Aspectos gerais e diagnóstico clinicolaboratorial da intoxicação por paraquat

Schmitt, Gabriela Cristina; Paniz, Clóvis; Grotto, Denise; Valentini, Juliana; Schott, Karen Lílian; Pomblum, Valdeci Juarez; Garcia, Solange Cristina

doi:10.1590/s1676-24442006000400003

Cited by 19 publications

(14 citation statements)

References 58 publications

(100 reference statements)

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“…In this scenario, paraquat (PQ) intoxication is a serious public health problem because of its high mortality index, mainly due to the lack of an effective antidote or treatment, which is associated with its wide use even in countries where its application is forbidden. [36][37][38][39][40] One of the main mechanism for PQ toxicity is associated with the redox cycle of PQ, where formation of superoxide anion, singlet oxygen, and other reactive oxygen species (ROS) occurs. Higher levels of these ROS lead to many deleterious effects, including lipid peroxidation in cells and tissue, protein damage, and depletion of NADPH.…”

Section: Introductionmentioning

confidence: 99%

“…45 In this line, some studies demonstrated that melatonin could be a good antioxidant in cases of PQ-poisoning. 38,39,43,44 International Journal of Nanomedicine 2015:10 submit your manuscript | www.dovepress.com…”

Section: Introductionmentioning

confidence: 99%

“…39,42 There are no accepted guidelines for the treatment of patients intoxicated with PQ, and the treatment normally is based on supportive care and combinations of different drugs, such as immune modulators, antioxidant therapy, hemoperfusion, and hemodialysis. 62,63 Nevertheless, the mortality remains approximately 50% in hospitals that routinely practice such treatments.…”

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confidence: 99%

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Caenorhabditis elegans as an alternative in vivo model to determine oral uptake, nanotoxicity, and efficacy of melatonin-loaded lipid-core nanocapsules on paraquat damage

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Brucker

et al. 2015

IJN

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Caenorhabditis elegans is an alternative in vivo model that is being successfully used to assess the pharmacological and toxic effects of drugs. The exponential growth of nanotechnology requires the use of alternative in vivo models to assess the toxic effects of theses nanomaterials. The use of polymeric nanocapsules has shown promising results for drug delivery. Moreover, these formulations have not been used in cases of intoxication, such as in treatment of paraquat (PQ) poisoning. Thus, the use of drugs with properties improved by nanotechnology is a promising approach to overcome the toxic effects of PQ. This research aimed to evaluate the absorption of rhodamine B-labeled melatonin (Mel)-loaded lipid-core nanocapsules (LNC) by C. elegans , the application of this model in nanotoxicology, and the protection of Mel-LNC against PQ damage. The formulations were prepared by self-assembly and characterized by particle sizing, zeta potential, drug content, and encapsulation efficiency. The results demonstrated that the formulations had narrow size distributions. Rhodamine B-labeled Mel-LNC were orally absorbed and distributed in the worms. The toxicity assessment of LNC showed a lethal dose 50% near the highest dose tested, indicating low toxicity of the nanocapsules. Moreover, pretreatment with Mel-LNC significantly increased the survival rate, reduced the reactive oxygen species, and maintained the development in C. elegans exposed to PQ compared to those worms that were either untreated or pretreated with free Mel. These results demonstrated for the first time the uptake and distribution of Mel-LNC by a nematode, and indicate that while LNC is not toxic, Mel-LNC prevents the effects of PQ poisoning. Thus, C. elegans may be an interesting alternative model to test the nanocapsules toxicity and efficacy.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

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Caenorhabditis elegans as an alternative in vivo model to determine oral uptake, nanotoxicity, and efficacy of melatonin-loaded lipid-core nanocapsules on paraquat damage

Charão

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Brucker

et al. 2015

IJN

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“…Caso a mucosa do trato gastrintestinal fique comprometida, pelo poder de corrosão do herbicida, o percentual absorvido é suscetível de ser mais elevado, pela absorção por difusão passiva (Dinis-Oliveira et al 2008). Por inalação, o PQ acumula-se, principalmente nos pulmões, onde pode alcançar concentrações letais em menos de 10 horas, além de rins, músculos, coração, fígado (Xarau & Laita 2000) cérebro e adrenais (Schimitt et al 2006, Almeida et al 2007.…”

Section: Propriedades Biológicas E Ricos Toxicológicos Do Paraquatunclassified

“…A formação de EROs como o radical superóxido (O 2 -), o peróxido de hidrogênio (H 2 O 2 ) e o radical hidroxila (OH), além de instáveis, reagem rapidamente com ácidos graxos, provocando lesões nas membranas, proteínas e DNA das células (Schimitt et al 2006, Dinis-Oliveira et al 2008, Martins 2013.…”

Section: Propriedades Biológicas E Ricos Toxicológicos Do Paraquatunclassified

Efeito protetor da melatonina sobre intoxicações por herbicidas

et al. 2016

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RESUMO.-O uso inadequado de herbicidas pode resultar em intoxicações agudas e, às vezes, crônicas por exposição em longo prazo a baixos níveis desses agentes tóxicos, podendo o herbicida atuar também como agentes teratogêni-cos, mutagênicos, cancerígenos e desreguladores endócri-nos, com o aparecimento de doenças neurodegenerativas e distúrbios reprodutivos. Estudos têm revelado que a melatonina tem propriedades antioxidantes, anti-inflamatórias e imunomoduladoras e atua na reprodução. Essa indolamina está entre os agentes que têm se mostrado benéfico em intoxicações por herbicidas, porém não há relatos do uso de melatonina contra intoxicações por Glifosato-Roundup ® , muito menos em associação com o Paraquat. Dessa forma, o maior interesse no tratamento das intoxicações por herbicidas, tem-se concentrado em medidas que impeçam ou minimizem as lesões celulares provocadas nos diversos sistemas biológicos. Assim, a melatonina, como antioxidante conhecido, pode ser mais uma alternativa contra as intoxicações por herbicidas associados e/ou individuais. TERMOS DE INDEXAÇÃO: Herbicidas, melatonina, intoxicação por herbicidas. INTRODUÇÃOA utilização de herbicidas ocorre no Brasil desde a déca-da de 1950. Naquela década, a agricultura volta-se para o mercado interno tentando viabilizar o aumento de safras e levando, consequentemente, os agricultores a utilizarem produtos químicos para controlar pragas, fitopatologias e plantas daninhas (Carraro 1997, IBGE 2010, ANVISA 2014. Além disso, o Brasil possui um destaque negativo no cenário mundial como o maior consumidor de agrotóxicos, sendo responsável, na América Latina, por 86% do emprego desses produtos nas lavouras agrícolas, enquanto herbicidas e inseticidas são responsáveis por 60% dos produtos comercializados no país (Pires et al. 2005, ANVISA 2014 A preocupação crescente de especialistas e ambientalistas em relação ao uso de herbicidas é pela grande quantidade utilizadas nas práticas agrícolas que resultam em impactos ambientais pouco conhecidos, além dos inúme-ros problemas relacionados à saúde pública (Mascarenha & Pessoa 2013

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Development of a sequential injection–square wave voltammetry method for determination of paraquat in water samples employing the hanging mercury drop electrode

2010

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This work describes the development and optimization of a sequential injection method to automate the determination of paraquat by square-wave voltammetry employing a hanging mercury drop electrode. Automation by sequential injection enhanced the sampling throughput, improving the sensitivity and precision of the measurements as a consequence of the highly reproducible and efficient conditions of mass transport of the analyte toward the electrode surface. For instance, 212 analyses can be made per hour if the sample/standard solution is prepared off-line and the sequential injection system is used just to inject the solution towards the flow cell. In-line sample conditioning reduces the sampling frequency to 44 h(-1). Experiments were performed in 0.10 M NaCl, which was the carrier solution, using a frequency of 200 Hz, a pulse height of 25 mV, a potential step of 2 mV, and a flow rate of 100 µL s(-1). For a concentration range between 0.010 and 0.25 mg L(-1), the current (i(p), µA) read at the potential corresponding to the peak maximum fitted the following linear equation with the paraquat concentration (mg L(-1)): i(p) = (-20.5 ± 0.3)C (paraquat) - (0.02 ± 0.03). The limits of detection and quantification were 2.0 and 7.0 µg L(-1), respectively. The accuracy of the method was evaluated by recovery studies using spiked water samples that were also analyzed by molecular absorption spectrophotometry after reduction of paraquat with sodium dithionite in an alkaline medium. No evidence of statistically significant differences between the two methods was observed at the 95% confidence level.

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Aspectos gerais e diagnóstico clinicolaboratorial da intoxicação por paraquat

Cited by 19 publications

References 58 publications

Caenorhabditis elegans as an alternative in vivo model to determine oral uptake, nanotoxicity, and efficacy of melatonin-loaded lipid-core nanocapsules on paraquat damage

Caenorhabditis elegans as an alternative in vivo model to determine oral uptake, nanotoxicity, and efficacy of melatonin-loaded lipid-core nanocapsules on paraquat damage

Efeito protetor da melatonina sobre intoxicações por herbicidas

Development of a sequential injection–square wave voltammetry method for determination of paraquat in water samples employing the hanging mercury drop electrode

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