Corpo Discente - Egressos
Jessica Silva Felix Bastos
| Título | Avaliação de extratos de P. permucronatum no controle de fitopatógenos e sobre a funcionalidade de neutrófilos humanos | ||||||||||||||||||||||||
| Data da Defesa | 24/11/2023 | ||||||||||||||||||||||||
| Download | Visualizar a Tese(1.79MB) | ||||||||||||||||||||||||
Banca
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| Palavras-Chaves | Fitopatógenos; Gênero Piper; Extratos vegetais; Sistema imunológico; Neutrófilos | ||||||||||||||||||||||||
| Resumo | vii estimular a produção de espécies reativas de oxigênio (ROS) em neutrófilos, sugerindo que os extratos e de P. permucronatum não interferem na viabilidade de neutrófilos humanos. Os resultados obtidos nesse estudo indicam o potencial dos extratos da espécie P. permucronatum, fonte de moléculas bioativas com potencial contra fungos e bactérias fitopatogênicos, podendo após pesquisas adicionais, torna-se uma estratégia de controle desses microrganismos, que apresente menor impacto à saúde humana quando comparados aos agrotóxicos convencionais | ||||||||||||||||||||||||
| Abstract | Brazil is among the largest agricultural producers in the world, however the country`s production tends to be limited by the occurrence of diseases that affect crops. This fact has boosted the indiscriminate use of pesticides in the country, which is the largest consumer of these products in the world, although they are considered efficient, these products can trigger resistance of microorganisms in addition to causing serious damage to the environment and human health. Plant extracts with microbicidal potential stand out as an alternative method in the control of phytopathogens, in this perspective extracts of species of the genus Piper are the target of research in the control of microorganisms. The objective of this work was to carry out phytochemical screening and evaluate the potential of extracts of the species P. permucronatum and its fractions in controlling the fungi Rhizoctonia solani and Sclerotium rolfsii and the bacteria Xanthomonas axonopodis pathovar vesicatoria and Ralstonia pseudosolanacearum, and to identify the cytotoxic profile of the extracts using the following functionalities of human neutrophils: cell viability and the production of reactive oxygen species. For this, aqueous and alcoholic extracts (50mg/ml crude extract) were prepared from the leaves, stems and inflorescences of the plant, and organic, basic and aqueous fractions of each extract, from liquid-liquid fractionation, totaling 15 treatments. The phytochemical screening identified the absence and presence of nine classes of secondary metabolites, among which Coumarins and Alkaloids were identified in the extracts of the three parts of the studied plant. The antifungal and antibacterial activities were tested by means of antibiogram assays, where the extracts were deposited in BDA culture medium for fungi and incorporated into Kado and Heskett medium for bacteria, in which the inhibition halos formed were measured. In both antibiograms, alcoholic extracts from the species P. permucronatum showed efficiency in inhibiting the growth of pathogens. Among the fractions obtained from the liquid-liquid fractionation, the 1st fractions (organic phase) of leaves, stems and inflorescences showed inhibition halos in the control of fungi and bacteria of interest in this study. The alcoholic extract and the 1st fraction from the plant stems stood out in a promising way from the other treatments, which showed significant means of inhibition for both fungi and bacteria. The extracts of leaves, stems and inflorescences of P. permucronatum showed no toxicity on human neutrophils. The extracts were also able to stimulate the production of reactive oxygen species (ROS) in neutrophils, ix suggesting that P. permucronatum extracts do not interfere with the viability of human neutrophils. The results obtained in this study indicate the potential of extracts from the species P. permucronatum, a source of bioactive molecules with potential against phytopathogenic fungi and bacteria, which, after additional research, could become a control strategy for these microorganisms, which has less impact on human health. when compared to conventional pesticides. | ||||||||||||||||||||||||
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