Feasibility Study of Developing a Saline-Based Antiviral Nanoformulation Containing Lipid-Soluble EGCG: A Potential Nasal Drug to Treat Long COVID

Abstract:

A recent estimate indicates that up to 23.7 million Americans suffer from long COVID, and approximately one million workers may be out of the workforce each day due to associated symptoms, leading to a USD 50 billion annual loss of salary. Post-COVID (Long COVID) neurologic symptoms are due to the initial robust replication of SARS-CoV-2 in the nasal neuroepithelial cells, leading to inflammation of the olfactory epithelium (OE) and the central nervous system (CNS), and the OE becoming a persistent infection site.

Previously, our group showed that Epigallocatechin-3-gallate-palmitate (EC16) nanoformulations possess strong antiviral activity against human coronavirus, suggesting this green tea-derived compound in nanoparticle formulations could be developed as an intranasally delivered new drug to eliminate the persistent SARS-CoV-2 infection, leading to restored olfactory function and reduced inflammation in the CNS. The objective of the current study was to determine the compatibility of the nanoformulations with human nasal primary epithelial cells (HNpECs).

Methods: Nanoparticle size was measured using the ZetaView Nanoparticle Tracking Analysis (NTA) system; contact antiviral activity was determined by TCID50 assay for cytopathic effect on MRC-5 cells; post-infection inhibition activity was determined in HNpECs; and cytotoxicity for these cells was determined using an MTT assay. The rapid inactivation of OC43 (a β-coronavirus) and 229E (α-coronavirus) viruses was further characterized by transmission electron microscopy.

Results: A saline-based nanoformulation containing 0.1% w/v EC16 was able to inactivate 99.9999% β-coronavirus OC43 on direct contact within 1 min. After a 10-min incubation of infected HNpECs with a formulation containing drug-grade EC16 (EGCG-4′ mono-palmitate or EC16m), OC43 viral replication was inhibited by 99%. In addition, all nanoformulations tested for their effect on cell viability were comparable to normal saline, a regularly used nasal irrigation solution. A 1-min incubation of an EC16 nanoformulation with either OC43 or 229E showed an altered viral structure.

Conclusion: Nanoformulations containing EC16 showed properties compatible with nasal application to rapidly inactivate SARS-CoV-2 residing in the olfactory mucosa and to reduce inflammation in the CNS, pending additional formulation and safety studies.

Source: Frank N, Dickinson D, Garcia W, Liu Y, Yu H, Cai J, Patel S, Yao B, Jiang X, Hsu S. Feasibility Study of Developing a Saline-Based Antiviral Nanoformulation Containing Lipid-Soluble EGCG: A Potential Nasal Drug to Treat Long COVID. Viruses. 2024; 16(2):196. https://doi.org/10.3390/v16020196 https://www.mdpi.com/1999-4915/16/2/196 (Full text)

Ginkgo Biloba and Long COVID: In Vivo and In Vitro Models for the Evaluation of Nanotherapeutic Efficacy

Abstract:

Coronavirus infections are neuroinvasive and can provoke injury to the central nervous system (CNS) and long-term illness consequences. They may be associated with inflammatory processes due to cellular oxidative stress and an imbalanced antioxidant system. The ability of phytochemicals with antioxidant and anti-inflammatory activities, such as Ginkgo biloba, to alleviate neurological complications and brain tissue damage has attracted strong ongoing interest in the neurotherapeutic management of long COVID.
Ginkgo biloba leaf extract (EGb) contains several bioactive ingredients, e.g., bilobalide, quercetin, ginkgolides A–C, kaempferol, isorhamnetin, and luteolin. They have various pharmacological and medicinal effects, including memory and cognitive improvement. Ginkgo biloba, through its anti-apoptotic, antioxidant, and anti-inflammatory activities, impacts cognitive function and other illness conditions like those in long COVID. While preclinical research on the antioxidant therapies for neuroprotection has shown promising results, clinical translation remains slow due to several challenges (e.g., low drug bioavailability, limited half-life, instability, restricted delivery to target tissues, and poor antioxidant capacity).
This review emphasizes the advantages of nanotherapies using nanoparticle drug delivery approaches to overcome these challenges. Various experimental techniques shed light on the molecular mechanisms underlying the oxidative stress response in the nervous system and help comprehend the pathophysiology of the neurological sequelae of SARS-CoV-2 infection.
To develop novel therapeutic agents and drug delivery systems, several methods for mimicking oxidative stress conditions have been used (e.g., lipid peroxidation products, mitochondrial respiratory chain inhibitors, and models of ischemic brain damage). We hypothesize the beneficial effects of EGb in the neurotherapeutic management of long-term COVID-19 symptoms, evaluated using either in vitro cellular or in vivo animal models of oxidative stress.
Source: Akanchise T, Angelova A. Ginkgo Biloba and Long COVID: In Vivo and In Vitro Models for the Evaluation of Nanotherapeutic Efficacy. Pharmaceutics. 2023; 15(5):1562. https://doi.org/10.3390/pharmaceutics15051562 https://www.mdpi.com/1999-4923/15/5/1562 (Full text)