Regina Maria Silva Sousa's research while affiliated with Universidade Estadual do Piauí and other places

Abstract Medicinal plants are used as a food and therapeutic resource by civilizations throughout human history. However, knowledge at the biological level is rarely discussed in the classroom. Thus, the study aimed to survey the knowledge of high school students about the use of medicinal plants for therapeutic purposes in a public school in the state of Piauí. Thus, data were collected by electronic form and applied to 33 high school students from public schools in the state of Piauí. Then, the data were subjected to descriptive statistical analysis of frequency and analytical categories for qualitative data. The students cited 17 specimens of plants, where tea and leaves were the main forms of use and preparation, respectively. The plants were used, mainly in the treatment of respiratory and gastrointestinal problems, and the most cited specimens were mint and lemon balm. It was also observed that the students had fragmented knowledge about medicinal plants' therapeutic purposes and the possible damages caused to the genetic material. As plants are a natural resource, students believed that they did not cause damage to the organism. Thus, it appears that traditional knowledge about medicinal plants is present in the lives of students, despite the little associated scientific knowledge.

The aim of this study was to assess the genotoxic and antigenotoxic effects of Poincianella bracteosa bark aqueous extract on DNA damage induced by doxorubicin (DXR) a chemotherapeutic agent using SMART (Somatic Mutation and Recombination Test). The analysis was performed using the somatic mutation and recombination test in Drosophila melanogaster. Larvae from the standard and high-bioactivity crosses were chronically treated with four concentrations of P. bracteosa bark tea, alone and in association with DXR. The results revealed no mutagenic effect of bark extract for any of the concentrations tested. A modulating effect of aqueous extract in reducing the genotoxic action of DXR was observed for all concentrations tested in descendants of both crosses, but inhibition was more effective in those from the high-bioactive cross. The modulating effect observed may be associated with the presence of tannins and reducing sugars, as observed in phytochemical studies, since they are capable of capturing and stabilizing free radicals. Given the widespread use of P. bracteosa bark in folk medicine, further studies to elucidate the mechanism of action of these cellular compounds and with other experimental models would be useful to confirm that P. bracteosa extract is beneficial to human health.

Terminalia actinophylla (Mart), commonly known as "chapada", is used in folk medicine for the treatment of diarrhea, diabetes and anti-inflammatory. However, studies on its toxicity are still incipient. The present work was carried out with the objective of evaluating the phytochemical profile and the cytogenotoxic effect of the ethanolic extract of the T. actinophylla bark using the Allium cepa L. seed. Seeds of A. cepa were subjected to different extract concentrations (1.25, 2.5, 5 and 10 mg/mL), a negative control (NC - distilled water) as well as trifluralin (PC - positive control), during 24 h of exposure. The phytochemical profile of the extract was obtained to identify the main secondary metabolites. The cytotoxicity (mitotic index) and the genotoxicity (chromosomal alterations) were analyzed by means of the collection of 5,000 meristematic cells. The statistical analysis was carried out using the Kruskal-Wallis test (p<0.05). The phytochemicals present in the extract were tannins, saponins and reducing sugars. Only the lowest concentration (1.25 mg/ml) of T. actinophylla was cytotoxic in comparison with NC. There was a significant increase in the total average of chromosomal changes to lower concentrations (1.25 and 2.5 mg/ml) compared to NC. Probably, phytochemicals in the extract interfere with the cell cycle and cause DNA damage in A. cepa in lower concentrations. However, if bad studies must be carried out on mammals, since the extract with medicinal purpose can have harmful effects on the organism.

Introducción: Poincianella bracteosa (Tul.) L.P. Queiroz. (Fabaceae), conocida como catingueira, es tradicionalmente utilizada en la medicina para tratar diarrea, hepatitis y anemia. Sin embargo, no hay estudios sobre los efectos tóxico genéticos de la P. bracteosa. Objetivo: En el presente estudio se tuvo como objetivo investigar el perfil fitoquímico y el potencial mutagénico y antimutagénico del extracto acuoso de la cáscara de P. bracteosa en Allium cepa y Mus musculus. Métodos: El extracto de la cáscara fue diluido en agua destilada para fornecer las cuatro concentraciones (2, 4, 8 y 16 mg/ml) utilizadas en el bioensayo A. cepa y las tres dosis (10, 20 y 40 mg / Kg) fueron administradas a los ratones (5 animales por grupo). El perfil fito-químico fue realizado por el test colorimétrico para identificar los principales metabólitos secundarios en el extracto de la cáscara. Tras el tratamiento, 5 000 células meristemáticas fueron analizadas para determinar el índice mitótico, el promedio de alteraciones cromosómicas y el porcentaje de reducción de daños. Para ratones, tras 24, 48 y 72 h, la sangre de la cola de cada animal fue recolectado para la preparación de dos láminas por animal. Para cada animal, 2 000 eritrocitos normocromáticos por ratón fueron evaluados para establecer el número de micronúcleos y el efecto protector. Se analizaron los dados por el test de Kruskal-Wallis (P < 0.05). El estudio fito-químico del extracto detectó azúcares reductores y taninos. Resultados: Ninguna de las concentraciones del extracto fue citotóxica y en todos los tratamientos (pre, simultáneo y después) fue observado el efecto citoprotetor en A. cepa. El promedio total de las alteraciones cromosómicas en todas las concentraciones apuntó actividad no mutagénica de la cáscara. El porcentaje de reducción del daño fue observada en los tratamientos pre (de 77.6 al 90.5 %), simultáneo (del 95.6 al 114.7 %) y tras (de 84.8 al 117.7 %). En los ratones, ninguna de las dosis del extracto presentó efecto mutagénico y el porcentaje de reducción del daño osciló de -21.2 al 78.6 % (pre); de 27.5 al 101.3 % (simultánea) y de 85.5 al 120.6 % (tras-tratamiento). Probablemente, los fito-químicos presentes en el extracto no interfirieron en el ciclo celular (A. cepa), tampoco causaron daños al DNA (A. cepa y ratones) y presentaron efecto protector en las dos especies estudiadas. Los datos observados apuntan la importancia del extracto de la cáscara de P. bracteosa para inhibición del daño y quimio prevención. Sin embargo, más estudios deben ser realizados para garantizar su efecto protector sobre el material genético.