The Antiviral Activity of Bacterial, Fungal, and Algal Polysaccharides as Bioactive Ingredients: Potential Uses for Enhancing Immune Systems and Preventing Viruses

Viral infections may cause serious human diseases. For instance, the recent appearance of the novel virus, SARS-CoV-2, causing COVID-19, has spread globally and is a serious public health concern. The consumption of healthy, proper, functional, and nutrient-rich foods has an important role in enhancing an individual's immune system and preventing viral infections. Several polysaccharides from natural sources such as algae, bacteria, and fungi have been considered as generally recognized as safe (GRAS) by the US Food and Drug Administration. They are safe, low-toxicity, biodegradable, and have biological activities. In this review, the bioactive polysaccharides derived from various microorganisms, including bacteria, fungi, and algae were evaluated. Antiviral mechanisms of these polysaccharides were discussed. Finally, the potential use of microbial and algal polysaccharides as an antiviral and immune boosting strategy was addressed. The microbial polysaccharides exhibited several bioactivities, including antioxidant, anti-inflammatory, antimicrobial, antitumor, and immunomodulatory activities. Some microbes are able to produce sulfated polysaccharides, which are well-known to exert a board spectrum of biological activities, especially antiviral properties. Microbial polysaccharide can inhibit various viruses using different mechanisms. Furthermore, these microbial polysaccharides are also able to modulate immune responses to prevent and/or inhibit virus infections. There are many molecular factors influencing their bioactivities, e.g., functional groups, conformations, compositions, and molecular weight. At this stage of development, microbial polysaccharides will be used as adjuvants, nutrient supplements, and for drug delivery to prevent several virus infections, especially SARS-CoV-2 infection.

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Advances in the study of emodin: an update on pharmacological properties and mechanistic basis

Chinese Medicine ◽

10.1186/s13020-021-00509-z ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Qi Zheng ◽

Shuo Li ◽

Xiaojiaoyang Li ◽

Runping Liu

Keyword(s):

Targeted Delivery ◽

Pathogenic Bacteria ◽

Molecular Mechanisms ◽

Viral Infections ◽

Therapeutic Potential ◽

Biological Activities ◽

Molecular Targets ◽

Virus Infections ◽

Recent Developments ◽

Mechanistic Basis

AbstractRhei Radix et Rhizoma, also known as rhubarb or Da Huang, has been widely used as a spice and as traditional herbal medicine for centuries, and is currently marketed in China as the principal herbs in various prescriptions, such as Da-Huang-Zhe-Chong pills and Da-Huang-Qing-Wei pills. Emodin, a major bioactive anthraquinone derivative extracted from rhubarb, represents multiple health benefits in the treatment of a host of diseases, such as immune-inflammatory abnormality, tumor progression, bacterial or viral infections, and metabolic syndrome. Emerging evidence has made great strides in clarifying the multi-targeting therapeutic mechanisms underlying the efficacious therapeutic potential of emodin, including anti-inflammatory, immunomodulatory, anti-fibrosis, anti-tumor, anti-viral, anti-bacterial, and anti-diabetic properties. This comprehensive review aims to provide an updated summary of recent developments on these pharmacological efficacies and molecular mechanisms of emodin, with a focus on the underlying molecular targets and signaling networks. We also reviewed recent attempts to improve the pharmacokinetic properties and biological activities of emodin by structural modification and novel material-based targeted delivery. In conclusion, emodin still has great potential to become promising therapeutic options to immune and inflammation abnormality, organ fibrosis, common malignancy, pathogenic bacteria or virus infections, and endocrine disease or disorder. Scientifically addressing concerns regarding the poor bioavailability and vague molecular targets would significantly contribute to the widespread acceptance of rhubarb not only as a dietary supplement in food flavorings and colorings but also as a health-promoting TCM in the coming years.

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Antiviral Effects of Anthocyanins and Phytochemicals as Natural Dietary Compounds on Different Virus Sources

Current Research in Nutrition and Food Science Journal ◽

10.12944/crnfsj.8.3.01 ◽

2020 ◽

Vol 8 (3) ◽

pp. 674-681

Author(s):

Dhriti Choudhary ◽

Min-Hsiung Pan

Keyword(s):

Defense Mechanism ◽

Viral Infections ◽

Health Benefit ◽

Infectious Agent ◽

Health Concern ◽

Virus Infections ◽

Life Threatening ◽

Antiviral Activities ◽

Anti Oxidant ◽

Anti Fungal

Virus, an infectious agent is the main reason causing the deaths by life-threatening diseases, including HIV, cancer, influenza, herpes, dengue, hepatitis, chikungunya all around the world. Virus infections are a global health concern, due to worldwide travel and gradual modernization, the viral eruption is an epidemic menace and can be avoided by minimizing publicity to infectious viruses. Even with so many precautions, viral diseases can still spread and cause great risk to human health and requires proper sanitation by disinfectants or anti-viral agents. Very few vaccines are available that can effectively treat viral infections. As there are many advances progressing in the health care sector, there are some efficient anti-viral treatments and therapies, still some virus does not have effective vaccinations and therapies yet. For the past few years, there has been an intensive effort to study the defense mechanism of natural products such as foods and drinks we normally consume in our day-to-day life that may inhibit some anti-viral activities and some advantages over synthetic vaccines. The development of natural vaccines, that work against the virus is still a major goal. As it has been identified that the natural dietary compounds such as phytochemicals, anthocyanins, flavonoids, curcumins, polyphenols, and many more have some health benefit properties which may include anti-inflammation, anti-oxidant, anti-bacterial, anti-cancer, anti-viral, anti-fungal activities. This mini-review generally summarizes the antiviral activities of anthocyanins and phytochemicals from various natural plant sources on different virus origins.

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Th17 Cells in Viral Infections—Friend or Foe?

Cells ◽

10.3390/cells10051159 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1159

Author(s):

Iury Amancio Paiva ◽

Jéssica Badolato-Corrêa ◽

Débora Familiar-Macedo ◽

Luzia Maria de-Oliveira-Pinto

Keyword(s):

Immune Response ◽

Th17 Cells ◽

Viral Infections ◽

Critical Role ◽

Virus Infections ◽

Effector Functions ◽

Epithelial Barriers ◽

Bacteria And Fungi ◽

Pro Inflammatory Cytokines

Th17 cells are recognized as indispensable in inducing protective immunity against bacteria and fungi, as they promote the integrity of mucosal epithelial barriers. It is believed that Th17 cells also play a central role in the induction of autoimmune diseases. Recent advances have evaluated Th17 effector functions during viral infections, including their critical role in the production and induction of pro-inflammatory cytokines and in the recruitment and activation of other immune cells. Thus, Th17 is involved in the induction both of pathogenicity and immunoprotective mechanisms seen in the host’s immune response against viruses. However, certain Th17 cells can also modulate immune responses, since they can secrete immunosuppressive factors, such as IL-10; these cells are called non-pathogenic Th17 cells. Here, we present a brief review of Th17 cells and highlight their involvement in some virus infections. We cover these notions by highlighting the role of Th17 cells in regulating the protective and pathogenic immune response in the context of viral infections. In addition, we will be describing myocarditis and multiple sclerosis as examples of immune diseases triggered by viral infections, in which we will discuss further the roles of Th17 cells in the induction of tissue damage.

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Therapeutic Exploitation of Viral Interference

Infectious Disorders - Drug Targets ◽

10.2174/1871526519666190405140858 ◽

2020 ◽

Vol 20 (4) ◽

pp. 423-432 ◽

Cited By ~ 1

Author(s):

Imre Kovesdi ◽

Tibor Bakacs

Keyword(s):

Broad Spectrum ◽

Viral Infections ◽

Viral Vector ◽

Antiviral Treatment ◽

Type I ◽

Virus Infections ◽

Emerging Viruses ◽

Viral Interference ◽

Pathogenic Virus ◽

Hepatitis C Rna

: Viral interference, originally, referred to a state of temporary immunity, is a state whereby infection with a virus limits replication or production of a second infecting virus. However, replication of a second virus could also be dominant over the first virus. In fact, dominance can alternate between the two viruses. Expression of type I interferon genes is many times upregulated in infected epithelial cells. Since the interferon system can control most, if not all, virus infections in the absence of adaptive immunity, it was proposed that viral induction of a nonspecific localized temporary state of immunity may provide a strategy to control viral infections. Clinical observations also support such a theory, which gave credence to the development of superinfection therapy (SIT). SIT is an innovative therapeutic approach where a non-pathogenic virus is used to infect patients harboring a pathogenic virus. : For the functional cure of persistent viral infections and for the development of broad- spectrum antivirals against emerging viruses a paradigm shift was recently proposed. Instead of the virus, the therapy should be directed at the host. Such a host-directed-therapy (HDT) strategy could be the activation of endogenous innate immune response via toll-like receptors (TLRs). Superinfection therapy is such a host-directed-therapy, which has been validated in patients infected with two completely different viruses, the hepatitis B (DNA), and hepatitis C (RNA) viruses. SIT exerts post-infection interference via the constant presence of an attenuated non-pathogenic avian double- stranded (ds) RNA viral vector which boosts the endogenous innate (IFN) response. SIT could, therefore, be developed into a biological platform for a new “one drug, multiple bugs” broad-spectrum antiviral treatment approach.

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Associated microflora of medicinal ferns: biotechnological potentials and possible applications

International Journal of Bioassays ◽

10.21746/ijbio.2016.03.0017 ◽

2016 ◽

Vol 5 (03) ◽

pp. 4927 ◽

Cited By ~ 3

Author(s):

Shubhi Srivastava ◽

Paul A. K.

Keyword(s):

Secondary Metabolites ◽

Growth Promotion ◽

Biological Activities ◽

Hydrolytic Enzymes ◽

In Vitro Production ◽

Wide Range ◽

Negative Effect ◽

Bacteria And Fungi

Plant associated microorganisms that colonize the upper and internal tissues of roots, stems, leaves and flowers of healthy plants without causing any visible harmful or negative effect on their host. Diversity of microbes have been extensively studied in a wide variety of vascular plants and shown to promote plant establishment, growth and development and impart resistance against pathogenic infections. Ferns and their associated microbes have also attracted the attention of the scientific communities as sources of novel bioactive secondary metabolites. The ferns and fern alleles, which are well adapted to diverse environmental conditions, produce various secondary metabolites such as flavonoids, steroids, alkaloids, phenols, triterpenoid compounds, variety of amino acids and fatty acids along with some unique metabolites as adaptive features and are traditionally used for human health and medicine. In this review attention has been focused to prepare a comprehensive account of ethnomedicinal properties of some common ferns and fern alleles. Association of bacteria and fungi in the rhizosphere, phyllosphere and endosphere of these medicinally important ferns and their interaction with the host plant has been emphasized keeping in view their possible biotechnological potentials and applications. The processes of host-microbe interaction leading to establishment and colonization of endophytes are less-well characterized in comparison to rhizospheric and phyllospheric microflora. However, the endophytes are possessing same characteristics as rhizospheric and phyllospheric to stimulate the in vivo synthesis as well as in vitro production of secondary metabolites with a wide range of biological activities such as plant growth promotion by production of phytohormones, siderophores, fixation of nitrogen, and phosphate solubilization. Synthesis of pharmaceutically important products such as anticancer compounds, antioxidants, antimicrobials, antiviral substances and hydrolytic enzymes could be some of the promising areas of research and commercial exploitation.

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Phytochemical Composition and Biological Activities of Scorzonera Species

International Journal of Molecular Sciences ◽

10.3390/ijms22105128 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5128

Author(s):

Karolina Lendzion ◽

Agnieszka Gornowicz ◽

Krzysztof Bielawski ◽

Anna Bielawska

Keyword(s):

Biological Activities ◽

Folk Medicine ◽

Quinic Acid ◽

Hepatoprotective Activity ◽

Phytochemical Composition ◽

Starting Point ◽

Microbial Infections ◽

Bacteria And Fungi ◽

Bioactive Potential

The genus Scorzonera comprises nearly 200 species, naturally occurring in Europe, Asia, and northern parts of Africa. Plants belonging to the Scorzonera genus have been a significant part of folk medicine in Asia, especially China, Mongolia, and Turkey for centuries. Therefore, they have become the subject of research regarding their phytochemical composition and biological activity. The aim of this review is to present and assess the phytochemical composition, and bioactive potential of species within the genus Scorzonera. Studies have shown the presence of many bioactive compounds like triterpenoids, sesquiterpenoids, flavonoids, or caffeic acid and quinic acid derivatives in extracts obtained from aerial and subaerial parts of the plants. The antioxidant and cytotoxic properties have been evaluated, together with the mechanism of anti-inflammatory, analgesic, and hepatoprotective activity. Scorzonera species have also been investigated for their activity against several bacteria and fungi strains. Despite mild cytotoxicity against cancer cell lines in vitro, the bioactive properties in wound healing therapy and the treatment of microbial infections might, in perspective, be the starting point for the research on Scorzonera species as active agents in medical products designed for miscellaneous skin conditions.

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A Preliminary Report on Alcohol-Associated DNA Methylation Changes and Suicidal Behavior: Evidence Using Mendelian Randomization

Illness Crisis & Loss ◽

10.1177/1054137320952246 ◽

2021 ◽

pp. 105413732095224

Author(s):

Charleen D. Adams

Keyword(s):

Public Health ◽

Dna Methylation ◽

Suicidal Behavior ◽

Genome Wide Association Study ◽

Mendelian Randomization ◽

Causal Effect ◽

Economic Stress ◽

Self Report ◽

Health Concern ◽

The Us

Suicide is a major public health concern. In 2015, it was the 10th leading cause of death in the US. The number of suicides increased by 30% in the US from 1999 to 2016, and a greater uptick in suicides is predicted to occur as a result of the COVID-19 crisis, for which the primary public-health strategy is physical distancing and during which alcohol sales have soared. Thus, current strategies for identifying at-risk individuals and preventing suicides, such as relying on self-reported suicidal ideation, are insufficient, especially under conditions of physical distancing, which exacerbate isolation, loneliness, economic stress, and possibly alcohol consumption. New strategies are urgent now and into the future. To that aim, here, a two-sample Mendelian randomization (an instrumental variables technique using public genome-wide association study data as data sources) was performed to determine whether alcohol-associated changes in DNA methylation mediate risk for suicidal behavior. The results suggest that higher alcohol-associated DNA methylation levels at cg18120259 confer a weak causal effect. Replication and triangulation of the results, both experimentally and with designs other than Mendelian randomization, are needed. If the findings replicate, the information might be utilized to raise awareness about the biological links between alcohol and suicide and possibly explored as a biomarker of risk, perhaps especially for early detection of those who may not self-report suicidal intent.

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IgG and IgM antibody formation to spike and nucleocapsid proteins in COVID-19 characterized by multiplex immunoblot assays

BMC Infectious Diseases ◽

10.1186/s12879-021-06031-9 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jyotsna Shah ◽

Song Liu ◽

Hari-Hara Potula ◽

Prerna Bhargava ◽

Iris Cruz ◽

...

Keyword(s):

Viral Infections ◽

Antibody Responses ◽

Nucleocapsid Proteins ◽

Igm Antibodies ◽

Igm Antibody ◽

Specificity And Sensitivity ◽

The Us ◽

Autoimmune Conditions ◽

Antibody Positivity ◽

Recombinant Nucleocapsid Protein

Abstract Background Rapid and simple serological assays for characterizing antibody responses are important in the current COVID-19 pandemic caused by SARS-CoV-2. Multiplex immunoblot (IB) assays termed COVID-19 IB assays were developed for detecting IgG and IgM antibodies to SARS-CoV-2 virus proteins in COVID-19 patients. Methods Recombinant nucleocapsid protein and the S1, S2 and receptor binding domain (RBD) of the spike protein of SARS-CoV-2 were used as target antigens in the COVID-19 IBs. Specificity of the IB assay was established with 231 sera from persons with allergy, unrelated viral infections, autoimmune conditions and suspected tick-borne diseases, and 32 goat antisera to human influenza proteins. IgG and IgM COVID-19 IBs assays were performed on 84 sera obtained at different times after a positive RT-qPCR test from 37 COVID-19 patients with mild symptoms. Results Criteria for determining overall IgG and IgM antibody positivity using the four SARS-CoV-2 proteins were developed by optimizing specificity and sensitivity in the COVID-19 IgG and IgM IB assays. The estimated sensitivities and specificities of the COVID-19 IgG and IgM IBs for IgG and IgM antibodies individually or for either IgG or IgM antibodies meet the US recommendations for laboratory serological diagnostic tests. The proportion of IgM-positive sera from the COVID-19 patients following an RT-qPCR positive test was maximal at 83% before 10 days and decreased to 0% after 100 days, while the proportions of IgG-positive sera tended to plateau between days 11 and 65 at 78–100% and fall to 44% after 100 days. Detection of either IgG or IgM antibodies was better than IgG or IgM alone for assessing seroconversion in COVID-19. Both IgG and IgM antibodies detected RBD less frequently than S1, S2 and N proteins. Conclusions The multiplex COVID-19 IB assays offer many advantages for simultaneously evaluating antibody responses to different SARS-CoV-2 proteins in COVID-19 patients.

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Innate Immunity in Children and the Role of ACE2 Expression in SARS-CoV-2 Infection

Pediatric Reports ◽

10.3390/pediatric13030045 ◽

2021 ◽

Vol 13 (3) ◽

pp. 363-382

Author(s):

Mario Dioguardi ◽

Angela Pia Cazzolla ◽

Claudia Arena ◽

Diego Sovereto ◽

Giorgia Apollonia Caloro ◽

...

Keyword(s):

Innate Immunity ◽

Viral Infections ◽

Respiratory Infections ◽

Viral Disease ◽

Receptor Expression ◽

Virus Infections ◽

Search Terms ◽

Bibliographic Search ◽

Meta Analyses

COVID-19 (Coronavirus Disease 2019) is an emerging viral disease caused by the coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), which leads to severe respiratory infections in humans. The first reports came in December 2019 from the city of Wuhan in the province of Hubei in China. It was immediately clear that children developed a milder disease than adults. The reasons for the milder course of the disease were attributed to several factors: innate immunity, difference in ACE2 (angiotensin-converting enzyme II) receptor expression, and previous infections with other common coronaviruses (CovH). This literature review aims to summarize aspects of innate immunity by focusing on the role of ACE2 expression and viral infections in children in modulating the antibody response to SARS-CoV-2 infection. This review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles deemed potentially eligible were considered, including those dealing with COVID-19 in children and providing more up-to-date and significant data in terms of epidemiology, prognosis, course, and symptoms, focusing on the etiopathogenesis of SARS-CoV-2 disease in children. The bibliographic search was conducted using the search engines PubMed and Scopus. The following search terms were entered in PubMed and Scopus: COVID-19 AND ACE2 AND Children; COVID-19 AND Immunity innate AND children. The search identified 857 records, and 18 studies were applicable based on inclusion and exclusion criteria that addressed the issues of COVID-19 concerning the role of ACE2 expression in children. The scientific literature agrees that children develop milder COVID-19 disease than adults. Milder symptomatology could be attributed to innate immunity or previous CovH virus infections, while it is not yet fully understood how the differential expression of ACE2 in children could contribute to milder disease.

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Antiviral Role of Phenolic Compounds against Dengue Virus: A Review

Biomolecules ◽

10.3390/biom11010011 ◽

2020 ◽

Vol 11 (1) ◽

pp. 11

Author(s):

Vanessa Loaiza-Cano ◽

Laura Milena Monsalve-Escudero ◽

Carlos da Silva Maia Bezerra Filho ◽

Marlen Martinez-Gutierrez ◽

Damião Pergentino de Sousa

Keyword(s):

Phenolic Compounds ◽

Dengue Virus ◽

Biological Activities ◽

Antiviral Effect ◽

Health Concern ◽

Host Proteins ◽

Viral Particles ◽

Antiviral Role ◽

Productive Replication

Phenolic compounds have been related to multiple biological activities, and the antiviral effect of these compounds has been demonstrated in several viral models of public health concern. In this review, we show the antiviral role of phenolic compounds against dengue virus (DENV), the most widespread arbovirus globally that, after its re-emergence, has caused multiple epidemic outbreaks, especially in the last two years. Twenty phenolic compounds with anti-DENV activity are discussed, including the multiple mechanisms of action, such as those directed against viral particles or viral proteins, host proteins or pathways related to the productive replication viral cycle and the spread of the infection.

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