The discovery came after tests carried out in the laboratory, in which the researchers observed that the molecule extracted from the reptile’s venom inhibited the ability of the virus to multiply in monkey cells by 75%. The results obtained in the work were published in an article in the international scientific journal Molecules.
The efficiency of the peptide was tested at the Institute of Biomedical Sciences (ICB) of the University of São Paulo (USP), where a sample of the coronavirus is isolated.
The preliminary study presents a promising path in the search for drugs to treat patients contaminated by Covid-19.
The great challenge for the creation of a new drug is to ensure that it is efficient against a certain pathology and, at the same time, does not generate adverse reactions for those who are taking it.
In the initial tests carried out during the research, the results were encouraging, according to Eduardo Maffud Cilli, a professor at the IQ and one of the authors of the work.
“WE FOUND A PEPTIDE THAT IS NOT TOXIC TO CELLS, BUT THAT INHIBITS VIRUS REPLICATION. WITH THAT, 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”, HE SAID.
The peptide found in jararacuçu is a molecule that interacts and blocks PLPro, one of the enzymes of the new coronavirus responsible for its multiplication in cells.
According to the IQ professor, this mechanism of action is interesting because all SARS-CoV-2 variants have PLPro, so the tendency is that the reptile molecule maintain its effectiveness against different virus mutations.
Although several vaccines have been approved recently, the complete immunization of the world population will still take time, which, together with the emergence of new variants, reinforces the importance of the search for effective treatments.
The idea of investigating the snake venom’s potential against the new coronavirus came when scientists at the Chemistry Institute of Unesp recently discovered that the snake peptide had antibacterial activity, which motivated them to carry out new tests to assess whether it could also act on viral particles.
Initially, the effects were not so high, but after some small changes in the chemical structure of the molecule synthesized in IQ, its antiviral activity began to increase until it inhibited 75% of the virus’s ability to multiply in cells.
Briefly, the assay is done as follows: laboratory-grown monkey cells receive the peptide and, after one hour, the virus is added to the culture.
Two days later, the researchers evaluate the results and, through some calculations, discover how much the virus stopped reproducing. This is possible because researchers already know in advance how the virus would multiply under normal conditions, that is, if it were in contact only with cells.
In a second stage of the study, in which the researchers identified one of the mechanisms of action of the snake peptide, the compound was specifically tested against the PLPro enzyme, which was obtained at the São Carlos Institute of Physics (IFSC) at USP.
In the next steps of the study, the experts will evaluate the efficiency of different dosages of the molecule, as well as whether it can perform other functions in the cell, such as protection, even preventing the virus from invading it.
After the end of these tests, the goal 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.
The research was financed by the Foundation for Research Support of the State of São Paulo (Fapesp). In addition to Professor Cilli, scientists Paulo Sanches, Natália Bitencourt and Norival Santos Filho took part in the study by IQ. The work also included the participation of researchers from the ICB, IFSC, the Federal University of São Carlos (UFSCar) and the Federal University of São Paulo (Unifesp).