Banca de QUALIFICAÇÃO: MARIA LUCIA DA SILVA CORDEIRO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARIA LUCIA DA SILVA CORDEIRO
DATE: 08/09/2023
TIME: 09:00
LOCAL: Videoconferencia
TITLE:

TALISIA ESCULENTA EXTRACTS AS SOURCE OF ACTIVE MOLECULES 

KEY WORDS:

Sapindaceae; oxidative stress; Tenebrio molitor; medicinal plant; Zebrafish

PAGES: 113
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUBÁREA: Química de Macromoléculas
SUMMARY:

Popularly known as Pitombeira, Talisia esculenta (Sapindaceae) is a species native to northeastern Brazil that has economic and medicinal potential. The infusion of its leaves is used in folk medicine with indications against hip pain, rheumatism, and high blood pressure; however, so far, studies evaluating its pharmacological, toxicological, and chemical composition are scarce. The fruits of this plant are used in food, and its bark currently has little pharmacological potential and is being discarded without any biotechnological application. Given this context, this study aimed to obtain the hydroethanolic extracts and the infusion of the leaves and barks of the fruits of T. esculenta, perform their phytochemical characterization, and measure their antioxidant capacity in vitro, toxicity, and antioxidant potential in vivo in two cell models (NHI/3T3 and RAW 264. 7) and animals (Tenebrio molitor and Zebrafish) and analyze its anti-inflammatory potential in RAW 264.7 macrophages. For this purpose, the hydroethanolic extract (70%) and the aqueous extract (infusion) were prepared from the fresh leaves and fruit peels of the species, obtaining the hydroethanolic extract of the leaves (HF), infusion of the leaves, hydroethanolic extract of the fruit peels (HC), and infusion of the fruit peels (IC). The evaluation of antioxidant capacity is carried out in vitro through the Total Antioxidant Capacity (CAT), DPPH radical scavenging, reducing power, and copper chelation assays. The tests revealed that both extracts showed satisfactory radical scavenging capacity and a high copper ion chelation capacity. The cytotoxicity and antioxidant capacity were evaluated in the cell model using the NHI/3T3 strain by MTT and wound assays. It was observed that T. esculenta extracts showed no effects on MTT reduction or cell migration, and protected the cells from CuSO₄ and ascorbate-induced oxidative stress. IF and HC were selected to have their effects investigated on T. molitor. Survival analysis showed that IF and HC did not present significant toxicity on the animals at the concentrations evaluated and were able to reduce the effect of CuSO₄ exposure on T. molitor larvae since an increase in the survival of larvae treated with the extracts was verified in relation to the positive control, as well as a reduction in melanization in the animals. The phytochemical characterization was performed by quantifying the content of phenolics and flavonoids and analyzing them by CLAE-DAD. From these analyses, it was possible to verify the presence of several compounds of the flavonoid class, and the presence of gallic acid, quercitrin and rutin was identified. In our work, no cytotoxicity was observed in the RAW 264.7 macrophage strain (MTT assay). In addition, all four T. esculenta extracts were able to reduce the damage caused by H₂O₂-induced oxidative stress in macrophages. However, only HC was able to reduce nitric oxide (NO) production in LPS-stimulated macrophages. In addition, the protective effects of T. esculenta extracts on H₂O₂ and CuSO₄ and ascorbate-induced oxidative stress model in zebrafish were investigated in this study based on the analysis of reactive oxygen species (ROS) levels by fluorescence microscopy. All extracts reduced ROS levels in larvae exposed to H₂O₂, however a more significant reduction was verified for HF, IF and HC which were statistically equal to the negative control. Although HC also showed protective effects by reducing ROS levels in the CuSO₄ and ascorbate-induced stress models, greater effects were verified for HF, IF, and IC, which reduced fluorescence intensity to lower levels than the negative control. Together, these data indicate that T. esculenta is a source of compounds with potent antioxidant effects and possible anti-inflammatory potential that should be further studied in future investigations.

COMMITTEE MEMBERS:
Presidente - 2962496 - RAFAEL BARROS GOMES DA CAMARA
Externa à Instituição - JAILMA ALMEIDA DE LIMA - LACEN
Externo à Instituição - WESLLEY DE SOUZA PAIVA - UFRN