Degradation evaluation and toxicity profile of bilobol, a promising eco-friendly larvicide. (January 2021)

• Record Type: Journal Article
• Authors: Schulte, Heidi Luise; Barreto Sousa, João Paulo; Sousa-Moura, Diego; Grisolia, Cesar Koppe; Espindola, Laila Salmen
• Is Part Of: Chemosphere. Volume 263(2021)
• Publication Date: 2021-01
• Subjects: Bilobol -- Aedes aegypti -- Larvicidal activity -- Acute toxicity -- Zebrafish -- Biodegradation -- Bilobol quantification; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128323
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Aedes aegypti is the main arbovirus vector transmitting chikungunya, Zika and dengue. The current vector control strategies are limited due to multiple insecticide resistance, deleterious impacts on the environment, and toxicity to non-target organisms. Bilobol, an alkylresorcinol isolated from the plant species Schinus terebinthifolia, demonstrated larvicidal activity against Aedes aegypti (LC50 7.67 mg/L in less than 24 h). To ensure that bilobol presents a viable alternative as an eco-friendly larvicide, this study aimed to explore the degradation process and acute toxicity of this alkylresorcinol in zebrafish, a non-target organism. A quantification method with validated parameters was developed and used to evaluate bilobol degradation in water over time. The Fish Embryo Toxicity (FET) test was applied to evaluate the acute toxicity of bilobol together with its degradation derivates. Results demonstrated that bilobol gradually degrades over time and almost completely disappears after 96 h, turning into small aliphatic chains which are less toxic than bilobol in its fundamental form. Therefore, it was possible to conclude that bilobol does not present significant toxicity to zebrafish embryos nor does it show signs of persistence in the environment. Additionally, bilobol can be found in high quantities not only in S. terebinthifolia, but also in cashew nut industry waste. Thus, bilobol constitutes an alternative environmentally friendly insecticide because it is not persistent, has indications of low toxicity to non-target organisms and presents a way to exploit massive quantities of material discarded by the food industry. Graphical abstract: Image 1 Highlights: Development of an efficient and reliable UPLC method to quantify bilobol in water. Monitoring of bilobol degradation profile showed rapid reduction of bilobol content. Bilobol degradation compounds identified as small aliphatic chains using NMR analysis. Acute toxicity evaluation indicated that bilobol is environmentally safe. Bilobol is a strong candidate for a new 'green' larvicide against Aedes aegypti .