Antinociceptive effect and mechanism of supercritical carbon dioxide extract of Aloysia gratissima leaves in mice.

BACKGROUND: A. gratissima is a shrub used in folk medicine as analgesic and sedative. However, studies on its antinociceptive activity are scarce. This research aimed to evaluate the antinociceptive effect of a supercritical carbon dioxide (SCCO2) extract of A. gratissima leaves (EAG) in mice. METHODS: A. gratissima leaves were subjected to extraction with supercritical CO2 (60 °C, 200 bar). The chemical composition of EAG was determined by gas chromatography-mass spectrometry (GC-MS). The antinociceptive profile of the extract (1, 10 and 30 mg/kg, p.o.) was established using acetic acid-induced abdominal contraction tests and formalin-induced paw-licking tests. The open field and rota-rod tests were used to evaluate a possible interference of EAG on mice motor performance. The contribution of the opioid system and adenosine triphosphate (ATP) sensitive K+ channels in the mechanism(s) of EAG action was evaluated by specific receptor blockers. EAG's acute toxicity was investigated using OECD 423 guideline. RESULTS: The GC-MS revealed the presence of sesquiterpenes (guaiol and pinocamphone) in the EAG. Doses of 10 mg/kg and 30 mg/kg significantly reduced the number of abdominal writhes and paw licking time in mice in the formalin test. The EAG did not affect the locomotor activity and motor coordination of the mice. The antinociceptive effect of the EAG was prevented by glibenclamide in the mice formalin test, unlike naloxone pre-treatment. The acute administration of EAG caused no mortality. CONCLUSION: A. gratissima leaves possess antinociceptive effect, mediated by K+ channels sensitive to ATP.

Eugenia umbelliflora mediated reduction of silver nanoparticles incorporated into O-carboxymethylchitosan/y-Fe2O3: Synthesis, antimicrobial activity and toxicity.

The purpose of this study was to synthesize a new magnetic material with antimicrobial properties, incorporated into a biopolymer and containing silver nanoparticles (Ag NP) prepared extract of Eugenia umbelliflora as a reducing agent. Silver nanoparticles incorporated into magnetic nanocomposite O-carboxymethylchitosan/y-Fe2O3/Ag0 (CMAgE) composite were synthesized using an extract of E. umbelliflora. The antimicrobial activity of the pathogenic microorganism is reported here. The synthesized nanoparticles were also characterized, and quantified by Ag analysis. The minimum inhibitory concentrations (MIC) of CMAgE against Staphylococcus aureus, Escherichia coli, and Candida albicans were 16.5, 1000 and 500 µg/mL, respectively. The results show that these materials have significant synergistic effect on each other. The potential phytotoxic effect of the nanocomposites was evaluated using Cucumis sativus seeds. The positive values for seedling elongation inhibition (SEI) show that CMAgE and methanol extract of Eugenia umbelliflora (Eug) cause growth inhibition at a concentration of 1000 mg/L. The germination index (GI) values of 40% and 80% at 1000 mg/L, for CMAgE and Eug, respectively, showed inhibition of germination. CMAgE and Eug showed cytotoxic effects against Artemia salina nauplii, with LC50 values of 72.5 µL/mL and < 5.0 µL/mL respectively, after 48 h.

Nanoecotoxicology study of the response of magnetic O-Carboxymethylchitosan loaded silver nanoparticles on Artemia salina.

Magnetic silver nanoparticles (MNPAg) are interesting nanotechnology materials with borderless environmental science, that can be used to disinfect water contaminated with pathogenic bacteria. The use of MNPAg leads to increased risk of nanomaterial contamination in the environment, especially natural water sources, with harmful effects on the ecosystem. This study investigating survival and enzyme activity of magnetic O-carboxymethylchitosan loaded silver nanoparticle on Artemia salina. The results showed that mortality increased with increasing concentrations of MNPAg. O-Carboxymethylchitosan loaded silver nanoparticles were found to be more toxic, with a LC50 of 902.1 mg/L for γ-Fe2O3/Ag without reducing agent. Accumulation of silver on Artemia salina depends on the type of nanoparticle. Accumulation of nanoparticle containing polymers (carboxymethylchitosan/γ-Fe2O3/Ag without reducing agent, carboxymethylchitosan/γ-Fe2O3/Ag reduced with sucrose and carboxymethylchitosan/γ-Fe2O3/Ag reduced with NaBH4) were found to be higher than γ-Fe2O3/Ag reduced with NaBH4, γ-Fe2O3/Ag reduced with sucrose and γ-Fe2O3/Ag without reducing agent under the same experimental conditions. The antioxidant enzyme (CAT, SOD and GST) activities increased slightly following exposure, indicating that the toxic effects are related to oxidative stress. The combined results so far indicate that MNPA does not have the potential to affect aquatic organisms when released into the ecosystem.

Cárie dentária e fatores associados em crianças com três anos de idade cadastradas em Unidades de Saúde da Família do Município de Rondonópolis, Mato Grosso, Brasil / Dental caries and factors associated in children aged three years enrolled in Family Health Units in the Municipality of Rondonópolis, Mato Grosso, Brazil

Objetivo: o estudo pretende determinar a prevalência de cárie precoce na infância e fatores associados em crianças nascidas vivas em 2006, em áreas cobertas pela Estratégia Saúde da Família no Município de Rondonópolis, Estado do Mato Grosso, Brasil. Métodos: estudo transversal com população-alvo de 1.235 nascidos vivos; exames clínicos bucais verificaram a prevalência de cáriedentária, defeitos no esmalte e biofilme visível em amostra de 247 crianças em idade pré-escolar (com 3 anos de idade período deste estudo, 2009); aplicou-se um questionário junto aos pais/responsáveis e os dados foram submetidos a análise multivariada. Resultados: a prevalência de cárie nas crianças em idade pré-escolar foi de 34,2 por cento, associada a defeitos de esmalte e hábitos de higiene e dieta desfavoráveis; e o índice de dentes decíduos cariados, com extração indicada e obturados (índice ceo-d), 0,79; as variáveis associadas à cárie em pré-escolares foram presença de defeitos de formação de esmalte, hábito de mamar durante o sono e presença de biofilme visível. Conclusão: a prevalência de cárie indica a necessidade intensificação do atendimento preventivo e curativo a essas crianças, devido à presença de doença ativa, e a identificação precoce da população sob risco.

Objective: the study aims to determinate the prevalence of early childhood carie and factors associated in live birth children in 2006, in areas covered by the Family Health Strategy in the Municipality of Rondonópolis, State of Mato Grosso, Brazil. Methods: transversal study in a target population of 1,235 live birth; oral examinations verified prevalence of early childhood carie, enamel defects and visible bacterial plaque in a sample of 247 preschool children (aged 3 years in the period of this study, 2009); questionnaires were applied to parents and data were submitted to multivariate analysis. Results: the prevalence of carie in preschooler age children was 32.4 per cent; and the number of decayed, missing and filled teeth due to caries (DMFT index), 0.79; characteristics associated to carie in preschoolers were presence of enamel defects, breastfeeding or bottle-feeding while sleeping and presence of visible bacterial plaque. Conclusion: the prevalence of carie indicates intensification of preventive and curative actions to these children, due to the existence of active disease, and early identification of those at risk.