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

Abstract

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.

Study Bioprospecting of Medicinal Plant Extracts of the Semiarid Northeast: Contribution to the Control of Oral Microorganisms

“…This result was consistent with that discussed by Goleniowski et al [14] and de Barros et al [15]. This confirmed that antibiofilm activity can be related to the higher proportion of tannins and flavonoids in the plant like the observed by Siqueira et al [33]. …”

New strategies for drug discovery in tropical forests based on ethnobotanical and chemical ecological studies

“…For example, Araújo et al (2008) concluded that plants indicated for the treatment of inflammation have high levels of tannic compounds in comparison to plants indicated for other therapeutic uses. More recently, Siqueira et al (2012) found the same to be true of plants popularly listed as antimicrobials. Across habitats, Almeida et al (in press) found that medicinal plants harvested in the Caatinga exhibited higher antimicrobial activity than plants of the same species harvested in the Atlantic Forest.…”

Validação de metodologia analítica para determinação de taninos pelo método de difusão radial

“…A maior aplicabilidade do método de difusão radial encontra-se quando da necessidade de análise de um grande número de amostras, requisitada, principalmente, em estudos de triagem para seleção de plantas com potenciais atividades terapêuticas, e os que visam comparação de determinadas condições a que a espécie vegetal está submetida e como estas condições são refletidas no metabolismo secundário da planta Siqueira et al, 2011).…”