The frequent contamination of water resources with drugs comprises one the most important environmental problems. In order to avoid serious disturbances for aquatic life, efficient and economically viable procedures should be developed for removing common pollutants, as paracetamol. From these considerations, the present work evaluated the efficiency of sugar cane bagasse (SCB) and vegetable sponge (VS), two natural adsorbents commonly found in Brazil, for retaining paracetamol molecules dispersed in aqueous solutions. Thus, systems composed of glass columns and peristaltic pumps were optimized and, for pH, the best value was 7.0. After optimisation, adsorption isotherms were built and it was possible to calculate the MAC F values for SCB (120.5 µg/g) and VS (37.5 µg/g). Additionally, real matrices of pretreated water, from a municipal plant for water catchment, were enriched with paracetamol at 5 µM and passed through glass columns packed with SCB, VS and activated carbon (AC). The results showed that SCB was more attractive than AC in terms of price and efficiency (60% against 45% adsorption, respectively), while VS was responsible for removing 40% of paracetamol dissolved in the enriched water samples. Thus, the proposed natural adsorbents can be classified as viable materials to remove paracetamol from water used for human consumption.

Neste trabalho foi desenvolvida uma metodologia de remoção do corante carcinogênico congo red de sistemas aquosos. Os resultados mostraram uma elevada eficiência de remoção sendo de 64 ± 6% para soluções sintéticas de vermelho congo, e 94 ± 5% para efluente industrial enriquecido com vermelho congo utilizando 10 g de bioadsorvente. A capacidade máxima adsotiva encontrada foi de 4,43 mg/g. Os testes de percolação revelaram independência das porcentagens adsortivas em relação às vazões das colunas. Estes resultados indicam viabilidade de uso do bagaço de cana-de-açucar no tratamento de efluentes contendo o congo red.

A methodology involving sugar cane bagasse bioadsorbent was developed in order to remove the carcinogenic congo red dye from aqueous medium. The results showed high efficiency with retention of 64 ± 6% in synthetic congo red solution and 94 ± 5% in effluent enriched with congo red, at 10.0 g of the bioadsorbent. The adsorption system provided a maximum adsorption capacity of 4.43 mg/g. Tests showed independence adsorption properties, when compared with the column flow rates. The treatment units could be operated with flexibility. From the results, it was possible to conclude that sugar cane bagasse could be an adequate bioadsorbent.

Foi determinado o mecanismo de fotooxidação de albumina de soro bovino (BSA), L-triptofano (Trp) e células vermelhas do sangue (RBC) por cloro(5,10,15,20-tetrafenilporfirinato) de índio(III) (InTPP). A velocidade de fotooxidação de Trp, BSA e RBC por InTPP foi diminuída na presença de NaN3. A presença de D2O aumentou a velocidade de fotooxidação de Trp e BSA e diminuiu a de RBC. Esta diminuição provavelmente está correlacionada com a redução da constante de associação entre InTPP e RBC na presença de D2O. Não foi observada variação significativa na fluorescência das biomoléculas ou sobre a porcentagem de hemólise quando supressores de radicais (ferricianeto, manitol e superóxido dismutase) foram usados. Experimentos usando espectroscopia de ressonância paramagnética (EPR) mostraram que somente o ¹O2 foi gerado por InTPP. Foi proposto um modelo cinético para a fotooxidação de Trp e BSA. A concordância entre os resultados experimentais e este modelo corrobora a predominância do mecanismo via ¹O2 na fotooxidação das biomoléculas pelo InTPP.

The photooxidation mechanism of bovine serum albumin (BSA), L-tryptophan (Trp) and red blood cells (RBC) by chloro(5,10,15,20-tetraphenylporphyrinato)indium(III) (InTPP) was investigated. The photooxidation rate of Trp, BSA and RBC by InTPP was decreased in the presence of NaN3. The presence of D2O increases the photooxidation rate of Trp and BSA and decreases that of RBC. This decrease is probably related to a reduction of the binding constant between InTPP and RBC in the presence of D2O. No significant change in biomolecule fluorescence or in the percent of hemolysis was observed when radical quenchers (ferricyanide, mannitol and dismutase superoxide) were used. Experiments using electron paramagnetic resonance (EPR) show that only ¹O2 was generated by InTPP. A mechanistic model based on the preferential oxidation of Trp and BSA by singlet oxygen is proposed. The agreement between the experimental data and the kinetic model gives additional support to the predominance of a mechanism via ¹O2 in biomolecule photooxidation by InTPP.

A descoberta do poder inseticida do DDT, primeiro inseticida orgânico sintético, além de render a Paul Mueller o prêmio Nobel de Fisiologia e Medicina, em 1948, deu início à era dos pesticidas organoclorados. A partir do DDT, foram surgindo números cada vez maiores de pesticidas. Apesar dos benefícios, o uso indiscriminado desta classe de substâncias gerou graves problemas ecológicos. Hoje, estima-se que a porcentagem de seres vivos, vegetais e animais, não contaminados, seja relativamente baixa. Este artigo de revisão focaliza os graves problemas de contaminação e saúde gerados pelos organoclorados, bem como a busca de soluções para minimizar tais problemas.

The discovery of DDT, the first synthetic organic insecticide, besides giving Paul Mueller, in 1948, the Nobel Prize of Physiology and Medicine, started the age of organochlorine pesticides. After the appearance of DDT, there has been an ever increasing number of pesticides available on the market. Despite the benefits, the indiscriminate use of this substance created serious ecological problems. Currently it is estimated that the percentage of living beings, vegetables and animals, that remain uncontaminated, is relatively low. This article focuses on the serious problem of contamination created by organochlorides, as well as the attemps to solve these problems.

A terapia fotodinâmica (TFD) é um promissor tratamento clínico que emprega a combinação de luz visível, oxigênio e uma substância fotossensibilizadora para tratar doenças de caráter oncológico. Esse tipo de tratamento induz a morte celular programada (apoptose) em tecido tumoral. No entanto, o mecanismo de indução de apoptose por TFD não está bem caracterizado. Muitos fotossensibilizadores possuem como alvo principal a mitocôndria. O tratamento com TFD causa danos nessa organela e induz a apoptose através da liberação de citocromo c, fator de indução de apoptose, Smac/DIABLO e certas pró-caspases. A liberação dessas proteínas, a partir da mitocôndria, é regulada por uma família de proteínas pró e antiapoptóticas, conhecida como família BCL-2. A proposta dessa minirrevisão é apresentar algumas publicações recentes que focalizam o envolvimento da mitocôndria em apoptose de células cancerígenas induzida por TFD.

Photodynamic therapy (PDT), a promising cancer treatment that employs a combination of a photosensitizing chemical, oxygen, and visible light, induces apoptosis in tumor cells. However, the precise mechanism of PDT-induced apoptosis is not well characterized. Many of the photosensitizers currently in clinical or pre-clinical studies of PDT are localized in or have a major influence on mitochondria. The treatment with PDT causes mitochondrial damage and induces apoptosis through the release of cytochrome c (cyt c), apoptosis-inducing factor (AIF), Smac/DIABLO and certain procaspases. Proapoptotic and antiapoptotic members of BcL-2 family regulate the release of these proteins from mitochondria. The purpose of this mini-review is to present some recent publications that focus on the involvement of the mitochondria in apoptosis of cancer cells induced by PDT.