Antonio Fernando Morais de Oliveira

Caatinga, the Brazilian dry tropical forest: can it tolerate climate changes?

Our review focuses on the projections of climate change in the Brazilian semiarid region, the Caatinga, based on recent publications about global climate change and biology. We found several vulnerable points in the initial estimates, the main one being that the data were collected and analyzed without a multidisciplinary knowledge. This review discusses several studies that show the current knowledge in many semiarid regions around the world. Some of these studies argue for the increase in vegetation greenness responses even under severe and prolonged drought, based on the high resilience the Caatinga native species show under severe drought conditions over the years. Additionally, we include in this review recent data produced by our group on key ecophysiological variables under drought conditions. We also show successful examples of deforested areas recovery in the semiarid region of the Central America. It is critical that the recovery of semiarid areas is coupled with the implementation of socio-environmental policies, engaging the local population and providing subsidies for life wealth improvement. These are key aspects for a long-term recovery and conservation of the Brazilian dry tropical forest.

Plantas medicinais utilizadas na comunidade urbana de Muribeca, Nordeste do Brasil

As modernas condicoes de vida das comunidades urbanas comprometem o uso e transmissao do conhecimento tradicional sobre plantas medicinais. Neste trabalho foi verificada a alteracao provocada por treinamento sobre plantas medicinais de um grupo de seis moradoras da comunidade de Muribeca (Jaboatao do Guararapes, PE), comparando-as com vinte moradores com conhecimento adquirido tradicionalmente. A partir de 26 entrevistas semi-estruturadas foram calculados o Fator de Consenso dos Informantes (FCI) e a Importância Relativa (IR) das plantas citadas pelos dois grupos. As moradoras com treinamento no uso e manipulacao citaram 70 especies, das quais Petiveria alliacea L. e Ocimum selloi Benth. apresentaram os maiores valores de IR (2,0 e 1,6); os sistemas corporais mais indicados e respectivos FCI foram: doencas infecciosas (1,0), doencas das glândulas endocrinas, da nutricao e metabolismo (0,9) e do sistema osteomuscular e tecido conjuntivo (0,89). Os moradores sem treinamento citaram 55 especies, com maiores valores de IR para Cymbopogon citratus (DC) Stapf (2,0), Lippia alba (Mill.) N.E. Br. (2,0) e Mentha x villosa Huds. (1,8); os sistemas corporais mais indicados e respectivos FCI foram: doencas parasitarias (1,0), transtornos dos sistemas nervoso (0,79) e gastrintestinal (0,72). As especies citadas sao semelhantes, mas o treinamento influenciou a importância relativa e indicacoes de usos das plantas.

Myrmecochores can target high-quality disperser ants: variation in elaiosome traits and ant preferences for myrmecochorous Euphorbiaceae in Brazilian Caatinga

Recent evidence suggests that the traditional view of myrmecochory as a highly diffuse interaction between diaspores and a wide range of ant species attracted to their elaiosomes may not be correct. The effectiveness of dispersal varies markedly among ant species, and combined with differential attractiveness of diaspores due to elaiosome size and composition, this raises the potential for myrmecochorous plants to target ant species that offer the highest quality dispersal services. We ask the question: Do particular physical and chemical traits of elaiosomes result in disproportionate removal of Euphorbiaceae diaspores by high-quality disperser ants in Caatinga vegetation of north-eastern Brazil? We offered seeds of five euphorb species that varied in morphological and chemical traits of elaiosomes to seed-dispersing ants. High-quality seed-disperser ants (species of Dinoponera, Ectatomma and Camponotus) were identified as those that rapidly collected and transported diaspores to their nests, often over substantial distances, whereas low-quality disperser ants (primarily species of Pheidole and Solenopsis) typically fed on elaiosomes in situ, and only ever transported diaspores very short distances. Low-quality disperser ants were equally attracted to the elaiosomes of all study species. However, high-quality dispersers showed a strong preference for diaspores with the highest elaiosome mass (and especially proportional mass). As far as we are aware, this is the first study to identify a mechanism of diaspore selection by high-quality ant dispersers based on elaiosome traits under field conditions. Our findings suggest that myrmecochorous plants can preferentially target high-quality seed-disperser ants through the evolution of particular elaiosome traits.

Organic extracts from Indigofera suffruticosa leaves have antimicrobial and synergic actions with erythromycin against Staphylococcus aureus

A characteristic feature of Staphylococcus aureus is its ability to acquire resistance to antimicrobial agents. There is a need, therefore, for new approaches to combat this pathogen; for example, employing a combination of plant-derived products and antibiotics to overcome bacterial resistance. Indigofera suffruticosa is a plant popularly used to treat infections and has verified antimicrobial action. Here, we investigate the antimicrobial activity of different extracts from I. suffruticosa against S. aureus and their synergistic effects with erythromycin. Leaves of I. suffruticosa were extracted sequentially using diethyl ether, chloroform and acetone and the antimicrobial activity of each extract then tested against nine clinical isolates of S. aureus. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by microdilution tests, while the fractional inhibitory concentration (FIC) was assessed by checkerboard assay. All organic solvent extracts showed antimicrobial activity against S. aureus strains. The acetone extract was the most potent inhibitor of S. aureus (MIC and MBC of 0.78 and 3.12 mg/mL), followed by the chloroform extract (MIC and MBC of 3.12 and 6.25 mg/mL). Furthermore, acetone or chloroform extracts of I. suffruticosa enhanced the activity of erythromycin against S. aureus (FIC ≤ 0.5). We conclude that organic extracts from leaves of I. suffruticosa, alone or combined with erythromycin, are promising natural products for the development of new anti-S. aureus formulations.

Epicuticular-wax removal influences gas exchange and water relations in the leaves of an exotic and native species from a Brazilian semiarid region under induced drought stress

The primary physiological function of the leaf cuticle is to limit water loss. Thus, in the present study, we examined the hypothesis that variation in the quality and content of the epicuticular wax between different species influences leaf gas exchange. Plants of Jatropha mollissima (Pohl) Bailon, a Brazilian semiarid native, and Jatropha curcas L. (Euphorbiaceae), an exotic species, were subjected to a water deficit in the presence or absence of epicuticular wax. Plants were grown in 10-L pots under greenhouse conditions. The relative water content, gas-exchange parameters and primary carbon metabolism were measured at 21 days after the irrigation was reduced to induce a water deficit. The well-watered plants of both species showed recovery of gas exchange days after the removal of epicuticular wax. Furthermore, under drought, a gradual increase in transpiration rates was observed only in the leaves of native species without wax, although the stomatal conductance did not differ between the species. High relative water content was maintained, except in the leaves under drought and without wax from Day 13 onward, when compared with all other treatments. The wax production was induced in both species under water shortage. Nevertheless, the native species showed a higher content of long-chain n-alkanes. In fact, the barrier to water vapour under reduced stomatal conductance was highest in the native species.

Leaf epidermal characteristics of Cissampelos L. (Menispermaceae) species from Northeastern Brazil.

The morphological similarities among the species of Cissampelos are remarkable and the difficult to distinguish them as well. This article presents a comparative anatomical study of the leaves of common Northeastern Brazilian species of Cissampelos, carried out using light and scanning electron microscopy. The leaf epidermal was studied to obtain data on epidermal characteristics and to evaluate their taxonomic significance. As results, some micromorphological characters on the leaf epidermal like the cuticular waxes, the presence of papillae in epidermis and nonglandular trichomes, the anticlinal walls epidermal cells, the distribution, density and type of trichomes, and also the type and distribution of epicuticular wax proved to be the most useful characteristics to distinguish the species in taxonomic studies. Microsc. Res. Tech., 2011.

A comparative study of nutritional composition and potential use of some underutilized tropical fruits of Arecaceae

In this study, pulp and kernel of fruits from six Arecaceae species were subjected to proximate analysis, fatty acid composition and total carotenoid content analysis. The species with the highest carbohydrate, lipid and protein values were Ptychosperma macarthurii(70.1 g/100 g in the kernel), Syagrus cearensis(40.6 g/100 g in the kernel), andS. coronata(20.6 g/100 g in the pulp). The ash content ranged from 0.61 to 7.51 g/100 g. Lauric, palmitic, and oleic acids were the major fatty acids identified. The total carotenoid contents and retinol activity equivalents were highest in the Pinanga kuhlii (180.3 µg/g) and Acrocomia intumescens (138.0 µg/g) pulp oils. Retinol activity equivalents varied between the investigated species (456 to 1515 μg RAE/100 g). Native species such as A. intumescens, S. coronata, and S. cearensis are good sources of fresh food for the underserved populations that inhabit poorly developed areas such as the semi-arid region of Brazil. P. macarthurii, an exotic species, is an excellent source of ash and carotenoids, demonstrating its potential both as a food source and as bioactive compounds. Pulp and kernel ofA. intumescens,could be a good alternative feedstock for soap and biodiesel production, respectively.

Xanthosoma sagittifolium and Laportea aestuans: Species used to prevent osteoporosis in Brazilian traditional medicine

Context: Xanthosoma sagittifolium Schott. (Araceae) and Laportea aestuans (L.) Chew (Urticaceae) are two medicinal species used as food and to prevent and treat bone diseases, such as osteoporosis, in traditional Brazilian medicine.Objective: To investigate the free calcium concentration and further support the traditional use of these species as medicine.Materials and methods: L. aestuans and X. sagittifolium leaves were dehydrated and cooked to evaluate the presence of free calcium. The total oxalate content was determined by heat digestion in H2SO4, oxalate precipitation with CaCl2 and permanganate titration.Results: The calcium content found in L. aestuans was quite significant (638.00 mg/100 g), whereas the fresh and cooked leaves of X. sagittifolium demonstrated a low content of calcium, at 273.17 and 369.81 mg/100 g, respectively.Discussion and conclusion: The use of this species for the prevention and treatment of bone diseases is in agreement with the results of the free calcium (Ca++) analyses. ...Context: Xanthosoma sagittifolium Schott. (Araceae) and Laportea aestuans (L.) Chew (Urticaceae) are two medicinal species used as food and to prevent and treat bone diseases, such as osteoporosis, in traditional Brazilian medicine. Objective: To investigate the free calcium concentration and further support the traditional use of these species as medicine. Materials and methods: L. aestuans and X. sagittifolium leaves were dehydrated and cooked to evaluate the presence of free calcium. The total oxalate content was determined by heat digestion in H2SO4, oxalate precipitation with CaCl2 and permanganate titration. Results: The calcium content found in L. aestuans was quite significant (638.00 mg/100 g), whereas the fresh and cooked leaves of X. sagittifolium demonstrated a low content of calcium, at 273.17 and 369.81 mg/100 g, respectively. Discussion and conclusion: The use of this species for the prevention and treatment of bone diseases is in agreement with the results of the free calcium (Ca++) analyses. Our data show that each species may be used as a health supplement in poor communities, provided that studies validate their safe use.

Fatty-Acid Composition of Seeds and Chemotaxonomic Evaluation of Sixteen Sapindaceae Species

Circumscriptions for the Sapindaceae family and its infrafamilial relationships have been widely discussed. Certain groups are highly morphologically similar; thus, it is difficult to identify certain taxa. DNA Analyses have also indicated complex phylogenetic relationships, and it is difficult to relate such analyses to morphological data. Given the above concerns, this study aimed to investigate the fatty‐acid profiles of the seed oils of 16 Sapindaceae species belonging to five tribes and to evaluate their potential chemotaxonomic significance. In total, eleven fatty acids were identified, and eicosenoic acid predominated in nine species. Multivariate analyses (principal component and cluster analyses) of the fatty‐acid profiles of the seed oils allowed to separate them in two major clusters. The first cluster, characterized by oils with high eicosenoic acid levels, included all species belonging to the Paullinieae tribe (Cardiospermum, Paullinia, and Serjania species). In the second main cluster, the chemical similarity of the oils was lower, and the species belonged to different tribes. Nevertheless, the tree investigated Allophylus species (Thouinieae tribe) constituted a separate subcluster. Thus, the results showed that the fatty‐acid composition of the seed oils of Sapindaceae species provide chemotaxonomic support for the separation of the Paullinieae tribe from the other tribes studied.

Conhecimento e uso da carnaúba e da algaroba em comunidades do Sertão do Rio Grande do Norte, Nordeste do Brasil

RESUMO – Em comunidades rurais do Vale do Acu, sertao do Rio Grande do Norte, investigaram-se o conhecimento e uso de Copernicia prunifera (carnauba), palmeira nativa do Nordeste do Brasil; e de Prosopis juliflora (algaroba), leguminosa originaria do Peru, intencionalmente introduzida na mesma regiao na decada de 1940. Foram entrevistados 74 moradores de quatro comunidades estabelecidas no Municipio de Carnaubais, que citaram o uso de 142 especies vegetais, nativas e introduzidas. Os dados foram analisados considerando-se a faixa etaria dos entrevistados e as categorias de uso das plantas por eles citadas. Avaliou-se o indice de significado cultural de cada especie que apontou seu valor para a sobrevivencia biologica e cultural dos membros da comunidade. Os usos da carnauba citados por 59% dos informantes se enquadravam nas categorias artesanato, combustivel e medicinal. A categoria que mais contribuia para o uso da carnauba era a categoria construcao (UDs Coper 0,72). A algaroba tem uso como combustivel e forragem, citados por 61% dos entrevistados. Calculou-se o valor da diversidade de uso mostrando que a categoria combustivel (UDs Pros 0,37) era a que mais contribuia para o uso da algaroba nas comunidades rurais. Apesar do desequilibrio ambiental ocasionado por sua introducao, a algaroba ajuda na subsistencia das comunidades estudadas e aumentou o repertorio de especies fornecedoras de madeira para lenha, carvao e construcao. A carnauba, antes bastante utilizada pela populacao, vem sendo substituida por outras especies, sendo estas atualmente as novas fontes de renda para a populacao local.