Interaction of polyunsaturated fatty acids with animal cells and enveloped viruses

Antimicrobial Efficacy of a Vegetable Oil Plasticizer in PVC Matrices

The growing prevalence of bacterial and viral infections, highlighted by the recent COVID-19 pandemic, urgently calls for new antimicrobial strategies. To this end, we have synthesized and characterized a novel fatty acid epoxy-ester plasticizer for polymers, named GDE. GDE is not only sustainable and user-friendly but also demonstrates superior plasticizing properties, while its epoxy components improve the heat stability of PVC-based matrices. A key feature of GDE is its ability to confer antimicrobial properties to surfaces. Indeed, upon contact, this material can effectively kill enveloped viruses, such as herpes simplex virus type 1 (HSV-1) and the β-coronavirus prototype HCoV-OC43, but it is ineffective against nonenveloped viruses like human adenovirus (HAdV). Further analysis using transmission electron microscopy (TEM) on HSV-1 virions exposed to GDE showed significant structural damage, indicating that GDE can interfere with the viral envelope, potentially causing leakage. Moreover, GDE demonstrates antibacterial activity, albeit to a lesser extent, against notorious pathogens such as Staphylococcus aureus and Escherichia coli. Overall, this newly developed plasticizer shows significant potential as an antimicrobial agent suitable for use in both community and healthcare settings to curb the spread of infections caused by microorganisms contaminating physical surfaces.

Individual ingredients of NP-101 (Thymoquinone formula) inhibit SARS-CoV-2 pseudovirus infection

Thymoquinone TQ, an active ingredient of Nigella Sativa, has been shown to inhibit COVID-19 symptoms in clinical trials. Thymoquinone Formulation (TQF or NP-101) is developed as a novel enteric-coated medication derivative from Nigella Sativa. TQF consists of TQ with a favorable concentration and fatty acids, including palmitic, oleic, and linoleic acids. In this study, we aimed to investigate the roles of individual ingredients of TQF on infection of SARS-CoV-2 variants in-vitro, by utilizing Murine Leukemia Virus (MLV) based pseudovirus particles. We demonstrated that NP-101, TQ, and other individual ingredients, including oleic, linoleic, and palmitic acids inhibited SARS-CoV-2 infection in the MLV-based pseudovirus model. A large, randomized phase 2 study of NP-101 is planned in outpatient COVID-19 patients.

Isolation of porcine reproductive and respiratory syndrome virus from feed ingredients and complete feed, with subsequent RT-qPCR analysis

We used virus isolation (VI) to determine tissue culture infectivity and reverse-transcription quantitative PCR (RT-qPCR) to determine the stability of porcine reproductive and respiratory syndrome virus 2 (PRRSV) strain P129 in solvent-extracted soybean meal (SBM), dried distillers grains with solubles (DDGS), complete swine feed (FEED), or medium (DMEM) at 4°C, 23°C, or 37°C for up to 3 d. Samples of each treatment were taken at regular intervals and processed. Supernatant was titrated and used to inoculate confluent MARC-145 cells to determine infectivity. RNA was extracted from each supernatant sample and tested by RT-qPCR to determine any change in detectable virus RNA across matrix type, temperature, and time. An interaction (p = 0.028) was observed for matrix × temperature × hour for live virus detected by VI. At 4°C, the concentration of infectious virus was greatest in DMEM, intermediate in SBM, and lowest in DDGS and FEED. DMEM also had the greatest concentration of infectious PRRSV at 23°C over time; a higher infectious virus concentration was maintained in SBM for longer than in DDGS or FEED. At 37°C, a greater concentration of infectious virus was sustained in DMEM than in the feedstuffs, with concentrations decreasing until 48 h post-inoculation. Only matrix type influenced the quantity of viral RNA detected by RT-qPCR (p = 0.032). More viral RNA was detected in the virus control than in DDGS; SBM and FEED were intermediate. By VI, we found that infectious virus could be harbored in SBM, DDGS, and FEED for a short time.

RNase L-activating 2'-5' oligoadenylates bind ABCF1, ABCF3 and Decr-1

A notable signalling mechanism employed by mammalian innate immune signalling pathways uses nucleotide-based second messengers such as 2'3'-cGAMP and 2'-5'-oligoadenylates (OAs), which bind and activate STING and RNase L, respectively. Interestingly, the involvement of nucleotide second messengers to activate antiviral responses is evolutionarily conserved, as evidenced by the identification of an antiviral cGAMP-dependent pathway in Drosophila. Using a mass spectrometry approach, we identified several members of the ABCF family in human, mouse and Drosophila cell lysates as 2'-5' OA-binding proteins, suggesting an evolutionarily conserved function. Biochemical characterization of these interactions demonstrates high-affinity binding of 2'-5' OA to ABCF1, dependent on phosphorylated 2'-5' OA and an intact Walker A/B motif of the ABC cassette of ABCF1. As further support for species-specific interactions with 2'-5' OA, we additionally identified that the metabolic enzyme Decr1 from mouse, but not human or Drosophila cells, forms a high-affinity complex with 2'-5' OA. A 1.4 Å co-crystal structure of the mouse Decr1-2'-5' OA complex explains high-affinity recognition of 2'-5' OA and the mechanism of species specificity. Despite clear evidence of physical interactions, we could not identify profound antiviral functions of ABCF1, ABCF3 or Decr1 or 2'-5' OA-dependent regulation of cellular translation rates, as suggested by the engagement of ABCF proteins. Thus, although the biological consequences of the here identified interactions need to be further studied, our data suggest that 2'-5' OA can serve as a signalling hub to distribute a signal to different recipient proteins.

Identification of alpha-linolenic acid as a broad-spectrum antiviral against zika, dengue, herpes simplex, influenza virus and SARS-CoV-2 infection

Zika virus (ZIKV) has garnered global attention due to its association with severe congenital defects including microcephaly. However, there are no licensed vaccines or drugs against ZIKV infection. Pregnant women have the greatest need for treatment, making drug safety crucial. Alpha-linolenic acid (ALA), a polyunsaturated ω-3 fatty acid, has been used as a health-care product and dietary supplement due to its potential medicinal properties. Here, we demonstrated that ALA inhibits ZIKV infection in cells without loss of cell viability. Time-of-addition assay revealed that ALA interrupts the binding, adsorption, and entry stages of ZIKV replication cycle. The mechanism is probably that ALA disrupts the membrane integrity of the virions to release ZIKV RNA, inhibiting viral infectivity. Further examination revealed that ALA inhibits DENV-2, HSV-1, influenza virus and SARS-CoV-2 infection dose-dependently. ALA is a promising broad-spectrum antiviral agent.

Evaluation of antiviral activity of Carica papaya leaves against SARS-CoV-2 assisted by metabolomic profiling

The COVID-19 pandemic caused a huge health crisis all over the globe. SARS-CoV-2 is the virus responsible for the disease and it is highly contagious leaving millions of confirmed infected cases and a dangerous death toll. Carica papaya is a tropical plant known for its antiviral activity since it possesses different classes of compounds that are believed to combat various viral classes. In this study, the extracts prepared from C. papaya leaves cultivated in Egypt were evaluated for their anti-SARS-CoV-2 activity using crystal violet assay and for their cytotoxicity through MTT assay. The total methanolic extract, n-hexane, ethyl acetate, and n-butanol fractions of papaya leaves were used in the study and the results revealed that the n-hexane fraction has a high anti-SARS-CoV-2 activity with an IC₅₀ value = 1.98 μg mL^-1. Moreover, it also showed a high selectivity index value = 104.7. Dereplication of the secondary metabolites in the crude methanolic extract of C. papaya leaves revealed the presence of different classes of compounds including sterols, terpenes, fatty acid, alkaloids and flavonoids that are known to possess antiviral activities against various classes of viruses. The current study was assisted by molecular docking, molecular dynamics simulation and MM-PBSA calculations for the annotated compounds against 6 SARS-CoV-2 target proteins. The results of these in silico-based investigations showed high to moderate binding on the targeted proteins. This postulation may instigate further research studies concerning the compounds responsible for this high anti-SARS-CoV-2 activity of the n-hexane fraction of C. papaya leaves.

Relationships between plasma fatty acids in adults with mild, moderate, or severe COVID-19 and the development of post-acute sequelae

Background

SARS-CoV-2 has infected millions across the globe. Many individuals are left with persistent symptoms, termed post-acute sequelae of COVID-19 (PASC), for months after infection. Hyperinflammation in the acute and convalescent stages has emerged as a risk factor for poor disease outcomes, and this may be exacerbated by dietary inadequacies. Specifically, fatty acids are powerful inflammatory mediators and may have a significant role in COVID-19 disease modulation.

Objective

The major objective of this project was to pilot an investigation of plasma fatty acid (PFA) levels in adults with COVID-19 and to evaluate associations with disease severity and PASC.

Methods and procedures

Plasma from adults with (N = 41) and without (N = 9) COVID-19 was analyzed by gas chromatography-mass spectrometry (GC-MS) to assess differences between the concentrations of 18 PFA during acute infection (≤14 days post-PCR + diagnosis) in adults with varying disease severity. Participants were grouped based on mild, moderate, and severe disease, alongside the presence of PASC, a condition identified in patients who were followed beyond acute-stage infection (N = 23).

Results

Significant differences in PFA profiles were observed between individuals who experienced moderate or severe disease compared to those with mild infection or no history of infection. Palmitic acid, a saturated fat, was elevated in adults with severe disease (p = 0.04), while behenic (p = 0.03) and lignoceric acid (p = 0.009) were lower in adults with moderate disease. Lower levels of the unsaturated fatty acids, γ-linolenic acid (GLA) (p = 0.03), linoleic (p = 0.03), and eicosapentaenoic acid (EPA) (p = 0.007), were observed in adults with moderate disease. Oleic acid distinguished adults with moderate disease from severe disease (p = 0.04), and this difference was independent of BMI. Early recovery-stage depletion of GLA (p = 0.02) and EPA (p = 0.0003) was associated with the development of PASC.

Conclusion

Pilot findings from this study support the significance of PFA profile alterations during COVID-19 infection and are molecular targets for follow-up attention in larger cohorts. Fatty acids are practical, affordable nutritional targets and may be beneficial for modifying the course of disease after a COVID-19 diagnosis. Moreover, these findings can be particularly important for overweight and obese adults with altered PFA profiles and at higher risk for PASC.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT04603677].

Caprylate/chromatography process to produce highly purified tetanus immune globulin from human plasma

While tetanus toxoid vaccination has reduced the incidence of tetanus in the developed world, this disease remains a substantial health problem in developing nations. Tetanus immune globulin (TIG) is used along with vaccination for prevention of infection after major or contaminated wounds if vaccination status cannot be verified or for active tetanus infection. These studies describe the characterisation of a TIG produced by a caprylate/chromatography process. The TIG potency and presence of plasma protein impurities were analysed at early/late steps in the manufacturing process by chromatography, immunoassay, coagulation and potency tests. The caprylate/chromatography process has been previously shown to effectively eliminate or inactivate potentially transmissible agents from plasma-derived products. In this study, the caprylate/chromatography process was shown to effectively concentrate TIG activity and efficiently remove pro-coagulation factors, naturally present in plasma. This TIG drug product builds on the long-term evidence of the safety and efficacy of TIG by providing a product with higher purity and low pro-coagulant protein impurities.

Application of a caprylate/chromatography purification process for production of a high potency rabies immune globulin from pooled human plasma

BACKGROUND

Human rabies immunoglobulin (RIG) is an integral part of post-exposure prophylactic treatment of rabies (along with rabies vaccination). Infiltration of most, if not all, of the RIG dose at the wound site is recommended. RIG produced by a caprylate/chromatography manufacturing process (RIG-C; HyperRAB) increased the potency and purity of this product over the existing licensed RIG from a solvent/detergent process (RIG-S/D; HyperRAB-S/D).

METHODS

A series of studies were conducted to characterize the content and purity of RIG-C. A single-dose pharmacokinetic study in rabbits was performed to compare intramuscular (IM) immunoglobulin products manufactured by two different purification processes, solvent/detergent (IGIM-S/D) and caprylate/chromatography (IGIM-C).

RESULTS

RIG-C was found to be a highly purified IgG formulation with high monomer content and formulated with twice the anti-rabies potency of RIG-S/D while maintaining the same overall protein concentration. RIG-C facilitates IM administration at the wound site by halving the injection volume. The new caprylate/chromatography process eliminated detectible levels of pro-coagulant impurities and IgA that were carried through in the prior S/D process. These impurities have been associated with thrombotic complications and allergic reactions in susceptible patients. After single dose administration, IGIM-C was pharmacokinetically equivalent to IGIM-S/D in rabbits.

CONCLUSION

RIG-C is a more potent RIG formulation with less impurities yielding a safer and more convenient product with similar pharmacokinetic profile.

Role of food nutrients and supplementation in fighting against viral infections and boosting immunity: A review

BACKGROUND

The viral infections can be highly contagious and easily transmissible, which even can lead to a pandemic, like the recent COVID-19 outbreak, causing massive deaths worldwide. While, still the best practical way to prevent the transmission of viruses is to practice self-sanitation and follow social distancing principles, enhancing the individual's immunity through the consumption of proper foods containing balanced nutrients can have significant result against viral infections. Foods containing nutrients such as vitamins, minerals, fatty acids, few polysaccharides, and some non-nutrients (i.e. polyphenols) have shown therapeutic potential against the function of viruses and can increase the immunity of people.

SCOPE AND APPROACH

The results of conducted works aiming for studying the potential antiviral characteristics of diverse groups of foods and food's nutrients (in terms of polysaccharides, proteins, lipids, vitamins, and minerals) are critically discussed.

KEY FINDINGS AND CONCLUSION

Nutrients, besides playing an important role in maintaining normal physiology of human's body and healthiness, are also required for enhancing the immunity of the body and can be effective against viral infections. They can present antiviral capacity either by entering into the defensive mechanism directly through interfering with the target viruses, or indirectly through activating the cells associated with the adaptive immune system. During the current situation of COVID-19 pandemic (the lack of proper curative viral drug), enhancing the immunity of individual's body through proposing the appropriate diet (rich in both macro and micro-nutrients) is one of few practical preventive measures available in fighting against Coronaviruses, this significant health-threatening virus, as well as other viruses in general.

The mosquito protein AEG12 displays both cytolytic and antiviral properties via a common lipid transfer mechanism

The mosquito protein AEG12 is up-regulated in response to blood meals and flavivirus infection though its function remained elusive. Here, we determine the three-dimensional structure of AEG12 and describe the binding specificity of acyl-chain ligands within its large central hydrophobic cavity. We show that AEG12 displays hemolytic and cytolytic activity by selectively delivering unsaturated fatty acid cargoes into phosphatidylcholine-rich lipid bilayers. This property of AEG12 also enables it to inhibit replication of enveloped viruses such as Dengue and Zika viruses at low micromolar concentrations. Weaker inhibition was observed against more distantly related coronaviruses and lentivirus, while no inhibition was observed against the nonenveloped virus adeno-associated virus. Together, our results uncover the mechanistic understanding of AEG12 function and provide the necessary implications for its use as a broad-spectrum therapeutic against cellular and viral targets.

Polyunsaturated ω-3 fatty acids inhibit ACE2-controlled SARS-CoV-2 binding and cellular entry

The strain SARS-CoV-2, newly emerged in late 2019, has been identified as the cause of COVID-19 and the pandemic declared by WHO in early 2020. Although lipids have been shown to possess antiviral efficacy, little is currently known about lipid compounds with anti-SARS-CoV-2 binding and entry properties. To address this issue, we screened, overall, 17 polyunsaturated fatty acids, monounsaturated fatty acids and saturated fatty acids, as wells as lipid-soluble vitamins. In performing target-based ligand screening utilizing the RBD-SARS-CoV-2 sequence, we observed that polyunsaturated fatty acids most effectively interfere with binding to hACE2, the receptor for SARS-CoV-2. Using a spike protein pseudo-virus, we also found that linolenic acid and eicosapentaenoic acid significantly block the entry of SARS-CoV-2. In addition, eicosapentaenoic acid showed higher efficacy than linolenic acid in reducing activity of TMPRSS2 and cathepsin L proteases, but neither of the fatty acids affected their expression at the protein level. Also, neither reduction of hACE2 activity nor binding to the hACE2 receptor upon treatment with these two fatty acids was observed. Although further in vivo experiments are warranted to validate the current findings, our study provides a new insight into the role of lipids as antiviral compounds against the SARS-CoV-2 strain.

Pharmaconutrition in the Clinical Management of COVID-19: A Lack of Evidence-Based Research But Clues to Personalized Prescription

A scientific interest has emerged to identify pharmaceutical and nutritional strategies in the clinical management of coronavirus disease 2019 (COVID-19). The purpose of this narrative review is to critically assess and discuss pharmaconutrition strategies that, secondary to accepted treatment methods, could be candidates in the current context of COVID-19. Oral medicinal doses of vitamin C (1–3 g/d) and zinc (80 mg/d elemental zinc) could be promising at the first signs and symptoms of COVID-19 as well as for general colds. In critical care situations requiring parenteral nutrition, vitamin C (3–10 g/d) and glutamine (0.3–0.5 g/kg/d) administration could be considered, whereas vitamin D3 administration (100,000 IU administered intramuscularly as a one-time dose) could possess benefits for patients with severe deficiency. Considering the presence of n-3 polyunsaturated fatty acids and arginine in immune-enhancing diets, their co-administration may also occur in clinical conditions where these formulations are recommended. However, despite the use of the aforementioned strategies in prior contexts, there is currently no evidence of the utility of any nutritional strategies in the management of SARS-CoV-2 infection and COVID-19. Nevertheless, ongoing and future clinical research is imperative to determine if any pharmaconutrition strategies can halt the progression of COVID-19.

The antiviral effect of mollusk mucus on measles virus

Measles is a viral disease highly contagious spread by respiratory transmission. Although infection can be controlled by vaccination, numerous cases of measles have been registered in many areas of the world, highlighting the need for additional interventions. Terrestrial gastropods exude mucus on their body surface when traveling, to protect the body from mechanical injury, desiccation or contact with harmful substances. The mucus of mollusks has been studied as a source of new natural compounds with diverse biological activities. In this study, the antiviral activity of the mucus of the land slug P. boraceiensis was demonstrated in vitro using Vero cells infected with measles virus. The crude sample and four fractions were tested in cultures infected with measles virus and the antiviral activity was assessed by the cytopathic effect in infected cell cultures as well as by immunofluorescence and qPCR. Fractions 39 and 50 of the mucus from P. boraceiensis were analyzed by HPLC-DAD-ESI-MS/MS and infrared spectroscopy. A mixture of polyunsaturated fatty acids was found in the two fractions. A reduction in the growth of the measles virus was observed, measured by qPCR, with a protection index of 80% in Vero cells infected with measles and treated with fraction 39. Fraction 39 exhibited the best antiviral action in vitro and high contents of hydroxy-tritriacontapentaenoic acid and hydroxy-pentatriacontapentaenoic acid were found in this fraction.

Antimicrobial properties and microbial contaminants of breast milk--an update

A review of recent studies of antibacterial, antiviral and antiprotozoan factors in human breast milk is presented. Also reviewed are the microbial contaminants that have been detected in human milk with a particular focus on cytomegalovirus and rubella virus, both of which have recently been shown to infect infants via breast milk.

Viricidal effects of Lactobacillus and yeast fermentation

The survival of selected viruses in Lactobacillus- and yeast-fermented edible waste material was studied to determine the feasibility of using this material as a livestock feed ingredient. Five viruses, including Newcastle disease virus, infectious canine hepatitis virus, a porcine picornavirus, frog virus 3, and bovine virus diarrhea, were inoculated into a mixture of ground food waste (collected from a school lunch program) containing Lactobacillus acidophilus. Mixtures were incubated at 20, 30, and 40 degrees C for 216 h. In a second trial, four viruses, including Newcastle disease virus, infectious canine hepatitis virus, frog virus 3, and a porcine picornavirus, were inoculated into similar edible waste material containing Saccharomyces cerevisiae. Mixtures were incubated at 20 and 30 degrees C for 216 h. Samples were obtained daily for quantitative (trial 1) and qualitative (trial 2) virus isolation. Temperature, pH, and redox potential were monitored. Controlled pH and temperature studies were also done and compared with the inactivation rates in the fermentation processes. In trial 1 (Lactobacillus fermentation), infectious canine hepatitis virus survived the entire test period in the fermentation process but was inactivated below pH 4.5 in the controlled studies. Newcastle disease virus was inactivated by day 8 in the fermentation process and appeared to be primarily heat sensitive and secondarily pH sensitive in the controlled studies. The porcine picornavirus survived the fermentation process for 8 days at 20 degrees C but was inactivated more rapidly at 30 and 40 degrees C. The controlled studies verified these findings. Frog virus 3 was inactivated by day 3 in the fermentation process and appeared to be sensitive to low pH in the controlled studies. Bovine virus diarrhea was rapidly inactivated in the fermentation process (less than 2 h) and was pH and temperature sensitive. In trial 2 (yeast fermentation), infectious hepatitis virus survived the entire test period in the fermentation process. Newcastle disease virus was inactivated by day 7 at 20 degrees C and day 6 at 30 degrees C. The porcine picornavirus was inactivated by day 7 at 30 degrees C but survived the entire test period at 20 degrees C. Frog virus 3 was inactivated by day 3 at 20 degrees C and day 2 at 30 degrees C.

Photochemical destruction of the virucidal activities of retinoids and unsaturated fatty acids

Photochemical damage either to retinoids by near-ultraviolet radiation or to unsaturated fatty acids by near-ultraviolet radiation in the presence of a hydrophobic photosensitizer destroys the virucidal activities of the compounds, as determined by studies on the enveloped bacteriophage ø6.