Indian Herb-Derived Phytoconstituent-Based Antiviral, Antimicrobial and Antifungal Formulation: An Oral Rinse Candidate for Oral Hygiene and the Potential Prevention of COVID-19 Outbreaks

Therapeutic implications of quercetin and its derived-products in COVID-19 protection and prophylactic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel human coronavirus, which has triggered a global pandemic of the coronavirus infectious disease 2019 (COVID-19). Outbreaks of emerging infectious diseases continue to challenge human health worldwide. The virus conquers human cells through the angiotensin-converting enzyme 2 receptor-driven pathway by mostly targeting the human respiratory tract. Quercetin is a natural flavonoid widely represented in the plant kingdom. Cumulative evidence has demonstrated that quercetin and its derivatives have various pharmacological properties including anti-cancer, anti-hypertension, anti-hyperlipidemia, anti-hyperglycemia, anti-microbial, antiviral, neuroprotective, and cardio-protective effects, because it is a potential treatment for severe inflammation and acute respiratory distress syndrome. Furthermore, it is the main life-threatening condition in patients with COVID-19. This article provides a comprehensive review of the primary literature on the predictable effectiveness of quercetin and its derivatives docked to multi-target of SARS-CoV-2 and host cells via in silico and some of validation through in vitro, in vivo, and clinically to fight SARS-CoV-2 infections, contribute to the reduction of inflammation, which suggests the preventive and therapeutic latency of quercetin and its derived-products against COVID-19 pandemic, multisystem inflammatory syndromes (MIS), and long-COVID.

Efficacy of a mouthwash containing ε-poly-L-lysine, funme peptides and domiphen in reducing halitosis and supragingival plaque: a randomized clinical trial

OBJECTIVE

To evaluate the antibacterial effectiveness of a combination of ε-poly-L-lysine (ε-PL), funme peptide (FP) as well as domiphen against oral pathogens, and assess the efficacy of a BOP® mouthwash supplemented with this combination in reducing halitosis and supragingival plaque in a clinical trial.

MATERIALS AND METHODS

The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the compound against Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans were determined by the gradient dilution method. Subsequently, the CCK-8 assay was used to detect the toxicity of mouthwash on human gingival fibroblastst, and the effectiveness in reducing halitosis and supragingival plaque of the mouthwash supplemented with the combination was analyzed by a randomized, double-blind, parallel-controlled clinical trial.

RESULTS

The combination exhibited significant inhibitory effects on tested oral pathogens with the MIC < 1.56% (v/v) and the MBC < 3.13% (v/v), and the mouthwash containing this combination did not inhibit the viability of human gingival fibroblasts at the test concentrations. The clinical trial showed that the test group displayed notably lower volatile sulfur compounds (VSCs) at 0, 10, 24 h, and 7 d post-mouthwash (P < 0.05), compared with the baseline. After 7 days, the VSC levels of the and control groups were reduced by 50.27% and 32.12%, respectively, and notably cutting severe halitosis by 57.03% in the test group. Additionally, the Plaque Index (PLI) of the test and control group decreased by 54.55% and 8.38%, respectively, and there was a significant difference in PLI between the two groups after 7 days (P < 0.01).

CONCLUSIONS

The combination of ε-PL, FP and domiphen demonstrated potent inhibitory and bactericidal effects against the tested oral pathogens, and the newly formulated mouthwash added with the combination exhibited anti-dental plaque and anti-halitosis properties in a clinical trial and was safe.

TRIAL REGISTRATION

The randomized controlled clinical trial was registered on Chinese Clinical Trial Registry (No. ChiCTR2300073816, Date: 21/07/2023).

Development of a pseudo-typed virus particle based method to determine the efficacy of virucidal agents

The ongoing Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has highlighted the threat that viral outbreaks pose to global health. A key tool in the arsenal to prevent and control viral disease outbreaks is disinfection of equipment and surfaces with formulations that contain virucidal agents (VA). However, assessment of the efficacy of virus inactivation often requires live virus assays or surrogate viruses such as Modified Vaccinia Virus Ankara (MVA), which can be expensive, time consuming and technically challenging. Therefore, we have developed a pseudo-typed virus (PV) based approach to assess the inactivation of enveloped viruses with a fast and quantitative output that can be adapted to emerging viruses. Additionally, we have developed a method to completely remove the cytotoxicity of virucidal agents while retaining the required sensitivity to measure PV infectivity. Our results indicated that the removal of cytotoxicity was an essential step to accurately measure virus inactivation. Further, we demonstrated that there was no difference in susceptibility to virus inactivation between PVs that express the envelopes of HIV-1, SARS-CoV-2, and Influenza A/Indonesia. Therefore, we have developed an effective and safe alternative to live virus assays that enables the rapid assessment of virucidal activity for the development and optimization of virucidal reagents.

In vivo efficacy of 2% povidone iodine, chlorhexidine gluconate, and herbal extract mouthwash on SARS-CoV-2 viral load in saliva: A randomized clinical trial

Background

One of the major techniques to reduce the transmission rate of COVID-19 would be to decrease the viral titers of SARS-CoV-2 in the saliva of infected patients and it is particularly useful in a dental setting. The present study evaluated the change in salivary viral load of COVID-19 patients using povidone iodine (PI), chlorhexidine (CHX), and an herbal extract (RightSure®) oral antiviral herbal mouthwash (HM) at clinically recommended duration and concentrations.

Materials and Methods

Thirty individuals with SARS-CoV-2 were randomly allocated to three groups: (1) Group 1, PI mouthwash; (2) Group 2, CHX mouthwash; and (3) Group 3, HM mouthwash. A baseline salivary throat sample was collected from all the participants who were later instructed to rinse with their respective mouthwash for 30 s. A second salivary sample was collected 30 min after rinsing. The SARS-CoV-2 viral load was analyzed using real-time reverse-transcription polymerase chain reaction wherein the cyclic threshold (Ct) values were evaluated.

Results

Independent t-test analysis reported a statistically significant difference concerning the PI group (before-after comparison) (P < 0.05). The rest of the two study groups failed to report any significant difference in the nucleocapsid gene and open reading frame 1a gene levels.

Conclusion

While all three types of mouthwash increased the Ct values, a statistically significant difference was observed with PI mouthwash, indicating that it might potentially reduce the spread of the SARS-CoV-2 virus, especially via aerosol but further studies with larger sample size and longer follow-up periods are required to investigate this relationship.

Quinones as Promising Compounds against Respiratory Viruses: A Review

Respiratory viruses represent a world public health problem, giving rise to annual seasonal epidemics and several pandemics caused by some of these viruses, including the COVID-19 pandemic caused by the novel SARS-CoV-2, which continues to date. Some antiviral drugs have been licensed for the treatment of influenza, but they cause side effects and lead to resistant viral strains. Likewise, aerosolized ribavirin is the only drug approved for the therapy of infections by the respiratory syncytial virus, but it possesses various limitations. On the other hand, no specific drugs are licensed to treat other viral respiratory diseases. In this sense, natural products and their derivatives have appeared as promising alternatives in searching for new compounds with antiviral activity. Besides their chemical properties, quinones have demonstrated interesting biological activities, including activity against respiratory viruses. This review summarizes the activity against respiratory viruses and their molecular targets by the different types of quinones (both natural and synthetic). Thus, the present work offers a general overview of the importance of quinones as an option for the future pharmacological treatment of viral respiratory infections, subject to additional studies that support their effectiveness and safety.

Efficacy of Mouth Rinses and Nasal Spray in the Inactivation of SARS-CoV-2: A Systematic Review and Meta-Analysis of In Vitro and In Vivo Studies

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) is a global and evolving pandemic associated with heavy health and financial burdens. Considering the oral cavity as the major reservoir for SARS-CoV-2, a systematic review and meta-analysis were conducted to assess the efficacy of mouth rinses and nasal sprays in reducing the salivary viral load of SARS-CoV-2. All in vivo and in vitro studies that assessed the virucidal efficacy of mouth rinses and nasal sprays against SARS-CoV-2 and were published in the English language from December 2019 to April 2022 were considered for analyses. Special Medical Subject Headings terms were used to search Pubmed, Scopus, Embase Ovid, and Web of Science databases. The toxicological data reliability assessment tool (ToxRToool) was used to assess the quality of the included studies. Thirty-three studies (11 in vivo and 22 in vitro) were deemed eligible for inclusion in this analysis. Results of the pooled data showed that povidone-iodine is the most efficacious intervention in vivo in terms of reducing the SARS-CoV-2 salivary viral load, followed by chlorhexidine. The mean difference in the viral load was 86% and 72%, respectively. Similarly, povidone-iodine was associated with the highest log₁₀ reduction value (LRV) in vitro, followed by cetylpyridinium chloride, (LRV = 2.938 (p < 0.0005) and LRV = 2.907 (p = 0.009), respectively). Povidone-iodine-based oral and nasal preparations showed favourable results in terms of reducing SARS-CoV-2 viral loads both in vivo and in vitro. Considering the limited number of patients in vivo, further studies among larger cohorts are recommended.

Potential of Azadirachta indica as a Capping Agent for Antiviral Nanoparticles against SARS-CoV-2

A rare type of pneumonia later on referred to as COVID-19 was reported in China in December 2019. Investigations revealed that this disease is caused by a coronavirus previously identified as SARS-CoV-2, and since then, it has become a global pandemic with new strains emerging rapidly as a result of genetic mutations. Various therapeutic options are being explored in order to eradicate this pandemic even though approved vaccine candidates are being currently rolled out globally. Most medicinal plant extracts have astonishing properties, and they can therefore be used in the biosynthesis of effective antiviral nanoparticles. In this systematic review, we aimed to highlight the specific attributes that make Azadirachta indica (neem plant) a suitable candidate for the biosynthesis of anti-SARS-CoV-2 nanoparticles. A systematic investigation was therefore carried out in PubMed, Scopus, Web of Science, and AJOL databases with the keywords “Nanoparticles,” “Biosynthesis,” “Antivirals,” “SARS-CoV-2,” and “Azadirachta indica.” 1216 articles were retrieved by the 21^st of February 2022, but we screened studies that reported data on biomedical and antimicrobial assessment of Azadirachta indica extracts. We also screened studies that were reporting nanoparticles possessing antiviral properties against SARS-C0V-2, narrowing our results to 98 reports. Herein, the SARS-CoV-2 viral structure is briefly discussed with nanoparticles of biomedical importance in the design of SARS-CoV-2 antivirals. Most importantly, we focused on the biomedical and antiviral properties of Azadirachta indica extracts that could be of importance in the design of potential anti-SARS-CoV-2 nanoformulations.