Alternative methods in toxicity testing: the current approach

Alternative methods are being developed to reduce, refine, and replace (3Rs) animals used in experiments, aimed at protecting animal welfare. The present study reports alternative tests which are based on the principles of the 3Rs and the efforts made to validate these tests. In Europe, several methodologies have already been implemented, such as tests of irritability, cell viability, and phototoxicity as well as in vitro mathematical models together with the use of in silico tools. This is a complex process that spans from development to regulatory approval and subsequent adoption by various official entities. Within this regulatory framework is REACH, the European Community Regulation for chemicals and their safe use. In Brazil, the BraCVAM (Brazilian Center for the Validation of Alternative Methods) was recently established to validate alternative methods and stimulate incorporation of new methodologies. A new vision of toxicology is emerging for the 21st century (Tox-21), and the subsequent changes are shaping a new paradigm.Métodos alternativos estão sendo desenvolvidos para a redução, o refinamento e a substituição (3R) do número de animais utilizados em experimentos, visando ao seu bem-estar. Esses testes alternativos baseiam-se no princípio dos 3R e esforços têm sido empregados para que sejam validados. Na Europa, diversas metodologias já foram implantadas tais como: testes de irritabilidade, testes de viabilidade celular, testes de fototoxicidade e modelos matemáticos in vitro, além do uso de ferramentas in silico. Esse é um processo complexo, que abrange desde o seu desenvolvimento até a aceitação regulatória e posterior adoção por diversas organizações oficiais. No contexto regulatório está o REACH, o Regulamento da Comunidade Européia, para produtos químicos e sua utilização segura. No Brasil, o BraCVAM (Centro Brasileiro de Validação de Métodos Alternativos) foi recentemente estabelecido para validação de métodos alternativos e estímulo à incorporação de novas metodologias. Uma nova visão de toxicologia vem surgindo para o século XXI (Tox-21) e as mudanças ocasionadas promoverão um novo paradigma

Avaliação da atividade antiulcerogênica da Maytenus truncata Reiss (Celastraceae).

Maytenus truncata Reiss (Celastraceae) e uma planta nativa da Bahia (Brasil), sendo conhecida como “espinheira-santa”. E usada popularmente na forma de decoto das folhas (chas) como antiulcerogênico, similarmente a Maytenus ilicifolia, a verdadeira “espinheira-santa”. O objetivo do presente estudo foi avaliar a atividade antiulcera e cicatrizante, assim como o perfil fotoquímico dos extratos brutos em acetato de etila e metanol da Maytenus truncata. A administração per os desses extratos nas doses de 120 mg/kg e 240 mg/kg reduziu a severidade da lesão gástrica induzida pelo estresse ao frio (-18 °C por 45 minutos) em ratos, com resultados mais significativos para o extrato bruto obtido em metanol. A administração dos extratos provocou o aumento do pH. Os resultados obtidos na administração do extrato bruto em metanol não contrariam seu uso popular, não somente pela atividade observada, mas também por se tratar de um extrato de alta polaridade cujos princípios podem ser obtidos a partir de uma infusão, embora estudos clínicos devam ser realizados para confirmação dessa hipótese.Maytenus truncata Reiss (Celastraceae) is a native plant from Bahia (Brazil), known as “espinheira-santa”. It is popularly used in the form of decoct of leaves (tea) as antiulcerogenic, similarly to Maytenus ilicifolia, the true “espinheira-santa”. This study aims to evaluate antiulcerogenic and healing activities, as well as the phytochemical profile, of ethyl acetate and methanol crude extracts of Maytenus truncata. Per os administration of these extracts at 120 mg/kg and 240 mg/kg doses decreased the severity of gastric lesions induced by cold-restraint stress (-18 °C for 45 minutes) in rats, with more significant results for the crude methanol extract. The administration of the extracts caused pH increase. The results obtained with the administration of crude methanol extract are not contrary to its popular use, not only for the activity observed but, also, for its high polarity that enables the obtention of the active principles through infusion, though clinical studies should be performed to confirm this assertion

Multicenter observational study of abobotulinumtoxinA neurotoxin in cervical dystonia: The ANCHOR-CD registry

BACKGROUND: The ANCHOR-CD prospective observational registry study evaluated the effectiveness of abobotulinumtoxinA in adult idiopathic cervical dystonia (CD) in clinical practice. METHODS: Adults with CD were eligible. Treating physicians determined abobotulinumtoxinA dose and treatment interval. The primary endpoint was patient response rate (Toronto Western Spasmodic Torticollis Rating Scale [TWSTRS] score reduction≥25% and Patient Global Impression of Change [PGIC] score of +2 or +3 at Week 4 of Cycle 1). RESULTS: 350 patients enrolled (75% women; mean age 59±13.6years; 27.4% botulinum neurotoxin-naive) and 347 received at least 1 treatment. The median abobotulinumtoxinA dose for Cycle 1 was 500 Units. At Week 4, the responder rate was 30.6% (n=304) and the TWSTRS total score decreased 27.4% from baseline. PGIC of at least Much improved was documented in 43.6% of patients and maintained in Cycles 2 through 4 (43.3%, 48.9%, and 52.8%, respectively). A total of 39 adverse events (31 study drug-related) were reported in 17 patients (5%); the most common were dysphagia (n=6), muscle weakness (n=4), and neck pain (n=3). CONCLUSION: This study confirmed the beneficial effect of abobotulinumtoxinA on CD in routine clinical practice as measured by improvements in TWSTRS and PGIC. No new safety concerns were identified

Multicenter observational study of abobotulinumtoxinA neurotoxin in cervical dystonia: The ANCHOR-CD registry

The ANCHOR-CD prospective observational registry study evaluated the effectiveness of abobotulinumtoxinA in adult idiopathic cervical dystonia (CD) in clinical practice. Adults with CD were eligible. Treating physicians determined abobotulinumtoxinA dose and treatment interval. The primary endpoint was patient response rate (Toronto Western Spasmodic Torticollis Rating Scale [TWSTRS] score reduction≥25% and Patient Global Impression of Change [PGIC] score of +2 or +3 at Week 4 of Cycle 1). 350 patients enrolled (75% women; mean age 59±13.6years; 27.4% botulinum neurotoxin-naive) and 347 received at least 1 treatment. The median abobotulinumtoxinA dose for Cycle 1 was 500 Units. At Week 4, the responder rate was 30.6% (n=304) and the TWSTRS total score decreased 27.4% from baseline. PGIC of at least “Much improved” was documented in 43.6% of patients and maintained in Cycles 2 through 4 (43.3%, 48.9%, and 52.8%, respectively). A total of 39 adverse events (31 study drug-related) were reported in 17 patients (5%); the most common were dysphagia (n=6), muscle weakness (n=4), and neck pain (n=3). This study confirmed the beneficial effect of abobotulinumtoxinA on CD in routine clinical practice as measured by improvements in TWSTRS and PGIC. No new safety concerns were identified. •CD presents clinically with a wide range of symptom severity and comorbidities.•AbobotulinumtoxinA efficacy in “real life” was consistent with controlled trials.•Most common adverse events were dysphagia, muscular weakness, neck pain, and rhinorrhea.•Safety profile was consistent with the pivotal placebo-controlled trials

Cyclic adenosine monophosphate protects renal cell lines against amphotericin B toxicity in a PKA-independent manner.

Amphotericin B is the ??gold standard?? agent in the management of serious systemic fungal infections. However, this drug can cause nephrotoxicity, which contributes up to 25% of all acute kidney injuries in critically ill patients. Cyclic adenosine monophosphate can protect kidney cells from death due to injury or drug exposure in some cases. Hence, the objective of this work was to evaluate if cAMP could prevent cell death that occurs in renal cell lines subjected to AmB treatment and, if so, to assess the involvement of PKA in the transduction of this signal. Two different renal cell lines (LLC-PK1 and MDCK) were used in this study. MTT and flow cytometry assays showed increased cell survival when cells were exposed to cAMP in a PKA-independent manner, which was confirmed by western blot. This finding suggests that cAMP (db-cAMP) may prevent cell death caused by exposure to AmB. This is the first time this effect has been identified when renal cells are exposed to AmB?s nephrotoxic potential

Alteration in cellular viability, pro-inflammatory cytokines and nitric oxide production in nephrotoxicity generation by Amphotericin B : involvement of PKA pathway signaling.

Amphotericin B is one of the most effective antifungal agents; however, its use is often limited owing to adverse effects, especially nephrotoxicity. The purpose of this study was to evaluate the effect of inhibiting the PKA signaling pathway in nephrotoxicity using Amphotericin B from the assessment of cell viability, pro-inflammatory cytokines and nitric oxide (NO) production in LLC-PK1 and MDCK cell lines. Amphotericin B proved to be cytotoxic for both cell lines, as assessed by the mitochondrial enzyme activity (MTT) assay; caused DNA fragmentation, determined by flow cytometry using the propidium iodide (PI) dye; and activated the PKA pathway (western blot assay). In MDCK cells, the inhibition of the PKA signaling pathway (using the H89 inhibitor) caused a significant reduction in DNA fragmentation. In both cells lines the production of interleukin-6 (IL)-6 proved to be a dependent PKA pathway, whereas tumor necrosis factor-alpha (TNF-?) was not influenced by the inhibition of the PKA pathway. The NO production was increased when cells were pre-incubated with H89 followed by Amphotericin B, and this production produced a dependent PKA pathway in LLC-PK1 and MDCK cells lines. Therefore, considering the present study?s results as a whole, it can be concluded that the inhibition of the PKA signaling pathway can aid in reducing the degree of nephrotoxicity caused by Amphotericin B

Estudo fitoquímico do decocto das folhas de Maytenus truncata Reissek e avaliação das atividades antinociceptiva, antiedematogênica e antiulcerogênica de extratos do decocto Phytochemical study of the decoct from the leaves of Maytenus Truncata Reissek and the evaluation of the antinociceptive, antiedematogenic and antiulcerogenic activities of the decoct extracts

<abstract language="eng">The present paper describes the phytochemical investigation and biological activities of the chloroform, ethyl acetate and methanol extracts of leaf decocts of M. truncata Reiss (Celastraceae). Our studies afforded two flavonoid glycosides, quercetin-3-O-rhamnopyranosyl-O-glucopyranosyl- O-rhamnopyranosyl-O-galactopyranoside (1) and kampferol-3-O-rhamnopyranosyl-O-glucopyranosyl- O-rhamnopyranosyl-O-galactopyranoside (2) from the methanolic extract and dulcitol (3) from the ethyl acetate extract. Ethyl acetate and methanol extracts exhibited considerable antiulcerogenic and analgesic activities. The results of the phytochemical studies suggest that the healing activity of methanol extracts can be related to the presence of glycosyl flavonoids