Virucidal Effect Research Articles

Evaluation for Antiviral Potential of Ficus deltoidea Against Dengue Virus Type-2

Dengue is one of the most widespread arthropod-borne viral diseases that cause negative impact globally. Presently, no effective drug is available to safeguard people against dengue. Ficus deltoidea is Malaysia's famous traditional herb belonging to Moraceae family due to its pharmacological potential. F. deltoidea leaves (FDL) were extracted with n-hexane, ethyl acetate and methanol. Cell cytotoxicity study using MTT assay measuring the formazan absorbance was conducted to determine maximum non-toxic concentration on Vero cells. The antiviral activities of various concentrations of FDL extracts were assessed using virus reduction neutralisation tests against dengue virus type 2. The CC20 value of n-hexane, ethyl acetate and methanol FDL extracts were 2.99 ± 0.31, 22.15 ± 2.39, and 25.22 ± 0.42 µg/mL, respectively. Methanol FDL extract at maximum non-toxic concentration exerted strongest direct extracellular virucidal effect against DENV-2. In cell protection assay, ethyl acetate FDL extract achieved highest reduction in viral infectivity (98.17%), whereas n-hexane FDL extract showed strongest inhibition in DENV-2 viral replication in post-infection assay. Methanol FDL extract showed highest selectivity index value in direct virus inhibition, cell protection and post-infection assay. Conclusively, FDL extracts, especially methanol FDL showed potential antiviral activity against DENV-2, thus considered as promising anti-dengue agent.

Antiviral and Virucidal Activities of Uncaria tomentosa (Cat's Claw) against the Chikungunya Virus.

Uncaria tomentosa (UT) is a medicinal plant popularly known as cat's claw belonging to the Rubiaceae family that has been reported to display antiviral and anti-inflammatory activities. The chikungunya virus (CHIKV) outbreaks constitute a Brazilian public health concern. CHIKV infection develops an abrupt onset of fever, usually accompanied by a skin rash, besides incapacitating polyarthralgia. There is no vaccine available or treatment for CHIKV infection. The present study evaluates the hydroalcoholic extract of UT bark as a potential antiviral against CHIKV. The in vitro antiviral activity of the UT extract against the Brazilian CHIKV strain was assessed using quantitative reverse transcription polymerase chain reaction, flow cytometry, and plaque assay. Results obtained demonstrated that UT inhibits CHIKV infection in a dose-dependent manner. At the non-cytotoxic concentration of 100 µg/mL, UT exhibited antiviral activity above 90% as determined by plaque reduction assay, and it reduced the viral cytopathic effect. Similarly, a significant virucidal effect of 100 µg/mL UT was observed after 24 and 48 h post-infection. This is the first report on the antiviral activity of UT against CHIKV infection, and the data presented here suggests UT as a potential antiviral to treat CHIKV infection.

Investigating the Effectiveness of Melatonin in the Treatment of Critically Ill Patients with COVID-19 Hospitalized in the Intensive Care Unit: A Double-Blind Randomized Clinical Trial.

Melatonin, a tryptophan product, has anti-inflammatory and virucidal effects. A study evaluated whether melatonin is more effective than placebo in critically ill COVID-19 patients. The present study used a double-blind, randomized clinical trial in patients with COVID-19 hospitalized in the intensive care unit of Rasool Akram Hospital, Tehran. Iran. Melatonin 10 mg and placebo were given to the patients at night before bed. Patients were randomly divided into 2 groups. The first group was given melatonin with a therapeutic dose of 10 mg daily, and the second group was given a placebo with the same dose of 10 mg daily. Patients received melatonin or placebo for 7 days.The chi-square or Fisher exact test was used to compare qualitative variables. The study analyzed the mean of the variables under investigation by conducting a 2-factor repeated measures analysis of variance at 3 different time intervals in those administered medication or placebo. The study analyzed 44 melatonin patients and 42 placebo groups. The mean intensive care unit (ICU) hospitalization days were 11.23 ± 4.73 days in the melatonin group and 11.90 ± 6.52 days in the placebo group (P = 0.582). The mean days of hospitalization in the melatonin group were 19.70 ± 8.77 days and 21.48 ± 10.85 days in the placebo group (P = 0.407). The mean oxygen saturation before and after discharge from ICU in the melatonin group was 81 ± 6.73%, 91.02 ± 1.17%, and in the placebo group, 83.36 ± 8.27%, 91.21 ± 1.26, respectively (P = 0.467 and P = 0.150). Melatonin can significantly reduce inflammation and oxidative stress markers in patients, making it a promising therapeutic option for COVID-19 patients. Further research is needed to determine the optimal treatment dosage and duration. Nonetheless, these results offer a promising avenue for future research and clinical practice.

A Comparison Between the Photodynamic Action of “Hypocrellin A” and “Pheophorbide A” Against Bacteria and SARS-CoV-2 Virus --- A MiniReview

Abstract: Hypocrellin A and Pheophorbide a are well-known organic chemicals that may be contained in herbal products. They can act as photosensitizers and have a strong photodynamic effect on bacteria. In any case, are these photosensitizers appropriate for photodynamic treatment against the SARS-CoV-2 infection? The principles of photodynamic therapy are the same regardless of the target. It causes selective cytotoxicity at the site of infection through activation of photosensitizer under light irradiation to generate cytotoxic reactive oxygen species (ROS), leading to the death of infected cells. Is antimicrobial photodynamic therapy a good choice against the SARS-CoV-2 virus? Methods: Nine electronic databases were searched, including WanFang Data, PubMed, Science Direct, Scopus, Web of Science, Springer Link, SciFinder, and China National Knowledge Infrastructure (CNKI), regardless of term, and language restrictions. All eligible studies were analyzed and summarized in this review. Results: “Hypocrellin A” and “Pheophorbide a” were effective for bacterial and SARS-CoV-2 in photodynamic therapy. 99.98 % of S. aureus was killed when incubated with the 10-3 M Hypocrellin A and illuminated a 490 nm in 30 mW/cm2 for 120 min. The difference was Pheophorbide a could also inhibit gram-negative bacteria, such as P. aeruginosa with a concentration of 1 µg/ml for 2 hr irradiated of a 671 nm laser in 0.3 W of 1 J, and a nearly 100 % suppression rate. “Hypocrellin A” and “Pheophorbide a” with antiviral activity, and virucidal effects for preventing and treating the infection. Conclusion: Based on previous studies, “Hypocrellin A” and “Pheophorbide a” are photosensitizers used for photodynamic therapy against bacteria or SARS-CoV-2, however, much more works need to be done in the future including the development of a better way for systematic infectious disease, and its correlated infections for the application of photodynamic therapy.

In vitro inhibition of rotavirus multiplication by copper oxide nanoparticles.

Group A rotaviruses are the most common cause of gastroenteritis in children under five years of age worldwide. Rotavirus gastroenteritis can be related to mild to severe diarrhea in children and in some cases, can lead to death due to severe dehydration. Approximately 146,480 people die annually from rotavirus infection worldwide, and most of these deaths occur in low-income countries in Africa and Asia. Since there are no specific effective drugs to treat rotavirus infections, and infected patients can only be treated supportively, new antiviral agents need to be developed. Copper oxide nanoparticles (CuO NPs) have a wide range of applications in the magnetic and electrical industries, as well as in biology. The antiviral activity of nanoparticles (CuO NPs) is well documented. This study aimed to investigate the antiviral effect of CuO NPs on rotaviruses. The cytotoxic effects of CuO NPs on MA-104 cells were examined by methyl thiazolyl tetrazolium assay. In addition, the anti-rotavirus activity of CuO NPs was evaluated by TCID50 and real-time polymerase chain reaction PCR assay. Our results showed that exposure of rotavirus-infected cells to various non-toxic concentrations of CuO NPs did not cause a decrease in viral titer, compared to the control. However, the virucidal effect of CuO NPs on rotavirus was observed at concentrations of 80 and 100 μg/ml (P<0.001). Our study suggested that CuO NPs had significant antiviral activity against rotavirus replication. However, the exact mechanism of anti-rotavirus activity of CuO NPs remained unknown. According to the virucidal assay, it appears that the loss of capsid integrity and genome disruption in the presence of CuO NPs are possible mechanisms of its anti-rotavirus activity.

Anti-rheumatic colchicine phytochemical exhibits potent antiviral activities against avian and seasonal Influenza A viruses (IAVs) via targeting different stages of IAV replication cycle

BackgroundThe continuous evolution of drug-resistant influenza viruses highlights the necessity for repurposing naturally-derived and safe phytochemicals with anti-influenza activity as novel broad-spectrum anti-influenza medications.MethodsIn this study, nitrogenous alkaloids were tested for their viral inhibitory activity against influenza A/H1N1 and A/H5N1 viruses. The cytotoxicity of tested alkaloids on MDCK showed a high safety range (CC50 > 200 µg/ml), permitting the screening for their anti-influenza potential. ResultsHerein, atropine sulphate, pilocarpine hydrochloride and colchicine displayed anti-H5N1 activities with IC50 values of 2.300, 0.210 and 0.111 µg/ml, respectively. Validation of the IC50 values was further depicted by testing the three highly effective alkaloids, based on their potent IC50 values against seasonal influenza A/H1N1 virus, showing comparable IC50 values of 0.204, 0.637 and 0.326 µg/ml, respectively. Further investigation suggests that colchicine could suppress viral infection by primarily interfering with IAV replication and inhibiting viral adsorption, while atropine sulphate and pilocarpine hydrochloride could directly affect the virus in a cell-free virucidal effect. Interestingly, the in silico molecular docking studies suggest the abilities of atropine, pilocarpine, and colchicine to bind correctly inside the active sites of the neuraminidases of both influenza A/H1N1 and A/H5N1 viruses. The three alkaloids exhibited good binding energies as well as excellent binding modes that were similar to the co-crystallized ligands. On the other hand, consistent with in vitro results, only colchicine could bind correctly against the M2-proton channel of influenza A viruses (IAVs). This might explicate the in vitro antiviral activity of colchicine at the replication stage of the virus replication cycle.ConclusionThis study highlighted the anti-influenza efficacy of biologically active alkaloids including colchicine. Therefore, these alkaloids should be further characterized in vivo (preclinical and clinical studies) to be developed as anti-IAV agents.

PH-dependent virucidal effects of weak acids against pathogenic viruses

BackgroundWeak acids, such as acetic acid, show virucidal effects against viruses, and disinfectants are considered effective virucidal agents possibly because of their low pH, depending on the proton concentration. This study aimed to evaluate the efficacy of different weak acids (acetic, oxalic, and citric acids) and eligible vinegars under different pH conditions by comparing their inactivation efficacies against enveloped and non-enveloped viruses.MethodsAcetic, oxalic, and citric acids were adjusted to pH values of 2, 4 and 6, respectively. They were also diluted from 1 M to 0.001 M with distilled water. Enveloped influenza A virus (FulV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and non-enveloped feline calicivirus (FCV) were treated with adjusted weak acids for up to 30 min. These viruses were also reacted with white distilled vinegar (WDV) and grain-flavored distilled vinegar (GV) for up to 30 min. Infectious viral titers after the reactions were expressed as plaque-forming units per mL.ResultsAcetic acid showed virucidal effects against FulV at pH 4, whereas citric and oxalic acids did not. Acetic and citric acids inactivated SARS-CoV-2 at pH 2, whereas oxalic acid did not. All acids showed virucidal effects against FVC at pH 2; however, not at pH 4. The virucidal effects of the serially diluted weak acids were also reflected in the pH-dependent results. WDV and GV significantly reduced FulV titers after 1 min. SARS-CoV-2 was also susceptible to the virucidal effects of WDV and GV; however, the incubation period was extended to 30 min. In contrast, WDV and GV did not significantly inactivate FCV.ConclusionsThe inactivation efficacy of weak acids is different even under the same pH conditions, suggesting that the virucidal effect of weak acids is not simply determined by pH, but that additional factors may also influence these effects. Moreover, eligible vinegars, the main component of which is acetic acid, may be potential sanitizers for some enveloped viruses, such as FulV, in the domestic environment.

Methods for SARS-CoV-2 hospital disinfection, in vitro observations

IntroductionEscalation of chemical disinfection during the COVID-19 pandemic raised occupational hazard concerns. Alternative and potentially safer methods such as ultraviolet-C (UVC) irradiation and ozone are desirable, notwithstanding the lack of standardized criteria for their use in the healthcare environment. AimCompare the virucidal activity of 70% ethanol, sodium dichloroisocyanurate (NaDCC), chlorhexidine, ozonated water, UVC-222 nm, UVC-254 nm against three SARS-CoV-2 variants of concern cultured in vitro. MethodsInactivation of three SARS‐CoV‐2 variants (alpha, beta, gamma) by the following chemical methods was tested: ethanol 70%, NaDCC (100 ppm, 500 ppm, 1000 ppm), chlorhexidine (2%, 1% and 0.5%), ozonated water 7 ppm. For irradiation, a je2Care 222nm UVC Lamp was compared to a Sylvania G15 UV254 nm lamp on SARS-CoV-2 variants. ResultsViral inactivation by >3 log was achieved with ethanol, NaDCC and chlorhexidine. The minor virucidal effect of ozonated water was <1 log. Virus treatment with UVC-254 nm reduced viral activity by 1-5 logs with higher inactivation after exposure for 3 minutes compared to 6 seconds. For all three variants, under equivalent conditions, exposure to UVC-222 nm did not achieve time-dependent inactivation as was observed with treatment with UVC-254 nm. ConclusionThe virucidal activity on replication-competent SARS-CoV-2 by conventional chemical methods, including chlorhexidine at concentrations as low as 0.5%, was not matched by UVC irradiation, and to an even lesser extent by ozonated water treatment.

Virucidal activity of chlorine dioxide in combination with acetic acid or citric acid and a surfactant, in presence of interfering substances, against polio-, adeno- and murine norovirus in suspension-, carrier- and four-field tests.

The aim of the study was to investigate whether the virucidal effectiveness of chlorine dioxid against adenovirus and murine norovirus can be improved by combining it with carboxylic acids and surfactants. The virucidal efficacy against polio-, adeno- and murine norovirus has been tested in presence of interfering substances in the quantitative suspension test according to EN 14476, the carrier test without mechanical action according to EN 16777, and in the four-field test according to EN 16615.Three chlorine-dioxide-based surface disinfectants were tested: a two-component cleaning disinfectant concentrate for large surfaces, a ready-to-use (RTU) foam, and an RTU gel. Cleaning and disinfecting preparations based on chlorine dioxide, applied at various concentrations, in combination with acetic acid or citric acid and surfactants, are virucidally active against polio-, adeno-, and norovirus after an exposure time of 5 minutes in presence of interfering substances.

Bioactive potentials of the truffle mushrooms Tirmania nivea, Tirmania pinoyi and Tuber indicum

Background Truffles are ectomycorrhizal wild mushrooms that have ethnomycological importance as a folklore remedy used to treat different skin and eye diseases and they are currently known as expensive food and potential sources of bioactive compounds. Objective This study aims to investigate the in vitro bioactive potential of the ethyl acetate extracts of three truffle species Tirmania nivea, Tirmania pinoyi, and Tuber indicum collected from Egypt, Saudi Arabia, and China. Results and discussion Inhibition of α-glucosidase was investigated as an indication of the antidiabetic potential of extracts. Tuber indicum extract caused 21.7% inhibition at a concentration of 100ppm. On the other hand, inhibition of nitric oxide is evaluated as a key way to regulate inflammation. Tuber indicum extract at a concentration of 100μg/ml achieved the highest inhibition (50.2%) and had the lowest IC50 (86.0±0.09μg/ml) among tested extracts, while Tirmania pinoyi extract achieved the lowest inhibition (21.7%) with the highest IC50 (104.1±0.12μg/ml). Cell migration was used to evaluate the wound healing activity of extracts. Tirmania pinoyi extract at a concentration of 100μg/ml caused 74.71% wound closure followed by 73.43% and 62.38% by Tuber indicum and Tirmania nivea extracts, respectively. Finally, investigating the antiviral potential of extracts against coxsackie virus B3 revealed that Tirmania pinoyi extract showed the highest virucidal effect and pretreatment antiviral activity while Tuber indicum extract achieved the highest post-treatment antiviral activity. Results achieved by these truffles encourage further investigations to be used as functional foods or as sources of bioactive compounds.

Emerging Potentials of Oral Gold Therapeutics (Swarna Prashana ) For Pediatric Age in Post COVID Era

Objective- To review the potential benefits of Swarna / Swarnaprashana (a kind of gold therapeutics) in pediatric age for infectious diseases. Data Source- various published researches has been reviewed. Review Methods- qualitative analysis of the themes of the researches done previously was done and potential benefits and future prospects and idea was generated. Results- Swarna (gold) nanoparticles has proven virucidal effect. Conclusion- The use of Swarna in Indian system of medicine is from very ancient times. This sacred element had very broad use since it was incorporated in human civilizations. Today we are facing the covid-19 pandemic with such a disastrous effect on public health. This era has shown the mankind that whatever be the understanding and developments of modern medical system for infectious diseases, the microbe world is always a step ahead of us and modifying itself. The ancient use of Swarna as swarnaprashana in children has better chances of improving the immunity and fighting certain viral infections.

Virucidal effect of mouthwash on acyclovir-resistant herpes simplex virus.

The symptoms of herpes simplex viruses type 1 (HSV-1) infections might be severe and persistent in immunocompromised patients in whom they reactivate at a high frequency. The development of Acyclovir (ACV) resistant strains due to long-term treatment with antiviral agents in those patients is not uncommon. The aim of the present study was to assess the virucidal effect of commercially available mouthwashes against ACV-resistant HSV-1 strains. Two acyclovir-resistant HSV-1 strains were exposed for 30 s to essential oil-based (Listerine Fresh Burst® and Listerine Zero®), chlorhexidine gluconate 0.2% (Hexidyl®) and povidone-iodine 7.5% (Betadine Gargle®) mouthwashes. Loss of virus infectivity was determined by means of plaque reduction assays in a cell culture system. All 4 of the tested solutions significantly reduced virus infectivity, with the essential oil-based and povidone-iodine mouthwashes being slightly more efficacious, compared to chlorhexidine. The findings of this analysis revealed that the tested oral rinses demonstrated in-vitro antiviral activity against ACV-resistant HSV. Comparative clinical trials are required to establish the clinical effectiveness of daily use of oral rinses in reducing the appearance of oral HSV lesions in immunocompromised patients.

Broad-spectrum virucidal activity of a hydroalcoholic extract of grape pomace

Grape pomace is a by-product of winemaking often disposed of before full exploitation. Indeed, this natural product holds great potential for sustainable utilization. In this study, dried grape pomace was reprocessed to assess its potential as a valuable source of antiviral metabolites. The antiviral activity of the extract was assessed against Herpes Simplex virus type-2, Feline Calicivirus, Coxsackievirus B5, and Influenza type-A virus, revealing potent broad virucidal effect. Indeed, it abolished viral infection when the extract was incubated with viruses before or during infection, whereas no significant toxic effects were observed up to 3 mg/mL.UHPLC-MS/MS analysis identified quercetin, gallic acid, and ethyl gallate as its primary constituents. These did not fully account for its virucidal action, suggesting the presence of additional active components and/or synergistic effect of more compounds.Thus, grape pomace may be exploited as a sustainable source for the preparation of environmentally friendly broad-spectrum virucidal disinfectants.

Hoveniae Semen Seu Fructus water extract inhibits influenza A virus infection

Hoveniae Semen Seu Fructus (HSF) is a fruit and seed of Hovenia dulcis Thunb. Here, we first report HSF water extract contains a potent anti-influenza A virus (IAV) effect via inhibition of neuraminidaseand hemagglutinin and a direct virus-killing effect. We examined the effect of WHSF on IAV infection using GFP-tagged Influenza A/PR/8/34. FACS analysis and fluorescent microscopy showed a dose-dependent inhibitory effect of WHSF against IAV infection. WHSF also suppressed the cytopathic effects of H1N1 and H3N2 IAV. Immunofluorescence and qPCR analyses confirmed WHSF significantly decreases IAV protein and RNA expressions. Time of addition and plaque assays revealed WHSF affects viral replication in the early stage via modulatinghemagglutinin and inducing virucidal effects. Furthermore, WHSF suppressed the neuraminidase activity of H1N1 and H3N2 IAV. Quercetin, not taxifolin in WHSF inhibited IAV infection. Our results suggest WHSF could be developed as a natural antiviral agent to prevent IAV infection.

Rapid and efficient inactivation of viruses in seawater by LIG electrodes

Water-borne viral diseases are a significant concern for public health. In particular, they threaten the health of people and animals in countries that lack proper water treatment facilities. Novel water treatment technology may efficiently improve water quality and prevent the spread of waterborne viral pathogens. Laser-induced graphene (LIG) has been shown to inactivate viruses and bacteria with its photothermal properties, electrochemical reaction, and rough surface texture. However, LIG's activity to prevent virus transmission via contaminated water has not been fully explored. Here, we demonstrated that enveloped and non-enveloped viruses in seawater could be rapidly inactivated by LIG technology. After being activated by 3 V of electricity, the LIG electrodes inactivated both types of viruses spiked in water within 30 min. In addition, the electrolyzed seawater exhibited virucidal effects even after the cessation of the electrical charge. The generation of different oxidants, such as chlorine, chlorine dioxide, and hydrogen peroxide, may play an essential role in the antiviral mechanism of the LIG electrodes. Furthermore, after 10 min of electrolysis, the pH of the seawater dropped from approximately 8–5, which may also have contributed to the virucidal effects of the LIG technology. The virucidal activity of LIG technology highlighted its potential for preventing the spread of viral infections via seawater systems which may have public health implications in areas where seawater is used in the sewage system. It may also have applications in aquaculture, where viral diseases do not have treatments and can cause high fish mortality.

Emerging insights into the structure-activity relationship of water-soluble polysaccharides in antiviral therapy

This review provides an overview of recent advancements in understanding the antiviral activities and mechanism of action of water-soluble polysaccharides (WSPs). Water-soluble polysaccharides are complex carbohydrate molecules derived from various natural sources, including plants, microorganisms, and fungi. Their unique structural characteristics make them intriguing candidates for antiviral therapeutics. However, in this review, we highlight the emerging insights into the multifaceted antiviral properties of water-soluble polysaccharides. These substances have exhibited the ability to hinder the activity of various viruses, encompassing both enveloped and non-enveloped types. Their mechanisms of action encompass interference with viral attachment and entry, inhibition of viral replication, modulation of the host immune response, and even direct virucidal effects. Furthermore, we delve into the structural features of water-soluble polysaccharides that underpin their antiviral potential. Factors such as molecular weight, branching patterns, sulfation, and acetylation play pivotal roles in their antiviral activity. Additionally, we explore the importance of water-soluble polysaccharide conformation, size, shape, solubility, charge density, and stereochemistry in influencing their interactions with viral particles and host cell receptors. Moreover, this review provides the growing significance of water-soluble polysaccharides as promising antiviral agents and emphasizes the need for further research to harness their full therapeutic potential in the fight against viral diseases.

Neutrophil Virucidal Activity Against SARS-CoV-2 Is Mediated by Neutrophil Extracellular Traps.

Inflammation in the lungs and other vital organs in COVID-19 is characterized by the presence of neutrophils and a high concentration of neutrophil extracellular traps (NETs), which seems to mediate host tissue damage. However, it is not known whether NETs could have virucidal activity against SARS-CoV-2. We investigated whether NETs could prevent SARS-CoV-2 replication in neutrophils and epithelial cells and what the consequence of NETs degradation would be in K18-humanized ACE2 transgenic mice infected with SARS-CoV-2. Here, by immunofluorescence microscopy, we observed that viral particles colocalize with NETs in neutrophils isolated from patients with COVID-19 or healthy individuals and infected in vitro. The inhibition of NETs production increased virus replication in neutrophils. In parallel, we observed that NETs inhibited virus abilities to infect and replicate in epithelial cells after 24 hours of infection. Degradation of NETs with DNase I prevented their virucidal effect in vitro. Using K18-humanized ACE2 transgenic mice, we observed a higher viral load in animals treated with DNase I. However, the virucidal effect of NETs was not dependent on neutrophil elastase or myeloperoxidase activity. Our results provide evidence of the role of NETosis as a mechanism of SARS-CoV-2 viral capture and inhibition.

Evaluation of anti-adenoviral effects of the polyvinyl alcohol iodine ophthalmic solution.

To investigate the virucidal effects of a polyvinyl alcohol iodine, Saniode, against 16 types of human mastadenovirus (HAdV) causing ophthalmic, respiratory, gastrointestinal, urinary, and systemic infections. Laboratory investigation METHODS: Fifty microliters of Saniode were exposed to 10 μL each containing HAdV virus stock solution of 1 × 106copies/μL of HAdV-1, -2, -3, -4, 5, -6, -7, -8, -11, -37, -53, -54, -56, -64, -81, and -85 for 10 s, 30 s, 1 min, and 3 min. After neutralization with 0.5% sodium thiosulfate, the mixture was diluted by ten-fold serial dilution and inoculated into 24 wells containing confluent A549 cell monolayers. Virucidal effects were calculated relative to the positive control on days 7-10 and observed until 30 days post-infection. Saniode satisfied the EN-14476 criterion for virucidal effects (>99.99%) for all HAdV types at all exposure times, including at 10s on days 7 to 10 post-infection. All types of HAdVs that reacted for > 1 min achieved 99.99% reduction, including after 30 days. Saniode displayed virucidal effects against all tested HAdV types. Currently, with no specific medication available for HAdVs in ocular infection, this could be an option to prevent the spread of keratoconjunctivitis.

HDL mimetics protect Alzheimer’s patients carrying APOE ε4 from SARS-CoV-2 invasion

Patients with Alzheimer’s disease (AD) inheriting Apolipoprotein (APOE) ε4 are susceptible to COVID-19, but the underlying mechanism of how such a neurodegenerative disease promotes respiratory vulnerability to viral infections remains insufficiently understood. The uncovering of genetic basis of COVID-19 outcome holds the potential to establish disease models for therapeutic development. Here, using human iPSC-derived type II alveolar epithelial cells (hAECII) from AD patients with APOE ε4 and healthy individuals, we showed that AECII of AD had a greater level of SARS-CoV-2 invasion but not replication, along with increased expressions of viral receptor and co-receptors, while reduced pulmonary surfactant proteins. Since low serum HDL-C levels have been implicated in the onset of both AD and COVID-19, we further revealed that HDL mimetics, including 4 F dimeric peptide and its phospholipid conjugate pHDL, were effective in protecting AECII bearing APOE ε4 against SARS-CoV-2 invasion. In AD, concomitant with improved AD pathological phenotypes, HDL mimetics specifically restored the defective basal SP-D, a pulmonary innate immune lipoprotein that targets glycans of the spike protein to neutralize invading viruses. Moreover, HDL mimetics demonstrated strong SP-D-independent virucidal effects, which additionally restricted the entry of coronaviral particles into non-AD AECII models and lungs of human ACE2-transgenic mice in response to Alpha and Omicron variants of SARS-CoV-2. Our work offers critical insights into the respiratory sensitivity of AD patients carrying APOE ε4 to viral infection and repurpose HDL-based therapeutics as potential preventive interventions in respiratory viral pandemics.

In vitro antiviral effect of cinnamon oil, Moringa oleifera extract, Manuka honey, and Nigella sativa oil against SARS-CoV-2 compared to remdesivir

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of a public health importance as it is continually evolving due to random mutations. New mutations can potentially affect the degree of infectiousness, virulence, and can increase the virus’ capability to evade adaptive immune responses of the body. Immunity is one of the key factors determining the extent of severity of SARS-CoV-2 patients. Therefore, thinking about natural remedies is the way to boost immunity, keep the body protected, and able to fight the SARS-CoV-2 virus. We aimed to make progress in the field of anti-SARS-CoV-2 nutraceuticals, thus providing a safe and natural alternative to traditional chemically manufactured medications.MethodsThe cytotoxic activity (CC50) of the natural products was tested experimentally in vitro on the VERO-E6 cells using a crystal violet assay. The cells were then treated with different concentrations of the natural products of Moringa oleifera leaves extract, cinnamon bark oil extract, Manuka honey, and Nigella sativa oil. The inhibitory concentration 50 (IC50) value and the CC50 value were calculated in order to measure the antiviral effect of on SARS-CoV-2 virus compared to antiviral Remdesivir drug.ResultsThe tested natural products of honey and extracts exhibited pronounced virucidal effect against one of the most challenging viruses worldwide which is the SARS-CoV-2 virus. The results showed that the highest selectivity index was the Manuka honey + 20 UMF with SI of 10.23. The second sample following Manuka honey regarding its efficiency was the mixture of the three extracts with the honey (SI = 7.12), then followed by Remdesivir antiviral drug (SI = 3.3), then Moringa oleifera leaves extract (SI = 2.1). The last two products showing the least SI were Nigella sativa oil (SI = 1.6) and cinnamon bark oil (SI = 1.08), respectively.ConclusionsManuka honey + 20 UMF alone or combined with other three extracts of Moringa oleifera, Nigella sativa, and cinnamon bark oil have a much stronger in vitro antiviral effect on SARS-CoV-2 virus than the traditional antiviral drug Remdesivir. Further research will be needed to test the effectiveness of these natural products in vivo as an antiviral remedy against SARS-CoV-2 virus.