A Phase II Study on the Effect of Taurisolo® Administered via AEROsol in Hospitalized Patients with Mild to Moderate COVID-19 Pneumonia: The TAEROVID-19 Study

Antiviral Potential and In Silico Insights of Polyphenols as Sustainable Phytopharmaceuticals: A Comprehensive Review

Polyphenols, particularly flavonoids, are reported to have health-promoting, disease-preventing abilities and several polyphenols having a wide spectrum of antiviral activities can be explored for preventive and/or therapeutic purposes. We have compiled the updated literature of diverse polyphenols active against common viral diseases, including herpes, hepatitis, influenza, rota and SARS-corona-viruses. The antiviral activity of bioactive polyphenols depends on the hydroxyl and ester groups of polyphenol molecules, as compounds with five or more hydroxyl groups and three specific methoxy groups showed antiviral potential, like anti-rabies activity. This comprehensive review will explore selective polyphenols isolated from common ethnomedicinal or food plants. Comparing bioactivities of structurally related polyphenols and using bioinformatics studies, we have explored the three most promising phyto-antivirals, including chrysin, resveratrol and quercetin, available in many foods and medicinal plants. Quercetin showed a maximum interaction score with human genes. We also explore the intricate structure-activity relationship between these polyphenols and pathogenic viruses with their mechanisms of antiviral action in selected virus models. Here, we report the promising potential of some phyto-polyphenols in the management of viral diseases through an in-depth analysis of the structure and bioactivity of these compounds.

Antiviral activity of Taurisolo® during bovine alphaherpesvirus 1 infection

Bovine alphaherpesvirus 1 (BoAHV-1), the pathogen causing Infectious Bovine Rhinotracheitis (IBR) and predisposing to polymicrobial infections in cattle, provokes farm economic losses and trading restrictions in the world. However, nontoxic antiviral agents for BoAHV-1 infection are still unavailable, but plant extracts, such as flavonoid derivatives possess activity against BoAHV-1. Taurisolo®, a nutraceutical produced by Aglianico grape pomace, has recently shown promising antiviral activity. Herein, the potential activity of Taurisolo® during BoAHV-1 infection in Madin Darby bovine kidney (MDBK) cells was tested. Taurisolo® enhanced cell viability and reduced morphological death signs in BoAHV-1-infected cells. Moreover, Taurisolo® influenced the expression of bICP0, the key regulatory protein of BoAHV-1, and it strongly diminished virus yield. These effects were associated with an up-regulation of aryl hydrocarbon receptor (AhR), a transcription factor involved in microbial metabolism and immune response. In conclusion, our findings indicate that Taurisolo® may represent a potential antiviral agent against BoAHV-1 infection. Noteworthy, AhR could be involved in the observed effects and become a new target in antiviral therapy.

Association of dietary intake of polyphenols, lignans, and phytosterols with immune-stimulating microbiota and COVID-19 risk in a group of Polish men and women

Objectives

Devastating consequences of COVID-19 disease enhanced the role of promoting prevention-focused practices. Among targeted efforts, diet is regarded as one of the potential factors which can affect immune function and optimal nutrition is postulated as the method of augmentation of people's viral resistance. As epidemiological evidence is scarce, the present study aimed to explore the association between dietary intake of total polyphenols, lignans and plant sterols and the abundance of immunomodulatory gut microbiota such as Enterococcus spp. and Escherichia coli and the risk of developing COVID-19 disease.

Methods

Demographic data, dietary habits, physical activity as well as the composition of body and gut microbiota were analyzed in a sample of 95 young healthy individuals. Dietary polyphenol, lignan and plant sterol intakes have been retrieved based on the amount of food consumed by the participants, the phytochemical content was assessed in laboratory analysis and using available databases.

Results

For all investigated polyphenols and phytosterols, except campesterol, every unit increase in the tertile of intake category was associated with a decrease in the odds of contracting COVID-19. The risk reduction ranged from several dozen percent to 70 %, depending on the individual plant-based chemical, and after controlling for basic covariates it was statistically significant for secoisolariciresinol (OR = 0.28, 95% CI: 0.11-0.61), total phytosterols (OR = 0.47, 95% CI: 0.22-0.95) and for stigmasterols (OR = 0.34, 95% CI: 0.14-0.72). We found an inverse association between increased β-sitosterol intake and phytosterols in total and the occurrence of Escherichia coli in stool samples outside reference values, with 72% (OR = 0.28, 95% CI: 0.08-0.86) and 66% (OR = 0.34, 95% CI: 0.10-1.08) reduced odds of abnormal level of bacteria for the highest compared with the lowest tertile of phytochemical consumption. Additionally, there was a trend of more frequent presence of Enterococcus spp. at relevant level in people with a higher intake of lariciresinol.

Conclusion

The beneficial effects of polyphenols and phytosterols should be emphasized and these plant-based compounds should be regarded in the context of their utility as antiviral agents preventing influenza-type infections.

Antiherpetic Activity of Taurisolo®, a Grape Pomace Polyphenolic Extract

Herpes simplex virus (HSV) is widespread in the population, causing oral or genital ulcers and, rarely, severe complications such as encephalitis, keratitis, and neonatal herpes. Current available anti-HSV drugs are acyclovir and its derivatives, although long-term therapy with these agents can lead to drug resistance. Thus, the discovery of novel antiherpetic compounds merits additional studies. In recent decades, much scientific effort has been invested in the discovery of new synthetic or natural compounds with promising antiviral properties. In our study, we tested the antiviral potential of a novel polyphenol-based nutraceutical formulation (named Taurisolo^®) consisting of a water polyphenol extract of grape pomace. The evaluation of the antiviral activity was carried out by using HSV-1 and HSV-2 in plaque assay experiments to understand the mechanism of action of the extract. Results were confirmed by real-time PCR, transmission electron microscope (TEM), and fluorescence microscope. Taurisolo^® was able to block the viral infection by acting on cells when added together with the virus and also when the virus was pretreated with the extract, demonstrating an inhibitory activity directed to the early phases of HSV-1 and HSV-2 infection. Altogether, these data evidence for the first time the potential use of Taurisolo^® as a topical formulation for both preventing and healing herpes lesions.

A potential host and virus targeting tool against COVID-19: Chemical characterization, antiviral, cytoprotective, antioxidant, respiratory smooth muscle relaxant effects of Paulownia tomentosa Steud

COronaVIrus Disease 2019 (COVID-19) is a newly emerging infectious disease that spread across the world, caused by the novel coronavirus Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2). Despite the advancements in science that led to the creation of the vaccine, there is still an urgent need for new antiviral drugs effective against SARS-CoV-2. This study aimed to investigate the antiviral effect of Paulownia tomentosa Steud extract against SARS-CoV-2 and to evaluate its antioxidant properties, including respiratory smooth muscle relaxant effects. Our results showed that P. tomentosa extract can inhibit viral replication by directly interacting with both the 3-chymotrypsin-like protease and spike protein. In addition, the phyto complex does not reduce lung epithelial cell viability and exerts a protective action in those cells damaged by tert-butyl hydroperoxide , a toxic agent able to alter cells' functions via increased oxidative stress. These data suggest the potential role of P. tomentosa extract in COVID-19 treatment, since this extract is able to act both as an antiviral and a cytoprotective agent in vitro.