Ascorbic acid in the prevention and treatment of cancer / Ácido ascórbico na prevenção e no tratamento do câncer

Summary This review is aimed at the systematic mapping of ascorbic acid in the prevention and/or treatment of cancer in clinical and non-clinical studies from 2011 to 2015, in order to understand dose-response variations as well as its mechanisms of action as an antioxidant and antitumor agent. Seventy-eight articles were retrieved from the PubMed/Bireme database, of which only 30 included ascorbic acid in the prevention and/or treatment of cancer. However, there are controversies regarding doses and a lack of clinical studies featuring its mechanism of action more clearly. Other studies are needed to understand dose-response variations, as well as its targeting mechanisms of action, both as an antioxidant and antitumor agent, to assist treatment and prevention of cancer, aiming at better quality of life for both patients and the general population.

Resumo Este estudo de revisão teve como objetivo fazer o mapeamento sistemático do ácido ascórbico na prevenção e/ou no tratamento do câncer como antioxidante e/ou pró-oxidante em estudos clínicos e não clínicos, entre 2011 e 2015, para o entendimento das variações de dose-resposta, bem como dos seus mecanismos de ação como agente antioxidante e antitumoral. Nas bases de dados Pubmed e Bireme, foram identificados 78 artigos, dos quais apenas 30 apontavam o ácido ascórbico na prevenção e/ou no tratamento do câncer. Contudo, há controvérsias sobre as doses utilizadas e faltam estudos clínicos que caracterizem melhor o seu mecanismo de ação. Outros estudos devem ser realizados para o entendimento das variações de dose-resposta, bem como de seus mecanismos de ação, como agente antioxidante ou antitumoral, para auxiliar o tratamento e a prevenção do câncer, visando à melhor qualidade de vida dos pacientes e da população em geral.

Exposição ocupacional de trabalhadores rurais a agrotóxicos / Occupational exposure of rural workers to pesticides

Resumo Objetivos Avaliar o perfil dos trabalhadores rurais do município de Picos, no Estado do Piauí e suas práticas e atitudes quanto à utilização de agrotóxicos. Métodos A coleta dos dados (n=159) foi realizada em Picos com levantamento de dados socioeconômicos, utilização de equipamentos de proteção individual (EPIs), armazenamento e destino das embalagens de agrotóxicos, toxicidade e risco ambiental. Resultados A maioria dos agricultores era do sexo feminino (63%), não concluiu o ensino fundamental (55,6%), tinha entre 31 e 50 anos (55,3%), com renda de até um salário mínimo (66%) e possuía água encanada (84,3%). Quanto ao uso, 64,1% (102) utilizavam agrotóxicos, principalmente na agricultura (86,3%). Eles obtiveram informações sobre essas substâncias com vizinhos (44,2%), liam o rótulo para utilizar o produto (64,8%), usavam agroquímicos devido à ação rápida (81,4%), compravam em casas agropecuárias (87,4%), sem receituário agronômico (92%) e armazenavam embalagens dentro da própria casa (33,6%). Mais da metade não usava EPIs (56,8%), embora considerassem os agrotóxicos prejudiciais à saúde humana (94,1%) e ao meio ambiente (80,4%), além de 15% (24 pessoas) terem sentido algum sintoma de envenenamento. Conclusões Os entrevistados, em sua maioria, usavam agrotóxicos inadequadamente, tinham baixa escolaridade e conheciam sobre os riscos individuais e coletivos aos quais estavam expostos, mas não usavam EPIs.

Abstract Objectives To evaluate rural workers’ profile at Picos (Piauí, Brazil) and their practices and attitudes regarding the use of pesticides. Methods Data collection (n=159) was performed in Picos (Piauí, Brazil) to describe socioeconomic information, use of personal protective equipment (PPE), storage and disposal of pesticide packaging, toxicity and environmental risk. Results Most farmers were women (63%), with incomplete primary education (55.6%), age between 31-55 years-old (55.3%), income of up to a 1 minimum wage (66%) and with access to city water (84.3%). In relation to the use, 64.1% (102) use pesticides, especially in agriculture (86.3%). They receive information about pesticides with neighbors (44.2%), read label to use the product (64.8%), use pesticides due to their quick action (81.4%), purchase in agricultural houses (87.4%) without agronomic prescription (92%) and store packages indoors (33.6%). More than half do not use PPE (56.8%), though they consider pesticides damaging products to the human health (94.1%) and environment (80.4%) and 15% (24 persons) reported some poisoning symptoms. Conclusions The majority of the farmers use pesticides incorrectly, has low educational status and know about the individual and collective risks to which they are exposed but do not use PPE.

Avaliação do risco de mutagenicidade e anormalidades nucleares decorrente da exposição ao benzeno e a seus derivados em trabalhadores de oficinas automotivas em Teresina-PI, Brasil / Risk assessment of mutagenicity and nuclear abnormalities resulting from exposure to benzene and its derivatives in workers of automotive workshops in Teresina-PI, Brazil

O monitoramento biológico da exposição a substâncias químicas no local de trabalho tem adquirido crescente importância na avaliação dos riscos para a saúde. Oficinas de reparação de veículos automotores constituem um ramo de atividade pouco estudado.Os trabalhadores nessas oficinas são expostos às tintas e solventes, que sãoconstituídos quimicamente por benzeno e seus derivados. O presente estudo avaliou o risco de mutagenicidade e anormalidades nucleares (cariorexe, cariólise e células binucleadas) em células de mucosa oral desses trabalhadores, com a aplicação do testede micronúcleos. Foram analisados 42 trabalhadores, da cidade de Teresina, PI. Os resultados obtidos foram correlacionados com o estilo de vida desses profissionais. A frequência de micronucleos no grupo exposto foi estatisticamente significante (* P < 0,05 – Teste T- Student) assim como a frequência de anormalidades nucleares (***P < 0,0001– Teste T- Student). Houve correlação positiva entre a frequência de micronucleos e o nãouso de equipamentos de proteção individual (EPIs) e a frequência das anormalidades nucleares (carriorrexe e cariólise) com o não consumo de vegetais e o hábito de fumar. É possível concluir a partir deste estudo que a exposição crônica ocupacional a tintaspode conduzir a um aumento no risco de dano genético em trabalhadores de oficinas automotivas...

Chemical composition and anxiolytic-like effects of the Bauhinia platypetala

The pantropical genus Bauhinia, Fabaceae, known popularly as cow's foot, is widely used in folk medicine as antidiabetic. Behavioral effects of the ethanolic extract and ethereal, aqueous and ethyl acetate fractions from B. platypetala Benth. ex Hemsl. leaves were studied in male Swiss mice. The ethanolic extract and fractions were administered intraperitoneally and its effects on spontaneous motor activity (total motility, locomotion, rearing and grooming behavior) were monitored. Anxiolytic-like properties were studied in the elevated plus-maze test and the possible antidepressant-like actions were evaluated in the forced swimming test. The results revealed that only the highest dose of the ethereal fraction (50 mg/kg, i.p.) caused a significant decrease in total motility, locomotion and rearing. Sole dose injected (50 mg/kg) of ethanolic extract and ethereal fractions increased the exploration of the elevated plus-maze open arms in a similar way to that of diazepam (2 mg/kg, i.p.). In the forced swimming test, the ethanolic extract and their fractions (12.5, 25 or 50 mg/kg) was not as effective as paroxetine (10 or 20 mg/kg, i.p.) and imipramine (25 or 50 mg/kg, i.p.) in reducing immobility. These results suggest that some of the components of the ethanolic extract and of the ethereal fraction from B. platypetala, such as p-cymene, phytol, D-lactic acid, hexadecanoic acid, among others, may have anxiolytic-like properties, which deserve further investigation. Furthermore, the results obtained indicate that ethanolic extract from B. platypetala and their fractions do not present antidepressive properties. However, these properties cannot be related to the chemical constituents identified in this specie.

Antimutagenic activity of cashew apple (Anacardium occidentale Sapindales, Anacardiaceae) fresh juice and processed juice (cajuína) against methyl methanesulfonate, 4-nitroquinoline N-oxide and benzo[a]pyrene

Cashew apple juice (CAJ), produced from the native Brazilian cashew tree (Anacardium occidentale), and has been reported to have antibacterial, antifungal, antitumor, antioxidant and antimutagenic properties. Both the fresh unprocessed juice and the processed juice (cajuína in Portuguese) has been shown to consist of a complex mixture containing high concentrations of anacardic and ascorbic acids plus several carotenoids, phenolic compounds and metals. We assessed both types of juice for their antimutagenic properties against the direct mutagens methyl methanesulfonate (MMS) and 4-nitroquinoline-N-oxide (4-NQO) and the indirect mutagen benzo[a]pyrene (BaP) using pre-treatment, co-treatment and post-treatment assays with Salmonella typhimurium strains TA100, TA102, and TA97a. In pre-treatment experiments with strains TA100 and TA102 the fresh juice showed high antimutagenic activity against MMS but, conversely, co-treatment with both juices enhanced MMS mutagenicity and there was an indication of toxicity in the post-treatment regime. In pre-, co-, and post-treatments with TA97a as test strain, antimutagenic effects were also observed against 4-NQO and BaP. These results suggest that both fresh and processed CAJ can protect the cells against mutagenesis induced by direct and indirect mutagens.

Cashew (Anacardium occidentale) apple juice lowers mutagenicity of aflatoxin B1 in S. typhimurium TA102

Cashew (Anacardium occidentale) is a medicinal plant native to Brazil and also yields a nutritious fruit juice. Its large pulpy pseudo-fruit, referred to as the cashew apple, contains high concentrations of vitamin C, carotenoids, phenolic compounds and minerals. Natural and processed cashew apple juice (CAJ/cajuina) are amongst the most popular juices in Brazil, especially in the north-east. Both juices have antioxidant potential and suppress mutagenicity of hydrogen peroxide. In the present study we evaluated the inhibitory effects of CAJ/cajuina on Aflatoxin B1(AFB1)-induced mutation, using the Salmonella/microsome assay with the experimental approaches of pre-, co- and post-treatments. Both CAJ/cajuina suppress AFB1-induced mutagenesis in strain TA102 when applied in co- and in post-treatment. Possible mechanisms for anti-mutagenicity in co-treatment are (a) interaction with S9 enzymes, (b) metabolization to non-mutagenic compounds of AFB1 or (c) inactivation of S9 potential. Total suppression of AFB1 mutagenicity was observed in co-treatment with both CAJ and cajuina. Post-treatment anti-mutagenicity of both juices suggests a modulation of activity of error-prone DNA repair. CAJ/cajuina may be considered promising candidates for control of genotoxicity of AFB1 and may thus be considered as health foods with anti-carcinogenic potential. This promising characteristic warrants further evaluation with in vivo studies.