Scientists from the Butantan Institute and the Federal University of São Paulo (Unifesp) are investigating Brazilian venomous snakes in search of new components for medicines. In two different studies, supported by Fapesp, the group identified peptides — protein fragments — that can benefit people treating high blood pressure (hypertension) due to their potential antihypertensive effect.
One of the most promising peptides for hypertensive patients was found in the venom of the surucucu-pico-de-jaca or just surucucu ( Lachesis muta ). Meanwhile, another was located in the hemorrhagic toxins of the black-bellied pit viper ( Bothrops cotiara ), also known as cotiara.
Potential of poisons
“Poisons never tire of surprising us” due to their potential, says Alexandre Tashima, professor at the Escola Paulista de Medicina da Unifesp and coordinator of the studies, for the Fapesp Agency
Although studies with the venom of these animals are already a tradition in Brazilian science, new analyzes can always identify molecules and peptides with unknown uses in medicine. “Despite so much technology available, there is still a lot to be studied about these toxins”, adds the researcher.
When you think about snakes, some species are at risk of extinction and, if they are not studied today, they may never be again. “We have to take advantage of the good fortune of being able to study these species, as many must have become extinct before they were even known,” comments Tashima.
Surucucu
In the first study published in the journal Biochemical and Biophysical Research Communications the group focused on the surucucu snake, found in different parts of South America.
Scientists are investigating the venom of snakes, including the surucucu, in search of proteins with medicinal effects (Image: Sávio Stefanini Sant' Anna/Instituto Butantan)
In total, 151 peptides were screened, 126 of which were reported for the first time. Among them was the Lm-10a. This is a fragment of hemorrhagic toxin, that is, it is part of the protein that causes hemorrhage located in the snake's fangs.
However, its function is closer to that of peptides that inhibit the angiotensin-converting enzyme (ACE) and which can inhibit blood pressure, such as the drug captopril, prescribed for the treatment of hypertension and for some cases of heart failure. The antihypertensive effect still needs to be better studied, but it is a promising bet.
Black-bellied pit viper
In addition to the surucucu snake, the researchers investigated the black-bellied pit viper, common in southern Brazil, and described the findings in an article in the journal Biochimie . This time, 197 peptides were found in the venom of this species, including 189 never described.
Among the peptides in the species' venom, the authors highlight Bc-7a. This is because this fragment has the potential ability to control blood pressure, which must be confirmed in subsequent studies.
Effect for hypertensive patients
Today, there are already safe and effective treatments against hypertension, but this does not rule out the importance of research into new drugs and substances with application in the area of biotechnology. Furthermore, the researchers highlight that current medications are still associated with some unwanted adverse effects, such as dry cough, dizziness and excess potassium in the blood.
To understand whether these peptides can really be beneficial, it is necessary to continue research and verify the effects in pre-clinical and, later, clinical tests (with humans). In the future, this could culminate in new medicines.
Source: Biochemical and Biophysical Research Communications, Biochimie and Agência Fapesp