Banca de QUALIFICAÇÃO: MARCIO MICHAEL PONTES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : MARCIO MICHAEL PONTES
DATE: 20/02/2026
TIME: 09:00
LOCAL: Auditório do departamento de química-UFRPE
TITLE:

EVALUATION OF THE CHEMICAL PROFILE, ANTIOXIDANT POTENTIAL, ANTIMICROBIAL ACTIVITY AND ANTIVIRULENCE MODULATING EFFECT OF Schinopsis brasiliensis Engl. (ANACARDIACEAE)

KEY WORDS:

Antimicrobial resistance; Staphylococcus aureus; staphylococcal mastitis; barauna.

PAGES: 70
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Inspeção de Produtos de Origem Animal
SUMMARY:

Antimicrobial resistance represents a growing challenge in animal health, especially in dairy cattle farming, where staphylococcal mastitis is one of the main causes of production losses and animal culling. Staphylococcus aureus, frequently associated with persistent intramammary infections and resistant strains, complicates conventional treatment and reinforces the need for effective and safe therapeutic alternatives. In this context, medicinal plants from the Brazilian Caatinga have attracted scientific interest due to their chemical diversity and biological potential. Schinopsis brasiliensis Engl. (Anacardiaceae), popularly known as “baraúna,” is a species widely used in traditional medicine; however, it remains underexplored from a pharmacological and microbiological perspective. Thus, the present study aimed to evaluate the chemical profile, antioxidant potential, antimicrobial and cytotoxic activities, as well as the modulatory effect on virulence factors of the ethanolic extract and fractions obtained from the leaves of S. brasiliensis, with emphasis on the control of resistant S. aureus strains associated with bovine mastitis. The plant material was subjected to ethanol extraction followed by solvent partitioning with solvents of different polarities. Chemical characterization was performed by gas chromatography (GC-MS) and liquid chromatography (HPLC-DAD-qTOF-MS/MS, negative mode). Antioxidant activity was assessed using DPPH and ABTS assays, while antimicrobial activity was investigated against standard MRSA strains and clinical isolates. Additionally, modulation of staphyloxanthin production was evaluated as an antivirulence marker, as well as cytotoxicity in the MAC-T cell line. GC-MS analysis of the hexane fraction allowed the identification of 13 apolar compounds, predominantly steroids (campesterol, stigmasterol, stigmastanol, and β-sitosterol) and triterpenes (lupeol, α-amyrin, and β-amyrin). The results demonstrated that the ethanolic extract and, particularly, the ethyl acetate fraction exhibited high antioxidant activity, associated with a high content of phenolic compounds. A significant antimicrobial effect was observed against resistant S. aureus strains, along with a reduction in staphyloxanthin production, suggesting interference with bacterial virulence mechanisms. Cytotoxicity assays indicated low toxicity at bioactive concentrations, reinforcing the safety potential of the samples. Overall, these findings point to S. brasiliensis as a promising source of natural compounds for the development of alternative therapeutic strategies to control resistant bacterial infections. Antimicrobial resistance represents a growing challenge in animal health, especially in dairy cattle farming, where staphylococcal mastitis is a major cause of production losses and animal culling. Staphylococcus aureus, frequently associated with persistent intramammary infections and resistant strains, hinders conventional treatment and reinforces the need for effective and safe therapeutic alternatives. In this context, medicinal plants from the Brazilian Caatinga have attracted scientific interest due to their chemical diversity and biological potential. Schinopsis brasiliensis Engl. (Anacardiaceae), popularly known as baraúna, is a species widely used in traditional medicine, but still little explored from a pharmacological and microbiological point of view. Thus, the present study aimed to evaluate the chemical profile, antioxidant potential, antimicrobial and cytotoxic activity, and modulating effect on virulence factors of the ethanolic extract and its fractions obtained from the leaves of S. brasiliensis, with emphasis on the control of resistant strains of Staphylococcus aureus associated with bovine mastitis. The plant material was subjected to ethanolic extraction, followed by fractionation with solvents of different polarities. Chemical characterization was performed using chromatographic and spectrometric techniques, including HPLC-DAD and LC-MS in negative mode, allowing the identification of secondary metabolites, especially phenolic compounds and flavonoids. Antioxidant activity was evaluated by the DPPH and ABTS methods, while antimicrobial activity was investigated against standard MRSA strains and clinical isolates. Additionally, the modulation of staphyloxanthin pigment production as an antivirulence marker was evaluated, as well as cytotoxicity in the MAC-T cell line. The results demonstrate that the ethanolic extract and, mainly, the ethyl acetate fraction exhibit high antioxidant activity, related to the high content of phenolic compounds. A significant antimicrobial effect was observed against resistant strains of S. aureus, in addition to a reduction in staphyloxanthin production, suggesting interference in bacterial virulence mechanisms. Cytotoxicity assays indicated low toxicity at bioactive concentrations, reinforcing the safety potential of the samples. Thus, the findings point to S. brasiliensis as a promising source of natural compounds with application in the development of alternative therapeutic strategies for the control of resistant bacterial infections.

COMMITTEE MEMBERS:
Presidente - TANIA MARIA SARMENTO DA SILVA
Interna - ANA LUCIA FIGUEIREDO PORTO
Externo à Instituição - ERYVELTON DE SOUZA FRANCO