Toxicity of Mucura (Petiveria alliacea) extracts from the peruvian amazon against Daphnia magna for environmental protection and sustainable development

Toxicidade de extratos de Mucura (Petiveria alliacea) da Amazônia peruana frente a Daphnia magna para a proteção ambiental e o desenvolvimento sustentável

Abstract

Natural products, specifically plant extracts with biological activity and the ability to act as botanical biopesticides are often mistakenly considered nontoxic. Scientific evidence indicates the contrary, and for this reason, the objective of this work was to evaluate the toxicity of extracts obtained from Petiveria alliacea L. (Caryophyllales, Phytolaccaceae) using Daphnia magna Straus (Cladocera, Daphniidae) as a bioindicator to identify the plant extracts and the respective concentrations that present the highest toxicity. Leaves of P. alliacea were collected in the Peruvian amazone. From this material, three types of extract (hexane, ethanolic and aqueous) were prepared, which were used in the bioassays with D. magna to find the least toxic extract. Acute toxicity bioassays with D. magna during 48 h of exposure to hexane, ethanolic, and aqueous extracts yielded median lethal concentration (LC₅₀) values of 26.9, 230.6, and 657.9 mg L^-1, respectively. The aqueous extract presented the lowest toxicity, causing minimal D. magna mortality in the range of 6.67 to 13.33% at concentrations of 10 and 100 mg L^-1. This result enables the efficient use of this plant species in a sustainable manner with a minimal environmental impact for the future development of natural products for pest control.

Keywords:
bioassay; botanical pesticide; Daphnia magna; LC_50, toxicity