Human blood markers of cholinergic neurotoxicity and neuropathy: A useful guide for laboratory applications.

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are useful markers to assess the effects of exposure to anticholinesterase insecticides (Anti-AChE). In addition, lymphocyte neuropathy target esterase (LNTE) has been used as biomarker of neuropathic organophosphate compounds (OPs). Thus, this study evaluates the main types of circulating biomarkers related to the cholinergic system and to the neuropathy induced by OPs in standardized human samples. To achieve this objective, total protein of human plasma, erythrocytes and lymphocytes were first standardized, and then AChE, BChE and LNTE activities in human blood were evaluated in the presence of inhibitors. The acceptance criteria of the regulatory agency were respected with coefficients of regression of curves of 0.9972 for cholinesterase and 0.9956 for LNTE analyses. The wavelength established to perform cholinesterase assay was 450 nm and the time of incubation of the enzymes with inhibitors was 30 min. Differences were observed among the IC50 values regarding the in vitro inhibition of AChE, BChE and LNTE in the presence of OPs. In conclusion, the procedures demonstrated by the present work were simple, fast, inexpensive, sensitive, easy to be replicated and suitable to make conclusions about the neurotoxicity induced by Anti-AChE and neuropathic OPs.

Occupational Evaluation of Federal Highway Police Officers Exposed to Cholinesterase Inhibiting Insecticides.

OBJECTIVE: The aim of this study is to evaluate the effects of occupational exposure of federal highway police (PRF) officers to cholinesterase-inhibiting insecticides. METHODS: We evaluate erythrocyte and plasma cholinesterase activity, pulse rate, systolic and diastolic pressure, and clinical evaluation through the Mini-Mental State Examination and the Diagnostic and Statistical Manual of Mental Disorders , Fifth Edition . RESULTS: All PRF officers evaluated were male, between 22 and 49 years of age. Pulse rate of the subjects were statistically superior in the post-exposure moment when compared with pre-exposure moment. Inhibition of acetylcholinesterase and butyrylcholinesterase was significant in the post-exposure moment when compared with pre-exposure moment. CONCLUSIONS: The results of the present work show that there are significant biochemical changes, which can be the beginning of serious deleterious effects to the health of PRF officers.

Plasma and erythrocyte magnesium levels: from validation of the method to analysis in volunteers diagnosed to migraine

Deficiency of serum magnesium is associated with the incidence of migraine attacks. The present study aimed to evaluate plasma and erythrocyte magnesium levels in a group of patients diagnosed with migraine. Human donors were selected from basic health units (migraine, n = 25) and from a collection and transfusion unit (control, n = 25), both located in the city of Sinop, Brazil. Plasma and erythrocyte magnesium were assessed using flame atomic absorption. Plasma magnesium concentration was significantly lower in the migraine group (0.172 ± 0.018) compared to the control group (0.197 ± 0.020 mg/L), and erythrocyte magnesium concentration was also lower in the migraine group (0.393 ± 0.053 mg/L) compared to the control group (0.432 ± 0.056 mg/L). The method for analysis of magnesium in human plasma and erythrocytes by flame atomic absorption was shown to be in accordance with validation guidelines. This study shows that plasma and erythrocyte magnesium levels were significantly lower in volunteers diagnosed with migraine compared to healthy volunteers. Furthermore, erythrocyte magnesium proved to be a better marker than plasma magnesium for patients with migraine.

The Antidiabetic Drug Liraglutide Minimizes the Non-Cholinergic Neurotoxicity of the Pesticide Mipafox in SH-SY5Y Cells.

Organophosphorus (OPs) compounds have been widely used in agriculture, industry, and household, and the neurotoxicity induced by them is still a cause of concern. The main toxic mechanism of OPs is the inhibition of acetylcholinesterase (AChE); however, the delayed neuropathy induced by OPs (OPIDN) is mediated by other mechanisms such as the irreversible inhibition of 70% of NTE activity (neuropathy target esterase) that leads to axonal degeneration. Liraglutide is a long-lasting GLP-1 analog clinically used as antidiabetic. Its neurotrophic and neuroprotective effects have been demonstrated in vitro and in experimental models of neurodegenerative diseases. As in OPIDN, axonal degeneration also plays a role in neurodegenerative diseases. Therefore, this study investigated the protective potential of liraglutide against the neurotoxicity of OPs by using mipafox as a neuropathic agent (at a concentration able to inhibit and age 70% of NTE activity) and a neuronal model with SH-SY5Y neuroblastoma cells, which express both esterases. Liraglutide protected cells against the neurotoxicity of mipafox by increasing neuritogenesis, the uptake of glucose, the levels of cytoskeleton proteins, and synaptic-plasticity modulators, besides decreasing the pro-inflammatory cytokine interleukin 1ß and caspase-3 activity. This is the first study to suggest that liraglutide might induce beneficial effects against the delayed, non-cholinergic neurotoxicity of OPs.

L- and T-type calcium channel blockers protect against the inhibitory effects of mipafox on neurite outgrowth and plasticity-related proteins in SH-SY5Y cells.

Some organophosphorus compounds (OP), including the pesticide mipafox, produce late onset distal axonal degeneration, known as organophosphorus-induced delayed neuropathy (OPIDN). The underlying mechanism involves irreversible inhibition of neuropathy target esterase (NTE) activity, elevated intracellular calcium levels, increased activity of calcium-activated proteases and impaired neuritogenesis. Voltage-gated calcium channels (VGCC) appear to play a role in several neurologic disorders, including OPIDN. Therefore, this study aimed to examine and compare the neuroprotective effects of T-type (amiloride) and L-type (nimodipine) VGCC blockers induced by the inhibitory actions of mipafox on neurite outgrowth and axonal proteins of retinoic-acid-stimulated SH-SY5Y human neuroblastoma cells, a neuronal model widely employed to determine the neurotoxicity attributed to OP. Both nimodipine and amiloride significantly blocked augmentation of intracellular calcium levels and activity of calpains, as well as decreased neurite length, number of differentiated cells, and lowered concentrations of growth-associated protein 43 (GAP-43) and synapsin induced by mipafox. Only nimodipine inhibited reduction of synaptophysin levels produced by mipafox. These findings demonstrate a role for calcium and VGCC in the impairment of neuronal plasticity mediated by mipafox. Data also demonstrated the neuroprotective potential of T-type and L-type VGCC blockers to inhibit OP-mediated actions, which may be beneficial to counteract cases of pesticide poisoning.

High concentration of trichlorfon (1mM) disrupts axonal cytoskeleton and decreases the expression of plasticity-related proteins in SH-SY5Y cells.

Some organophosphorus compounds (OPs) induce a neurodegenerative disorder known as organophosphate-induced delayed neuropathy (OPIDN), which is related to irreversible inhibition of neuropathy target esterase (NTE) and impairment of neurite outgrowth. The present study addresses the effects of trichlorfon, mipafox (neuropathic model) and paraoxon (non-neuropathic model) on neurite outgrowth and neuroplasticity-related proteins in retinoic-acid-stimulated SH-SY5Y cells, a cellular model widely used to study the neurotoxicity of OPs. Mipafox (20µM) decreased cellular differentiation and the expression of neurofilament 200 (NF-200), growth associated- (GAP-43) and synaptic proteins (synapsin I and synaptophysin); whereas paraoxon (300µM) induced no effect on cellular differentiation, but significant decrease of NF-200, GAP-43, synapsin I and synaptophysin as compared to controls. However, the effects of paraoxon on these proteins were significantly lower than the effects of mipafox. In conclusion, axonal cytoskeletal proteins, as well as axonal plasticity-related proteins are more effectively affected by neuropathic (mipafox) than by non-neuropathic (paraoxon) OPs, suggesting that they might play a role in the mechanism of OPIDN. At high concentration (1mM), trichlorfon induced effects similar to those of the neuropathic OP, mipafox (20µM), but also caused high inhibition of AChE. Therefore, these effects are unlikely to occur in humans at non-lethal doses of trichlorfon.

Farmácia magistral: sua importância e seu perfil de qualidade / Magistral pharmacies: importance and quality profile / Farmacia magistral: su importancia y su perfil de calidad

O setor magistral representa um importante segmento do mercado brasileiro de medicamentos. Entretanto, a qualidade dos produtos fornecidos pelos estabelecimentos é frequentemente discutida e a Agência Nacional de Vigilância Sanitária (ANVISA) tem demonstrado uma preocupação com os produtos magistrais, pela promoção de consultas públicas abordando o assunto e pelo aumento do rigor nas legislações específicas. Assim sendo, as farmácias magistrais desempenham um importante papel no contexto da Política Nacional de Medicamentos, que objetiva garantir a promoção do uso racional e o acesso da população a medicamentos essenciais. Tendo em vista a importância da abordagem da qualidade dos produtos manipulados, este artigo apresenta relevantes informações sobre o perfil de qualidade do serviço de saúde prestado por esse setor, mediante a revisão da legislação e de trabalhos científicos que englobam o assunto.

The magistral sector represents a significant segment in the Brazilian pharmaceutical market. However, the quality of magistral formulations is often questioned and the National Agency of Sanitary Vigilance (ANVISA) has demonstrated a concern regarding these products, which has been verified in many public consultations approaching this subject and in new legislation aiming to improve public health. Thus, magistral pharmacies play an important role in the context of the National Medicine Politics, which aim to assure promotion of rational use and population access to essential medicines. Due to the paramount importance of the magistral formulation quality, this article presents information about the basic importance and the quality profile of these products, through the revision of the legislation and of scientific works that approach the subject.

El sector magistral representa un importante segmento del mercado brasileño de medicinas. Sin embargo, la calidad de los productos ofrecidos por estos establecimientos es frecuentemente discutida y la Agencia Nacional de Vigilância Sanitária (ANVISA), ha demostrado preocupación con los productos magistrales, por la promoción de consultas públicas abordando el asunto y por el aumento del rigor en las legislaciones específicas. Siendo así, las farmacias magistrales desempeñan importante rol en el contexto de la política Nacional de Medicinas, que busca garantizar la promoción del uso racional y el acceso de la población a las medicinas esenciales. Considerando la importancia del abordaje sobre la calidad de los productos manipulados, este artículo presenta relevantes informaciones sobre el perfil de la calidad del servicio de la salud ofrecido por ese sector, a través de la revisión de la legislación y de trabajos científicos que engloban el asunto.