Introduction

In 2017, grape output on a global scale totalled 73 million tonnes, whereas the amount of wine consumed was 244 hectolitres, indicating that grapevine is one of the world's most important horticultural crops. Grapes are high in primary and secondary metabolites, which impact quality. A grapefruit contains three distinctive tissues (skin, pulp, and seeds) containing several categories of chemicals such as organic acids, sugars, volatile compounds, polyphenols, and phenolic acids.¹

Grape seeds contain 60–70% of the polyphenols that are common in grapes. Multiple pharmacological and therapeutic advantages, including antioxidant, cardioprotective, hepatoprotective, anticarcinogenic, antidiabetic, antimicrobial, and antiviral effects, have been associated with these active ingredients.²

Antiviral properties of grape compounds

Resveratrol in grape skin

Several writers have indicated that resveratrol, an active component in grape skin, has antiviral properties. GSE was effective in inhibiting the hepatitis C virus (HCV) from replicating within HepG2 cells. Commercial GSE (Gravinol-S) was used to treat feline calicivirus (FCVF9), murine norovirus (MNV-1) and bacteriophage MS2, as well as hepatitis A virus (HAV; strain HM175).³

Furthermore, resveratrol administered topically to mice infected subcutaneously or vaginally with HSV decreased lesion formation and death rates considerably in vivo (Docherty et al., 2004, 2005). It is unclear how resveratrol inhibits herpes simplex virus (HSV) replication through an antiviral mechanism, though. The experiment aimed to determine the mechanism or mechanisms by which resveratrol prevents HSV reproduction however, it is unclear how resveratrol inhibits HSV replication through an antiviral mechanism.⁴

Resveratrol against varicella-zoster virus (VZV)

Resveratrol was tested against varicella-zoster virus (VZV) since it has previously been found to suppress herpes simplex virus (HSV) and human cytomegalovirus (HCMV) in vitro and HSV in vivo when given topically. Our findings show that resveratrol suppresses VZV replication in vitro and acts upon an at-first necessary regulatory protein of VZV.

The reversibility of the impact of resveratrol's suppression of VZV replication was investigated. For seventy-two hours, VZV-infected cells were exposed to 219 milligrams of resveratrol. A batch of infected cells was subjected to a 24-hour interval substitution of a non-resveratrol-containing medium with media containing resveratrol. It is clear from the results that resveratrol significantly reduced the ability of varicella-zoster virus to replicate.

But as soon as the resveratrol was eliminated after 24 hours, the virus started to spread. Replication of varicella-zoster virus was postponed for an extra 24 hours after the medication was withdrawn if resveratrol was present for 48 hours.⁵

Grape seed extract (GSE) and antiviral properties

On the other hand, research on grape seed extract’s antiviral properties is minimal. In GSE, the anti-human immunodeficiency virus (HIV) actions have been connected to the decreased levels of HIV-1 entrance co-receptor expression.

 Therefore, it is conceivable that grape seed extract has a higher impact on perhaps inhibiting the receptors on host cells, which in turn stops viral entrance, replication, and infection.

Other researchers demonstrated that grape seed extract inhibited the replication of human norovirus surrogates using ELISA-based techniques.⁶

Human norovirus is a kind of foodborne virus belonging to the Caliciviridae family. It causes gastroenteritis, which is characterized by indicators such as vomiting, diarrhoea, nausea, stomach cramps, and fever. The virus is extremely infectious and can be passed from person to person via the fecal-oral pathway.⁷

For the creation of antiviral medications to treat human or virus infections, grape seed extract is an excellent option and an extremely valuable resource.⁸

Resveratrol (RV) is a non-flavonoid polyphenol found in grape seeds and skin and is formed in response to physiological stimuli and environmental stress. Resveratrol has been demonstrated to be effective against a broad range of viruses. According to reports, RV has potent antiviral action against polyomavirus, varicella-zoster virus, and herpes simplex virus type 1. It also significantly inhibits the in vitro and in vivo reproduction of influenza viruses.

Other phenolic compounds in grape seed extract

Numerous phenolic chemicals, including epicatechin, gallic acids, dimeric procyanidin, (+) catechin, and proanthocyanidins, are found in grape seed extract and are potential bioactive components for a variety of illnesses.

Hepatitis C virus (HCV)-elevated COX-2 expression and HCV replication are both substantially suppressed by grape seed proanthocyanidins extract (GSPE) therapy.

Grape seed extract and human enteric viruses

It has not been researched whether grape seed extract has any antiviral properties against human enteric viruses.⁹

Summary

Grapes aren’t just a delicious fruit—they’re packed with compounds that have impressive health benefits, especially in their seeds. These compounds, like polyphenols, have been linked to a range of positive effects, including antiviral properties. For instance, resveratrol, which is found in grape skin, has been shown to fight off viruses such as hepatitis C, herpes simplex, and even varicella-zoster by blocking their ability to replicate.

Grape seed extract (GSE) also has antiviral potential, though research on it is still growing. Studies suggest GSE could help slow down infections from viruses like HIV and norovirus. While the full scope of its effects, especially on human enteric viruses, is still being explored, the potential is exciting. With these findings, it’s clear that grapes hold a lot more power than we might have thought, especially when it comes to antiviral properties.