Plant extract shown to reduce Sars-CoV-2 viral replication in lab: CSIR study

The plant and root extract of velvetleaf can inhibit the replication of the Sars-CoV-2 virus, which causes Covid-19, by up to 98% in cell cultures, shows a yet-to-be peer reviewed study by three laboratories of the Indian government's Council for Industrial and Scientific Research. The extract is used in Ayurveda for fever, especially dengue, and the researchers found that it mimicked the working of several antivirals.

In the cell cultures, the researchers found that the whole plant aqueous extract reduced the viral content by 57% and the hydroalcoholic extract (a solution made with water and alcohol) reduced it by 98%.

The researchers also tested the various molecules found in the extract individually against Sars-CoV-2 virus and found pareirarine had the highest inhibition of 80%, according to the pre-print study uploaded on BioRxiv on Sunday.

"First we used connectivity map – a platform that has information on the pathways of various drug – to see how the plant extract likely works. What we found is that it has similar pathways of action like many antivirals. When we did the lab-based study, we found this to be true," said Dr Mitali Mukerji, senior scientist at Genomics and molecular medicine department at CSIR-Institute of Genomics and Integrative Biology.

She added, "This plant extract is already used in Ayurveda for fever, dengue, and some hormonal problems. So, the safety is established. Now, only a randomised clinical trial can tell whether it does help in reducing the severity or duration of the infection in people."

Drug expert CM Gulati said, "The principle of using plant extract for treating ailments is not new. The best examples would be quinine used to treat malaria that is derived from Cinchona trees and digoxin used to treat cardiac ailments derived from digitalis plants. But the current research is in very, very early stages. The scientists have to zero in on an active ingredient, decipher its chemical structure, and then develop a usable medicine."