Colesterol: Uma temática para contextualizar o ensino de Química / Cholesterol: A Theme to Contextualize the Teaching of Chemistry

A Química é uma ciência que busca compreender os processos naturais e não-naturais que ocorrem no nosso meio, tornando-se importante a compreensão no que tange a alimentação do ser humano. A intencionalidade deste estudo se faz acerca dos hábitos alimentares saudáveis por estudantes do ensino médio da Educação de Jovens e Adultos – EJA, no município de Alegrete/RS. A proposta se dá em três etapas: a primeira denominada de Pré-Oficina que foi realizada por meio de um questionário investigativo. A segunda foi a abordagem de conceitos de Carboidratos, Proteínas e Lipídios e sua finalização, por meio de uma palestra. E a terceira etapa foi a Pós-Oficina, na qual foi realizado um questionário avaliativo. Com os resultados obtidos, verificou-se que os estudantes desconheciam os conceitos “corretos” referentes ao Colesterol e que houve evolução nas concepções dos estudantes acerca dos tópicos estudados, bem como da temática abordada. Desta forma, contatou-se que a intervenção promoveu a contextualização dos conteúdos químicos e uma proximidade com a ciência

Purple pitanga extract and loaded liposomes effects in a tumorous Caenorhabditis elegans model

The Purple Pitanga Extract (PPE) demonstrated apoptotic and anti-cancer effects in previous studies with cells. Therefore, the investigation of specific pathways involved in the development of cancer using in vivo models is necessary. The objective of this study was to evaluate the safety and efficacy of PPE and PP-loaded liposomes (PPL) using Caenorhabditis elegans (C. elegans) that develop the multivulva (Muv) phenotype caused by the gain of function of let-60 (gf), a homologous of the human Ras. Treatment for 48h up to 100 μg CAE/mL of PPE was safe for the mutant worms and decreased the Muv phenotype formation, improving the egg-laying. PPE promoted an increase in the worms longevity, with activation of DAF-16 and apoptosis. However, the PPL formulation failed to expand the safe concentrations and improve the extract effectiveness. In worms with let-60 gf, PPL formulation did not demonstrate a suitable option for chronic treatment. However, PPE modulated the apoptotic signaling, which resulted in an effect against the Muv phenotype. These results demonstrated that it is possible to use a non-mammal hyperplasia model to evaluate new alternative therapies with reduced side effects against cellular targets involved with the tumorigenesis processes and that PPE is promising in reducing tumor formation

Phytochemical Analysis, Antioxidant Activity, Antimicrobial Activity, and Cytotoxicity of Chaptalia nutans Leaves

Context. Chaptalia nutans (L.) Pol. (family: Asteraceae) is widely used in traditional medicine as laxative and anticough medications and especially in the traumatisms, wounds, and hemorrhages in topical preparations. Objective. This work was to evaluate the chemical constitution of the hydromethanolic (30/70 methanol-water) macerating extract obtained from the leaves of C. nutans, as well as to study the antioxidant, antimicrobial, cytotoxic, and genotoxic activity of the species. Materials and methods. Phytochemical screening, antioxidant activity (total phenolic, total flavonoid, condensed tannins content, DPPH radical, and FRAP), antibacterial activity (P. aeruginosa, B. cereus, E. epidermidis, E. coli, S. aureus, E. faecalis, P. mirabilis, Candida glabrata (clinical isolate), Candida tropicalis (clinical isolate), C. krusei (clinical isolate), and C. albicans (clinical isolate)), and oxidative stress parameters (TBARS, carbonyl protein, and DCFH) were analyzed according to the literature. Toxicity of C. nutans was evaluated using an alternative method, D. melanogaster, as well as a locomotor assay. Results. The phytochemical screening test of methanolic leaves extract revealed the presence of alkaloids, coumarins, quaternary bases, phenolics, flavonoids, tannins, and free steroids. A quantitative phytochemical study indicated the total phenol (30.17 ± 1.44 mg/g), flavonoid (21.64 ± 0.66 mg/g), and condensed tannins (9.58 ± 0.99 mg/g). DPPH (345.41 ± 5.35 μg/mL) and FRAP (379.98 ± 39.25 μM FeSO4/mg sample) show to extract of C. nutans leaves an intermediate value, indicating moderate antioxidant activity of the extract. Antibacterial results revealed only a positive result (antimicrobial activity) for the hexane fraction which significantly inhibited the microorganisms E. epidermidis, C. tropicalis, C. glabrata, and C. krusei at a concentration of 1000 μg/mL. TBARS, carbonyl protein, and DCFH demonstrate that the extract has the ability to protect the cell from protein and lipid damage, as well as the inhibition of oxygen-derived radicals at the three concentrations tested: 0.1, 1, and 10 mg/mL. Regarding the toxicity of C. nutans extract against D. melanogaster, it was found that until the concentration of 15 mg/mL, the extract showed no toxicity and that the LC50 obtained was 24 mg/mL. Results show that the C. nutans extract leaves used to prevent PQ damage were effective in reducing flies’ mortality and improving locomotor capacity. Conclusion. Our studies demonstrated for the first time that C. nutans crude leaf extract has high antioxidant capacity both in vitro and in vivo through different analysis techniques. These results make it possible to infer future applications in the pharmacological area, evidenced by the low toxicity observed in D. melanogatser, as well as the ability to neutralize different sources of RONS