, 0.60, and 1.20 mg/ml final PAC concentration, or water and incubated for 1 h at room temperature. Viral infectivity after treatments was evaluated using standardized plaque assays. At low viral titers, FCV-F9 was undetectable after exposure to CJ or the three tested PAC solutions. MNV-1 was reduced by 2.06 log(10) PFU/ml with CJ, and 2.63, 2.75, and 2.95 log(10) PFU/ml with 0.15, 0.30, and 0.60 mg/ml PAC, respectively. MS2 titers were reduced by 1.14 log(10) PFU/ml with CJ, and 0.55, 0.80, and 0.96 log(10) PFU/ml with 0.15, 0.30, and 0.60 mg/ml PAC, respectively. phi-X174 titers were reduced by 1.79 log(10) PFU/ml with CJ, and 1.95, 3.67, and 4.98 log(10) PFU/ml with PAC at 0.15, 0.30, and 0.60 mg/ml, respectively. Experiments using high titers showed similar trends but with decreased effects. CJ and PAC show promise as natural antivirals that could potentially be exploited for foodborne viral illness treatment and prevention.