Research suggests that Ginkgo biloba extract contains naturally occurring inhibitors against SARS-CoV-2

By Angela Betsaida B. Laguipo, BSNApr 27 2021

The coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), further spreads across the globe, causing skyrocketing cases in some countries.

Finding effective agents against the virus is crucial to combat the current global health crisis. Past evidence has shown that Gingko Biloba, also known as maidenhair, can inhibit viral proteins, inhibiting replication.

Researchers at Shihezi University in China found that Gingko Biloba leaves extract contains the most potent SARS-CoV-2 3-Chymotrypsin-like protease (3CLpro). This virally encoded main proteinase is essential for viral replication in coronaviruses.

Study: Discovery of naturally occurring inhibitors against SARS-CoV-2 3CLpro from Ginkgo biloba leaves via large-scale screening. Image Credit: Damian Lugowski / Shutterstock

Study background

The coronavirus pandemic is spreading like wildfire across many countries and has infected over 147 million people. Of these, 3.11 million people have died, and the virus has spread to 192 countries and regions.

The lack of effective drugs and the high infectivity of the virus contributed to the unprecedented spread of SARS-CoV-2, overwhelming health care systems.

Currently, scientists worldwide are trying to find effective therapeutics for combating COVID-19 by targeting various therapeutic targets. Among all the identified targets, the conserved 3-chymotrypsin-like protease (3CLpro) has been dubbed a vital target since it plays an imperative role in coronavirus replication.

Any disruption or strong inhibition on the 3CLpro will block viral replication. Finding an agent to inhibit this protease may help fight the current pandemic.

Finding key active ingredients

It is well-known that the phytochemicals from medicinal plants are potential candidates. The study, published in the journal Fitoterapia, aims to discover the naturally occurring SARS-CoV-2 3CLpro inhibitors from herbal medicines. It also investigated the inhibitory mechanism of the newly found effective SARS-CoV-2 3CLpro inhibitors.

The researchers conducted a large-scale screening to determine biochemicals that may have antiviral activity, collecting 80 herbal products. They also used a biochemical approach to determine if these herbal products can inhibit SARS-CoV-2 3CLpro.

After the screening, they identified Gingko Biloba leaves extract (GBLE) as the most potent action against SARS-CoV-2 3CLpro. Further, the team wanted to determine the critical ingredients of GBLE responsible for inhibiting SARS-CoV-2.

A total of 20 natural ingredients were isolated from Gingko Biloba leaves. The researchers assayed these constituents to determine which ones are potential inhibitors, which can be used to mitigate the spread of COVID-19.

Of all the natural ingredients, bioflavonoids and ginkgolic acids (GAs) were observed to have the most potent inhibitory mechanisms on the 3CLpro molecules. Finding these active ingredients can help pave the way for developing novel anti-COVID-19 agents.

Bioflavonoids, also known as flavonoids, are natural pigments that give vegetables and fruits their color. The current study found that the bioflavonoids isolated from GBLE demonstrated potent inhibition against SARS-CoV-2 3CLpro potency. The study findings suggest that bioflavonoids could act as promising lead compounds to develop anti-SARS-CoV-2 agents. The compound can also become a lead ingredient in anti-coronavirus drugs to prevent future outbreaks.

“Collectively, our findings revealed the key constituents in GBLE responsible for SARS-CoV-2 3CLpro inhibition, which offered several promising lead compounds for developing novel 3CLpro inhibitors to treat COVID-19 or other coronaviruses,” the researchers concluded in the study.

Gingko biloba potential

COVID-19 is a complicated illness, which affects a multitude of organs. Usually, apart from respiratory disease, the condition also causes hypercoagulable inflammation.

Meanwhile, Gingko Biloba is a popular herbal medicine due to its wide range of health benefits. The herbal medicine is an anti-coagulant, anti-inflammatory, anti-obesity, anti-oxidative, and can lower blood pressure.

Scientists believe that Gingko Biloba can benefit patients with COVID-19, particularly those with underlying health conditions, by mitigating the major symptoms.

This is a significant step towards finding a treatment for COVID-19, which continues to spread. The United States and India report the highest number of cases, reaching 32 million and 17  million cases, respectively.

India has reported a healthcare collapse as hospitals and treatment facilities cannot accommodate all COVID-19 patients. For the past four days, the country has reported over 350,000 new cases of infection.

With the sudden surge of new cases, probably linked to new circulating variants, health officials urge the public to observe social distancing, wear their masks at all times, especially when indoors with poor ventilation, handwash regularly, and refrain from going to crowded places and events.