Seleção de plantas medicinais : um estudo sobre a estrutura e funcionalidade de sistemas médicos locais

Abstract

This thesis analyzed the selection of plants in local medical systems based on two main investigative axes. In the first axis we investigated the role of the local perception of illness in the selection of medicinal plants. In the second axis we seek to understand the relationships among the factors availability and resource efficacy in the differential use of medicinal plants. For this, we conducted interviews with local experts in two communities located in the municipality of Crato, Ceará, Northeastern Brazil. Semi-structured interviews were applied with the experts to obtain information on medicinal plants, illnesses in which plants are used, symptoms perceived by people for each illness and the perception of informants on the effectiveness of each plant mentioned. In addition, a participatory workshop was held to access the perceptions of informants on the relationship between illnesses. In a second step, the experts conducted a ranking of most used plants for each illness and then they indicated the criteria used to justify the position of each plant in the ordering. The local perception of illnesses is important in the selection of medicinal resources as the repertoire of medicinal plants varies as informants perceive different subtypes of the same illness. Furthermore, it was observed that people tend to select plants based on the perception of symptoms of illnesses, since illnesses sharing symptoms also share a common set of plants. It was also observed that the factors (1) perceived availability and (2) the perceived therapeutical efficacy were important in the differential use of medicinal plants; however, the two factors are not necessarily correlated in the differential use. Furthermore, the perceived efficacy cannot always be associated with the recognition of organoleptic properties. The present findings allow us to advance in the understanding of the factors involved both in structure and functionality of local medical systems, such as the local perception of illnesses, the availability and the efficacy of the medicinal resource efficacy.