Banca de DEFESA: DANIELE FERREIRA DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DANIELE FERREIRA DA SILVA
DATE: 29/09/2022
TIME: 14:00
LOCAL: https://meet.google.com/fik-ndms-eht
TITLE:

Reuse of Handroanthus serratifolius wood residue as a proposal for an antibacterial topical formulation on Astrocaryum murumuru vegetable butter base

KEY WORDS:

Yellow ipê. Drug delivery system. Anti-Bacterial Agents. Waste Reuse

PAGES: 102
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

There is a growing search for new natural products with antimicrobial properties to combat multi-resistant bacteria such as Staphylococcus aureus, responsible for several diseases, including dermatological infections. Some plants used in traditional medicine are candidates in the prospection of antibiotic bioactives, with emphasis on Handroanthus serratifolius (yellow ipê) that have diverse biological properties, due to their chemical composition with naphthoquinones and lapachol. This study aimed to obtain and characterize plant extracts from the reuse of wood residue from H. serratifolius to develop a semi-solid formulation with antibacterial action. For this, It was used the sawdust of H. serratifolius that presented moisture content and total ash within acceptable limits to ensure sample quality and moderately coarse dust classification. Three extracts were obtained, aqueous from the decoction of the sample, hydroalcoholic from maceration in 70% alcohol and ethanolic from maceration in absolute ethyl alcohol. They were lyophilized to generate crude dry extracts, whose phytochemical characterization showed quinones, anthraquinones and steroids. Only in aqueous extract revealed tannins. It was used thin layer chromatography in the chemical composition of all extracts to verify the presence of lapachol. Subsequently, these were submitted to the antimicrobial test to detect the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against pathogenic skin bacteria: S. aureus, S. aureus MRSA, S. pyogenes, E. faecalis, E. coli and P. aeruginosa, where gram-positive bacteria were showed sensitive. The aqueous extract stood out with better bactericidal performance in the largest number of strains tested, with S.pyogenes being more sensitive with MIC of 0,156 mg/mL and MBC of 0,625 mg/mL. Thus, 1% of the aqueous dry extract was incorporated into the semi-solid formulation based on Astrocaryum murumuru butter, with a pH of 5,8, compatible for use on skin and mucous membranes. The polarized light microscopy of the formulation revealed the presence of liquid crystals with a hexagonal phase, which could allow the sustained release of the actives for a longer period of time. The formulation was shown to be stable for 90 days, regardless of storage temperature, and maintained antibacterial activity against bacteria sensitive to the aqueous extract. Comparisons between a formulation with 1% of extract and a formulation with 0.5% of lapachol, under the same conditions, it was shown that both exhibit satisfactory antibacterial action against S. aureus, whose extract is as efficient as the isolated substance (p> 0.05). In silico prediction to skinsensitization, the components identified in the formulation, the lapachol presented a skin sensitizer alert to susceptible individuals, by the Bayesian method. However, there were no signs of toxic skin risk in the Toxtree database, thus allowing for the assurance of topical use. Therefore, this study contributed to highlight the alternative proposal of an antibacterial herbal formulation for skin infections, emphasizing the quality of waste discarded by the wood sector as a potential source of extraction of bioactive compounds.

BANKING MEMBERS:
Interna - 1833953 - SILVIA KATRINE RABELO DA SILVA
Interna - 2375623 - GABRIELA BIANCHI DOS SANTOS
Externo à Instituição - MADSON RALIDE FONSECA GOMES
Externo à Instituição - EDILENE GADELHA DE OLIVEIRA - UFRGS