According to the Ministry of Health, the recent surge in temperatures and a lax approach by the population regarding precautions to prevent the proliferation of the Aedes aegypti mosquito in stagnant water have led to a significant increase in dengue and chikungunya cases in Brazil at the beginning of this year. Data from January 30th revealed a threefold increase in the number of infected individuals compared to the previous year. Some states, including Minas Gerais, have declared a state of emergency due to the dengue outbreak.
While waiting for the nationwide availability of the Qdenga vaccine provided by the Ministry of Health, Brazilian researchers have developed an insecticide capable of killing mosquito larvae, contributing to prevention efforts. Even more promising, the product is derived from a native Brazilian plant and is selective, meaning it kills Aedes aegypti larvae while sparing other species found in aquatic environments.
The developed insecticide is the result of a multidisciplinary scientific collaboration involving researchers from the Federal Fluminense University (UFF), the Oswaldo Cruz Foundation (Fiocruz), and the Federal University od Viçosa (UFV). The UFF and Fiocruz researchers identified the insecticidal potential in the essential oil of a pindaíba species (Xylopia ochrantha), commonly found along the entire Brazilian coast in restingas. According to Professor Leandro Rocha (UFF), after identifying the plant’s insecticidal capacity, they encapsulated the molecules through nanoemulsification—a technique where the essential oil drops are in nanoscale, allowing better release of insecticidal compounds over time and extending the larvicidal action of the product. The technology uses low energy and does not employ organic solvents, making the product biodegradable. Another advantage is the ability to extract essential oil from parts of the plant without destroying it.
UFV was responsible for testing the product’s selective ability. Professor Eugênio Oliveira, one of the authors and from the Department of Entomology, explained, “There are many plants with insecticidal potential, but for them to be used sustainably for the environment and without greater harm to human health, they need to kill only the target insect – in our case, the larvae of the dengue-transmitting mosquito.” He further emphasized that this selective capacity reduces undesirable effects on non-target species and distinguishes natural from synthetic insecticides.
The product was tested on Aedes aegypti larvae and water bugs (Belostoma anurum), a common water bug and natural predator of larvae from other insects. According to researcher Milton Campaz, supervised by Professor Eugênio in this work, the insecticide showed selectivity towards other organisms in aquatic environments that are phylogenetically close. It was observed that when applied in recommended concentrations in a water tank, it does not harm fish or other insects, such as the water bug. This quality makes it superior to many synthetic larvicides.
The research article has been published in the journal “Sustainable Chemistry and Pharmacy.” Additionally, this research aligns with Sustainable Development Goals (SDGs) 3 (Good Health and Well-being), 6 (Clean Water and Sanitation), and 14 (Life Below Water).
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