Banca de DEFESA: LUCAS GABRIEL PITA DOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LUCAS GABRIEL PITA DOS SANTOS
DATE: 05/07/2024
TIME: 09:00
LOCAL: Departamento de Biologia/UFRPE
TITLE:

CHEMICAL CHARACTERIZATION OF LEAF PREPARATIONS OF Annona squamosa L. AND INVESTIGATION OF INSECTICIDE AND ANTIMICROBIAL POTENTIAL

KEY WORDS:

Bibliometric analysis; custard apple; dengue mosquito; maize weevil; non-target toxicity; insecticidal formulation.

PAGES: 111
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Medicina Veterinária Preventiva
SPECIALTY: Saneamento Aplicado a Saúde do Homem
SUMMARY:

Plant metabolites have aroused interest due to their biotechnological potential, which includes insecticidal and antimicrobial effects. Annona squamosa L. (Annonaceae) is a medicinal plant with edible fruits and commonly known as custard apple. The present Thesis aimed to characterize the saline extract of A. squamosa leaves in terms of chemical composition and investigate its insecticidal and antimicrobial potential. Recent trends in research involving plant bioactives against the arbovirus vector Aedes aegypti and the economically important pests Sitophilus zeamais and Nasutitermes corniger were studied through a bibliometric analysis. A. squamosa leaves (10 g) were dried and homogenized with 0.15M NaCl (100 mL). After centrifugation, the supernatant corresponded to the extract that was analyzed by thin layer chromatography (TLD) and high-performance liquid chromatography (HPLC). Then, the protein concentration, the presence of lectins using rabbit erythrocytes and the protease inhibitory activity using the substrate N-α-benzoyl-DL-arginine-4-nitroanilide (BApNA) were determined. The insecticidal potential of the extract was investigated against third instar larvae (L3) of Ae. aegypti, S. zeamais adults, as well as N. corniger workers and soldiers, while non-target toxicity was evaluated for the microcrustacean Hyalella sp. Tablets based on the extract were produced and investigated for their effects on the survival and morphology of the L3 midgut of Ae. aegypti. In addition, the effect of the extract on the growth of goat mastitis isolates was investigated. The bibliometric analysis revealed the concentration of research on the insecticidal activity of natural products in tropical regions, where there is a greater occurrence of diseases caused by Ae. aegypti, which corresponded to the largest number of reports compared to N. corniger and S. zeamais. Furthermore, the synthesis of metallic nanoparticles from natural products has emerged as a strong current trend. The characterization of the extract by CCD revealed the presence of flavonoids, cinnamic derivatives, saponins, anthraquinones, terpenes and steroids, while HPLC identified derivatives of cinnamic acid, rutin and chlorogenic acid; 22.9 mg/mL of proteins were also found, including lectins (21,333.33 UAHS) and trypsin inhibitors (15.6 U/mg). The extract caused mortality (LC50 = 1.9% m/v) and altered the permeability of the Ae. aegypti L3 peritrophic membrane, as well as exerted a strong food deterrent effect and killed adult S. zemais with mortality rates ranging from 51.2% to 63.8%. The extract did not affect the survival of N. corniger soldiers and workers, but juvenile Hyallela sp. were strongly sensitive to the treatment. Tablets based on leaf extract killed 47% of L3 at a concentration equivalent to the free extract LC50 and caused damage to the morphology of the larval midgut, including hypertrophy of the epithelium and the synthesis of apocrine vesicles. The extract was not able to interfere with the growth of bacteria that cause goat mastitis. In conclusion, A. squamosa leaf extract kills Ae. aegypti L3 and S. zeamais adults, by increasing the permeability of the peritrophic membrane and exhibiting a strong food deterrent effect, respectively. However, the use of the extract must involve caution due to high non-target toxicity. The effects of the extract may be linked to the presence of lectins, trypsin inhibitors, rutin and chlorogenic acid. The leaf extract-based tablet is a larvicidal agent for Ae. Aegypti L3 for damage the midgut structure of larvae. Furthermore, recent trends in research with metallic nanoparticles from plant extracts can be considered in future formulations to increase the stability and larvicidal efficacy of A. squamosa leaf extract.

COMMITTEE MEMBERS:
Presidente - EMMANUEL VIANA PONTUAL
Interna - TATIANA SOUZA PORTO
Externa à Instituição - LEYDIANNE LEITE DE SIQUEIRA PATRIOTA - UFPE
Externo à Instituição - THIAGO HENRIQUE NAPOLEÃO - UFPE
Externo à Instituição - WELTON AARON DE ALMEIDA - UFRPE