Pharmacological Potential of Flavonoids against Neurotropic Viruses

Abstract

Flavonoids are a group of natural compounds that have been described in the literature as having anti-inflammatory, antioxidant, and neuroprotective compounds. Although they are considered versatile molecules, little has been discussed about their antiviral activities for neurotropic viruses. Hence, the present study aimed to investigate the pharmacological potential of flavonoids in the face of viruses that can affect the central nervous system (CNS). We carried out research from 2011 to 2021 using the Pubmed platform. The following were excluded: articles not in the English language, letters to editors, review articles and papers that did not include any experimental or clinical tests, and papers that showed antiviral activities against viruses that do not infect human beings. The inclusion criteria were in silico predictions and preclinical pharmacological studies, in vitro, in vivo and ex vivo, and clinical studies with flavonoids, flavonoid fractions and extracts that were active against neurotropic viruses. The search resulted in 205 articles that were sorted per virus type and discussed, considering the most cited antiviral activities. Our investigation shows the latest relevant data about flavonoids that have presented a wide range of actions against viruses that affect the CNS, mainly influenza, hepatitis C and others, such as the coronavirus, enterovirus, and arbovirus. Considering that these molecules present well-known anti-inflammatory and neuroprotective activities, using flavonoids that have demonstrated both neuroprotective and antiviral effects could be viewed as an alternative for therapy in the course of CNS infections.

Antiviral and Possible Prophylactic Significance of Myricetin for COVID-19

“…One of these was MYR, having a docking score of −21.987 kcal/mol and, consequently, was considered as an inhibitor of NS2B-NS3. 119 The pharmacological potential of flavonoids against neurotropic viruses has been recently reviewed by Castro e Silva et al 120…”

“…One of these was MYR, having a docking score of −21.987 kcal/mol and, consequently, was considered as an inhibitor of NS2B-NS3. 119 The pharmacological potential of flavonoids against neurotropic viruses has been recently reviewed by Castro e Silva et al 120 Antiviral effects of 60% aqueous methanol extracts of Zanthoxylum armatum and Hibiscus sabdariffa were demonstrated on murine norovirus. 121 Of the constituents, the phenolic compounds myricetin, quercetin, kaempferol, and luteolin exhibited significant activity, but quercetin showed the most significant logarithmic viral reductions.…”

Aurones: A Promising Scaffold to Inhibit SARS-CoV-2 Replication

“…In this context, the importance of natural products (NPs) as sources of new drugs is highlighted due to their privileged structures and high safety profile . Within NPs, flavonoids represent one of the largest and most diverse groups, showing promising biological activities such as anticancer, − antimicrobial, , antiparasitic, and anti-inflammatory. − Furthermore, flavonoids have also been described as a class of phytochemicals with potential antiviral activity against different DNA and RNA viruses, such as HIV, HSV, influenza, SARS, SARS-CoV-2, and others. , …”

“…20−22 Furthermore, flavonoids have also been described as a class of phytochemicals with potential antiviral activity against different DNA and RNA viruses, such as HIV, HSV, influenza, SARS, SARS-CoV-2, and others. 23,24 Concerning the SARS-CoV-2 outbreak, in 2020 Su et al 25 reported the natural flavone baicalein (Figure 1) as the first noncovalent and non-peptidomimetic inhibitor of SARS-CoV-2 main protease (M pro ), also known as 3CL pro (IC 50 = 0.9 μM), by determination of the crystal structure of the enzyme−ligand complex. The antiviral activity was reported in a cell-based system, using Vero E6 (African green monkey kidney cells) as the model (EC 50 = 2.9 μM).…”