Ethnobotany applied to the selection of medicinal plants for agroecological crops in rural communities in the Southern End of Bahia, Brazil

The present work targeted the ethnobotanical survey of medicinal plants for introduction to agroecological crops in 9 rural communities in the southern end of the state of Bahia, Brazil, as an economic and therapeutic alternative for the local populations. Prior agreement from the communities was requested and the research was submitted to the ethics committee; the registration of access to genetic heritage and associated traditional knowledge was performed. The following methodologies were used: participant observation, “snowball”, “walking in the woods”; semi-structured questionnaires and calculation of the Main Uses Concordance index (CUPc). The species were evaluated according to their origin and degree of threat. 233 species, distributed in 73 families, were cited, with emphasis on Asteraceae (27spp.), Fabaceae (18 spp.) and Lamiaceae (16 spp.). Among these, 48% are native, 52% are naturalized and/or exotic and one vulnerable species was found (Euterpe edulis Mart.) and one endangered (Cariniana legalis (Mart.) Kuntze). The CUPc revealed 25 spp. with a value equal to or greater than 50% in at least one community. These results are expected to contribute to the selection of medicinal plants that serve as an economic and therapeutic alternative for vulnerable communities, as well as in stimulating the preservation of sociobiodiversity.


Introduction
Since the beginning of human civilization, medicinal plants have been used as resources in the treatment of diseases aiming at their prevention or even the cure. The empirical knowledge about the use of these plants has been passed down until today, becoming a common practice in popular medicine [1,2] .
Although the use of medicinal plants is recurrent in popular medicine, only recently the pharmaceutical area has turned its attention to the subject. Until the mid-1980's, the pharmaceutical industry produced medicines by means of the recognition, isolation and synthesis of molecules. However, starting in the 1990s, due to the high cost of producing these drugs and the discovery of phytocomplexes, a movement began for the valorization of the traditional use of medicinal plants, as well as the developement of herbal medicines [3][4][5] .
This valorization process was strengthened in Brazil with the implementation of the National Policy on Medicinal Plants and Herbal Plants (PNPMF) [6] which aims to promote actions, mainly focused on Sistema Único de Saúde (SUS) (Unified Health System), aimed at safe and rational use of medicinal plants and herbal medicines. Specific legal instruments have also been created, such as the Resolution of the Collegiate Board of ANVISA -RDC nº 26 [7] that defines the categories of herbal medicines and traditional herbal products in addition to establishing the minimum requirements for their registration.
Even with the advent of SUS, the use of medicinal plants represents, in several Brazilian communities, the role of a sole therapeutic resource. It is believed that this practice is benefical to human health, as long as the user has prior knowledge of its purpose, risks and benefits [8] .
This scenario has been favoring ethnobotany research focused on the area of medicinal plants. According to Fonseca-Kruel et al. [9] , this discipline can subsidize works on the sustainable use of biodiversity, through the utilization and valorization of the popular knowledge of human societies. Almassy Jr. [10] considers that ethnobotany, besides having a multi and interdisciplinary character, seeks, together with traditional communities, comprehension of human relations with the environment and can recover management strategies. The importance of these studies, in this context, allows the recording of information connected to ethnopharmacology, as well as the environmental preservation of the different medicinal species used [11] .
It is worth mentioning that, together with these conditions, rural settlements are areas whose populations are composed of people from different regions of the country and, therefore, rich in sociobiodiversity. Thus, ethnobotanical studies also allow an evaluation of how the residents gather information brought from their places of origin with that obtained in the place where they have settled in order to adapt, in this new environment, the plants that are useful to their needs [12] .
In the southern region of the state of Bahia, some of the last fragments of the remaining Brazilian Atlantic Rainforest are concentrated, in addition to several rural communities that live in isolation from the great urban centers, representing a space for research on the traditional knowledge focused on medicinal plants species.
Despite the ecological importance of the Atlantic Rainforest areas, associated with the rich sociobiodiversity, there is very little information about the potential and dynamics of these fragments. This knowledge gap is one of the causes of the slowness in the search for medicines that have long been part of the therapy of traditional communities, not to mention the fact that the value of medicinal resources derived from plants has significant potential as an alternative economic resource for the communities in the region [13] .
In view of the issues presented, the purpose of the present work was to carry out an ethnobotanical survey in rural communities and agrarian reform settlements in the southern end region of Bahia, aiming at the selection of medicinal plants to be inserted in agroecological cultivation systems as an economic and therapeutic alternative for the local populations.

Areas of study
The areas of study were chosen when the Center for Innovation in Biodiversity and Health The southern end of Bahia is a region that is classified by the State of Bahia both as an identity territory, due to its cultural diversity, and as one of the main economic regions of the state. The southern end is composed of twenty one municipalities and its borders are demarcated as follows: to the North, Southwest of Bahia and the South Coast of Bahia; to the South, with the State of Espírito Santo; to the West, with the State of Minas Gerais; and, to the East, with the Atlantic Ocean [14] . This region is also known for its low Human Development Index (IDH), economies based on agriculture, monoculture of eucalyptus and problems with unemployment and violence. The monitoring of health conditions shows a large proportion of rural deaths without medical assistance, making clear the lack of inclusion of these communities in public health policies [15] .

Sampling and data analysis
The data were collected from june 2016 to june 2017. At the beginning of the work, a meeting was organized with each of the nine communities in order to present the project and its objectives. In these meetings, the statement of prior consent was presented, and the consent of the community was also requested for the development of the work. The selection of respondents to carry out the ethnobotanical survey began through indications from the communities in the first meetings and then proceeded with the snowball method [16] .
In the fieldwork, aiming to collect information on medicinal plants and socioeconomic aspects of the communities, direct observation [17] was applied along with semi-structured interviews based on a form. The collection of plant species was carried out after the interviews, with the respondents follow-up, using the "walking in the woods" method [18,19] . The plant species were herborized, assembled, identified and The spelling of the scientific names was checked using the database of Flora do Brasil 2020 [20] . For the listing of the taxa, the APG IV (2016) [21] was followed.
In order to understand the relationship between conservation and indication of medicinal plants, we sought to classify the species according to their origin and degrees of threat by consulting the database of Flora do Brasil 2020 [20] and of National Flora Conservation Center (CNCFlora), respectively [22] .
Aiming to select, among the total species of the survey, which should be indicated for insertion in agroecological productive systems, we chose to favor the ones that presented the highest rate of Main Uses Concordance index (CUPc) [23] . The final selection included species with a CUPc equal to or greater than 50% in at least one of the communities studied and was later compared with the list of medicinal plants of interest to the Unified Health System (Renisus) [24] .

Results and Discussion
Altogether, 180 people were interviewed, citing 233 species of medicinal plants distributed in 73 botanical families (TABLE 1), and the most representative ones were: Asteraceae (27 species); Fabaceae (18 species); Lamiaceae (16 species); Euphorbiaceae (9 species); Solanaceae (9 species) e Myrtaceae (8 species). According to Guarim Neto et al. [25] , the greater the number of species in a botanical family, the greater the possibility that they will be used by human populations using flora resources. Galvão et al. [26] , however, believe that this probability can increase according to the presence of a great number of species of economic importance or of easy harvesting of the parts used, mainly for medicinal purposes.
Consequently, the tendency of the presence of the Asteraceae, Fabaceae and Lamiaceae families can be justified among the most cited families in a large part of the ethnobotany works involving medicinal plants. came from the states of Pernambuco, Ceará, Espírito Santo and Minas Gerais. Those who live in the communities of Ribeirão and Pouso Alegre claim to have lived in these localities for over 20 years, and the others have resided in the MST settlements since the date of its creation (on average 10 years at the time the survey was carried out). The predominance of women and elderly individuals may be related to the fact that, according to Viu et al. [27] , women have historical and cultural value when considering the food tradition of a region and they are responsible for the health of the family and their food safety. Melo et al. [28] , however, point out that elderly individuals in general are able to recognize a greater number of plants than younger ones and, therefore, they have more chances of being appointed as local specialists to be interviewed.
The respondents are primarily dedicated to agriculture as an economic activity (95%) and the average family income reaches up to one minimum wage for 91% of their families. As for the level of education, 53% claim to have elementary education, 7% secondary education and 37% did not have access to formal education.
When asked about the origin of their knowledge about medicinal plants, 91% claim to have learned it with their own families and the remaining 8% with neighboring communities, including indigenous communities.
Most of the respondents (88%) declare that they are regularly approached in order to indicate plants and their uses, however, this approach is restricted to relatives and neighbors who reside in the same community. plants. According to Bandeira [29] , ethnobiological studies involving the process of knowledge transmission and acquisition are scarce, however, it may be inferred that this local knowledge is acquired and transmitted through practices and beliefs developed by adaptive processes, which are culturally transmitted between generations [30] , especially within family nuclei and among residents of a same community, as observed by Boscolo et al. [31][32][33] . The transmission of the wealth of this knowledge still finds obstacles frequently cited in ethnobotany studies, such as Boscolo et al. [31][32][33] , in which the following are noted: the process of losing the tradition of transmitting knowledge to successor generations due to the lack of interest of children and grandchildren; the disarticulation of traditional life systems and geographical distance [33] .
Among the 233 species of medicinal plants surveyed in the 9 communities it was found, by consulting the Flora Brasil 2020 list [20] that 48% are considered native, 26% are naturalized and 26% are exotic. As to the level of threat consulted at the CNC Flora database [22] , it was observed that 94% of the species have no evaluation, while the others are distributed in: Least concern (Pfaffia glomerata (Spreng. The predominance of naturalized and cultivated exotic species found in the present study could be related to a trend described by Bortolotto [33] , in which human populations select plants mainly for subsistence, as in rural communities. It is also worth mentioning that many species of the medicinal plant pharmacopoeia in South America were introduced in the period of the European conquests Bennett et al. [34] and are widely used until today. Another worrying factor in terms of conservation is the increasing anthropization of the southern end region of Bahia, where deforestation caused by large pulp and paper companies generates the loss of natural resources with the extensive eucalyptus culture [35] . As a consequence, plant resources for medicinal use also become increasingly scarce and the production of home medicines falls into disuse, making the search for allopathic medicines grow [25] . The presence of species at different degrees of threat observed in this study draws attention to the urgency of conducting research that values biodiversity and the traditional knowledge associated with it before these resources are lost. Thus, the importance of ethnobotany is evident for the development of sustainable exploitation of ecosystems, in contrast to the current forms of devastation [36] . Diseases related to the gastric system, respiratory and genitourinary systems (TABLE 1) were the most cited. Diseases of the gastric system can be related to the lack of basic sanitation and treated water in the communities studied [15] . The presence of a large number of citations related to the genitourinary system follows the same premise observed in Bortolotto [33] , where there was also a predominance of women in the sample and they cited species with uses related to the uterus, menstrual cramps and childbirth.
In the face of economic and infrastructure infeasibility to carry out the cultivation of the 233 species resulting from the survey, it was necessary to employ quantitative methods in order to select which would be most suitable for insertion in agroecological productive systems that could be used as therapeutic resources and also as an alternative source of income in the 9 communities studied. Therefore, it was decided to favor the ones which presented and index of concordance regarding the corrected main use (CUPc) equal to or greater than 50% in at least one of the communities in which they were mentioned (TABLE 2). According to Roque et al. [37] , the more respondents agree on a particular use, the greater is the probability of confirmation of this information which, in the future, may also serve as a basis for pharmacological studies.
Plectranthus barbatus Andr. 75% 57% 73% 79% 69% 64% 79% 69% - The nine communities from the southern end of Bahia contemplated in this study live in a scenario of low income and isolation, in a region of socioenvironmental conflicts, and which until the moment of this study did not have any visibility with the local SUS. Some of these communities did not have a defined geographical delimitation or occupy the border region between two cities, creating difficulties in recognizing which municipality would be responsible for providing medical assistance to their residents. According to Pilla et al. [38] , despite the fact that SUS does reach the rural zones, it is not able to properly meet the demand of the population that seeks aid with medicinal plants. Therein resides the importance of ethnobotanical studies that revitalize and systematize the traditional knowledge associated with medicinal plants that may be used to improve the quality of these populations, since for Chaves et al. [39] , the healing properties of some plants are the only alternative that several communities have in order to treat diseases.

Schinus terebinthifolia
The introduction of the species (present on TABLE 2) in agroecological productive systems in the communities studied not only provides an alternative for the treatment of diseases, but it is also important for the conservation of socio-biodiversity and in the generation of income. Santilli [40] states that agroecology is a tool for the preservation of sociobiodiversity, which in turn is an essential component of sustainable agricultural systems. The diversification of crops in a particular ecosystem, associated with ecological factors, guarantee stability and less need for pesticides and nitrogen fertilizers. The use of knowledge and management practices of the medicinal plants held by the respondents constitute an asset of immense value for the marketing of these products [12] , since according to Ethur et al. [41] , there is a market for both the commercialization of teas and parts of medicinal plants in natura or dehydrated, as for the production of seedlings, substrates and utensils.
These products cited by Ethur et al. [41] can be sold in markets and free fairs as well as offered to municipal