Plant-derived larvicide is effective against Aedes aegypti – 01/04/2024 – Health

Scientists from LPTN (Natural Technological Products Laboratory), UFF (Fluminense Federal University), and UFRJ (Federal University of Rio de Janeiro), among other institutions, produced an insecticide capable of killing mosquito larvae Aedes aegypti from an essential oil from a plant native to the Atlantic forest.

With sassafras cinnamon extracts (Ocotea indecora), a plant endemic to the restinga area, as the vegetation that occurs after the sand strip of the beaches and which is part of the Atlantic forest biome is known, the group isolated a molecule on a nanometer scale (very small) that can be dissolved in water, ending the larval stage of the insect.

Dengue is a disease caused by a virus and transmitted through the bite of a female mosquito. In 2023, Brazil showed an increase of around 16% in dengue cases, with an increase in deaths – the WHO (World Health Organization) classifies the country as having the highest incidence in the world.

The compound is also biodegradable and does not accumulate in the environment, a problem found in insecticides common in the fight against dengue, such as organophosphates (such as DDT, which can bioaccumulate in organisms and has already been found in the organisms of birds and other large vertebrates). size).

The find is the result of more than 25 years of research at the site and included the collaboration of researchers from Fiocruz (Fundação Oswaldo Cruz), Uerj (University of the State of Rio de Janeiro), UFV (Federal University of Viçosa) and UNIFAP (University of Amapá).

The compound’s mechanism of action was described in an article published in the journal Sustainable Chemistry and Pharmacy.

Cinnamon sassafras is found in the Restinga de Jurubatiba National Park area, which represents the largest continuous extension of restinga in the country, one of the last strongholds of this type of vegetation — threatened, however, by oil and gas activity in the region.

The extraction of essential oil uses only parts of the plant, and it is not necessary to remove it from the environment to obtain the product, explains professor and LPTN coordinator, Francisco Machado. According to him, this would be an incentive to preserve the forest, since the biological and chemical potential of restinga plants is still something to be explored.

“As a result, we believe in the concept of a ‘standing forest’, that is, it is more worth preserving this restinga area with the potential to obtain a compound that can help the health of thousands of people than deforestation,” he said.

The test of the nanobioinsecticide on mosquito larvae was carried out by entomologist Leandro Rocha, from Labi (Insect Biology Laboratory), also at UFF, who helped analyze the effects of the larvicide on the mosquito’s life cycle. A. aegypti.

Scientists observed a high mortality of mosquito larvae after applying the product. According to Rocha, the insecticide acts on the last larval stage of the insect and has a high specificity, that is, it only kills the mosquito, and is not effective against other species tested, such as bees.

The use of insecticides as a way to control the incidence of dengue is one of the Ministry of Health’s strategies to combat the disease. However, the agency mostly uses organophosphate insecticides.

According to Machado, this can be a natural, biological alternative that values ​​national biodiversity. “The difference between our product and the one available on the market is that it values ​​Brazilian biodiversity, more specifically the Atlantic Forest, one of the most devastated biomes in Brazil, and because it is a derivative of natural origin, it has an interesting rate of degradation” , he stated.

Now, the next step is to get the plant cultivated, since for now its use depends on the park’s extractivism. “For now, we only have laboratory production. So the next step would be to carry out a kind of cultivation, with controlled conditions, and, if we have a larger amount of material, even achieve scale production”, he adds.