Evaluation of the antifungal activity of Lippia alba essential oils through classical, microscopic, chemogenomic and molecular approaches

• Grant number: 23/03799-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: December 01, 2023
• End date: August 31, 2027
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Jorge Maurício Costa Mondego
• Grantee: Marina Erê Almeida Hummel Pimenta Santos
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

The use of plants to treat illnesses has always been present in everyday life, and the use of this type of traditional medicine has grown more and more due to its easy access and low cost. The contribution of natural products as a source of inspiration and raw material opens up the possibility of introducing phytomedicines as new products in the pharmaceutical sector and new agricultural defensives against phytopathogens. The species Lippia alba (Mill) N.E. Brown belongs to a group of most popular medicinal and aromatic plants in Brazil. It is used as a sedative, antidepressant and has bactericidal and fungicidal potential. From its leaves it is possible to extract the essential oil that contains therapeutic components, presenting qualitative and quantitative variation depending on the genotype and environmental factors. As it is among the medicinal plants recommended by ANVISA, the evaluation of the active principles of L. alba is extremely necessary. The present work aims to characterize the composition of essential oils (EOs) of L. alba plants cultivated in the germplasm of the Instituto Agronômico de Campinas. The oils will be extracted by hydrodistillation, being evaluated by gas chromatography coupled to mass spectrometry. In addition, its action against fungal pathogens of animals (i.e., Candida albicans) will be investigated through simple models of sensitivity by microdilution in broth. We will also verify its properties against phytopathogenic filamentous fungi such as Fusarium sp., Alternaria alternata, Colletotrichum sp. and Rhizoctonia solani. For a deeper understanding of the mechanisms of action of the evaluated oils, microscopic analyzes by scanning electron microscopy (SEM) will be performed. We will also use chemogenomic profiling (CGP) approaches to identify possible molecular targets or pathways affected by essential oils of L. alba in Saccharomyces cerevisae. Finally, proteins characterized by CGP as possible targets of the EOs will be purified by the Tandem Affinity Purification technique (TAP-tag) and used in assays of interaction between the prevalent terpenes in the EOs through Microscale Thermophoresis (MST).