48 research outputs found

    Biochemical mechanisms of the effect of environmental factors (diet, fluorine, alcohol and tobacco) on oral health

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    Nowadays, oral diseases are prevalent chronic diseases present in worldwide population. Dental caries results from a complex interaction between acid-producing bacteria, fermentable carbohydrates and host factors, including teeth and saliva. Risk factors for caries development include physical, biological, environmental, behavioral factors such as high numbers of cariogenic bacteria, inadequate salivary flow, poor oral hygiene and poor eating habits. Moreover, due to its efficacy in caries prevention, fluorine has been added to toothpaste, supplements and water. However, despite of its beneficial effect, excessive intake can lead to acute or chronic toxic effects, that depend on ingestion period and ingested amount, age, cardiovascular or renal problems and genetic changes. The most common adverse effects of excessive fluorine intake are dental and skeletal fluorosis. Another oral health problem is oral cancer, one of the most common cancers in the world and a highly relevant problem of global public health, mainly affecting lips and oral cavity. It is a preventable disease, where tobacco and alcohol, considered major risk factors, are present with a synergic effect in 90% of cases. Alcohol can act as a risk factor both locally and systemically, being causally associated with oropharyngeal and larynx cancer, esophageal cancer, among others.info:eu-repo/semantics/publishedVersio

    Ação inseticida do extrato de Derris amazonica Killip para Cerotoma arcuatus Olivier (Coleoptera: Chrysomelidae

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    A abundância e o potencial inseticida de Derris amazonica e a necessidade de controle de Cerotoma arcuatus Olivier (Coleoptera: Chrysomelidae) na cultura do feijão-caupi (Vigna unguiculata L. Walp) estimularam a realização desta pesquisa, que objetivou avaliar a ação inseticida do extrato de D. amazonica a adultos de C. arcuatus em condições de laboratório. Os bioensaios testaram as vias de intoxicação por ingestão de folhas contaminadas, contato com superfície contaminada e aplicação tópica, com delineamento experimental inteiramente casualizado, com quatro repetições. Os valores de mortalidade e consumo foliar dos insetos foram submetidos à análise de regressão, sendo utilizada a análise de Probit para determinação das CL50, da DL50 e dos TL50. O extrato de D. amazonica, contendo 3,7% de rotenona, foi tóxico para adultos de C. arcuatus via ingestão de folhas contaminadas (CL50=15,14 µL do extrato.mL-1 de água), superfície contaminada (CL50=0,45 µL do extrato.cm-2) e aplicação tópica (DL50=1,44 µL do extrato.g-1 do inseto). Mortalidades de adultos de C. arcuatus superiores a 80% e os menores tempos letais médios foram obtidos na concentração de 5% (v v-1) do extrato em todos os bioensaios. O consumo foliar de adultos de C. arcuatus foi inversamente proporcional a concentração do extrato quando expostos por via de ingestão foliar ou aplicação tópica, sendo inclusive observada inibição da alimentação dos indivíduos. O extrato de D. amazonica é tóxico para C. arcuatus e inibe a alimentação dos insetos a partir da concentração de 1% (v v-1).The abundance and insecticidal potential of Derris amazonica in addition to need of controlling Cerotoma arcuatus for bean crop stimulated this research. The objective of this work was to evaluate insecticide action of the extract of D. amazonica to adults of C. arcuatus in laboratory conditions. The bioassays were carried out using three distend methodologies: leaf intake, contact in treated surface (filter paper) and topical application. A completed randomized experimental design was used with four replications. Mortality values and leaf consumption of the insects were subjected to regression analyses, being the Probit analyses used to determine of the i.e., LC50, LT50 and LD50. The extract of D. amazonica containing 3.7% of rotenone was toxic to adults C. arcuatus when exposed to treated leaves (LC50 = 15.14 µl.mL-1), treated surface (LC50 = 0.45 µl.cm-2) and subjected to topical exposure (LD50 = 1.44 µl.g-1). In all bioassays the adults mortality was higher than 80% with lower median lethal times obtained with 5% (v.v-1) concentrations of the extract. Leaf consumption by adults C. arcuatus was inversely proportional to the concentration of the extract when exposed by leaf intake or topical application, also being observed inhibition of feeding individuals. The extract of D. amazonica is toxic to C. arcuatus and inhibits the feeding of insects from the concentration of 1% (v v-1)
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