‘The difference between a medicine and a poison is the dose’ is a maxim that has rarely strayed from reality. And a new reinforcement in this regard comes from research carried out by scientists at the Chemistry Institute (IQ) of Unesp, in Araraquara, which identified in the venom of the Brazilian snake Jararacuçu a peptide (piece of protein) capable of containing the reproduction of the new coronavirus.
To obtain this result, the researchers focused on laboratory analysis that showed the contact between the molecule extracted from the reptile’s venom with the cells of monkeys contaminated with the virus. The conclusion was that, with the action of the substance, the ability of the virus to multiply was reduced by 75%.
Confirmation of the finding was published last week in the international scientific journal Molecules, in a preliminary study.
“We found a peptide that is not toxic to cells, but that inhibits virus replication. With this, if the compound becomes a medicine in the future, the organism would gain time to act and create the necessary antibodies, since the virus would have its infection speed compromised and would not advance in the organism”, explains Eduardo Maffud Cilli, professor at IQ and one of the authors of the work.
How the peptide acts against the coronavirus
The piece of protein found in Jararacuçu is a molecule that interacts and blocks PLPro, one of the coronavirus enzymes responsible for its multiplication in cells. This enzyme is shared among all coronavirus variants, a factor that guarantees the effectiveness of the method against different virus mutations.
As reported by the Unesp press office, the idea of investigating the potential of the snake’s venom arose when scientists at the Unesp Chemistry Institute recently discovered that the snake’s peptide had antibacterial activity, which motivated them to carry out new tests for assess whether it could also act on viral particles. The effects were not so high in the first analysis, but after some modifications in the chemical structure of the synthesized molecule, the antiviral capacity rose to 75% of blocking reproduction.
In the next steps of the study, specialists will assess the efficiency of different dosages of the molecule, as well as whether it can play other roles in the cell, such as protection, even preventing the virus from invading it. After the end of these tests, the objective is for the research to advance to the pre-clinical stage, in which the effectiveness of the peptide to treat animals infected by the new coronavirus will be studied.
“Our results are promising and represent a valuable resource in the exploration of new molecules for the discovery and development of drugs against coronavirus infection,” says Cilli.