Do oral antiseptics used in the dental routine have anti-viral efficacy? a systematic review of in vitro studies / Os antissépticos orais utilizados na rotina odontológica têm eficácia anti-viral? Uma revisão sistemática de estudos in vitro / ¿Los antisépticos orales utilizados en la rutina odontológica tienen eficacia antiviral? Una revisión sistemática de estudios in vitro

Introduction: Mouthwashes play an important role in the dental clinic, but their role on viruses requires investigation. Objective:to review in vitro studies to identify the effect of different mouthwashes on the main viruses associated with routine dental care. Methodology:The following databases were searched in September 2023: PubMed, Embase, Scopus and Web of Science databases; the Cochrane Library and the Virtual Health Library (VHL); and grey literature. In vitro studies that used mouthwashes to reduce the viral load were selected. The PICOS strategy was considered to define eligibility criteria: the Population (viruses involved in the etiology of oral infection), the Intervention (oral antiseptics), the appropriate comparator (positive and negative controls), the Outcomes of interest (reduction of viral load) and the Study design (in vitro studies). Results:Considering the eligibility criteria, 19 articles were included in this review. The efficacy of povidone-iodine (PVP-I), chlorhexidine, Listerine®, essential oils, and cetylpyridinium chloride (CPC) rinses were investigated. PVP-I (0.23%) had its effects mainly associated with coronaviruses SARS(Severe Acute Respiratory Syndrome),demonstrating a significant reduction in viral load after 15 seconds of exposure. Chlorhexidine (0.05%; 0.1% and 0.5%) was ineffective against adenovirus, poliovirus, and rhinovirus respiratory viruses. Listerine® demonstrated superior efficacy against HSV-1 and 2 viruses and influenza A, and cetylpyridine chloride also demonstrated virucidal activity against influenza A. Conclusions:The type, concentration, and time of exposure to antiseptics varied between studies. PVP-I and chlorhexidine digluconate were the most studied substances, butin general, PVP-I was more effective in reducing viral titers, especially concerning coronaviruses. Other antiseptics such as CPC, H2O2 and Listerine® have also shown significant reduction in viral load, but this is a limited number of studies (AU).

Introdução: Os enxaguantes bucais desempenham um papel importante na clínica odontológico, porém seu papel sobre os vírus requer investigações. Objetivo: revisar estudos in vitro para identificar o efeito de diferentes colutórios sobre os principais vírus associados ao atendimento odontológico de rotina. Metodologia: As seguintes bases foram pesquisadas até setembro de 2023: PubMed, Embase, Scopus e Web of Science; a Biblioteca Cochrane e a Biblioteca Virtual em Saúde (BVS); e literatura cinzenta. Foram selecionados estudos in vitro que utilizaram bochechos com o objetivo de reduzir a carga viral. A estratégia PICOS foi considerada para a definição dos critérios de elegibilidade: População (vírus envolvidos na etiologia da infecção oral), Intervenção (antissépticos orais), Comparador (controles positivos e negativos), os Desfechos de interesse (redução da carga viral) e o desenho do estudo (estudos in vitro). Resultados: Considerando os critérios de elegibilidade, 19 artigos foram incluídos para esta revisão. A eficácia da povidona-iodo (PVP-I), clorexidina, Listerine®, óleos essenciais e lavagens com cloreto de cetilpiridínio foram investigadas. O PVP-I(0.23%)teve seus efeitos principalmente associados ao coronavírusSARS (Síndrome Respiratória Aguda Severa),demonstrando uma redução significativa da carga viral após 15 segundos de exposição. A clorexidina mostrou-se ineficaz contra vírus respiratórios de adenovírus, poliovírus e rinovírus. Listerine® demonstrou eficácia superior contra vírus HSV-1 e 2 e vírus influenza A, e cloreto de cetilpiridinio também demonstrou atividade virucida contra influenza A.Conclusões:O tipo, concentração e tempo de exposição aos antissépticos variaram entre os estudos. O PVP-I e o digluconato de clorexidina foram as substâncias mais estudadas, mas no geral, o PVP-I foi mais eficaz na redução dos títulos virais, principalmente no que diz respeito aos coronavírus. Outros antissépticos como CPC, H2O2 e Listerine® também mostraram redução significativa da carga viral, mas trata-se de um número limitado de estudos (AU).

Introducción: Los enjuagues bucales son importantesen la clínica dental, sin embargo, su efecto sobre los virus requiere investigaciones. Objetivo: Revisar estudios in vitro para identificar el efecto de enjuagues bucales sobre los principales virus asociados con larutinaodontológica. Metodología: Las siguientes bases de datos fueron investigadas hasta septiembrede 2023: PubMed, Embase, Scopus y Web of Science; Biblioteca Cochrane y Biblioteca Virtual en Salud (BVS); yliteratura gris. Se seleccionaron estudios in vitro que utilizaron enjuagues bucales con el objetivo de reducir la carga viral. Se consideró la estrategia PICOS para definir los criterios de elegibilidad: Población (virus implicados en la etiología de la infección oral), Intervención (antisépticos bucales), Comparador (controles positivos y negativos), Resultados de interés (reducción de la carga viral) y diseño del estudio (in vitro). Resultados: Considerando los criterios de elegibilidad, se incluyeron 19 artículos.Se investigó la eficacia de povidona yodada (PVP-I), clorhexidina, Listerine®,aceites esenciales y enjuagues de cloruro de cetilpiridinio (CPC). PVP-I(0.23%)mostró sus efectos principalmente asociados al coronavirus SARS(Síndrome Respiratorio Agudo Severo), demostrando una reducción significativa de la carga viral después de 15 segundos. Se ha demostrado que la clorhexidina es ineficaz contra losvirus respiratorios adenovirus, poliovirus y rinovirus. Listerine® demostró una eficacia superior contra los virus HSV-1 y 2 y el virus de la influenza A, y el CPCtambién mostró actividad virucida contra la influenza A.Conclusiones: El tipo, la concentración y el tiempo de exposiciónvariaron entre los estudios. PVP-I y digluconato de clorhexidina fueron las sustancias más estudiadas, pero,PVP-I fue más efectiva en la reducción de los títulos virales, especialmente en lo que respecta a los coronavirus. Otros antisépticos como CPC, H2O2 y Listerine® también mostraron una reducción significativa de la carga viral, pero se trata de un número limitado de estudios (AU).

Bactericera cockerelli Picorna-like Virus and Three New Viruses Found Circulating in Populations of Potato/Tomato Psyllids (Bactericera cockerelli).

An investigation of viruses circulating in populations of field and laboratory potato/tomato psyllids (Bactericera cockerelli) was conducted using high-throughput sequencing (HTS) technology and conventional RT-PCR. Three new viruses were discovered: one from the family Tymoviridae and two from the family Solemoviridae. A tymo-like virus sequence represented a nearly complete 6843 nt genome of a virus named Bactericera cockerelli tymo-like virus (BcTLV) that spanned five open reading frames (ORFs) which encoded RNA-dependent RNA polymerase (RdRP), helicase, protease, methyltransferase, and a capsid protein. Phylogenetic analyses placed the RdRP of BcTLV inside a divergent lineage of the viruses from the family Tymoviridae found in insect and plant hosts in a sister clade to the genera Tymovirus, Marafivirus, and Maculavirus. Four solemo-like virus sequences were identified in the HTS outputs, representing two new viruses. One virus found only in field-collected psyllids and named Bactericera cockerelli solemo-like virus 1 (BcSLV-1) had a 5479 nt genome which spanned four ORFs encoding protease and RdRP. Three solemo-like sequences displayed 87.4-99.7% nucleotide sequence identity among themselves, representing variants or strains of the same virus named Bactericera cockerelli solemo-like virus 2 (BcSLV-2). The genome of BcSLV-2 spanned only two ORFs that encoded a protease and an RdRP. Phylogenetic analysis placed the RdRPs of BcSLV-1 and BcSLV-2 in two separate lineages as sister clades to viruses from the genus Sobemovirus found in plant hosts. All three new psyllid viruses were found circulating in psyllids collected from potato fields in southern Idaho along with a previously identified Bactericera cockerelli picorna-like virus. Any possible role of the three viruses in controlling populations of the field psyllids remains to be elucidated.

Aesculus hippocastanum extract and the main bioactive constituent ß-escin as antivirals agents against coronaviruses, including SARS-CoV-2.

Respiratory viruses can cause life-threatening illnesses. The focus of treatment is on supportive therapies and direct antivirals. However, antivirals may cause resistance by exerting selective pressure. Modulating the host response has emerged as a viable therapeutic approach for treating respiratory infections. Additionally, considering the probable future respiratory virus outbreaks emphasizes the need for broad-spectrum therapies to be prepared for the next pandemics. One of the principal bioactive constituents found in the seed extract of Aesculus hippocastanum L. (AH) is ß-escin. The clinical therapeutic role of ß-escin and AH has been associated with their anti-inflammatory effects. Regarding their mechanism of action, we and others have shown that ß-escin and AH affect NF-κB signaling. Furthermore, we have reported the virucidal and broad-spectrum antiviral properties of ß-escin and AH against enveloped viruses such as RSV, in vitro and in vivo. In this study, we demonstrate that ß-escin and AH have antiviral and virucidal activities against SARS-CoV-2 and CCoV, revealing broad-spectrum antiviral activity against coronaviruses. Likewise, they exhibited NF-κB and cytokine modulating activities in epithelial and macrophage cell lines infected with coronaviruses in vitro. Hence, ß-escin and AH are promising broad-spectrum antiviral, immunomodulatory, and virucidal drugs against coronaviruses and respiratory viruses, including SARS-CoV-2.

Evaluation of a new automated viral RNA extraction platform for hepatitis A virus and human norovirus in testing of berries, lettuce, and oysters.

Fruits, vegetables, and shellfish are often associated with outbreaks of illness caused particularly by human norovirus (HuNoV) and hepatitis A virus (HAV), the leading causative agents of foodborne illness worldwide. The aim of this study was to evaluate a new automated nucleic acid extraction platform (EGENE-UP EASYPREP) for enteric viruses in several at-risk food matrices and to test its limit of detection in comparison to a semi-automated method (EGENE-UP) using Boom methodology for nucleic acid extraction as suggested in the reference method ISO 15216-2:2019. Fresh and frozen raspberries, frozen blackberries, romaine lettuce and oyster digestive glands were artificially contaminated with HAV, HuNoV GII.4 or HuNoV GI.7 at 102, 103 or 104 genome copies/sample. Virus was then recovered from the food matrix using the ISO method. Viral RNA extracted from frozen berry samples by the automated system was purified on a column for additional removal of RT-qPCR inhibitors. For fresh raspberry, oysters, and romaine lettuce, the two extraction platforms were deemed equivalent. For frozen raspberry, the automated platform appeared to be more efficient for viral recovery, particularly for HAV and HuNoV GI at lower concentrations. With frozen blackberries, the two platforms may be considered equivalent for all targeted viruses. However, the automated method led to less sample-associated inhibition of the PCR, 56.5 % of samples versus 95.0 % for the semi-automated. We thus found that the automated extraction can be performed easily by users while obtaining equivalent or even superior results to the ISO 15216-2:2019 method, and therefore appears to be suitable for routine sanitary monitoring in food processing and for tracing outbreaks of illness.

Medicinal Plants against Viral Infections: A Review of Metabolomics Evidence for the Antiviral Properties and Potentials in Plant Sources.

Most plants have developed unique mechanisms to cope with harsh environmental conditions to compensate for their lack of mobility. A key part of their coping mechanisms is the synthesis of secondary metabolites. In addition to their role in plants' defense against pathogens, they also possess therapeutic properties against diseases, and their use by humans predates written history. Viruses are a unique class of submicroscopic agents, incapable of independent existence outside a living host. Pathogenic viruses continue to pose a significant threat to global health, leading to innumerable fatalities on a yearly basis. The use of medicinal plants as a natural source of antiviral agents has been widely reported in literature in the past decades. Metabolomics is a powerful research tool for the identification of plant metabolites with antiviral potentials. It can be used to isolate compounds with antiviral capacities in plants and study the biosynthetic pathways involved in viral disease progression. This review discusses the use of medicinal plants as antiviral agents, with a special focus on the metabolomics evidence supporting their efficacy. Suggestions are made for the optimization of various metabolomics methods of characterizing the bioactive compounds in plants and subsequently understanding the mechanisms of their operation.

Treatment of waxborne honey bee (Hymenoptera: Apidae) viruses using time, temperature, and electron-beam irradiation.

Viruses are one of many serious threats to honey bee (Apis mellifera L.) health. There are many transmission routes for honey bee viruses, and there is potential for wax comb to act as a reservoir for transmission of viruses. Some work has been done on treating viruses on wax, focusing on irradiation as a potential treatment. However, irradiation is not universally available or economically viable for beekeepers in many regions. With increased colony deaths over winter beekeepers potentially risk further loss from reusing contaminated equipment from dead colonies. Here we explored the use of storage time and temperature on the reduction of waxborne virus levels from winter loss colony wax over 30 days and at -20, 5, and 20 °C. Furthermore, because irradiation has previously worked against waxborne viruses, we performed a dosage experiment with electron-beam irradiation. Winter loss wax was again used, and exposed to 10, 25, 35, and 45 kGy irradiation, including a nonirradiated transport control. Storage time decreased abundance of black queen cell virus and deformed wing virus at times equal or greater than 30 days but temperatures had no significant effect on virus levels. All irradiation doses decreased virus abundance and prevalence, yet only 35 and 45 kGy did so at a greater rate than the effect of transport alone.

The oral microbiome: diversity, biogeography and human health.

The human oral microbiota is highly diverse and has a complex ecology, comprising bacteria, microeukaryotes, archaea and viruses. These communities have elaborate and highly structured biogeography that shapes metabolic exchange on a local scale and results from the diverse microenvironments present in the oral cavity. The oral microbiota also interfaces with the immune system of the human host and has an important role in not only the health of the oral cavity but also systemic health. In this Review, we highlight recent advances including novel insights into the biogeography of several oral niches at the species level, as well as the ecological role of candidate phyla radiation bacteria and non-bacterial members of the oral microbiome. In addition, we summarize the relationship between the oral microbiota and the pathology of oral diseases and systemic diseases. Together, these advances move the field towards a more holistic understanding of the oral microbiota and its role in health, which in turn opens the door to the study of novel preventive and therapeutic strategies.

The social lives of viruses and other mobile genetic elements: a commentary on Leeks et al. 2023.

Illustration of life-histories of phages and plasmids through horizontal and vertical transmission (see Figure 1 for more information).

Virome Analysis of Aconitum carmichaelii Reveals Infection by Eleven Viruses, including Two Potentially New Species.

Aconitum carmichaelii is a herbaceous herb indigenous to China that has been cultivated for traditional medicine for centuries. Virus-like symptoms of A. carmichaelii plants were observed on leaves in some A. carmichaelii plantations in Zhanyi and Wuding Counties, Yunnan Province, southwest China. High-throughput sequencing (HTS) was performed on 28 symptomatic plants, and the results revealed infection with 11 viruses, including 2 novel viruses and 9 previously described viruses: Aconitum amalgavirus 1 (AcoAV-1), aconite virus A (AcVA), cucumber mosaic virus (CMV), currant latent virus (CuLV), apple stem grooving virus (ASGV), chilli veinal mottle virus (ChiVMV), tomato spotted wilt orthotospovirus (TSWV), tobacco vein distorting virus (TVDV), and potato leafroll virus (PLRV). Two novel viruses tentatively named Aconitum potyvirus 1 and Aconitum betapartitivirus 1, were supported by sequence and phylogenetic analysis results of their genomes. We proposed the names Potyvirus aconiti and Betapartitivirus aconiti. RT-PCR assays of 142 plants revealed the predominance and widespread distribution of CMV, AcVA, and AcoPV-1 in plantations. The detection of isolates of CuLV, ASGV, ChiVMV, TSWV, TVDV, and PLRV infections for the first time in A. carmichaelii expands their known host ranges.

Estimation of alkali dosage and contact time for treating human excreta containing viruses as an emergency response: a systematic review.

Water, sanitation, and hygiene provisions are essential during emergencies to prevent infectious disease outbreaks caused by improper human excreta management in settlements for people affected by natural disasters and conflicts. Human excreta disinfection is required when long-term containment in latrines is not feasible on-site. Alkali additives, including lime, are effective disinfectants for wastewater and faecal sludge containing large amounts of solid and dissolved organic matter. The aim of this study was to determine the minimum dose and contact time of alkali additives for treating virus-containing human excreta in emergency situations. We used literature data collected by searching Google Scholar and Web of Science. The date of the last search for each study was 31th May 2023. Only peer-reviewed articles that included disinfection practices in combination with quantitative data for the physicochemical data of a matrix and viral decay were selected for data extraction. Two reviewers independently collected data from each study. We extracted datasets from 14 studies that reported quantitative information about their disinfection tests, including viral decay over time, matrix types, and physicochemical properties. Three machine learning algorithms were applied to the collected dataset to determine the time required to achieve specified levels of virus inactivation under different environmental conditions. The best model was used to estimate the contact time to achieve a 3-log10 inactivation of RNA virus in wastewater and faeces. The most important variables for predicting the contact time were pH, temperature, and virus type. The estimated contact time for 3 log inactivation of RNA virus was <2 h at pH 12, which was achieved by adding 1.8 and 3.1% slaked lime to wastewater and faeces, respectively. The contact time decreased exponentially with the pH of the sludge and wastewater. In contrast, the pH of the sludge and wastewater increased linearly with the slaked lime dosage. Lime treatment is a promising measure where long-term containment in latrine is not feasible in densely populated areas, as 1 day is sufficient to inactivate viruses. The relationship we have identified between required contact time and lime dosage is useful for practitioners in determining appropriate treatment conditions of human waste.

Antiviral Natural Products, Their Mechanisms of Action and Potential Applications as Sanitizers and Disinfectants.

Plant extracts, natural products and plant oils contain natural virucidal actives that can be used to replace active ingredients in commercial sanitizers and disinfectants. This review focuses on the virucidal mechanisms of natural substances that may exhibit potential for indoor air and fomite disinfection. Review of scientific studies indicates: (1) most natural product studies use crude extracts and do not isolate or identify exact active antiviral substances; (2) many natural product studies contain unclear explanations of virucidal mechanisms of action; (3) natural product evaluations of virucidal activity should include methods that validate efficacy under standardized disinfectant testing procedures (e.g., carrier tests on applicable surfaces or activity against aerosolized viruses, etc.). The development of natural product disinfectants requires a better understanding of the mechanisms of action (MOA), chemical profiles, compound specificities, activity spectra, and the chemical formulations required for maximum activity. Combinations of natural antiviral substances and possibly the addition of synthetic compounds might be needed to increase inactivation of a broader spectrum of viruses, thereby providing the required efficacy for surface and air disinfection.

Development and application of reverse transcription-loop mediated isothermal amplification assay for sensitive detection of groundnut bud necrosis virus infecting potato.

Reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for detection of groundnut bud necrosis virus (GBNV) causing potato stem necrosis disease. The isothermal temperatures, reaction periods and concentrations of reaction mixture were optimized where, the assay worked well at 65 °C for 50 min, 6 U of WarmStart Bst 2.0 DNA polymerase, 1.4 mM dNTPs and 2.0 mM MgSO4. The optimized assay proved to be specific to GBNV with no cross reactivity to other viruses infecting potato in India. The specificity of RT-LAMP assay was found to be 100 fold more sensitive than that of RT-PCR. The developed assay was applied for the detection of GBNV from 80 potato leaf samples where 24 samples were found infected which was confirmed by RT-PCR. It was concluded that the RT-LAMP assay developed for detection of GBNV was specific, sensitive and suitable for its use in virus indexing under potato seed production programme.

Race between virus and inflammasomes: inhibition or escape, intervention and therapy.

The inflammasome is a multiprotein complex that further regulates cell pyroptosis and inflammation by activating caspase-1. The assembly and activation of inflammasome are associated with a variety of diseases. Accumulative studies have shown that inflammasome is a key modulator of the host's defense response to viral infection. Indeed, it has been established that activation of inflammasome occurs during viral infection. At the same time, the host has evolved a variety of corresponding mechanisms to inhibit unnecessary inflammasome activation. Therefore, here, we review and summarize the latest research progress on the interaction between inflammosomes and viruses, highlight the assembly and activation of inflammosome in related cells after viral infection, as well as the corresponding molecular regulatory mechanisms, and elucidate the effects of this activation on virus immune escape and host innate and adaptive immune defenses. Finally, we also discuss the potential therapeutic strategies to prevent and/or ameliorate viral infection-related diseases via targeting inflammasomes and its products.

Galdieria sulphuraria: An Extremophilic Alga as a Source of Antiviral Bioactive Compounds.

In the last decades, the interest in bioactive compounds derived from natural sources including bacteria, fungi, plants, and algae has significantly increased. It is well-known that aquatic or terrestrial organisms can produce, in special conditions, secondary metabolites with a wide range of biological properties, such as anticancer, antioxidant, anti-inflammatory, and antimicrobial activities. In this study, we focused on the extremophilic microalga Galdieria sulphuraria as a possible producer of bioactive compounds with antiviral activity. The algal culture was subjected to organic extraction with acetone. The cytotoxicity effect of the extract was evaluated by the 2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The antiviral activity was assessed through a plaque assay against herpesviruses and coronaviruses as enveloped viruses and poliovirus as a naked one. The monolayer was treated with different concentrations of extract, ranging from 1 µg/mL to 200 µg/mL, and infected with viruses. The algal extract displayed strong antiviral activity at non-toxic concentrations against all tested enveloped viruses, in particular in the virus pre-treatment against HSV-2 and HCoV-229E, with IC50 values of 1.7 µg/mL and IC90 of 1.8 µg/mL, respectively. However, no activity against the non-enveloped poliovirus has been detected. The inhibitory effect of the algal extract was confirmed by the quantitative RT-PCR of viral genes. Preliminary chemical profiling of the extract was performed using ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS), revealing the enrichment in primary fatty acid amides (PFAA), such as oleamide, palmitamide, and pheophorbide A. These promising results pave the way for the further purification of the mixture to explore its potential role as an antiviral agent.

EPs® 7630 Stimulates Tissue Repair Mechanisms and Modifies Tight Junction Protein Expression in Human Airway Epithelial Cells.

Airway epithelium repair after infection consists of wound repair, re-synthesis of the extracellular matrix (ECM), and tight junction proteins. In humans, EPs® 7630 obtained from Pelargonium sidoides roots reduces the severity and duration of acute respiratory tract infections. The effect of EPs® 7630 on tissue repair of rhinovirus-16 (RV-16) infected and control human airway epithelial cells was assessed for: (i) epithelial cell proliferation by manual cell counts, (ii) epithelial wound repair by "scratch assay", (iii) ECM composition by Western-blotting and cell-based ELISA, and (iv) epithelial tight junction proteins by Western-blotting. EPs® 7630 stimulated cell proliferation through cAMP, CREB, and p38 MAPK. EPs® 7630 significantly improved wound repair. Pro-inflammatory collagen type-I expression was reduced by EPs® 7630, while fibronectin was increased. Virus-binding tight junction proteins desmoglein2, desmocollin2, ZO-1, claudin1, and claudin4 were downregulated by EPs® 7630. The RV16-induced shift of the ECM towards the pro-inflammatory type was prevented by EPs® 7630. Most of the effects of EPs® 7630 on tissue repair and regeneration were sensitive to inhibition of cAMP-induced signaling. The data suggest that EPs® 7630-dependent modification of epithelial cell metabolism and function might underlie the faster recovery time from viral infections, as reported by others in clinical studies.

Virus-pathogen interactions improve water quality along the Middle Route of the South-to-North Water Diversion Canal.

Bacterial pathogens and viruses are the leading causes of global waterborne diseases. Here, we discovered an interesting natural paradigm of water "self-purification" through virus-pathogen interactions over a 1432 km continuum along the Middle Route of the South-to-North Water Diversion Canal (MR-SNWDC) in China, the largest water transfer project in the world. Due to the extremely low total phosphorus (TP) content (ND-0.02 mg/L) in the MR-SNWDC, the whole canal has experienced long-lasting phosphorus (P) limitation since its operation in 2015. Based on 4443 metagenome-assembled genomes (MAGs) and 40,261 nonredundant viral operational taxonomic units (vOTUs) derived from our recent monitoring campaign, we found that residential viruses experiencing extreme P constraints had to adopt special adaptive strategies by harboring smaller genomes to minimize nucleotide replication, DNA repair, and posttranslational modification costs. With the decreasing P supply downstream, bacterial pathogens showed repressed environmental fitness and growth potential, and a weakened capacity to maintain P acquisition, membrane formation, and ribonucleotide biosynthesis. Consequently, the unique viral predation effects under P limitation, characterized by enhanced viral lytic infections and an increased abundance of ribonucleotide reductase (RNR) genes linked to viral nuclear DNA replication cycles, led to unexpectedly lower health risks from waterborne bacterial pathogens in the downstream water-receiving areas. These findings highlighted the great potential of water self-purification associated with virus-pathogen dynamics for water-quality improvement and sustainable water resource management.

Essential Oils: Chemistry and Pharmacological Activities.

In this review, we provide an overview of the current understanding of the main mechanisms of pharmacological action of essential oils and their components in various biological systems. A brief introduction on essential oil chemistry is presented to better understand the relationship of chemical aspects with the bioactivity of these products. Next, the antioxidant, anti-inflammatory, antitumor, and antimicrobial activities are discussed. The mechanisms of action against various types of viruses are also addressed. The data show that the multiplicity of pharmacological properties of essential oils occurs due to the chemical diversity in their composition and their ability to interfere with biological processes at cellular and multicellular levels via interaction with various biological targets. Therefore, these natural products can be a promising source for the development of new drugs.

Chemical Profile, Antibacterial, Antibiofilm, and Antiviral Activities of Pulicaria crispa Most Potent Fraction: An In Vitro and In Silico Study.

Infectious diseases caused by viruses and bacteria are a major public health concern worldwide, with the emergence of antibiotic resistance, biofilm-forming bacteria, viral epidemics, and the lack of effective antibacterial and antiviral agents exacerbating the problem. In an effort to search for new antimicrobial agents, this study aimed to screen antibacterial and antiviral activity of the total methanol extract and its various fractions of Pulicaria crispa (P. crispa) aerial parts. The P. crispa hexane fraction (HF) was found to have the strongest antibacterial effect against both Gram-positive and Gram-negative bacteria, including biofilm producers. The HF fraction reduced the expression levels of penicillin binding protein (PBP2A) and DNA gyrase B enzymes in Staphylococcus aureus and Pseudomonas aeruginosa, respectively. Additionally, the HF fraction displayed the most potent antiviral activity, especially against influenza A virus, affecting different stages of the virus lifecycle. Gas chromatography/mass spectrometry (GC/MS) analysis of the HF fraction identified 27 compounds, mainly belonging to the sterol class, with ß-sitosterol, phytol, stigmasterol, and lupeol as the most abundant compounds. The in silico study revealed that these compounds were active against influenza A nucleoprotein and polymerase, PBP2A, and DNA gyrase B. Overall, this study provides valuable insights into the chemical composition and mechanism of action of the P. crispa HF fraction, which may lead to the development of more effective treatments for bacterial and viral infections.