Taxonomic affiliation influences the selection of medicinal plants among people from semi-arid and humid regions-a proposition for the evaluation of utilitarian equivalence in Northeast Brazil

Biocultural heritage of the Caatinga: a systematic review of Myrtaceae and its multiple uses

The Caatinga, an exclusively Brazilian biome, stands as a reservoir of remarkable biodiversity. Its significance transcends ecological dimensions, given the direct reliance of the local population on its resources for sustenance and healthcare. While Myrtaceae, a pivotal botanical family within the Brazilian flora, has been extensively explored for its medicinal and nutritional attributes, scant attention has been directed towards its contextual relevance within the Caatinga's local communities. Consequently, this inaugural systematic review addresses the ethnobotanical roles of Myrtaceae within the Caatinga, meticulously anchored in the PRISMA 2020 guidelines. We searched Scopus, MEDLINE/Pubmed, Scielo, and LILIACS. No date-range filter was applied. An initial pool of 203 articles was carefully scrutinized, ultimately yielding 31 pertinent ethnobotanical studies elucidating the utility of Myrtaceae amongst the Caatinga's indigenous populations. Collectively, they revealed seven distinct utilization categories spanning ~54 species and 11 genera. Psidium and Eugenia were the genera with the most applications. The most cited categories of use were food (27 species) and medicinal (22 species). The importance of accurate species identification was highlighted, as many studies did not provide enough information for reliable identification. Additionally, the potential contribution of Myrtaceae fruits to food security and human health was explored. The diversity of uses demonstrates how this family is a valuable resource for local communities, providing sources of food, medicine, energy, and construction materials. This systematic review also highlights the need for more ethnobotanical studies to understand fully the relevance of Myrtaceae species in the Caatinga, promoting biodiversity conservation, as well as support for local populations.

Modern drug discovery using ethnobotany: A large-scale cross-cultural analysis of traditional medicine reveals common therapeutic uses

For millennia, numerous cultures and civilizations have relied on traditional remedies derived from plants to treat a wide range of conditions and ailments. Here, we systematically analyzed ethnobotanical patterns across taxonomically related plants, demonstrating that congeneric medicinal plants are more likely to be used for treating similar indications. Next, we reconstructed the phytochemical space covered by medicinal plants to reveal that (i) taxonomically related medicinal plants cover a similar phytochemical space, and (ii) chemical similarity correlates with similar therapeutic usage. Lastly, we present several case scenarios illustrating how mining this information can be used for drug discovery applications, including: (i) investigating taxonomic hotspots around particular indications, (ii) exploring shared patterns of congeneric plants located in different geographic areas, but which have been used to treat the same indications, and (iii) showing the concordance between ethnobotanical patterns among non-taxonomically related plants and the presence of shared bioactive phytochemicals.

Treating leishmaniasis in Amazonia, part 2: Multi-target evaluation of widely used plants to understand medicinal practices

ETHNOPHARMACOLOGICAL RELEVANCE

Leishmaniasis are widely distributed among tropical and subtropical countries, and remains a crucial health issue in Amazonia. Indigenous groups across Amazonia have developed abundant knowledge about medicinal plants related to this pathology.

AIM OF THE STUDY

We intent to explore the weight of different pharmacological activities driving taxa selection for medicinal use in Amazonian communities. Our hypothesis is that specific activity against Leishmania parasites is only one factor along other (anti-inflammatory, wound healing, immunomodulating, antimicrobial) activities.

MATERIALS AND METHODS

The twelve most widespread plant species used against leishmaniasis in Amazonia, according to their cultural and biogeographical importance determined through a wide bibliographical survey (475 use reports), were selected for this study. Plant extracts were prepared to mimic their traditional preparations. Antiparasitic activity was evaluated against promastigotes of reference and clinical New-World strains of Leishmania (L. guyanensis, L. braziliensis and L. amazonensis) and L. amazonensis intracellular amastigotes. We concurrently assessed the extracts immunomodulatory properties on PHA-stimulated human PBMCs and RAW264.7 cells, and on L. guyanensis antigens-stimulated PBMCs obtained from Leishmania-infected patients, as well as antifungal activity and wound healing properties (human keratinocyte migration assay) of the selected extracts. The cytotoxicity of the extracts against various cell lines (HFF1, THP-1, HepG2, PBMCs, RAW264.7 and HaCaT cells) was also considered. The biological activity pattern of the extracts was represented through PCA analysis, and a correlation matrix was calculated.

RESULTS

Spondias mombin L. bark and Anacardium occidentale L. stem and leaves extracts displayed high anti-promatigotes activity, with IC₅₀ ≤ 32 μg/mL against L. guyanensis promastigotes for S. mombin and IC₅₀ of 67 and 47 μg/mL against L. braziliensis and L. guyanensis promastigotes, respectively, for A. occidentale. In addition to the antiparasitic effect, antifungal activity measured against C. albicans and T. rubrum (MIC in the 16-64 μg/mL range) was observed. However, in the case of Leishmania amastigotes, the most active species were Bixa orellana L. (seeds), Chelonantus alatus (Aubl.) Pulle (leaves), Jacaranda copaia (Aubl.) D. Don. (leaves) and Plantago major L. (leaves) with IC₅₀ < 20 μg/mL and infection rates of 14-25% compared to the control. Concerning immunomodulatory activity, P. major and B. orellana were highlighted as the most potent species for the wider range of cytokines in all tested conditions despite overall contrasting results depending on the model. Most of the species led to moderate to low cytotoxic extracts except for C. alatus, which exhibited strong cytotoxic activity in almost all models. None of the tested extracts displayed wound healing properties.

CONCLUSIONS

We highlighted pharmacologically active extracts either on the parasite or on associated pathophysiological aspects, thus supporting the hypothesis that antiparasitic activities are not the only biological factor useful for antileishmanial evaluation. This result should however be supplemented by in vivo studies, and attracts once again the attention on the importance of the choice of biological models for an ethnophamacologically consistent study. Moreover, plant cultural importance, ecological status and availability were discussed in relation with biological results, thus contributing to link ethnobotany, medical anthropology and biology.

Taste and chemical composition as drives for utilitarian redundancy and equivalence: a case study in local medical systems in Northeastern Brazil

BACKGROUND

We aimed to verify whether the taste and chemical composition influence the selection of plants in each medicinal category, whether within a socio-ecological system or between different socio-ecological systems. To this end, we use the theoretical bases of the Utilitarian Redundancy Model and the Utilitarian Equivalence Model. We studied the local medical systems of four rural communities in northeastern Brazil, used as models to test our assumptions.

METHODS

The data on medicinal plants and local therapeutic function were obtained from semi-structured interviews associated with the free-listing method, allowing to generate indexes of similarity of therapeutic use between the plants cited in each region. During the interviews, each informer was also asked to report the tastes of the plants cited. Subsequently, we classified each plant in each region according to the most cited taste. The data about the chemical composition of each plant were obtained from a systematic review, using Web of Knowledge and Scopus databases.

RESULTS

Pairs of plants with similar tastes are 1.46 times more likely to have the same therapeutic function within a local medical system (redundancy), but not between medical systems (equivalence). We also find that chemical compounds are not primarily responsible for utilitarian redundancy and equivalence. However, there was a tendency for alkaloids to be doubly present with greater expressiveness in pairs of equivalent plants.

CONCLUSIONS

The results indicate that each social group can create its means of using the organoleptic characteristics as clues to select new species as medicinal. Furthermore, this study corroborates the main prediction of the Utilitarian Equivalence Model, that people in different environments choose plants with traits in common for the same functions.

The Power of Wild Plants in Feeding Humanity: A Meta-Analytic Ethnobotanical Approach in the Catalan Linguistic Area

Wild food plants (WFP) have always been present in our kitchen, although they have not always been given the same importance as crops. In the Catalan linguistic area (CLA), covered in this paper, WFP were of great importance as a subsistence food not only during the years of the Spanish civil war (1936–1939) and World War II (1939–1945), but also long before these periods and in the years thereafter. The CLA has been well studied at the level of traditional knowledge on plant biodiversity, and much of this information is collected in a database by the EtnoBioFiC research group. The aim of this work is to carry out a meta-analysis of the WFP dataset of the CLA (only regarding edible uses, drinks excluded) and to identify the most quoted plants, and the information associated with them. With data from 1659 informants, we recorded 10,078 use reports of 291 taxa (278 of which at specific or subspecific levels and 13 only determined at generic level) belonging to 67 families. The most reported taxa, also with highest cultural importance indexes, are Thymus vulgaris, Foeniculum vulgare subsp. piperitum, Laurus nobilis, Rubus ulmifolius and Mentha spicata. The ethnobotanicity index for food plants is 6.62% and the informant consensus factor, also for food uses, is a very high 0.97, supporting the robustness of the information. The results provided and discussed in this work concern a significant part of the edible resources in the territory considered, which is, often and mainly, underestimated and underutilised. Its consideration could be an opportunity to promote closer and more sustainable agriculture. From the state-of-the-art of this question, it is possible to propose old, in some cases forgotten foods that could be newly introduced onto the market, first, but not only, at a local level, which could be interesting for new crop development in the frame of a valorisation of territorial identity.