Resveratrol suppresses persistent airway inflammation and hyperresponsivess might partially via nerve growth factor in respiratory syncytial virus-infected mice

Interaction of Human Respiratory Syncytial Virus (HRSV) Matrix Protein with Resveratrol Shows Antiviral Effect

The respiratory syncytial virus (RSV) matrix protein plays key roles in the virus life cycle and is essential for budding, as it stimulates the optimal membrane curvature necessary for the emergence of viral particles. Resveratrol, a polyphenol (3,4',5-trihydroxy-trans-stilbene) produced by plants, exhibits pharmacological effects, including anti-inflammatory and antiviral activities. In this study, resveratrol was tested in HEp-2 (Epidermoid carcinoma of the larynx cell) cells for its post-infection effects, and recombinant M protein was produced to characterize the biophysical mechanisms underlying this interaction. The CC50 (Cytotoxic concentration 50%) value for resveratrol was determined to be 297 μM over 48 h, and the results from the HEp-2 cell cultures demonstrated a viral inhibition of 42.7% in the presence of resveratrol, with an EC50 (Half maximal effective concentration) of 44.26 μM. This mechanism may occur through interaction with the M protein responsible for the budding of mature viral particles. Biophysical assays enabled us to characterize the interaction of the M/resveratrol complex as an entropically driven bond, guided by hydrophobic interactions at the dimerization interface of the M protein, which is essential for the stabilization and formation of the oligomers necessary for viral budding. These findings suggest that one of the targets for resveratrol binding is the M protein, indicating a potential site for blocking the progression of the infection.

Sonication-Assisted Self-Assembled Resveratrol Nanoparticles with Enhanced Antiviral and Anti-inflammatory Activity against Respiratory Syncytial Virus-Induced Pneumonia

Respiratory syncytial virus (RSV)-induced viral pneumonia in children is common worldwide. Its high occurrence and lack of an effective vaccine make it a leading cause of death in children. Severe RSV infection can trigger uncontrolled inflammatory responses in patients, so the development of small molecule drugs with the dual function of "direct antivirus" and "inflammatory response regulation" is welcome. Resveratrol (Res) has been reported to have antiviral and anti-inflammatory pharmacological effects, but its application is limited because of its poor water solubility and oral bioavailability. Based on small-molecule nanotechnology, we developed a sonication-assisted self-assembly method for preparing insoluble Res into highly soluble resveratrol nanoparticles (Res NPs). The obtained Res NPs exhibited a higher water solubility and a faster dissolution rate, which was more conducive to the effectiveness of Res in addressing RSV-induced viral pneumonia. In vitro studies had shown that Res NPs played an antiviral role by inhibiting RSV replication and reducing the production of pro-inflammatory cytokines. Nebulized inhalation administration of Res NPs prolonged the drug's residence time in the lungs, which appears to increase the accumulation and effectiveness of Res NPs. Additionally, in vivo studies had demonstrated significant benefits of Res NPs in inhibiting RSV viral load and improving the pulmonary microenvironment in RSV-infected mice. Both antiviral and anti-inflammatory experiments had confirmed that the pharmacological activity of Res NPs is superior to that of Res. This suggested that nanosizing Res was an effective way to enhance the original pharmacological activity of Res and also offered a new formulation strategy for treating viral pneumonia.

Effects of Nasal Solution Incorporating Resveratrol and Carboxymethyl-Β-Glucan in Preschool Non-Atopic Children with Wheezing

Upper respiratory tract infections (URTI) account for more than 80% of wheezing episodes in children with a high incidence of hospitalization in preschool age. Most children with symptoms of wheezing during an URTI are usually non-atopic. As the majority of wheezing episodes resulting from URTI are attributed to viral triggers, several studies have suggested the potential anti-inflammatory and antiviral properties of resveratrol. This study aims to identify the effect of resveratrol for pediatric non-atopic patients with recurrent wheezing triggered by URTIs. We conducted a prospective single-blind study to assess the effectiveness of a short course of nasal solutions incorporating resveratrol and carboxymethyl-β-glucan, administered for 7 days at the onset of URTIs, compared to standard nasal lavage with 0.9% saline solution. A total of 19 patients entered the active group, 20 patients were assigned to the placebo group. The comparison of overall wheezing days (p < 0.001), mean wheezing days per month (p < 0.01), and wheezing episodes per patient (p < 0.001) in the two groups showed a significant reduction in the group receiving resveratrol compared with the placebo group, with less hospital access (p < 0.001) and oral corticosteroid administration (p < 0.01). Our findings seem to suggest that, in non-atopic children with recurrent wheezing secondary to URTIs, nasal resveratrol could be effective to prevent or reduce the occurrence of wheezing, when started from the onset of upper airway symptoms.

Resveratrol inhibits respiratory syncytial virus replication by targeting heparan sulfate proteoglycans

Resveratrol, renowned as an antioxidant, also exhibits significant potential in combatting severe respiratory infections, particularly the respiratory syncytial virus (RSV). Nevertheless, the specific mechanism underlying its inhibition of RSV replication remains unexplored. Heparan sulfate proteoglycans (HSPGs) play a pivotal role as attachment factors for numerous viruses, offering a promising avenue for countering viral infections. Our research has unveiled that resveratrol effectively curbs RSV infection in a dose-dependent manner. Remarkably, resveratrol disrupts the early stages of RSV infection by engaging with HSPGs, rather than interacting with RSV surface proteins like fusion (F) protein and glycoprotein (G). Resveratrol's affinity appears to be predominantly directed towards the negatively charged sites on HSPGs, thus impeding the binding of viral receptors. In an in vivo study involving RSV-infected mice, resveratrol demonstrates its potential by ameliorating pulmonary pathology. This improvement is attributed to the inhibition of pro-inflammatory cytokine expression and a reduction in viral load within the lungs. Notably, resveratrol specifically alleviates inflammation characterized by an abundance of neutrophils in RSV-infected mice. In summation, our data first shows how resveratrol combats RSV infection through interactions with HSPGs, positioning it as a promising candidate for innovative drug development targeting RSV infections. Our study provides insight into the mechanism of resveratrol antiviral infection.

Reduced Serum Brain-Derived Neurotrophic Factor in Infants Affected by Severe Bronchiolitis

BACKGROUND

Bronchiolitis is an acute viral infection of the lower respiratory tract, typical of infants in their first year of life and causing hypoxia in the most serious cases. Bronchiolitis recognizes various demographic risk factors that are associated with greater clinical severity; however, no laboratory factors are yet able to correlate with the clinical severity. Neurotrophins as Brain-Derived Neurotrophic Factor (BDNF) are mediators of neuronal plasticity. BDNF is constitutively expressed in smooth muscle cells and epithelium of the lower respiratory tract, and as it is released during inflammatory conditions, serum levels may have a relevant role in the prognosis of infants with bronchiolitis.

OBJECTIVE

In the present pilot study, we aimed to disclose the presence of serum BDNF in infants hospitalized with bronchiolitis at discharge as a disease severity indicator.

METHODS AND RESULTS

Serum BDNF, measured at hospital discharge, was significantly lower in severe bronchiolitis (expressed as O2-supplemented infants). Furthermore, no changes were disclosed for the Tropomyosin receptor kinase B, the main BDNF receptor and neurofilament light chain, a biomarker of neuronal degeneration.

CONCLUSION

Low serum BDNF in infants with severe bronchiolitis could be associated with a higher utilization by lung cells or with an altered production by lung cells. Therefore, further research is required to study if a decreased production or increased consumption of this biomarker is at the base of the above-mentioned findings.

Anti-S100A4 antibody administration alleviates bronchial epithelial-mesenchymal transition in asthmatic mice

We elucidated the effect of S100A4 on airway remodeling by regulating airway inflammation and epithelial-mesenchymal transition (EMT) in mouse models of asthma. Asthmatic mouse models were established by sensitization and challenged with ovalbumin (OVA). Anti-S100A4 antibody or control IgG antibody was administered daily before the OVA challenge. After the last challenge, airway inflammation and airway hyperresponsiveness were measured; lung tissues and bronchoalveolar lavage fluid (BALF) were harvested. Lung tissue sections were stained and evaluated for pathological changes. Levels of inflammatory cytokines were measured using ELISA. Levels of S100A4 and EMT markers were determined via western blotting analysis. Human bronchial epithelial cells were stimulated with 100 mg/mL house dust mites (HDMs) to evaluate the effect of S100A4 downregulation on EMT in vitro. S100A4 was increased in lung tissues and BALF from asthmatic mice. The asthmatic mice presented airway hyperresponsiveness, airway inflammation, and airway remodeling. After anti-S100A4 antibody administration, pathophysiological signs, including airway hyperresponsiveness and increased infiltration of inflammatory cells, were attenuated. Additionally, anti-S100A4 administration downregulated vimentin and α-SMA expression and upregulated E-cadherin expression in OVA-challenged mice. S100A4 downregulation also inhibited EMT process in HDM-stimulated 16HBE cells. Anti-S100A4 antibody administration alters airway remodeling by preventing EMT in mouse models of asthma.

Specialized metabolites from plants as a source of new multi-target antiviral drugs: a systematic review

Viral infections have always been the main global health challenge, as several potentially lethal viruses, including the hepatitis virus, herpes virus, and influenza virus, have affected human health for decades. Unfortunately, most licensed antiviral drugs are characterized by many adverse reactions and, in the long-term therapy, also develop viral resistance; for these reasons, researchers have focused their attention on investigating potential antiviral molecules from plants. Natural resources indeed offer a variety of specialized therapeutic metabolites that have been demonstrated to inhibit viral entry into the host cells and replication through the regulation of viral absorption, cell receptor binding, and competition for the activation of intracellular signaling pathways. Many active phytochemicals, including flavonoids, lignans, terpenoids, coumarins, saponins, alkaloids, etc., have been identified as potential candidates for preventing and treating viral infections. Using a systematic approach, this review summarises the knowledge obtained to date on the in vivo antiviral activity of specialized metabolites extracted from plant matrices by focusing on their mechanism of action.

Necroptosis signaling and NLRP3 inflammasome cross-talking in epithelium facilitate Pseudomonas aeruginosa mediated lung injury

Pseudomonas aeruginosa induced acute lung injury is such a serious risk to public health, but the pathological regulation remains unclear. Here, we reported that PA mediated epithelial necroptosis plays an important role in pathological process. Pharmacological and genomic ablation of necroptosis signaling ameliorate PA mediated ALI and pulmonary inflammation. Our results further proved NLRP3 inflammasome to involve in the process. Mechanism investigation revealed the cross-talking between inflammasome activation and necroptosis that MLKL-dependent necroptosis signaling promotes the change of mitochondrial membrane potential for the release of reactive oxygen species (ROS), which is the important trigger for functional inflammasome activation. Furthermore, antioxidants such as Mito-TEMPO was confirmed to significantly restrain inflammasome activation in epithelium, resulting in a reduction in PA induced pulmonary inflammation. Taken together, our findings revealed that necroptosis-triggered NLRP3 inflammasome in epithelium plays a crucial role in PA mediated injury, which could be a potential therapeutic target for pulmonary inflammation.

Persistence of RNA Viruses in the Respiratory Tract: An Overview

Respiratory RNA viruses are a major cause of acute lower respiratory tract infections and contribute substantially to hospitalization among infants, elderly, and immunocompromised. Complete viral clearance from acute infections is not always achieved, leading to persistence. Certain chronic respiratory diseases like asthma and chronic obstructive pulmonary disease have been associated with persistent infection by human respiratory syncytial virus and human rhinovirus, but it is still not clear whether RNA viruses really establish long-term infections as it has been recognized for DNA viruses as human bocavirus and adenoviruses. Herein, we summarize evidence of RNA virus persistence in the human respiratory tract, as well as in some animal models, to highlight how long-term infections might be related to development and/or maintenance of chronic respiratory symptoms.

Knockdown of Brg1 reduced mucus secretion in HDM stimulated airway inflammation

BACKGROUND

The Brg1 (Brahma-related gene 1) is an important chromatin remodeling factor protein. The Brg1 protein can promote the transcriptional activation or inhibit target genes through regulating ATP hydrolysis which rearranges the nucleosomes position and the histone DNA interaction. In this study, we explored the role of Brg1 in house dust mite (HDM) stimulated airway inflammation.

METHODS

The wild-type C57BL/6 mice (wild-type, WT) and alveolar epithelial cells specifically knockout Brg1 mice (Brg1^fl/fl) were selected as the experimental subjects. HDM was used to stimulate human bronchial epithelial cells (16HBE) to construct an model of airway inflammation in vitro. The asthma group was established with HDM, and the control group was treated with normal saline. Wright's staining for the detection of differential counts of inflammatory cells in bronchoalveolar lavage fluid (BALF). Invasive lung function was used to assess the airway compliance. Hematoxylin and eosin (HE) staining and periodic acid-schiff (PAS) staining were used to detect mucus secretion. Immunohistochemistry was used to measure mucin glycoprotein 5AC (MUC5AC) protein expression in airway epithelium. Western blotting was used to detect the MUC5AC and JAK1/2-STAT6 proteins in mouse lung tissues and 16HBE cells. Co-immunoprecipitation (Co-IP) and Chromatin Immunoprecipitation (CHIP) were used to detect whether Brg1 could regulate the JAK1/2-STAT6 signaling pathway.

RESULTS

The airway inflammation, pulmonary ventilation resistance, airway mucus secretion, MUC5AC and IL-13 in BALF and MUC5AC protein expression in lung tissue of Brg1 knockout mice stimulated by HDM were lower than those of wild-type mice. The expression of MUC5AC protein in HDM stimulated Brg1 knockdown 16HBE cells was significantly lower than that in the control group. In vivo and in vitro, it was found that the activation of JAK1/2-STAT6 signal pathway in mouse lung tissue or 16HBE cells was inhibited after knockdown of Brg1 gene. The Co-IP and CHIP results showed that Brg1 could bind to the JAK1/2 promoter region and regulate the expression of JAK1/2 gene.

CONCLUSION

The Brg1 may promote the secretion of airway mucus stimulated by HDM through regulating the JAK1/2-STAT6 pathway. Knockdown of Brg1 reduced mucus secretion in HDM stimulated airway inflammation.

Molecular Mechanisms of RSV and Air Pollution Interaction: A Scoping Review

RSV is one of the major infectious agents in paediatrics, and its relationship with air pollution is frequently observed. However, the molecular basis of this interaction is sparsely reported. We sought to systematically review the existing body of literature and identify the knowledge gaps to answer the question: which molecular mechanisms are implied in the air pollutants-RSV interaction? Online databases were searched for original studies published before August 2022 focusing on molecular mechanisms of the interaction. The studies were charted and a narrative synthesis was based upon three expected directions of influence: a facilitated viral entry, an altered viral replication, and an inappropriate host reaction. We identified 25 studies published between 1993 and 2020 (without a noticeable increase in the number of studies) that were performed in human (n = 12), animal (n = 10) or mixed (n = 3) models, and analysed mainly cigarette smoke (n = 11), particulate matter (n = 4), nanoparticles (n = 3), and carbon black (n = 2). The data on a damage to the epithelial barrier supports the hypothesis of facilitated viral entry; one study also reported accelerated viral entry upon an RSV conjugation to particulate matter. Air pollution may result in the predominance of necrosis over apoptosis, and, as an effect, an increased viral load was reported. Similarly, air pollution mitigates epithelium function with decreased IFN-γ and Clara cell secretory protein levels and decreased immune response. Immune response might also be diminished due to a decreased viral uptake by alveolar macrophages and a suppressed function of dendritic cells. On the other hand, an exuberant inflammatory response might be triggered by air pollution and provoke airway hyperresponsiveness (AHR), prolonged lung infiltration, and tissue remodeling, including a formation of emphysema. AHR is mediated mostly by increased IFN-γ and RANTES concentrations, while the risk of emphysema was related to the activation of the IL-17 → MCP-1 → MMP-9 → MMP-12 axis. There is a significant lack of evidence on the molecular basics of the RSV-air pollution interaction, which may present a serious problem with regards to future actions against air pollution effects. The major knowledge gaps concern air pollutants (mostly the influence of cigarette smoke was investigated), the mechanisms facilitating an acute infection or a worse disease course (since it might help plan short-term, especially non-pharmacological, interventions), and the mechanisms of an inadequate response to the infection (which may lead to a prolonged course of an acute infection and long-term sequelae). Thus far, the evidence is insufficient regarding the broadness and complexity of the interaction, and future studies should focus on common mechanisms stimulated by various air pollutants and a comparison of influence of the different contaminants at various concentrations.

The Multifaceted Roles of Autophagy in Infectious, Obstructive, and Malignant Airway Diseases

Autophagy is a highly conserved dynamic process by which cells deliver their contents to lysosomes for degradation, thus ensuring cell homeostasis. In response to environmental stress, the induction of autophagy is crucial for cell survival. The dysregulation of this degradative process has been implicated in a wide range of pathologies, including lung diseases, representing a relevant potential target with significant clinical outcomes. During lung disease progression and infections, autophagy may exert both protective and harmful effects on cells. In this review, we will explore the implications of autophagy and its selective forms in several lung infections, such as SARS-CoV-2, Respiratory Syncytial Virus (RSV) and Mycobacterium tuberculosis (Mtb) infections, and different lung diseases such as Cystic Fibrosis (CF), Chronic Obstructive Pulmonary Disease (COPD), and Malignant Mesothelioma (MM).

Application of network pharmacology in the study of the mechanism of action of traditional chinese medicine in the treatment of COVID-19

Network pharmacology was rapidly developed based on multidisciplinary holistic analysis of biological systems, which has become a popular tool in traditional Chinese medicine (TCM) research in recent years. Its characteristics of integrity and systematization provide a new approach for the study on complex TCM systems, which has many similarities with the holistic concept of TCM. It has been widely used to explain the mechanism of TCM treatment of diseases, drug repositioning, and interpretation of compatibility of TCM prescriptions, to promote the modernization of TCM. The use of TCM have provided crucial support on prevention and treatment of diseases such as the famous “three medicines and three prescriptions”. Furthermore, TCM has become an important part of the treatment of COVID-19 and is one of the main contents of the “Chinese plan” to fight the epidemic. The current review demonstrated the role of TCM in treating diseases with multiple components, multiple targets, and multiple pathways, interprets the connotation of TCM treatment method selection based on pathogenesis and also discusses the application of network pharmacology in the study of COVID-19 treatment in TCM including single drug and prescription. However, there are still some shortcomings such as the lack of experimental verification and regular upgrading of the TCM pharmacology network. Therefore, we must pay attention to the characteristics of TCM and develop a network pharmacology method suitable for TCM system research when applying network pharmacology to TCM research.

Resveratrol and Immune Cells: A Link to Improve Human Health

The use of polyphenols as adjuvants in lowering risk factors for various debilitating diseases has been investigated in recent years due to their possible antioxidant action. Polyphenols represent a fascinating and relatively new subject of research in nutraceuticals and nutrition, with interest rapidly expanding since they can help maintain health by controlling metabolism, weight, chronic diseases, and cell proliferation. Resveratrol is a phenolic compound found mostly in the pulp, peels, seeds, and stems of red grapes. It has a wide variety of biological actions that can be used to prevent the beginning of various diseases or manage their symptoms. Resveratrol can influence multiple inflammatory and non-inflammatory responses, protecting organs and tissues, thanks to its interaction with immune cells and its activity on SIRT1. This compound has anti-inflammatory, antioxidant, anti-apoptotic, neuroprotective, cardioprotective, anticancer, and antiviral properties, making it a potential adjunct to traditional pharmaceutical therapy in public health. This review aims to provide a comprehensive analysis of resveratrol in terms of active biological effects and mechanism of action in modifying the immune cellular response to promote human psychophysical health.

An overview on the RSV-mediated mechanisms in the onset of non-allergic asthma

Respiratory syncytial virus (RSV) infection is recognized as an important risk factor for wheezing and asthma, since it commonly affects babies during lung development. While the role of RSV in the onset of atopic asthma is widely recognized, its impact on the onset of non-atopic asthma, mediated via other and independent causal pathways, has long been also suspected, but the association is less clear. Following RSV infection, the release of local pro-inflammatory molecules, the dysfunction of neural pathways, and the compromised epithelial integrity can become chronic and influence airway development, leading to bronchial hyperreactivity and asthma, regardless of atopic status. After a brief review of the RSV structure and its interaction with the immune system and neuronal pathways, this review summarizes the current evidence about the RSV-mediated pathogenic pathways in predisposing and inducing airway dysfunction and non-allergic asthma development.

Resveratrol (RV): A pharmacological review and call for further research

Resveratrol (RV) is a well-known polyphenolic compound in various plants, including grape, peanut, and berry fruits, which is quite famous for its association with several health benefits such as anti-obesity, cardioprotective neuroprotective, antitumor, antidiabetic, antioxidants, anti-age effects, and glucose metabolism. Significantly, promising therapeutic properties have been reported in various cancer, neurodegeneration, and atherosclerosis and are regulated by several synergistic pathways that control oxidative stress, cell death, and inflammation. Similarly, RV possesses a strong anti-adipogenic effect by inhibiting fat accumulation processes and activating oxidative and lipolytic pathways, exhibiting their cardioprotective effects by inhibiting platelet aggregation. The RV also shows significant antibacterial effects against various food-borne pathogens (Listeria, Campylobacter, Staphylococcus aureus, and E. coli) by inhibiting an electron transport chain (ETC) and F0F1-ATPase, which decreases the production of cellular energy that leads to the spread of pathogens. After collecting and analyzing scientific literature, it may be concluded that RV is well tolerated and favorably affects cardiovascular, neurological, and diabetic disorders. As such, it is possible that RV can be considered the best nutritional additive and a complementary drug, especially a therapeutic candidate. Therefore, this review would increase knowledge about the blend of RV as well as inspire researchers around the world to consider RV as a pharmaceutical drug to combat future health crises against various inhumane diseases. In the future, this article will be aware of discoveries about the potential of this promising natural compound as the best nutraceuticals and therapeutic drugs in medicine.

Network Pharmacology Reveals That Resveratrol Can Alleviate COVID-19-Related Hyperinflammation

Hyperinflammation is related to the development of COVID-19. Resveratrol is considered an anti-inflammatory and antiviral agent. Herein, we used a network pharmacological approach and bioinformatic gene analysis to explore the pharmacological mechanism of Resveratrol in COVID-19 therapy. Potential targets of Resveratrol were obtained from public databases. SARS-CoV-2 differentially expressed genes (DEGs) were screened out via bioinformatic analysis Gene Expression Omnibus (GEO) datasets GSE147507, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis; then, protein-protein interaction network was constructed. The common targets, GO terms, and KEGG pathways of Resveratrol targets and SARS-CoV-2 DEGs were confirmed. KEGG Mapper queried the location of common targets in the key pathways. A notable overlap of the GO terms and KEGG pathways between Resveratrol targets and SARS-CoV-2 DEGs was revealed. The shared targets between Resveratrol targets and SARS-CoV-2 mainly involved the IL-17 signaling pathway, NF-kappa B signaling pathway, and TNF signaling pathway. Our study uncovered that Resveratrol is a promising therapeutic candidate for COVID-19 and we also revealed the probable key targets and pathways involved. Ultimately, we bring forward new insights and encourage more studies on Resveratol to benefit COVID-19 patients.

Effect of BDNF on airway inflammation in a rat model of COPD

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. The present study aimed to investigate the effect of brain-derived neurotrophic factor (BDNF) on lung function and airway inflammation in a rat model of COPD. A rat model of COPD was established in this study, and anti-BDNF antibody was injected to observe the effect of BDNF on pulmonary function and airway inflammation. Lung function and hematoxylin and eosin staining analyses were performed. BDNF in the airway was examined using immunohistochemistry, western blotting and enzyme-linked immunosorbent assay. Levels of oxidant stress and inflammatory cytokines were measured. After long-term heavy cigarette exposure, pulmonary inflammation and emphysema were observed, while lung function had deteriorated in the COPD, COPD + anti-BDNF and COPD + normal saline groups. Levels of BDNF expression, malondialdehyde, tumor necrosis factor-α and interleukin-6 were increased in rats with COPD compared with control rats, while levels of superoxide dismutase and glutathione peroxidase were decreased. Anti-BDNF intervention improved airway inflammation. To conclude, anti-BDNF intervention could alleviate inflammation and improve any imbalance between oxidation and antioxidation in the airway.

Efficacy of phytochemicals as immunomodulators in managing COVID-19: a comprehensive view

Throughout history, disease outbreaks have worked havoc upon humanity, sometimes reorienting the history and at times, signaling the end of entire civilizations and the modern pandemic that the world is dealing with, is COVID-19 or SARS-CoV-2. A healthy immunity could be an ideal gear for resisting COVID-19 for neither medicines nor vaccines have been ascertained till date. In view of the present scenario, there is a demanding necessity to analyze innovative and valid techniques for forestalling and cure of COVID-19 by re-evaluating the structure of the natural compounds for drug designing. The Ayurveda has come forward by prescribing a lot of medicinal herbs for combating this dreaded disease. We have searched from sources in Pubmed and Google Scholar and found 1509 items. The search criteria were limited to the effect of phytochemicals in certain immunomodulatory aspects of viral infection. The original research papers related to the works on phytochemicals in the down regulation of NF-kB, activation of NK and CD8+ cells, inhibition of inflammatory cytokine release and ROS scavenging were included in our study. Here, we try to focus on the immunoregulatory cells which have a vital aspect in COVID-19 and highlight the potential effects of the restorative use of phytochemicals as drugs or dietary supplements.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-021-00706-2.

Can Resveratrol-Inhaled Formulations Be Considered Potential Adjunct Treatments for COVID-19?

The pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has led to an extraordinary threat to the global healthcare system. This infection disease, named COVID-19, is characterized by a wide clinical spectrum, ranging from asymptomatic or mild upper respiratory tract illness to severe viral pneumonia with fulminant cytokine storm, which leads to respiratory failure. To improve patient outcomes, both the inhibition of viral replication and of the unwarranted excessive inflammatory response are crucial. Since no specific antiviral drug has been proven effective for the treatment of patients and the only upcoming promising agents are monoclonal antibodies, inexpensive, safe, and widely available treatments are urgently needed. A potential anti-inflammatory molecule to be evaluated, which possesses antiviral activities in several experimental models, is the polyphenol resveratrol. This compound has been shown to inhibit SARS-CoV-2 replication in human primary bronchial epithelial cell cultures and to downregulate several pathogenetic mechanisms involved in COVID-19 severity. The use of resveratrol in clinical practice is limited by the low bioavailability following oral administration, due to the pharmacokinetic and metabolic characteristics of the molecule. Therefore, topical administration through inhaled formulations could allow us to achieve sufficiently high concentrations of the compound in the airways, the entry route of SARS-CoV-2.

A Comprehensive Study on the Antimicrobial Properties of Resveratrol as an Alternative Therapy

Resveratrol is a polyphenolic antioxidant whose possible health benefits include anticarcinogenic, antiaging, and antimicrobial properties that have gained significant attention. The compound is well accepted by individuals and has been commonly used as a nutraceutical in recent decades. Its widespread usage makes it essential to study as a single agent as well as in combination with traditional prescription antibiotics as regards to antimicrobial properties. Resveratrol demonstrates the action of antimicrobials against a remarkable bacterial diversity, viruses, and fungus. This report explains resveratrol as an all-natural antimicrobial representative. It may modify the bacterial virulence qualities resulting in decreased toxic substance production, biofilm inhibition, motility reduction, and quorum sensing disturbance. Moreover, in conjunction with standard antibiotics, resveratrol improves aminoglycoside efficacy versus Staphylococcus aureus, while it antagonizes the deadly function of fluoroquinolones against S. aureus and also Escherichia coli. The present study aimed to thoroughly review and study the antimicrobial potency of resveratrol, expected to help researchers pave the way for solving antimicrobial resistance.

MicroRNA-98 reduces nerve growth factor expression in nicotine-induced airway remodeling

Evolving evidence suggests that nicotine may contribute to impaired asthma control by stimulating expression of nerve growth factor (NGF), a neurotrophin associated with airway remodeling and airway hyperresponsiveness. We explored the hypothesis that nicotine increases NGF by reducing lung fibroblast (LF) microRNA-98 (miR-98) and PPARγ levels, thus promoting airway remodeling. Levels of NGF, miR-98, PPARγ, fibronectin 1 (FN1), endothelin-1 (EDN1, herein referred to as ET-1), and collagen (COL1A1 and COL3A1) were measured in human LFs isolated from smoking donors, in mouse primary LFs exposed to nicotine (50 μg/ml), and in whole lung homogenates from mice chronically exposed to nicotine (100 μg/ml) in the drinking water. In selected studies, these pathways were manipulated in LFs with miR-98 inhibitor (anti-miR-98), miR-98 overexpression (miR-98 mimic), or the PPARγ agonist rosiglitazone. Compared with unexposed controls, nicotine increased NGF, FN1, ET-1, COL1A1, and COL3A1 expression in human and mouse LFs and mouse lung homogenates. In contrast, nicotine reduced miR-98 levels in LFs in vitro and in lung homogenates in vivo Treatment with anti-miR-98 alone was sufficient to recapitulate increases in NGF, FN1, and ET-1, whereas treatment with a miR-98 mimic significantly suppressed luciferase expression in cells transfected with a luciferase reporter linked to the putative seed sequence in the NGF 3'UTR and also abrogated nicotine-induced increases in NGF, FN1, and ET-1 in LFs. Similarly, rosiglitazone increased miR-98 and reversed nicotine-induced increases in NGF, FN1, and ET-1. Taken together, these findings demonstrate that nicotine-induced increases in NGF and other markers of airway remodeling are negatively regulated by miR-98.

Resveratrol, Rapamycin and Metformin as Modulators of Antiviral Pathways

Balanced nutrition and appropriate dietary interventions are fundamental in the prevention and management of viral infections. Additionally, accurate modulation of the inflammatory response is necessary to achieve an adequate antiviral immune response. Many studies, both in vitro with mammalian cells and in vivo with small animal models, have highlighted the antiviral properties of resveratrol, rapamycin and metformin. The current review outlines the mechanisms of action of these three important compounds on the cellular pathways involved with viral replication and the mechanisms of virus-related diseases, as well as the current status of their clinical use.

Can phytotherapy with polyphenols serve as a powerful approach for the prevention and therapy tool of novel coronavirus disease 2019 (COVID-19)?

Much more serious than the previous severe acute respiratory syndrome (SARS) coronavirus (CoV) outbreaks, the novel SARS-CoV-2 infection has spread speedily, affecting 213 countries and causing ∼17,300,000 cases and ∼672,000 (∼+1,500/day) deaths globally (as of July 31, 2020). The potentially fatal coronavirus disease (COVID-19), caused by air droplets and airborne as the main transmission modes, clearly induces a spectrum of respiratory clinical manifestations, but it also affects the immune, gastrointestinal, hematological, nervous, and renal systems. The dramatic scale of disorders and complications arises from the inadequacy of current treatments and absence of a vaccine and specific anti-COVID-19 drugs to suppress viral replication, inflammation, and additional pathogenic conditions. This highlights the importance of understanding the SARS-CoV-2 mechanisms of actions and the urgent need of prospecting for new or alternative treatment options. The main objective of the present review is to discuss the challenging issue relative to the clinical utility of plants-derived polyphenols in fighting viral infections. Not only is the strong capacity of polyphenols highlighted in magnifying health benefits, but the underlying mechanisms are also stressed. Finally, emphasis is placed on the potential ability of polyphenols to combat SARS-CoV-2 infection via the regulation of its molecular targets of human cellular binding and replication, as well as through the resulting host inflammation, oxidative stress, and signaling pathways.

Panax notoginseng saponin R1 modulates TNF-α/NF-κB signaling and attenuates allergic airway inflammation in asthma

BACKGROUD

Panax notoginseng saponin R1 (PNS-R1) is one of the most important chemical monomers derived from the panax notoginseng, and our previous study found that PNS-R1 reduced glucocorticoid-induced apoptosis in asthmatic airway epithelial cells. Thus, in this study, we explored the effects of the PNS-R1 on inflammation of allergic asthma.

METHODS

The asthmatic mice were administered 15 mg/kg PNS-R1 by intraperitoneal injection three days before sensitized to OVA. The effects of PNS-R1 on asthmatic mice were detected by airway hyperresponsiveness, inflammation, mucus hypersecretion and inflammatory cytokines such as interleukin (IL)-13, IL-4, IL-5, IL-8 and tumor necrosis factor (TNF)-α were studied. We also treated human bronchial epithelial cells (16HBE) with house dust mites (HDM) and then detected the secretion of cellular inflammatory factors (IL-13 and TNF-α). Western blot and immunofluorescence were used to examine the effect of PNS-R1 on TNF-α/NF-κB pathway. TNF-α/NF-κB/IKK signal pathway activator was used in PNS-R1-treated asthmatic mice.

RESULTS

PNS-R1 significantly reduced the airway inflammatory, mucus secretion and hyperresponsiveness in asthma model. It also reduced the levels of IL-13, IL-4, IL-5 and IL-8 in bronchoalveolar lavage fluid (BALF) and IgE and OVA-specific IgE in serum for asthma mice. PNS-R1 reduced IL-13 and TNF-α secretion in HDM-treated 16HBE cells. In addition, PNS-R1 suppressed TNF-α/NF-κB pathway in both asthmatic mice and 16HBE. Activation of NF-kB pathway reversed the therapeutic effect of PNS-R1 on asthmatic mice.

CONCLUSION

The results indicated that PNS-R1 effectively suppresses allergic airway inflammation of asthma partly through TNF-α/NF-κB pathway. PNS-R1 may play a potential role in allergic asthma treatment in the future.

Therapeutic potential of resveratrol against emerging respiratory viral infections

Resveratrol has been widely studied for its therapeutic potential due to its antioxidant, anti-inflammatory and anti-microbial properties. In particular, resveratrol has shown promising antiviral activity against numerous viruses responsible for severe respiratory infections. Amongst these, influenza virus, respiratory syncytial virus and the emerging SARS-cov-2 are known to cause pneumonia, acute respiratory distress syndrome or multi-organ failure, especially, in vulnerable individuals like immunocompromised patients or the elderly, leading to a considerable economic burden worldwide. In this context, resveratrol may have potential value for its anti-inflammatory activity, since most of the severe virus-associated complications are related to the overactivation of the host-immune response, leading to lung damage. Herein, we present an overview of the antiviral activity and potential mechanisms of resveratrol against the respiratory tract viruses considered as a public threat for their rapid transmission and high morbidity and mortality in the general population.

Neuroimmune regulation of lung infection and inflammation

The distal airway of the lung is innervated by vagus nerve. Upon stimulation, vagus nerve endings release acetylcholine or neuropeptides via C-fiber afferents to regulate lung infection and immunity. Vagal sensory nerve endings, brain integration center, acetylcholine and α7 nicotinic acetylcholine receptor (nAChR) expressing cells are key components of pulmonary parasympathetic inflammatory reflex. Meanwhile, this local machinery synergizes with spleen (as a functional hub of cholinergic anti-inflammatory pathway) to finely tune recruitment of the splenic α7 nAChR+CD11b+ cells into the inflamed lungs during lung infection. Recent studies have showed that lung group 2 innate lymphoid cells (ILC2) express both α7 nAChR and neuropeptide receptors. Acetylcholine and neuropeptides can regulate ILC2 and reshape pulmonary infection and immunity. Among the airway epithelial cells, pulmonary neuroendocrine cells are rare cell population; however, these cells are innervated by sensory nerve endings and they could secrete neuropeptides that influence lung infection and immunity.

High-mobility group box-1 protein from CC10+ club cells promotes type 2 response in the later stage of respiratory syncytial virus infection

The type 2 immune response, induced by infection of respiratory syncytial virus (RSV), has been linked to asthma development, but it remains unclear how the response is initiated. Here, we reported that the high-mobility group box-1 (HMGB1) protein promotes the type 2 response in the later stage of RSV infection. In mice, we found that type 2 cytokines were elevated in the later stages, which were strongly diminished after administration of anti-HMGB1 antibodies. Further investigation revealed that HMGB1 expression was localized to CC10⁺ club cells in the lung. In the clinic, levels of HMGB1 in nasopharyngeal aspirates in hospitalized infants with RSV bronchiolitis [median (interquartile range) 161.20 ng/ml (68.06-221.30)] were significantly higher than those without lower respiratory tract infections [21.94 ng/ml (12.12-59.82); P < 0.001]. Moreover, higher levels of HMGB1 correlated with clinical severity. These results reveal a link between viral infection and the asthma-like type 2 responses that are associated with long-term consequences.

An Interaction of LPS and RSV Infection in Augmenting the AHR and Airway Inflammation in Mice

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection (LRTI) in children under 5 years of age, especially infants with severe bronchiolitis. Our preliminary clinical experiments showed that bacterial colonization was commonly observed in children with virus-induced wheezing, particularly in those with recurrent wheezing, suggesting that bacterial colonization with an accompanying viral infection may contribute to disease severity. In most cases, RSV-infected infants were colonized with pathogenic bacteria (mainly Gram-negative bacteria). LPS is the main component of Gram-negative bacteria and acts as a ligand for Toll-like receptor 4 (TLR4). Relevant studies have reported that the TLR family is crucial in mediating the link between viral components and immunologic responses to infection. Of note, TLR4 activation has been associated with disease severity during RSV infection. In the present study, we identified that LPS aggravated RSV-induced AHR and airway inflammation in BALB/c mice using an RSV coinfection model. We found that the airway inflammatory cells and cytokines present in BALF and TRIF in lung tissue play a role in inducing AHR and airway inflammation upon RSV and bacteria coinfection, which might occur through the TRIF-MMP-9-neutrophil-MMP-9 signalling pathway. These results may aid in the development of novel treatments and improve vaccine design.

Brain targeting of resveratrol by nasal administration of chitosan-coated lipid microparticles

Lipid microparticles (LMs) uncoated or coated with chitosan and containing the neuroprotective polyphenol resveratrol were developed for its targeting to the brain via nasal administration. The lipid microparticles loaded with resveratrol (LMs-Res) were produced by melt emulsification, using stearic acid as lipid material and phosphatidylcholine as the surfactant. The chitosan coated particles LMs-Res-Ch (1.75% w/v chitosan solution) and LMs-Res-Ch-plus (8.75% w/v chitosan solution) were prepared by adding a chitosan solution to the formed particles. The mean diameter of the particles were 68.5 ± 3.1 μm, 76.3 ± 5.2 μm and 84.5 ± 8.1 μm for LMs-Res, LMs-Res-Ch and LMs-Res-Ch-plus respectively, suitable for nasal delivery. Chitosan coating changed the particle surface charge from a negative zeta potential value (-12.7 ± 2.1 mV) for the uncoated particles to a higher positive values respectively, 24.0 ± 4.7 and 44.6 ± 3.1 mV for the chitosan coated LM-Res-Ch and LM-Res-Ch-plus. Permeation studies across human NCM460 cell monolayers demonstrated that their transepithelial electrical resistance (TEER) values were not modified in the presence of free resveratrol, unloaded LMs, loaded LMs-Res or LMs-Res-Ch. On the other hand, the TEER values decreased from 150 ± 7 to 41 ± 3 Ω cm² in the presence of LMs-Res-Ch-plus, which corresponded to a significant increase in the apparent permeability (P_app) of resveratrol from 518 ± 8 × 10^-4 cm/min to 750 ± 98 × 10^-4 cm/min. In vivo studies demonstrated that no resveratrol was detected in the rat cerebrospinal fluid (CSF) after an intravenous infusion of the polyphenol. Conversely, the nasal delivery of resveratrol in a chitosan suspension or encapsulated in uncoated LMs-Res dispersed in water achieved the uptake of resveratrol in the CSF with C_max after 60 min of 1.30 ± 0.30 μg/ml and 0.79 ± 0.15 μg/ml, respectively. However, a dramatic increase in the levels of resveratrol reaching the CSF was attained by the administration of an aqueous suspension of LMs-Res-Ch-plus with a C_max after 60 min of 9.7 ± 1.9 μg/ml. This marked increase in the CSF bioavailability was achieved without any distribution in the systemic circulation, demonstrating a direct and specific nose to brain delivery.

Resveratrol as a potential therapeutic drug for respiratory system diseases

Respiratory system diseases are common and major ailments that seriously endanger human health. Resveratrol, a polyphenolic phytoalexin, is considered an anti-inflammatory, antioxidant, and anticancer agent. Thanks to its wide range of biological activities, resveratrol has become a hotspot in many fields, including respiratory system diseases. Indeed, research has demonstrated that resveratrol is helpful to relieve pulmonary function in the general population. Meanwhile, growing evidence indicates that resveratrol plays a protective role in respiratory system diseases. This review aimed to summarize the main protective effects of resveratrol in respiratory system diseases, including its anti-inflammatory, antiapoptotic, antioxidant, antifibrotic, antihypertensive, and anticancer activities. We found that resveratrol plays a protective role in the respiratory system through a variety of mechanisms, and so it may become a new drug for the treatment of respiratory system diseases.

Resveratrol improves efficacy of oral amoxicillin against childhood fast breathing pneumonia in a randomized placebo-controlled double blind clinical trial

Childhood pneumonia has been considered as a major cause of child morbidity and mortality worldwide. We aimed to investigate the effect of resveratral in synergizing with oral amoxicillin to improve the treatment outcome of oral amoxicillin administration against childhood fast breathing pneumonia. 647 children diagnosed fast breathing pneumonia were recruited and randomized to receive oral amoxicillin plus either resveratrol (AX + RV) or placebo (AX + placebo). The primary outcome was defined as treatment failure up to day 3, while the secondary outcome was defined as treatment failure at day 6 and 12 upon follow up. Incidences of treatment failure up to day 3 was significantly lower in the AX + RV group than the AX + placebo group. From day 6-12, the incidences of treatment failure were increased in both treatment groups. However, treatment failure cases were still much lower in the AX + RV group on both revisits. No serious adverse reaction to treatment drugs were found in either of the two groups. Resveratrol improves efficacy of oral amoxicillin against childhood fast breathing pneumonia, supporting the clincial potential of reseveratrol as a potent adjuvent of oral amoxicillin in the treatment of childhood pneumonia with no adverse effects.

Respiratory syncytial virus-Host interaction in the pathogenesis of bronchiolitis and its impact on respiratory morbidity in later life

Respiratory syncytial virus (RSV) is the most common agent of severe airway disease in infants and young children. Large epidemiologic studies have demonstrated a clear relationship between RSV infection and subsequent recurrent wheezing and asthma into childhood, thought to be predominantly related to long-term changes in neuroimmune control of airway tone rather than to allergic sensitization. These changes appear to be governed by the severity of the first RSV infection in infancy which in term depends on viral characteristics and load, but perhaps as importantly, on the genetic susceptibility and on the constitutional characteristic of the host. A variety of viral and host factors and their interplay modify the efficiency of the response to infection, including viral replication and the magnitude of structural and functional damage to the respiratory structures, and ultimately the extent, severity, and duration of subsequent wheezing.

NK cells contribute to persistent airway inflammation and AHR during the later stage of RSV infection in mice

RSV can lead to persistent airway inflammation and AHR and is intimately associated with childhood recurrent wheezing and asthma, but the underlying mechanisms remain unclear. There are high numbers of NK cells in the lung, which not only play important roles in the acute stage of RSV infection, but also are pivotal in regulating the pathogenesis of asthma. Therefore, in this study, we assumed that NK cells might contribute to persistent airway disease during the later stage of RSV infection. Mice were killed at serial time points after RSV infection to collect samples. Leukocytes in bronchoalveolar lavage fluid (BALF) were counted, lung histopathology was examined, and airway hyperresponsiveness (AHR) was measured by whole-body plethysmography. Cytokines were detected by ELISA, and NK cells were determined by flow cytometry. Rabbit anti-mouse asialo-GM-1 antibodies and resveratrol were used to deplete or suppress NK cells. Inflammatory cells in BALF, lung tissue damage and AHR were persistent for 60 days post-RSV infection. Type 2 cytokines and NK cells were significantly increased during the later stage of infection. When NK cells were decreased by the antibodies or resveratrol, type 2 cytokines, the persistent airway inflammation and AHR were all markedly reduced. NK cells can contribute to the RSV-associated persistent airway inflammation and AHR at least partially by promoting type 2 cytokines. Therefore, therapeutic targeting of NK cells may provide a novel approach to alleviating the recurrent wheezing subsequent to RSV infection.

[Airway inflammation induced by Poly(I:C) stimulation in the late stage of respiratory syncytial virus infection in mice and its mechanism]

OBJECTIVE

To investigate the pathogenic mechanisms of airway inflammation and recurrent wheezing induced by recurrent respiratory virus infection after respiratory syncytial virus (RSV) infection.

METHODS

Sixty-four female BALB/c mice (aged 6-8 weeks) were randomly divided into four groups: control, RSV, Poly(I:C), and RSV+Poly(I:C) (n=16 each). The bronchoalveolar lavage fluid (BALF) was collected on the 3rd day after Poly(I:C) administration, and the total cell number and differential counts in BALF were determined. Hematoxylin-eosin staining was used to observe pulmonary pathological changes. The airway responsiveness was detected. ELISA was used to measure the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-13 (IL-13), matrix metallopeptidase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in BALF.

RESULTS

Compared with the other three groups, the RSV+Poly(I:C) group had significant increases in the total number of inflammatory infiltrating cells in the airway, airway responsiveness, and MMP-9 level in BALF (P<0.05). The RSV+Poly(I:C) group showed more severe pulmonary tissue injuries compared with the control and RSV groups (P<0.01). Compared with the RSV group, the RSV+Poly(I:C) group showed significant reductions in the levels of IL-4 and TIMP-1 in BALF (P<0.01).

CONCLUSIONS

Viral re-infection in the late stage of RSV infection may cause an imbalance of MMP-9/TIMP-1 expression and thus contribute to aggravated airway inflammation.

Protective effect of resveratrol against pseudorabies virus-induced reproductive failure in a mouse model

Resveratrol (RES), a natural polyphenol that is abundant in grapes, exerts anti-inflammatory, anti-oxidative, and antiviral bioactive effects. Protective effects of RES against pseudorabies virus (PrV)- induced reproductive failure were investigated in a mice model. Injection of PrV partially induced stillbirth and abortion, and caused poor growth of progeny. Treatment with RES attenuated the reproductive failure induced by the virus with recovery of the serum progesterone level. RES improved the growth performance of newborn mice. RES can attenuate the reproductive failure induced by PrV in mice.

Pulmonary C Fibers Modulate MMP-12 Production via PAR2 and Are Involved in the Long-Term Airway Inflammation and Airway Hyperresponsiveness Induced by Respiratory Syncytial Virus Infection

Children with acute respiratory syncytial virus (RSV) infection often develop sequelae of persistent airway inflammation and wheezing. Pulmonary C fibers (PCFs) are involved in the generation of airway inflammation and resistance; however, their role in persistent airway diseases after RSV is unexplored. Here, we elucidated the pathogenesis of PCF activation in RSV-induced persistent airway disorders. PCF-degenerated and intact mice were used in the current study. Airway inflammation and airway resistance were evaluated. MMP408 and FSLLRY-NH2 were the selective antagonists for MMP-12 and PAR2, respectively, to investigate the roles of MMP-12 and PAR2 in PCFs mediating airway diseases. As a result, PCF degeneration significantly reduced the following responses to RSV infection: augmenting of inflammatory cells, especially macrophages, and infiltrating of inflammatory cells in lung tissues; specific airway resistance (sRaw) response to methacholine; and upregulation of MMP-12 and PAR2 expression. Moreover, the inhibition of MMP-12 reduced the total number of cells and macrophages in bronchiolar lavage fluid (BALF), as well infiltrating inflammatory cells, and decreased the sRaw response to methacholine. In addition, PAR2 was upregulated especially at the later stage of RSV infection. Downregulation of PAR2 ameliorated airway inflammation and resistance following RSV infection and suppressed the level of MMP-12. In all, the results suggest that PCF involvement in long-term airway inflammation and airway hyperresponsiveness occurred at least partially via modulating MMP-12, and the activation of PAR2 might be related to PCF-modulated MMP-12 production. Our initial findings indicated that the inhibition of PCF activity would be targeted therapeutically for virus infection-induced long-term airway disorders.

IMPORTANCE

The current study is critical to understanding that PCFs are involved in long-term airway inflammation and airway resistance after RSV infection through mediating MMP-12 production via PAR2, indicating that the inhibition of PCF activity can be targeted therapeutically for virus infection-induced long-term airway disorders.

Antiviral Activity of Resveratrol against Human and Animal Viruses

Resveratrol is a potent polyphenolic compound that is being extensively studied in the amelioration of viral infections both in vitro and in vivo. Its antioxidant effect is mainly elicited through inhibition of important gene pathways like the NF-κβ pathway, while its antiviral effects are associated with inhibitions of viral replication, protein synthesis, gene expression, and nucleic acid synthesis. Although the beneficial roles of resveratrol in several viral diseases have been well documented, a few adverse effects have been reported as well. This review highlights the antiviral mechanisms of resveratrol in human and animal viral infections and how some of these effects are associated with the antioxidant properties of the compound.