Potencial citotóxico do extrato de piretro encapsulado em nanopartículas lipídicas sólidas no intestino de Tetragonisca angustula

Abstract

Bees are exposed to a wide variety of pesticides during a foraging activity, such as pyrethroids, a chemical group of neurotoxic pesticides that affect like bees by causing damage to health and reducing the deficiency of disorders. Although ecotoxicological studies focus on the model species Apis mellifera, as native bees they are also exposed to pesticides and still have a different sensitivity to these substances, such as a species Tetragonisca angustula, a native stingless bee that has great potential for pollination of natural systems. In this sense, alternatives for the harmful effects of pesticides on bees can be found in the use of botanical insecticides and nanopesticides. Thus, this study aimed to diagnose the cytotoxic effects of the botanical insecticide pyrethrum extract on the midgut of T. angustula and its comparison with the insecticide encapsulated in solid and complete lipid nanoparticle and with the additional commercial deltamethrin. For this, workers of T. angustula were collected at the entrance of their colonies and submitted to oral exposure bioassay, being tested seven experimental groups in triplicate: Control, Acetone Control, Pure pyrethrum extract, Pyrethrum carried in nanoparticle, Isolated nanoparticle, Acetate of polyvinyl and Deltamethrin. After 48 hours of continuous exposure, the bees were subjected to dissection to remove the intestines, which were processed for microtomy and subsequent histological analysis. The slides containing the histological sections of each individual were stained with Hematoxylin and Eosin and analyzed for diagnosis of histological changes in the midgut. The semiquantitative results indicate that the pyrethrum extract was less cytotoxic than deltamethrin, but it did not differ with the pyrethrum encapsulated in the nanoparticle. It is concluded that the pure and nanoencapsulated botanical insecticide may represent a safer alternative for bees compared to synthetic pesticides.