Assessment of heavy metals and human health risk associated with the consumption of crops cultivated in industrial areas of Maputo, Mozambique.

This study aimed to evaluate heavy metals concentrations in soils and vegetables (cabbage, lettuce, and cassava) cultivated at Matola and Beluluane Industrial Parks, and to assess health risks linked to their consumption through estimated daily intake, hazard index (HI), and incremental lifetime cancer risk. Concentrations of Al, As, Co, Cd, Cr, Ni, Pb, and Zn were determined in the two sites. Soil concentrations of As at Beluluane site and As, Cd, and Cr at Matola site exceeded reference limits of the Food and Agriculture Organization/World Health Organization, showing heavy metal contamination. At Beluluane site, all studied vegetables presented As and Pb levels higher than reference limits, Cd concentrations were higher than the reference limit in cabbage, lettuce, and cassava leaves. At Matola site crops concentrations of As, Cd, Cr, and Pb exceeded the reference limits. Zinc exceeded the reference limit in all crops except in cabbage. HIs for vegetables from Beluluane exceeded 1.0 in cabbage (2.66), lettuce (2.27), and cassava leaves (2.37). Likewise, at Matola, HIs exceeded 1.0 in lettuce (1.67), cassava leaves (1.65), and root tubers (13). We found that vegetables cultivated in industrial parks present high carcinogenic risk due to heavy metal contamination, rendering them unsuitable for human consumption.

The impact of a bundle to prevent hospital-acquired pneumonia in a cohort of nonventilated patients on enteral nutrition.

We conducted a quasi-experimental study to evaluate a bundle to prevent nonventilator hospital-acquired pneumonia (NV-HAP) in patients on enteral tube feeding. After the intervention, there was an increase in bundle compliance from 55.9% to 70.5% (P < .01) and a significant decrease (34%) in overall NV-HAP rates from 5.71 to 3.77 of 1,000 admissions.

Elaboration and validation of a protocol for safe administration of enteral nutrition in hospitalized patients / Elaboración y validación de un protocol de administración segura para la nutrición enteral en pacientes hospitalizados / Elaboração e validação de um protocolo para administração segura de nutrição enteral em pacientes hospitalizados

Objective: To describe the elaboration and validation of a protocol for administration of enteral nutrition. Method: Validation study by consensus of experts conducted in a university hospital. The construction took place after literature review. The validation was guided by the tool: plan, do, study and act. For validation of the final protocol, 100% consensus was considered. After implementation, preceded by training, evaluation was carried out by using indicators. Results: The protocol describes the actions that guide the nursing team in enteral nutrition. In the validation, there was a 100% consensus on the protocol items. The presential training brought together 425 participants in 80 meetings. After the pilot period, the rate of care for patients with enteral nutrition increased from 39.5% to 73.3%. There was a reduction of 41 hours in the time to release the X-ray report. Conclusion: The protocol provided elements for the prevention of adverse events in patients with enteral nutrition. Keywords: Protocols. Enteral nutrition. Nursing care.  

RESUMENObjetivo: Describir la elaboración y validación de un protocolo para la administración de nutrición enteral.Método: Estudio de validación por consenso de expertos realizado en un hospital universitário. La construcción se llevó a cabo después de revisar la literatura. La validación estuvo guiada por la herramienta planificar, hacer, estudiar y actuar. Para la validación del protocolo final se considero un consenso del 100%. Después de la implementación, precedida por la capacitación, se llevó a cabo la evaluación mediante indicadores.Resultados: El protocolo describe las acciones que orientan al equioo de enfermería en nutrición enteral. En la validación , hubo un consenso del 100% en los ítems del protocolo. La información presencial reunió a 425 participantes en 80 reuniones. Después del período piloto, la tasa de atención a los pacientes con nutrición enteral aumento del 39,5% al 73,3%. Hubo una redución de 41 horas en el tempo para publicar el informe de rayos X.Conclusión: El protocolo aportó elementos para la prevención de eventos adversos en pacientes con nutrición enteral.Palabras clave: Protocolos. Nutrición enteral. Atención de enfermería.

RESUMO Objetivo: Descrever a elaboração e validação de um protocolo para administração de nutrição enteral. Método: Estudo de validação por consenso de especialistas conduzido em um hospital universitário. A construção ocorreu após revisão da literatura. A validação foi norteada pela ferramenta plan, do, study and act. Para validação do protocolo final foi considerado consenso de 100%. Após a implantação, precedida de capacitação, ocorreu a avaliação por meio de indicadores.   Resultados: O protocolo descreve as ações que guiam a equipe de enfermagem na nutrição enteral. Na validação, ocorreu consenso de 100% nos itens do protocolo. A capacitação presencial reuniu 425 participantes em 80 encontros. Após o período piloto, a taxa de cuidado ao paciente com nutrição enteral aumentou de 39,5% para 73,3%. Houve redução de 41 horas no tempo para liberação do laudo do raio X. Conclusão: O protocolo forneceu elementos para a prevenção de eventos adversos em pacientes com nutrição enteral. Palavras-chave: Protocolos. Nutrição enteral. Cuidados de enfermagem.

Accidental enteral feeding tube dislodgement with the use of a dedicated feeding tube attachment device versus adhesive tape as the securing method: a randomized clinical trial / Desplazamiento accidental de la sonda de alimentación enteral con el uso de un dispositivo de fijación de sonda de alimentación dedicado versus cinta adhesiva como método de aseguramiento: un ensayo clínico aleatorizado

Introduction: accidental dislodgement of enteral feeding tubes has been considered as an important quality indicator of the efficacy of enteral nutrition therapy. However, in clinical practice, the use of feeding tube attachment devices (FTADs), as an alternative to the traditional method of adhesive tape alone, has not yet been evaluated for its effectiveness in reducing inadvertent tube dislodgement. Objective: to evaluate the impact of using a dedicated FTAD compared with the traditional securing method with adhesive tape on the occurrence of accidental enteral feeding tube removal. Methods: a randomized clinical trial comparing two strategies for enteral feeding tube securement: use of traditional adhesive tape vs FTAD. The primary endpoint was the percentage of accidental enteral feeding tube dislodgement after randomization. Results: a total of 104 inpatients (mean age: 61.4?±?17.5 years) were included (52 patients per group). Most were women with cerebrovascular disease (35.6%), diabetes (28.8%) and neoplasia (27.9%). There were 39 (37.5%) cases of accidental tube removal, 30.8% in the FTAD group and 44.2% in the adhesive tape group (p?=?0.22). During follow-up, patients in the FTAD group received a mean of 60.0% of the volume of enteral nutrition prescribed, while patients in the adhesive tape group received 57.0% (p?=?0.61). There was no difference in skin lesions between the groups. Conclusion: the strategy of using a dedicated FTAD as the method for securing enteral feeding tubes did not reduce the risk of accidental tube dislodgement compared with the traditional securing method with adhesive tape

Introducción: la expulsión accidental de sondas de alimentación enteral se ha considerado un indicador importante de la calidad de la eficacia de la terapia de nutrición enteral. Sin embargo, en la práctica clínica, el uso de dispositivos de fijación de tubos de alimentación (FTAD, por sus siglas en inglés), como una alternativa al método tradicional de cinta adhesiva exclusivamente, aún no se ha evaluado por su eficacia para reducir el desprendimiento accidental de sondas. Objetivo: evaluar el impacto de usar un FTAD dedicado en comparación con el método tradicional de aseguramiento con cinta adhesiva en caso de que se produzca una extracción accidental de la sonda de alimentación enteral. Métodos: se realizó un ensayo clínico aleatorizado que comparó dos estrategias para asegurar la sonda de alimentación enteral: el uso de cinta adhesiva tradicional frente a FTAD. El punto final primario fue el porcentaje de desplazamiento accidental del tubo de alimentación enteral después de la aleatorización. Resultados: se incluyó un total de 104 pacientes hospitalizados (edad media 61,4 ± 17,5 años) (52 pacientes por grupo). La mayoría eran mujeres con enfermedad cerebrovascular (35,6%), diabetes (28,8%) y neoplasia (27,9%). Hubo 39 casos (37.5%) de extracción accidental de tubos, 30,8% en el grupo FTAD y 44,2% en el grupo de cinta adhesiva (p = 0,22). Durante el seguimiento, los pacientes del grupo FTAD recibieron una media del 60,0% del volumen de nutrición enteral prescrito, mientras que los pacientes del grupo de cinta adhesiva recibieron el 57,0% (p = 0,61). No hubo diferencia en las lesiones de la piel entre los grupos. Conclusión: la estrategia de utilizar un FTAD dedicado como método para asegurar las sondas de alimentación enteral no redujo el riesgo de retiradas accidentales en comparación con el método tradicional de sujeción con cinta adhesiva

Accidental enteral feeding tube dislodgement with the use of a dedicated feeding tube attachment device versus adhesive tape as the securing method: a randomized clinical trial.

INTRODUCTION: Introduction: accidental dislodgement of enteral feeding tubes has been considered as an important quality indicator of the efficacy of enteral nutrition therapy. However, in clinical practice, the use of feeding tube attachment devices (FTADs), as an alternative to the traditional method of adhesive tape alone, has not yet been evaluated for its effectiveness in reducing inadvertent tube dislodgement. Objective: to evaluate the impact of using a dedicated FTAD compared with the traditional securing method with adhesive tape on the occurrence of accidental enteral feeding tube removal. Methods: a randomized clinical trial comparing two strategies for enteral feeding tube securement: use of traditional adhesive tape vs FTAD. The primary endpoint was the percentage of accidental enteral feeding tube dislodgement after randomization. Results: a total of 104 inpatients (mean age: 61.4 ± 17.5 years) were included (52 patients per group). Most were women with cerebrovascular disease (35.6%), diabetes (28.8%) and neoplasia (27.9%). There were 39 (37.5%) cases of accidental tube removal, 30.8% in the FTAD group and 44.2% in the adhesive tape group (p = 0.22). During follow-up, patients in the FTAD group received a mean of 60.0% of the volume of enteral nutrition prescribed, while patients in the adhesive tape group received 57.0% (p = 0.61). There was no difference in skin lesions between the groups. Conclusion: the strategy of using a dedicated FTAD as the method for securing enteral feeding tubes did not reduce the risk of accidental tube dislodgement compared with the traditional securing method with adhesive tape.

INTRODUCCIÓN: Introducción: la expulsión accidental de sondas de alimentación enteral se ha considerado un indicador importante de la calidad de la eficacia de la terapia de nutrición enteral. Sin embargo, en la práctica clínica, el uso de dispositivos de fijación de tubos de alimentación (FTAD, por sus siglas en inglés), como una alternativa al método tradicional de cinta adhesiva exclusivamente, aún no se ha evaluado por su eficacia para reducir el desprendimiento accidental de sondas. Objetivo: evaluar el impacto de usar un FTAD dedicado en comparación con el método tradicional de aseguramiento con cinta adhesiva en caso de que se produzca una extracción accidental de la sonda de alimentación enteral. Métodos: se realizó un ensayo clínico aleatorizado que comparó dos estrategias para asegurar la sonda de alimentación enteral: el uso de cinta adhesiva tradicional frente a FTAD. El punto final primario fue el porcentaje de desplazamiento accidental del tubo de alimentación enteral después de la aleatorización. Resultados: se incluyó un total de 104 pacientes hospitalizados (edad media 61,4 ± 17,5 años) (52 pacientes por grupo). La mayoría eran mujeres con enfermedad cerebrovascular (35,6%), diabetes (28,8%) y neoplasia (27,9%). Hubo 39 casos (37.5%) de extracción accidental de tubos, 30,8% en el grupo FTAD y 44,2% en el grupo de cinta adhesiva (p = 0,22). Durante el seguimiento, los pacientes del grupo FTAD recibieron una media del 60,0% del volumen de nutrición enteral prescrito, mientras que los pacientes del grupo de cinta adhesiva recibieron el 57,0% (p = 0,61). No hubo diferencia en las lesiones de la piel entre los grupos. Conclusión: la estrategia de utilizar un FTAD dedicado como método para asegurar las sondas de alimentación enteral no redujo el riesgo de desalojos accidentales en comparación con el método tradicional de sujeción con cinta adhesiva.

Genotoxic alkenylbenzene flavourings, a contribution to risk assessment.

Alkenylbenzenes, such as estragole, myristicin and eugenol, are present is several flavourings, functional foods, plant food supplements (PFS) and in complementary and alternative medicines (CAM) including herbal medicines. The increase in consumption in functional foods observed worldwide requires a strict analysis of the scientific validity of their benefits and risk-benefit ratio associated with their intake. Some instances of acute toxicity have been reported associated with the use of herbal medicines and PFS, in particular because quality control is poor, and this poses a risk especially in internet marketed products. In particular, chronic exposure to low levels of these constituents may pose a hazard. However, given the variability in dietary habits, plant properties, plant misidentification or interaction with pharmaceutical drugs or nutrients, the assessment of risk due to the intake of alkenylbenzenes is difficult. We herein review the regulatory status of the most common alkenylbenzenes and their genotoxic activity and potential carcinogenic activity.

Fluorimetric Methods for Analysis of Permeability, Drug Transport Kinetics, and Inhibition of the ABCB1 Membrane Transporter.

The cell membrane P-glycoprotein (P-gp; MDR1, ABCB1) is an energy-dependent efflux pump that belongs to the ATP-binding cassette (ABC) family of transporters, and has been associated with drug resistance in eukaryotic cells. Multidrug resistance (MDR) is related to an increased expression and function of the ABCB1 (P-gp) efflux pump that often causes chemotherapeutic failure in cancer. Modulators of this efflux pump, such as the calcium channel blocker verapamil (VP) and cyclosporine A (CypA), can reverse the MDR phenotype but in vivo studies have revealed disappointing results due to adverse side effects. Currently available methods are unable to visualize and assess in a real-time basis the effectiveness of ABCB1 inhibitors on the uptake and efflux of ABCB1 substrates. However, predicting and testing ABCB1 modulation activity using living cells during drug development are crucial. The use of ABCB1-transfected mouse T-lymphoma cell line to study the uptake/efflux of fluorescent probes like ethidium bromide (EB), rhodamine 123 (Rh-123), and carbocyanine dye DiOC2, in the presence and absence of potential inhibitors, is currently used in our laboratories to evaluate the ability of a drug to inhibit ABCB1-mediated drug accumulation and efflux. Here we describe and compare three in vitro methods, which evaluate the permeability, transport kinetics of fluorescent substrates, and inhibition of the ABCB1 efflux pump by drugs of chemical synthesis or extracted from natural sources, using model cancer cell lines overexpressing this transporter, namely (1) real-time fluorimetry that assesses the accumulation of ethidium bromide, (2) flow cytometry, and (3) fluorescent microscopy using rhodamine 123 and DiOC2.

Myristicin from nutmeg induces apoptosis via the mitochondrial pathway and down regulates genes of the DNA damage response pathways in human leukaemia K562 cells.

Myristicin, an allylbenzene, is a major active component of various spices, such as nutmeg and cinnamon, plants from the Umbelliferae family or in some essential oils, such as oils of clove or marjoram. Human exposure to myristicin is low but widespread due to consumption of these spices and essential oils, added to food (e.g. cola drinks) or in traditional medicine. Occasionally high dose exposure occurs, leading to various clinical symptoms, however the molecular mechanisms underlying them are unknown. Our previous studies revealed that myristicin is not genotoxic and yet presented apoptotic activity. Therefore, in this work we assessed the apoptotic mechanisms induced by myristicin in human leukaemia cells. In order to gain further insight on the potential of myristicin to modulate gene expression we also analysed alterations in expression of 84 genes associated with the DNA damage response pathway. The results obtained show that myristicin can induce apoptosis as characterised by alterations in the mitochondrial membrane potential, cytochrome c release, caspase-3 activation, PARP-cleavage and DNA fragmentation. The gene expression profile revealed an overall down regulation of DNA damage response genes after exposure to myristicin, with significant under-expression of genes associated with nucleotide excision repair (ERCC1), double strand break repair (RAD50, RAD51) and DNA damage signalling (ATM) and stress response (GADD45A, GADD45G). On the whole, we demonstrate that myristicin can alter mitochondrial membrane function, induce apoptosis and modulate gene expression in human leukaemia K562 cells. This study provides further detail on the molecular mechanisms underlying the biological activity of myristicin.

Induction of sister chromatid exchange by acrylamide and glycidamide in human lymphocytes: role of polymorphisms in detoxification and DNA-repair genes in the genotoxicity of glycidamide.

Acrylamide (AA) is a probable human carcinogen generated in carbohydrate-rich foodstuffs upon heating. Glycidamide (GA), formed via epoxidation, presumably mediated by cytochrome P450 2E1, is considered to be the active metabolite that plays a central role in the genotoxicity of AA. The aim of this work was to evaluate the cytogenetic damage induced by AA and GA in cultured human lymphocytes by use of the sister chromatid exchange (SCE) assay. Furthermore, this report addresses the role of individual genetic polymorphisms in key genes involved in detoxification and DNA-repair pathways (BER, NER, HRR and NHEJ) on the induction of SCE by GA. While AA induced the number of SCE/metaphase only slightly, especially for the highest concentration tested (2000µM), GA markedly induced SCEs in a concentration-dependent manner up to concentrations of 750µM, leading to an increase in SCEs of up to about 10-fold compared with controls. By combining DNA damage in GA-treated lymphocytes and data on polymorphisms, associations between the induction of SCEs with GSTP1 (Ile105Val) and GSTA2 (Glu210Ala) genotypes are suggested.

Genetic polymorphisms in detoxification and DNA repair genes and susceptibility to glycidamide-induced DNA damage.

Acrylamide (AA) is a probable human carcinogen formed in carbohydrate-rich foodstuffs upon heating. Glycidamide (GA), the AA metabolite formed by epoxidation, is considered the ultimate genotoxic agent. In this study, the in vitro genotoxic potential of AA and GA in human whole blood leukocytes was compared using the alkaline comet assay. Although AA did not induce significant DNA damage in the concentrations tested (up to 1000 µM), GA markedly increased the percentage of tail DNA at concentrations ≥250 µM. Further, this study addressed the role of genetic polymorphisms in key genes involved in metabolism and DNA repair pathways (BER, NER, HRR, and NHEJ) on GA-induced genotoxicity assessed by the alkaline comet assay. The results obtained suggested associations between DNA damage and polymorphisms of BER (MUTYH Gln335His and XRCC1 Gln399Arg) and NER (XPC Ala499Val) genes, either alone or in combination.

Estragole: a weak direct-acting food-borne genotoxin and potential carcinogen.

We evaluated the genotoxicity of the food-flavouring agent estragole in V79 cells using the sister chromatid exchange (SCE) assay and the alkaline comet assay. Unexpectedly, we observed an increase in SCE without an exogenous biotransformation system (S9) and a decrease in its presence. Positive results were also observed in the alkaline comet assay without S9, indicating DNA strand breakage. To ascertain repair of damage, we performed the comet assay in V79 cells after two hours of recovery, and observed a reduction of the genotoxic response. Estragole did not produce strand breaks in plasmid DNA in vitro. We then evaluated the formation of DNA adducts in V79 cells by use of the (32)P-postlabelling assay and detected a dose-dependent formation of DNA adducts, which may be responsible for its genotoxicity. We then assayed estragole in the comet assay with two CHO cell lines, a parental AA8 cell line, and an XRCC1-deficient cell line, EM9. Results confirmed the genotoxicity of estragole without biotransformation in both cell lines, although the genotoxicity in EM9 cells compared with that in AA8 cells was not significantly different, suggesting that the XRCC1 protein is not involved in the repair of estragole-induced lesions. Estragole induces apoptosis, but only with high doses (2000µM), and after long treatment periods (24h). Overall, our results suggest that estragole, besides being metabolized to genotoxic metabolites, is a weak direct-acting genotoxin that forms DNA adducts.

DNA damage response in imatinib resistant chronic myeloid leukemia K562 cells.

Resistance to imatinib in patients with chronic myeloid leukemia can lead to advanced disease and blast crisis. Conventional chemotherapy with DNA damaging agents is then used, alone or in combination with other tyrosine kinase inhibitors (TKIs). Our aim was to assess whether imatinib resistant K562 cells were also resistant to DNA damaging agents. After treatment with H(2)O(2) and doxorubicin, but not camptothecin, cell survival was higher in imatinib resistant cells compared to parental cells. DNA damage, measured by comet and γ-H2AX assays, was lower in imatinib resistant cells. mRNA expression levels of 50 genes of the DNA damage response pathway showed increased expression of the base excision repair (BER) genes MBD4 and NTHL1. Knockdown of MBD4 and NTHL1 expression in resistant cells using siRNA decreased cell survival after treatment with H(2)O(2) and doxorubicin. Our results indicate that imatinib resistant cells display cross-resistance to oxidative agents, partly through up-regulation of BER genes. Expression of these genes in imatinib resistant patients was not significantly different compared to sensitive patients. However, the strategy followed in this study could help identify chemotherapeutic agents that are more effective as alternative agents in cases of resistance to TKIs.

Preparation of organometallic ruthenium-arene-diaminotriazine complexes as binding agents to DNA.

The reactions of two diaminotriazine ligands 2,4-diamino-6-(2-pyridyl)-1,3,5-triazine (2-pydaT) and 6-phenyl-2,4-diamino-1,3,5-triazine (PhdaT) with ruthenium-arene precursors led to a new family of ruthenium(II) compounds that were spectroscopically characterized. Four of the complexes were cationic, with the general formula [(η(6)-arene)Ru(κ(2)-N,N-2-pydaT)Cl]X (X=BF(4), TsO; arene=p-cymene: 1·BF(4), 1·TsO; arene=benzene: 2·BF(4), 2·TsO). The neutral cyclometalated complex [(η(6)-p-cymene)Ru(κ(2)-C,N-PhdaT*)Cl] (3) was also isolated. The structures of complexes 2·BF(4) and 3·H(2)O were determined by X-ray diffraction. Complex 1·BF(4) underwent a partial reversible-aquation process in water. UV/Vis and NMR spectroscopic measurements showed that the reaction was hindered by the addition of NaCl and was pH-controlled in acidic solution. At pH 7.0 (sodium cacodylate) Ru-Cl complex 1·BF(4) was the only species present in solution, even at low ionic strength. However, in alkaline medium (KOH), complex 1·BF(4) underwent basic hydrolysis to afford a Ru-OH complex (5). Fluorimetric studies revealed that the interaction of complex 1·BF(4) with DNA was not straightforward; instead, its main features were closely linked to ionic strength and to the [DNA]/complex ratio. The bifunctional complex 1·BF(4) was capable of interacting concurrently through both its p-cymene and 2-pydaT groups. Cytotoxicity and genotoxicity studies showed that, contrary to the expected behavior, the complex species was biologically inactive; the formation of a Ru-OH complex could be responsible for such behavior.

Genomics and cancer drug resistance.

Cellular drug resistance is a major obstacle in cancer therapy. Mechanisms of resistance can be associated with altered expression of ATP-binding cassette (ABC) family of transporters on cell membrane transporters, the most common cause of multi-drug resistance (MDR), but can also include alterations of DNA repair pathways, resistance to apoptosis and target modifications. Anti-cancer treatments may be divided into different categories based on their purpose and action: chemotherapeutic agents damage and kill dividing cells; hormonal treatments prevent cancer cells from receiving signals essential for their growth; targeted drugs are a relatively new cancer treatment that targets specific proteins and pathways that are limited primarily to cancer cells or that are much more prevalent in cancer cells; and antibodies function by either depriving the cancer cells of necessary signals or by causing their direct death. In any case, resistance to anticancer therapies leads to poor prognosis of patients. Thus, identification of novel molecular targets is critical in development of new, efficient and specific cancer drugs. The aim of this review is to describe the impact of genomics in studying some of the most critical pathways involved in cancer drug resistance and in improving drug development. We shall also focus on the emerging role of microRNAs, as key gene expression regulators, in drug resistance. Finally, we shall address the specific mechanisms involved in resistance to tyrosine kinase inhibitors in chronic myeloid leukemia.

ACMA (9-amino-6-chloro-2-methoxy acridine) forms three complexes in the presence of DNA.

The interaction of ACMA (9-amino-6-chloro-2-methoxy acridine) (D) with DNA (P) has been studied by absorbance, fluorescence, circular dichroism, spectrophotometry, viscometry and unwinding electrophoresis. A T-jump kinetic study has also been undertaken. The experimental data show that, totally unlike other drugs, ACMA is able to form with DNA three complexes (PD(I), PD(II), PD(III)) that differ from each other by the characteristics and extent of the binding process. The main features of PD(I) fulfil the classical intercalation pattern and the formation/dissociation kinetics have been elucidated by T-jump techniques. PD(II) and PD(III) are also intercalated species but, in addition to the dye units lodged between base pairs, they also bear dye molecules externally bound, more in PD(III) relative to PD(II). A reaction mechanism is put forward here. Comparison between absorbance, fluorescence and kinetic experiments has enabled us to determine the binding constants of the three complexes, namely (6.5 ± 1.1) × 10(4) M(-1) (PD(I)), (5.5 ± 1.5) × 10(4) M(-1) (PD(II)) and (5.7 ± 0.03) × 10(4) M(-1) (PD(III)). The Comet assay reveals that the ACMA binding to DNA brings about genotoxic properties. The mutagenic potential studied by the Ames test reveals that ACMA can produce frameshift and transversion/transition mutations. ACMA also is able to produce base-pair substitution in the presence of S9 mix. Moreover, the MTT assays have revealed cytotoxicity. The biological effects observed have been rationalized in light of these features.

Genotoxic and apoptotic activities of the food flavourings myristicin and eugenol in AA8 and XRCC1 deficient EM9 cells.

Some food flavourings, such as safrole and methyleugenol, are known for their genotoxic and hepatocarcinogenic properties whereas for others, such as myristicin, there is less data. Myristicin and eugenol are both alkenylbenzenes, and we compared their direct genotoxicity in repair proficient (AA8) and repair deficient XRCC(-) (EM9) Chinese hamster ovary cells. Cell viability was assessed by the MTT assay. The comet assay was used to evaluate DNA breaks, and the γ-H2AX assay to evaluate induction of double strand breaks. We assessed apoptosis by measuring caspases activation, and the TUNEL assay. Reduction of cell viability was similar in AA8 and EM9 cells, for both compounds. After 1h eugenol produced DNA strand breaks in the comet assay and induced double strand breaks in the γ-H2AX assay in AA8 cells, while myristicin was not genotoxic in both the comet and the γ-H2AX assays. Both flavourings were negative in EM9 cells. After 24h eugenol and myristicin induced DNA fragmentation detected by TUNEL in both cell lines, but only myristicin activated caspases. Myristicin was more apoptotic than eugenol, in both cell lines. The XRCC1 protein does not influence the apoptotic activity of either compound.

Alkylating potential of oxetanes.

Small, highly strained heterocycles are archetypical alkylating agents (oxiranes, beta-lactones, aziridinium, and thiirinium ions). Oxetanes, which are tetragonal ethers, are higher homologues of oxiranes and reduced counterparts of beta-lactones, and would therefore be expected to be active alkylating agents. Oxetanes are widely used in the manufacture of polymers, especially in organic light-emitting diodes (OLEDs), and are present, as a substructure, in compounds such as the widely used antimitotic taxol. Whereas the results of animal tests suggest that trimethylene oxide (TMO), the parent compound, and beta,beta-dimethyloxetane (DMOX) are active carcinogens at the site of injection, no studies have explored the alkylating ability and genotoxicity of oxetanes. This work addresses the issue using a mixed methodology: a kinetic study of the alkylation reaction of 4-(p-nitrobenzyl)pyridine (NBP), a trap for alkylating agents with nucleophilicity similar to that of DNA bases, by three oxetanes (TMO, DMOX, and methyloxetanemethanol), and a mutagenicity, genotoxicity, and cell viability study (Salmonella microsome test, BTC E. coli test, alkaline comet assay, and MTT assay). The results suggest either that oxetanes lack genotoxic capacity or that their mode of action is very different from that of epoxides and beta-lactones.

8,15-epoxylabdane and norlabdane diterpenoids from Eragrostis viscosa.

Four labdanes with a 8alpha,15-epoxy ring (8alpha,15-epoxylabdan-16beta-oic acid; 8alpha,15-epoxy-16-norlabdan-13-one; 8alpha,15-epoxy-16-norlabdane; and 16-acetoxy-8alpha,15-epoxylabdane) and the known compound ambreinolide were isolated from the hexane extract of the aerial parts of the grass Eragrostis viscosa. The structures of all compounds were established based on spectroscopic data and the X-ray analysis of 8alpha,15-epoxy-16-norlabdan-13-one. The hexane extract presented moderate activity against the snail Biomphalaria glabrata. 8alpha,15-Epoxylabdan-16beta-oic acid showed no mutagenic activity for doses up to 1000 microg/plate and no significant clastogenic activity for doses up to 100 microg/ml.

Biological assays and noncovalent interactions of pyridine-2-carbaldehyde thiosemicarbazonecopper(II) drugs with [poly(dA-dT)](2), [poly(dG-dC)] (2), and calf thymus DNA.

The interaction of the Cu(II) drugs CuL(NO(3)) and CuL'(NO(3)) (HL is pyridine-2-carbaldehyde thiosemicarbazone and HL' is pyridine-2-carbaldehyde 4N-methylthiosemicarbazone, in water named [CuL](+) and [CuL'](+)) with [poly(dA-dT)](2), [poly(dG-dC)](2), and calf thymus (CT) DNA has been probed in aqueous solution at pH 6.0, I = 0.1 M, and T = 25 degrees C by absorbance, fluorescence, circular dichroism, and viscosity measurements. The results reveal that these drugs act as groove binders with [poly(dA-dT)](2), with a site size n = 6-7, whereas they act as external binders with [poly(dG-dC)](2) and/or CT-DNA, thus establishing overall electrostatic interaction with n = 1. The binding constants with [CuL'](+) were slightly larger than with [CuL](+). The title compounds display some cleavage activity in the presence of thiols, bringing about the rupture of the DNA strands by the reactive oxygen species formed by reoxidation of Cu(I) to Cu(II); this feature was not observed in the absence of thiols. Mutagenic assays performed both in the presence and in the absence of S9 mix, probed by the Ames test on TA 98, TA 100, and TA 102, were negative. Weak genotoxic activity was detected for [CuL](+) and [CuL'](+), with a significative dose-response effect for [CuL'](+), which was shown to be more cytotoxic in the Ames test and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell proliferation assays. Methylation of the terminal NH(2) group enhances the antiproliferative activity of the pyridine-2-carbaldehyde thiosemicarbazones.