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.

Intracultural variation in the knowledge of medicinal plants in an urban-rural community in the atlantic forest from northeastern Brazil.

This study assessed the intracultural knowledge of the use of medicinal plants in an urban-rural community in an Atlantic forest fragment in northeastern Brazil. We examined the importance of native and exotic species and the effects of gender and age on that knowledge. We also compared data obtained from different groups of informants (local experts and general community). We conducted 194 interviews between June 2007 and January 2008, using the freelist technique and semistructured forms to collect ethnobotanical data. Information obtained from the community was compared with that from six local experts who participated in a survey in 2003. From a total of 209 ethnospecies, exotic and herbaceous plants presented higher richness. With respect to the number of citations, women and older informants were shown to know a higher number of medicinal plants. Comparing knowledge of local experts with that of the general community, we noted that experts know a similar wealth of plant families and therapeutic indications, but the community knows a greater species richness. These results indicate that local experts may provide useful information for studies that search for a quick diagnosis of the knowledge of a given community.

In vitro antibacterial and time-kill assay of ethanolic extract of Davilla nitida bark on multidrug resistant bacteria isolated from diabetic foot lesions.

This study reported the antimicrobial activity of the bark extract of Davilla nitida on multidrug resistant bacteria isolated from Diabetic Foot Infections. Antibacterial activity of the bark extract was evaluated by agar Disk-Diffusion (DD), Broth Dilution (BD), Checkerboard and Time-kill methods. The extract showed a significant antibacterial activity against all groups of bacteria tested. BD was more sensitive for determining the antibacterial activity of the bark extract than the DD method. The bark extract inhibited the growth of bacteria with high-levels of antibiotic-resistance, such as Pseudomonas spp. (100.0%), Enterobacer spp. (88.89%), Staphylococcus aureus (54.55%), Streptococcus pneumoniae (75.0%), Staphylococcus saprophyticus (92.86%). The combination of extract with antibiotics resulted in an additive effect against most of the strains tested. Time-kill kinetics profiles of bark extract showed bactericidal and time-dependent properties. Our results suggest that the bark extract of Davilla nitida is a source of bioactive compounds, which may be useful against antibiotic-resistant bacteria.

Medicinal plants and diabetes: an ethnopharmacological study in Brazilian Northeast / Plantas medicinales y diabetes: un estudio etnofarmacológico en el noreste brasileño

Despite access to conventional medical therapies, the use of complementary medicine is increasing in many communities. The present study aimed to evaluate the popular knowledge of medicinal plants used to treat diabetes and its co-morbidities, in four rural communities in the municipality of Vitória de Santo Antão, in the Brazilian State of Pernambuco. The relative importance of a particular medicinal plant was calculated based on the percentage of mentions (IR%). The similarity between the communities was quantified using the Sørensen index (Ss). Interviews were conducted with 141 patients, of these, 83 reported use of medicinal plants as an alternative treatment. Overall there were 186 mentions, covering 61 ethnospecies. In relation to IR%, Mentha × villosa presented the highest value.Knowing the factors that influence selection of medicinal plants sheds light on the mechanisms through which patterns of use develop and this may help to preserve this knowledge.

A pesar del acceso a las terapias médicas convencionales, el uso de la medicina complementaria está aumentando en muchas comunidades. El presente estudio tuvo como objetivo evaluar el conocimiento popular de las plantas medicinales utilizadas para el tratamiento de la diabetes y sus comorbilidades, en cuatro comunidades rurales del municipio de Vitória de Santo Antão, en el estado brasileño de Pernambuco. La importancia relativa de una planta medicinal en particular se calculó en base al porcentaje de menciones (% de IR). La similitud entre las comunidades se cuantificó mediante el índice de Sørensen (Ss). Se realizaron entrevistas con 141 pacientes, de estos, 83 informaron el uso de plantas medicinales como tratamiento alternativo. En total hubo 186 menciones, cubriendo 61 etnoespecies. En relación al% de RI, Mentha × villosa presentó el valor más alto. Conocer los factores que influyen en la selección de plantas medicinales arroja luz sobre los mecanismos a través de los cuales se desarrollan los patrones de uso y esto puede ayudar a preservar este conocimiento.

Evaluation of antibacterial activity of the bark and leaf extracts of Brosimum gaudichaudii Trécul against multidrug resistant strains.

Brosimum gaudichaudii Trécul., a plant that belongs to Moraceae family, is found throughout the Brazilian Cerrado. The antimicrobial activities of ethanolic bark and leaf extracts of B. gaudichaudii were tested against multiresistant bacteria isolated from diabetic foot infections (DFIs). Antimicrobial activity of the extracts was evaluated by agar disc diffusion (DD) and broth dilution (BD) methods. By BD method, bark (53.85, 45.83%) and leaf (42.31, 50.00%) extracts contained antimicrobial activity against both gram-negative and gram-positive bacteria. Increased antimicrobial activity was observed when bark and leaf extracts were tested against Staphylococcus aureus (63.64%) and Pseudomonas aeruginosa (66.67%). Statistical analyses of bark and leaf extract demonstrated antimicrobial activity against both gram-positive (p = 0.000) and gram-negative bacteria (p = 0.012). Extract of bark (p = 0.075) or leaf (p = 0.005) associated with ACA antibiotic showed antimicrobial activity against gram-positive bacteria. Our study suggests that the bark and leaf extracts contain bioactive compounds with antimicrobial activity against multidrug resistant strains.

Information Retrieval during Free Listing Is Biased by Memory: Evidence from Medicinal Plants.

Free listing is a methodological tool that is widely used in various scientific disciplines. A typical assumption of this approach is that individual lists reflect a subset of total knowledge and that the first items listed are the most culturally important. However, little is known about how cognitive processes influence free lists. In this study, we assess how recent memory of use, autonoetic and anoetic memory, and long-term associative memory can affect the composition and order of items in free lists and evaluate whether free lists indicate the most important items. Based on a model of local knowledge about medicinal plants and their therapeutic targets, which was collected via individual semi-structured interviews, we classify each item recorded in free lists according to the last time that the item was used by the informant (recently or long ago), the type of relevant memory (autonoetic or anoetic memory) and the existing associations between therapeutic targets (similar or random). We find that individuals have a tendency to recall information about medicinal plants used during the preceding year and that the recalled plants were also the most important plants during this period. However, we find no trend in the recall of plants from long-term associative memory, although this phenomenon is well established in studies on cognitive psychology. We suggest that such evidence should be considered in studies that use lists of medicinal plants because this temporal cognitive limit on the retrieval of knowledge affects data interpretation.