Diversity and biological activities of medicinal plants of Santiago island (Cabo Verde).

Plants continue to constitute key elements of medical practice in West African countries. The Cabo Verde archipelago hosts a great diversity of medicinal plants and local markets are considered important sites for trading plants harvested by rural communities. This study has two main goals: (i) to assess the medicinal uses of native species in Santiago, the biggest island of the archipelago, and (ii) to evaluate the antioxidant, antimicrobial and antidiabetic/antihyperglycemic activities of two native trees (Tamarix senegalensis and Sideroxylon marginatum) used in traditional medicine and traded in local markets. Our results revealed that on Santiago Island, 24 native plants are used in traditional medicine. The main uses of these species (e.g., forage, timber, food and fibres), their medicinal applications, the plant parts used, their mode of administration and conservation status are presented here for the first time. Moreover, the pharmacological characterization of two native tree species revealed that hydroethanolic extracts were richer in phenolic compounds and more active than their aqueous counterparts. All the studied extracts revealed significant antioxidant properties (DPPH and FRAP assays) and were generally moderately active against Gram-positive bacteria. All the extracts inhibited the activities of the carbohydrate digestive enzymes α-glucosidase and α-amylase in a dose-dependent manner. For α-glucosidase, the detected inhibitory activity (IC50 values from 2.0 ± 0.2 µg/mL to 9.9 ± 1.2 µg/mL) was significantly higher than that of acarbose, suggesting that extracts of both species can delay glucose absorption, thereby assisting in slowing down the progression of diabetes. Our findings highlight the crucial importance that medicinal plants have for the Cabo Verdean population, while also raising awareness on the need for sustainable use and conservation of native flora, and of tree species traded in local markets in particular.

Antimalarial and Cytotoxic Activity of Native Plants Used in Cabo Verde Traditional Medicine.

Medicinal plants have historically been a source of drugs in multiple applications, including the treatment of malaria infections. The Cabo Verde archipelago harbors a rich diversity of native plants, most of which are used for medicinal purposes. The present study investigated the in vitro antiplasmodial activities of four native plants from Cabo Verde (i.e., Artemisia gorgonum, Lavandula rotundifolia, Sideroxylon marginatum, and Tamarix senegalensis). Traditional preparations of these medicinal plants, namely aqueous extracts (infusions) and ethanolic extracts, were tested against both chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) Plasmodium falciparum strains using the SYBR Green detection method. The in vitro cytotoxicity was evaluated in Caco-2 and PLP2 cells using a sulforhodamine B colorimetric assay. An ethanolic extract of A. gorgonum and infusions of T. senegalensis exhibited high antiplasmodial activities (EC50 < 5 µg/mL) without cytotoxicity (GI50 > 400 µg/mL). Extracts of L. rotundifolia and S. marginatum exhibited moderate activities, with EC50 values ranging from 10-30 µg/mL. The A. gorgonum ethanolic extract showed activity toward early ring stages, and parasites treated with the T. senegalensis infusions progressed to the early trophozoite stage, although did not develop further to the late trophozoite or schizont stages. Antimalarial activities and the lack of cytotoxicity of the extracts are reported in the present study and support previous claims by traditional practitioners for the use of these plants against malaria while suggesting their ethnopharmacological usefulness as future antimalarials.

Diversity of Useful Plants in Cabo Verde Islands: A Biogeographic and Conservation Perspective.

Cabo Verde's biodiversity is threatened by activities that meet human needs. To counteract this, an integration of scientific and indigenous knowledge is required, but no comprehensive list of the useful local plants is available. Thus, in this work, we assess (1) their diversity and phytogeography; (2) the role of geophysical, historical, and socio-economic factors on species distribution and uses; and (3) potentially relevant species for sustainable development. Data were obtained from flora, scientific publications, historical documents, herbarium specimens and field work. Many species were introduced since the 15th century to support settlement and commercial interests. We identified 518 useful taxa, of which 145 are native, 38 endemic and 44 endangered. The number of useful taxa is correlated with altitude and agricultural area, as well as with rural population indicators, but not with total population or socio-economic indicators such as gross domestic product. Native taxa are mostly used for fuelwood, forage and utilitarian purposes. Agrobiodiversity and traditional practices seem crucial to cope with recurrent droughts and ensure food security. Most of the introduced species do not present conservation problems, contrasting with the overuse of some native taxa. The safeguarding of native populations will ensure the sustainable exploitation of these resources and benefit the local economy.

Trust your guts? The effect of gut section on diet composition and impact of Mus musculus on islands using metabarcoding.

DNA metabarcoding is widely used to characterize the diet of species, and it becomes very relevant for biodiversity conservation, allowing the understanding of trophic chains and the impact of invasive species. The need for cost-effective biodiversity monitoring methods fostered advances in this technique. One question that arises is which sample type provides a better diet representation.Therefore, with this study, we intended to evaluate if there were differences in diet estimates according to the section of the gastrointestinal tract analysed and which section(s) provided the best diet representation. Additionally, we intended to infer the ecological/economic impacts of an invader as a model of the potential effects in an originally mammal-free ecosystem.We examined the gut contents of the house mouse Mus musculus introduced to Cabo Verde, considering three sections: stomach, small intestine, and large intestine. We applied a DNA-metabarcoding approach using two genetic markers, one specific for plants and another for invertebrates.We showed that this invader consumed 131 taxa (73 plants and 58 invertebrates). We obtained significant differences in the composition of two of the three sections, with a higher incidence of invertebrates in the stomach and plants in the intestines. This may be due to stomach inhibitors acting on plants and/or to faster absorption of soft-body invertebrates compared to the plant fibers in the intestines. We verified that the impact of this invader in the ecosystem is predominantly negative, as at least 50% of the ingested items were native, endemic, or economically important taxa, and only 19% of the diet items were exotics.Overall, results showed the need to analyse only two gastrointestinal tract sections to obtain robust diet data, increasing the cost-effectiveness of the method. Furthermore, by uncovering the native taxa most frequently preyed on by mice, this DNA-metabarcoding approach allowed us to evaluate efficiently which are at the highest risk.

O metabarcoding de ADN é amplamente utilizado para a caracterização da dieta de espécies, e tornou­se bastante relevante para a conservação da biodiversidade, permitindo a compreensão sobre cadeias tróficas e o impacto de espécies invasoras. A necessidade de métodos de monitorização da biodiversidade com uma boa relação custo­benefício fomentaram avanços nesta técnica. Uma questão que se coloca é qual o tipo de amostra que fornece uma melhor representação da dieta. Deste modo, com este estudo, pretendemos avaliar se existem diferenças nas estimativas da dieta de acordo com a secção do tracto gastrointestinal analisada e qual(is) a(s) secção(ões) que proporciona(m) uma melhor representação da dieta. Adicionalmente, pretendemos inferir os impactos ecológicos/ económicos de um invasor como um modelo dos efeitos potenciais que este pode ter num ecossistema originalmente sem mamíferos. Analisámos os conteúdos gastrointestinais do rato doméstico Mus musculus introduzido em Cabo Verde, considerando três secções: estômago, intestino delgado e intestino grosso. Aplicámos uma abordagem de metabarcoding de ADN usando dois marcadores genéticos, um específico para plantas e outro para invertebrados. Mostrámos que este invasor consumiu 131 taxa (73 plantas e 58 invertebrados). Obtivemos diferenças significativas na composição de duas das três secções, com maior incidência de invertebrados no estômago e de plantas nos intestinos. Isto pode dever­se a inibidores estomacais que agem sobre as plantas e/ ou à absorção mais rápida de invertebrados de corpo mole em comparação com as fibras vegetais nos intestinos. Verificámos que o impacto deste invasor no ecossistema é predominantemente negativo, pois pelo menos 50% dos itens ingeridos eram nativos, endémicos ou economicamente importantes e apenas 19% dos itens da dieta eram exóticos. De modo geral, os resultados mostraram a necessidade de analisar apenas duas secções do tracto gastrointestinal para obter dados robustos da dieta, aumentando a relação custo­eficácia deste método. Além disso, ao descobrir os taxa nativos mais frequentemente predados por ratos, a abordagem de metabarcoding de ADN permitiu­nos avaliar com eficiência quais estão sob maior risco.