Elba Lúcia Cavalcanti de Amorim

A new approach to study medicinal plants with tannins and flavonoids contents from the local knowledge

AIM OF THE STUDY The present work tested the power of different methodological strategies for identifying plants that could be interesting in terms of their phenolic compounds (especially flavonoids and tannins) by comparing a new index in which priority-determining criteria are based on the free-listing technique as well as on two randomized methods for choosing plants within an ethnodirected based approach. MATERIALS AND METHODS The present study was undertaken in the rural area of the municipality of Altinho located in the central region of Pernambuco State, northeastern Brazil. The ethnobotanical survey was divided into three different stages. The first stage was a general survey of 101 individuals on the use and knowledge of medicinal plants within the community. During the second stage local specialists were selected on the basis of the quality and quantity of information they offered during the initial phase of the investigation. The third stage consisted of returning to the specialists a final time in order to apply the free-listing technique. We also assumed that a plant could demonstrate anti-inflammatory and healing effects even without the presence of the compounds of interest of this study. RESULTS There is a strong association between tannin content and the effects popularly attributed to wound-healing and anti-inflammatory plants. No relationships were observed between plants used by the community to treat inflammation or healing with their flavonoid contents. CONCLUSION Thus, identifying Caatinga medicinal plants known with anti-inflammatory activity and healing capacities is a good criterion for identifying species with high levels of tannins, although these same criteria are not useful for identifying plants with high flavonoid contents.

Taninos: uma abordagem da química à ecologia

Tannins are compounds of great interest in chemistry and ecology. They have various effects on food digestibility and the performance of animals. In this work, the chemistry, the biological activity and the ecology of tannins are examined. A brief discussion of several analytical methods for the determination of tannins is presented.

Medicinal plants popularly used in the Xingó region – a semi-arid location in Northeastern Brazil

The aim of this study was to identify plant species among the diverse flora of the caatinga ecosystem that are used therapeutically. Research was undertaken in the municipalities of Piranhas and Delmiro Gouveia, in the Xingó region (state of Alagoas, NE Brazil). In order to identify the medicinal plants used in this region, semi-structured questionnaires were applied. The species cited were collected and sent to the Xingó Herbarium for taxonomic analysis. The relative importance (RI) of each species cited was calculated to verify their cultural importance. The therapeutic indications attributed to the species were classified under 16 body systems. A total of 187 medicinal species were cited, from 64 families and 128 genera. The main indications for medicinal plant use were against common colds, bronchitis, cardiovascular problems, kidney problems, inflammations in general, and as tranquilizers. Approximately 16% (30 plant species) were versatile in relation to their use, with an Relative Importance value over 1, having been indicated for up to nine body systems. The body systems that stood out the most were: the respiratory system, the gastrointestinal system, and infectious diseases. Most cited plant parts used for medicinal purposes were flowers, leaves, and inner stem bark.

The Inclusion and Selection of Medicinal Plants in Traditional Pharmacopoeias—Evidence in Support of the Diversification Hypothesis

The Inclusion and Selection of Medicinal Plants in Traditional Pharmacopoeias—Evidence in Support of the Diversification Hypothesis. An ethnobotanical study with phytochemical analyses was undertaken to examine the medicinal plants used by residents of a small rural community in northeastern Brazil. The present work tested two ideas that attempt to explain the inclusion and selection of medicinal plants in a given culture: the diversification hypothesis and the concept of versatility. The study involved 101 people and used semistructured interviews. A total of 61 plants were selected, including 25 exotic and 36 native species. Plants were classified according to their habit and analyzed for their phytochemical components. In addition, the relative importance (RI) of these plants was calculated, and a chemical diversity index (CDI) was created and applied to each of the species. Exotic and native plants were found to have significantly different occurrences of certain classes of compounds; this result supports the diversification hypothesis. It was therefore concluded that exotic plants are included in traditional pharmacopoeias to fill therapeutic vacancies that native plants cannot satisfy.

A comparison of knowledge about medicinal plants for three rural communities in the semi-arid region of northeast of Brazil.

AIM The aim of this research was to understand the importance of native and exotic plants in local medical systems in the Caatinga of the Brazilian northeast, and the influence of socio-economic factors on the acquisition of knowledge about these resources. METHODS A total of 55 people were interviewed in three rural communities using free list and semi-structured interviewes. RESULTS A total of 108 ethnospecies were reported, 99 of which were identified; 43 of these were preferred by informants. Most of the plants cited were exotic (51) but the difference in diversity among these plants and native plants (48) was not considered significant (p>0.05). The exotic plants were predominantly herbaceous and used to cure diseases that native plants did not seem to treat. There were no differences between mens and womens knowledge of the plants (p>0.05). However, for some communities, factors such as age and income were correlated with the number of citations and indications for plants, which suggested that older people and those with higher income levels had more knowledge about these properties. CONCLUSION The data presented in this study showed the importance of exotic species in the region studied and demonstrated that plant knowledge can be perceived as a way to diversify options for medical treatment in the area.

Antiproliferative Activity, Antioxidant Capacity and Tannin Content in Plants of Semi-Arid Northeastern Brazil

The objective of this study was to evaluate antiproliferative activity, antioxidant capacity and tannin content in plants from semi-arid northeastern Brazil (Caatinga). For this study, we selected 14 species and we assayed the methanol extracts for antiproliferative activity against the HEp-2 (laryngeal cancer) and NCI-H292 (lung cancer) cell lines using the (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazole) (MTT) method. In addition, the antioxidant activity was evaluated with the DPPH (2,2-diphenyl-2-picrylhydrazyl) assay, and the tannin content was determined by the radial diffusion method. Plants with better antioxidant activity (expressed in a dose able to decrease the initial DPPH concentration by 50%, or IC50) and with higher levels of tannins were: Poincianella pyramidalis (42.95 ± 1.77 µg/mL IC50 and 8.17 ± 0.64 tannin content), Jatropha mollissima (54.09 ± 4.36µg/mL IC50 and 2.35 ± 0.08 tannin content) and Anadenanthera colubrina (73.24 ± 1.47 µg/mL IC50 and 4.41 ± 0.47 tannin content). Plants with enhanced antiproliferative activity (% living cells) were Annona muricata (24.94 ± 0.74 in NCI-H292), Lantana camara (25.8 ± 0.19 in NCI-H292), Handroanthus impetiginosus (41.8 ± 0.47 in NCI-H292) and Mentzelia aspera (45.61 ± 1.94 in HEp-2). For species with better antioxidant and antiproliferative activities, we suggest future in vitro and in vivo comparative studies with other pharmacological models, and to start a process of purification and identification of the possible molecule(s) responsible for the observed pharmacological activity. We believe that the flora of Brazilian semi-arid areas can be a valuable source of plants rich in tannins, cytotoxic compounds and antioxidant agents.

Medicinal plants used as antitumor agents in Brazil: an ethnobotanical approach.

We describe the medicinal plants that have been reported to be antitumor agents and that have been used in ethnobotanic research in Brazil to answer the following questions: what is the abundance of plants reported to be antitumor in Brazil? Have the plant species used for tumor treatment in traditional Brazilian medicine been sufficiently examined scientifically? Our analysis included papers published between 1980 and 2008. A total of 84 medicinal plant species were reported to be used for cancer and tumor prevention or treatment; 69.05% of these were cited as being used for the treatment of tumors and cancer in general and 30.95% for specific tumors or cancers. The plants that were cited at a higher frequency were Aloe vera, Euphorbia tirucalli, and Tabebuia impetiginosa. At least, one pharmacological study was found for 35.71% of the species. Majority of the studies selected were conducted in rural communities and urban areas and in areas with traditional healers in Brazil. We found the following molecules to be the most studied in vitro and in vivo: silibinin, β-lapachone, plumbagin and capsaicin. The species addressed here constitute interesting objects for future studies to various professionals in the field of natural products.

The effects of seasonal climate changes in the caatinga on tannin levels in Myracrodruon urundeuva (Engl.) Fr. All. and Anadenanthera colubrina (Vell.) Brenan

Examinou-se a influencia da sazonalidade climatica sobre as concentracoes de taninos em duas especies da Caatinga: Myracrodruon urundeuva (Engl.) Fr. All. e Anadenanthera colubrina (Vell.) Brenan. Empregou-se o metodo Folin-Ciocalteau para quantificar os fenois totais e o metodo de precipitacao da caseina para taninos. De maneira geral, existe uma forte relacao entre os teores de taninos e a pluviosidade, apesar das especies parecerem adotar diferentes estrategias de producao de compostos tânicos em resposta aos periodos de seca e chuva na caatinga.

Local Markets and Medicinal Plant Commerce: A Review with Emphasis on Brazil

Local Markets and Medicinal Plant Commerce: A Review with Emphasis on Brazil. Local markets unite, concentrate, maintain, and diffuse empirical knowledge about plant and animal resources and therefore help guarantee the resilience and maintenance of folk knowledge concerning useful species. A critical review is presented here that focuses on the importance of these local markets, emphasizing the diversity of medicinal products offered, the different approaches to this subject, and the evolution of the research approaches taken in studying the medicinal plant products sold. To this end, the scientific literature was examined for research on these markets so as to provide a panoramic view of the different approaches taken, the diversity of plants being sold, the methodological procedures employed in collecting research information, and the specific nature of the studies. From our point of view, it is necessary to intensify the ethnobotanical and ethnopharmacological investigation of these markets, especially with comparable methods and techniques.AbstractMercados locais e o comércio de plantas medicinais: Uma revisão com ênfase no Brasil. Os mercados tradicionais são importantes por reunir, concentrar, manter e difundir o saber empírico sobre a diversidade de recursos tanto da fauna como da flora, sendo fontes imprescindíveis para a resiliência e manutenção do conhecimento acerca dessas espécies medicinais. Essa proposta de revisão crítica enfocou a importância desses centros de compras, ressaltando a diversidade de produtos ofertados, os diferentes enfoques das pesquisas realizadas e a evolução das abordagens ao estudar os produtos vegetais comercializados nos mercados. Dessa forma, realizou-se uma busca em periódicos para evidenciar o desenvolvimento das pesquisas com mercados intencionando-se uma visão panorâmica das diferentes abordagens utilizadas. Sobre isso, foram abordados: a diversidade vegetal comercializada, as partes vegetais mais encontradas nos mercados, bem como os procedimentos metodológicos para coleta de informações e a natureza desses estudos. A partir das análises realizadas, recomendações foram sugeridas para futuras pesquisas em mercados tradicionais: a realização de inventários locais sobre espécies úteis associado a comparações com informações já existentes.

Levels of Tannins and Flavonoids in Medicinal Plants: Evaluating Bioprospecting Strategies

There are several species of plants used by traditional communities in the Brazilian semiarid. An approach used in the search for natural substances that possess therapeutic value is ethnobotany or ethnopharmacology. Active substances that have phenolic groups in their structure have great pharmacological potential. To establish a quantitative relationship between the species popularly considered to be antimicrobial, antidiabetic, and antidiarrheal, the contents of tannins and flavonoids were determined. The plant selection was based on an ethnobotanical survey conducted in a community located in the municipality of Altinho, northeastern Brazil. For determination of tannin content was utilized the technique of radial diffusion, and for flavonoids, an assay based on the complexation of aluminum chloride. The group of plants with antimicrobial indications showed a higher content of tannins compared to the control groups. The results evidence suggests a possible relationship between these compounds and the observed activity.