Brazilian National Network of Alternative Methods (RENAMA) 10th Anniversary: Meeting of the Associated Laboratories, May 2022.

The Brazilian National Network of Alternative Methods (RENAMA), which is linked to the Ministry of Science, Technology and Innovation, is currently comprised of 51 laboratories from CROs, academia, industry and government. RENAMA's aim is to develop and validate new approach methodologies (NAMs), as well as train researchers and disseminate information on their use - thus reducing Brazilian, and consequently Latin American, dependence on external technology. Moreover, it promotes the adoption of NAMs by educators and trained researchers, as well as the implementation of good laboratory practice (GLP) and the use of certified products. The RENAMA network started its activities in 2012, and was originally comprised of three central laboratories - the National Institute of Metrology, Quality and Technology (INMETRO); the National Institute of Quality Control in Health (INCQS); and the National Brazilian Biosciences Laboratory (LNBio) - and ten associated laboratories. In 2022, RENAMA celebrated its 10th anniversary, a milestone commemorated by the organisation of a meeting attended by different stakeholders, including the RENAMA-associated laboratories, academia, non-governmental organisations and industry. Ninety-six participants attended the meeting, held on 26 May 2022 in Balneário Camboriú, SC, Brazil, as part of the programme of the XXIII Brazilian Congress of Toxicology 2022. Significant moments of the RENAMA were remembered, and new goals and discussion themes were established. The lectures highlighted recent innovations in the toxicological sciences that have translated into the assessment of consumer product safety through the use of human-relevant NAMs instead of the use of existing animal-based approaches. The challenges and opportunities in accepting such practices for regulatory purposes were also presented and discussed.

Murine response to the opportunistic bacterium Pseudomonas aeruginosa infection in gut dysbiosis caused by 5-fluorouracil chemotherapy-induced mucositis.

AIMS: This manuscript aims to explain the relationship between mucositis caused by 5-FU over gut bacterial species and susceptibility to opportunistic infection caused by P. aeruginosa. MAIN METHODS: BALB/c mice were intraperitoneally treated with PBS or 5-FU. Bodyweight and faecal consistency were checked daily. Mice faecal DNA was extracted, and bacterial phylogenetic groups were analysed using qPCR or high-throughput sequencing. Immunofluorescence was used to evaluate BMDM activation by mice-treated faecal content. Mice were challenged intratracheally with virulent P. aeruginosa, and the CFU and histology were analysed. Faecal microbiota were transplanted to evaluate the gut microbiota and resistance to pulmonary P. aeruginosa recovery. KEY FINDINGS: The animals treated with 5-FU presented mucositis with great weight loss, altered faecal consistency, bacterial gut dysbiosis and histological changes in the intestinal mucosa. Mice under 5-FU treatment were more susceptible to lung infection by the bacteria P. aeruginosa and had more extensive tissue damage during their lung infection with greater pro-inflammatory gene expression. It was observed that the mucositis remained in the groups with 5-FU even with the FMT. The results caused by mucositis in animals that received allogeneic FMT were reversed, however, with a decrease in P. aeruginosa susceptibility in animals treated with 5-FU and allogeneic FMT compared to animals treated with 5-FU and autologous FMT. SIGNIFICANCE: Treatment with 5-FU in a murine model makes it more susceptible to pulmonary infection by the bacterium P. aeruginosa, FMT offers an opportunity to protect against this susceptibility to infection.

Pyrene-polyethylene glycol-modified multi-walled carbon nanotubes: Genotoxicity in V79-4 fibroblast cells.

The genotoxicity of pyrene-polyethylene glycol-modified multi-walled carbon nanotubes (MWCNT-PyPEG), engineered as a nanoplatform for bioapplication, was evaluated. Toxicity was assessed in hamster lung fibroblast cells (V79-4). MTT and Cell Titer Blue methods were used to evaluate cell viability. Genotoxicity was measured by the comet assay and the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay, and fluorescence in situ hybridization (FISH) was used to test induction of structural chromosome aberrations (clastogenic activity) and/or numerical chromosome changes (aneuploidogenic activity). Exogenous metabolic activation enzymes were used in the CBMN-Cyt and FISH tests. Only with metabolic activation, the hybrids caused chromosomal damage, by both clastogenic and aneugenic processes.

Acute oral toxicity, antinociceptive and antimicrobial activities of kava dried extracts and synthetic kavain.

Piper methysticum G. Forst, popularly known as kava, is a traditional medicinal plant widely used for the treatment of anxiety and insomnia. The aim of this study was to investigate new therapeutic applications of this plant. Nociceptive response induced by heat (hot-plate) was used as pain model. Susceptibility of different strains to kava ethanolic dried extracts was evaluated by broth microdilution method. Acute oral toxicity was performed according to Organisation for Economic Cooperation and Development (OECD) guideline. Administration of kava dried extracts and kavain inhibited the nociceptive response in the hot-plate model and did not affect the time mice spent in the rota-rod apparatus. The samples showed no significant antibacterial activity, however slight antifungal activity was verified. The extracts may be considered of low oral acute toxicity. Kava extracts exhibited promising antinociceptive activity in model of nociceptive pain, which should be deeper explored as a new therapeutic application of kava.

In silico, in vitro and in vivo evaluation of natural Bignoniaceous naphthoquinones in comparison with atovaquone targeting the selection of potential antimalarial candidates.

The natural naphthoquinones lapachol, α- and ß-lapachone are found in Bignoniaceous Brazilian plant species of the Tabebuia genus (synonym Handroanthus) and are recognized for diverse bioactivities, including as antimalarial. The aim of the present work was to perform in silico, in vitro and in vivo studies to evaluating the antimalarial potential of these three naphthoquinones in comparison with atovaquone, a synthetic antimalarial. The ADMET properties of these compounds were predicted in silico by the preADMET program. The in vitro toxicity assays were experimentally determined in immortalized and tumoral cells from different organs. In vivo acute oral toxicity was also evaluated for lapachol. Several favorable pharmacokinetics data were predicted although, as expected, high cytotoxicity was experimentally determined for ß-lapachone. Lapachol was not cytotoxic or showed low cytotoxicity to all of the cells assayed (HepG2, A549, Neuro 2A, LLC-PK1, MRC-5), it was nontoxic in the acute oral test and disclosed the best parasite selectivity index in the in vitro assays against chloroquine resistant Plasmodium falciparum W2 strain. On the other hand, α- and ß-lapachone were more potent than lapachol in the antiplasmodial assays but with low parasite selectivity due to their cytotoxicity. The diversity of data here reported disclosed lapachol as a promising candidate to antimalarial drug development.

Vancomycin-induced gut dysbiosis during Pseudomonas aeruginosa pulmonary infection in a mice model.

Pseudomonas aeruginosa is one of the most common opportunistic pathogens causing respiratory infections in hospitals. Vancomycin, the antimicrobial agent usually used to treat bacterial nosocomial infections, is associated with gut dysbiosis. As a lung-gut immunologic axis has been described, this study aimed to evaluate both the immunologic and histopathologic effects on the lungs and the large intestine resulting from vancomycin-induced gut dysbiosis in the P. aeruginosa pneumonia murine model. Metagenomic analysis demonstrated that vancomycin-induced gut dysbiosis resulted in higher Proteobacteria and lower Bacteroidetes populations in feces. Given that gut dysbiosis could augment the proinflammatory status of the intestines leading to a variety of acute inflammatory diseases, bone marrow-derived macrophages were stimulated with cecal content from dysbiotic mice showing a higher expression of proinflammatory cytokines and lower expression of IL-10. Dysbiotic mice showed higher levels of viable bacteria in the lungs and spleen when acutely infected with P. aeruginosa, with more lung and cecal damage and increased IL-10 expression in bronchoalveolar lavage. The susceptible and tissue damage phenotype was reversed when dysbiotic mice received fecal microbiota transplantation. In spite of higher recruitment of CD11b+ cells in the lungs, there was no higher CD80+ expression, DC+ cell amounts or proinflammatory cytokine expression. Taken together, our results indicate that the bacterial community found in vancomycin-induced dysbiosis dysregulates the gut inflammatory status, influencing the lung-gut immunologic axis to favor increased opportunistic infections, for example, by P. aeruginosa.

Extracellular protease profile of Acanthamoeba after prolonged axenic culture and after interaction with MDCK cells.

Free-living amoebae of the genus Acanthamoeba are causative agents of Acanthamoeba keratitis and amoebic encephalitis in humans, both of which are serious infections. The ability to produce proteases is one of the factors involved in the pathogenesis of Acanthamoeba infections. The aim of this study was to evaluate the secreted proteases of six Acanthamoeba strains from distinct genotypes (T1, T2, T4 and T11) maintained in prolonged axenic culture and following three successive passages in Madin-Darby Canine Kidney (MDCK) cells. Conditioned medium was obtained from cultures before and after interaction with the MDCK monolayers, resolved in SDS-PAGE containing gelatine, then subjected to quantitative azocasein assays. Zymography profiles varied between the strains, with the predominant proteases found to be serine-type proteases from 49 to 128 kDa. A T1 genotype strain isolated from dust showed quantitatively higher protease secretion compared to the other strains. No changes were detected in the zymography profiles of MDCK-interacted cultures compared to long-term axenic cultures. Two strains presented lower proteolytic activity post-MDCK interaction, while the remaining strains presented similar values before and after MDCK passages. In conclusion, this study confirms the predominance of serine-type protease secretion by Acanthamoeba, with distinct profiles presented by the different strains and genotypes studied. Also, interaction of trophozoites with MDCK cells did not alter the zymography pattern.

A critical review of adverse effects to the kidney: mechanisms, data sources, and in silico tools to assist prediction.

INTRODUCTION: The kidney is a major target for toxicity elicited by pharmaceuticals and environmental pollutants. Standard testing which often does not investigate underlying mechanisms has proven not to be an adequate hazard assessment approach. As such, there is an opportunity for the application of computational approaches that utilize multiscale data based on the Adverse Outcome Pathway (AOP) paradigm, coupled with an understanding of the chemistry underpinning the molecular initiating event (MIE) to provide a deep understanding of how structural fragments of molecules relate to specific mechanisms of nephrotoxicity. Aims covered: The aim of this investigation was to review the current scientific landscape related to computational methods, including mechanistic data, AOPs, publicly available knowledge bases and current in silico models, for the assessment of pharmaceuticals and other chemicals with regard to their potential to elicit nephrotoxicity. A list of over 250 nephrotoxicants enriched with, where possible, mechanistic and AOP-derived understanding was compiled. Expert opinion: Whilst little mechanistic evidence has been translated into AOPs, this review identified a number of data sources of in vitro, in vivo, and human data that may assist in the development of in silico models which in turn may shed light on the interrelationships between nephrotoxicity mechanisms.

Cross-talk between lung cancer and bones results in neutrophils that promote tumor progression.

Lung cancer is the leading cause of cancer mortality around the world. The lack of detailed understanding of the cellular and molecular mechanisms participating in the lung tumor progression restrains the development of efficient treatments. Recently, by using state-of-the-art technologies, including in vivo sophisticated Cre/loxP technologies in combination with lung tumor models, it was revealed that osteoblasts activate neutrophils that promote tumor growth in the lung. Strikingly, genetic ablation of osteoblasts abolished lung tumor progression via interruption of SiglecFhigh-expressing neutrophils supply to the tumor microenvironment. Interestingly, SiglecFhigh neutrophil signature was associated with worse lung adenocarcinoma patients outcome. This study identifies novel cellular targets for lung cancer treatment. Here, we summarize and evaluate recent advances in our understanding of lung tumor microenvironment.

In vitro evaluation of biomarkers of nephrotoxicity through gene expression using gentamicin.

Acute renal failure is one of the most frequent effects observed after taking medicine. Such situations have been tardily discovered, given that existing methods for assessing toxicity are not predictive. In this light, the present work evaluated the effects of gentamicin, a form of nephrotoxic drug, on HK-2 and HEK-293 cells. By using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and flow cytometry, both cells demonstrated that cytotoxicity occurs in a dose-dependent manner through the processes of apoptosis and cell necrosis. Gene expression analysis showed a relative increase of expression for genes related to cell processes and classic biomarkers, such as TP53, CASP3, CASP8, CASP9, ICAM-1, EXOC3, KIM-1, and CST3. A decrease in expression for genes BCL2L1 and EGF was observed. This study, therefore, indicates that, when the methods are used together, gene expression analysis is able to evaluate the nephrotoxic potential of a substance.

In vitro study of putative genomic biomarkers of nephrotoxicity through differential gene expression using gentamicin.

Drug-induced nephrotoxicity is one of the most frequently observed effects in long-term pharmacotherapy. The effects of nephrotoxicity are commonly discovered later due to a lack of sensitivity in in vivo methods. Therefore, researchers have tried to develop in vitro alternative methods for early identification of toxicity. In this study, LLC-PK1 cells were exposed to gentamicin through MTT and trypan blue assay. Concentrations of 4 (low), 8 (medium) and 12 (high) mM, were used to evaluate differential gene expression. A panel of genes was selected based on gene expression changes. The search for sequences of mRNA encoding proteins previously associated with kidney damage was conducted in the databases of the National Center for Biotechnology Information (USA). RNA was extracted from the cells, and RT-qPCR was performed to evaluate differential expression profiles of the selected genes. Among the 11 analyzed genes, four proved to be differentially up-regulated in cells exposed to gentamicin: HAVcr1, caspase 3, ICAM-1 and EXOC6. According to this study's results, we suggest that these genes play an important role in the mechanism of in vitro nephrotoxicity caused by gentamicin and can be used as early in vitro biomarkers to identify nephrotoxicity when developing safer drugs.

Biodistribution, pharmacokinetics and toxicity of a Vasconcellea cundinamarcensis proteinase fraction with pharmacological activity

Abstract Prior studies demonstrate that a proteinase fraction from Vasconcellea cundinamarcensis V.M. Badillo, Caricaceae, exhibits wound healing activity in gastric and cutaneous models and antitumoral/antimetastatic effects. Here, we present the toxicity, pharmacokinetics and biodistribution data for this proteinase fraction following a single dose into Swiss mice by i.v., s.c. or p.o. routes. The i.v. and s.c. toxicity assays demonstrate that proteinase fraction at ≤20 mg/kg is non-lethal after single injection, while parental administration (p.o.) of ≤300 mg/kg does not cause death. Based on p.o. acute toxicity dose using Organisation for Economic Cooperation and Development protocols, proteinase fraction ranks as Class IV “harmful” substance. Proteinase fraction shows high uptake determined as Kp (distribution tissue/blood) in organs linked to metabolism and excretion. Also, high bioavailability (≈100%) was observed by s.c. administration. The blood contents following i.v. dose fits into a pharmacokinetic bi-compartmental model, consisting of high removal constants – kel 0.22 h−1 and kd 2.32 h−1and a half-life – t½ = 3.13 h. The Ames test of proteinase fraction (0.01–1%) demonstrates absence of mutagenic activity. Likewise, genotoxic evaluation of proteinase fraction (5 or 10 mg/kg, i.p.) shows no influence in micronuclei frequency. In conclusion, the acute doses for proteinase fraction lack mutagenic and genotoxic activity, clearing the way for clinical assays.

Hepatobiliary transporters in drug-induced cholestasis: a perspective on the current identifying tools.

INTRODUCTION: Impaired bile formation leads to the accumulation of cytotoxic bile salts in hepatocytes and, consequently, cholestasis and severe liver disease. Knowledge of the role of hepatobiliary transporters, especially the bile salt export pump (BSEP), in the pathogenesis of cholestasis is continuously increasing. AREAS COVERED: This review provides an introduction into the role of these transport proteins in bile formation. It addresses the clinical relevance and pathophysiologic consequences of altered functions of these transporters by genetic mutations and drugs. In particular, the current practical aspects of identification and mitigation of drug candidates with liver liabilities employed during drug development, with an emphasis on preclinical screening for BSEP interaction, are discussed. EXPERT OPINION: Within the potential pathogenetic mechanisms of acquired cholestasis, the inhibition of BSEP by drugs is well established. Interference of a new compound with BSEP transport activity should raise a warning sign to conduct follow-up experiments and to monitor liver function during clinical development. A combination of in vitro screening for transport interaction, in silico predicting models, and consideration of physicochemical and metabolic properties should lead to a more efficient screening of potential liver liability.

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.

Toxicological evaluation of the João da Costa e Associações® on Beagle dogs

A toxicological study was performed in Beagle dogs treated for 180 days with the product João da Costa e Associações. Were used six males and six females distributed in control and treated groups (n=3). We used a dose of 566 mg/kg of the product according to preclinical study in rodents. The animals were weighed and evaluated by clinical and laboratory aspects. The product did not cause mortality or alter the normal behavior of animals, but interfered with the weight gain on males in the middle phase of the treatment. The group treated had a lower incidence of clinical abnormalities compared to control, checked by veterinary consultations. Laboratory data showed elevated blood glucose levels perhaps due to the high amount of sucrose present in the product; about the histopathological data no significant change was found. We conclude that the product Joao da Costa and Associações, at the dose tested, has low toxicity in Beagle dogs treated chronically.

A comparison of BGM and LLC-PK1 cells for the evaluation of nephrotoxicity.

Nephrotoxicity is one of the most frequent effects observed after the use of medicine. Such situations have been tardily discovered because of existing methods to determine toxicity. The validation of sensitive, alternative methods for the early identification of toxic effects is as important as restrictions on the use of animals. In this light, the present study evaluated the effects of gentamicin on BGM and LLC-PK1 cells, using MTT and Neutral Red (NR). Although the LLC-PK1 cell line is used for toxicological studies, the BGM cell line is relatively new for this purpose. MTT (BGM: EC(50) = 6.29 mM; LLC-PK1: EC(50) = 8.01 mM) was found to be more sensitive than NR (EC(50) was greater than 10 mM for both cells). By using MTT, both cells demonstrated the involvement of mitochondria in a manner that was dose dependent, with an apoptotic process occurring at the concentrations of 1 and 3 mM and necrosis at concentrations above 4 mM. It could, therefore, be concluded that 1) BGM appears to be useful in the study of the mechanism of nephrotoxicity caused by gentamicin and 2) because of its sensitivity to MTT, in addition to its ease of manipulation, it is believed that the BGM cell line can also be used as an alternative method to evaluate nephrotoxicity.

Evaluation of the immunotoxicological effects of Dimorphandra mollis Benth., Fabaceae, in rats / Avaliação dos efetos imunotoxicológicos de Dimorphandra mollis Benth., Fabaceae, em ratos

Dimorphandra mollis Benth., Fabaceae, also known as "faveira" or "fava-d'anta", is a plant common to the central woodsy meadow region of Brazil. It is well known for its antioxidant, antiplatelet and, principally, vasoprotective properties. Its principal component is rutin. The objective of this study is the evaluation of the safety of the use of the dried D. mollis extract in rodents. The rutin content of the standardized extract was 76.0±3 percent. With respect to the biochemical and hematological parameters evaluated, no alterations in the groups of rats that received 1000 and 2000 mg/kg doses of D. mollis were observed, but an increase in eosinophiles occurred. Hyperactivity of the white splenic pulp was detected in the group that received the 2000 mg/kg dose of D. mollis. In the evaluation of the lymphproliferative response with 1000 and 2000 mg/kg, no alterations were observed, and a decrease in IgG was only observed in the studies with a 2000 mg/kg dose. The results obtained with rodents suggest that no toxicity exists with the administration of dried D. mollis extract in a 1000 mg/kg dose.

A Dimorphandra mollis Benth., Fabaceae, conhecida como faveira ou fava-d'anta, é uma planta comum do cerrado central do Brasil, muito utilizada por suas propriedades antioxidante, antiplaquetária e, principalmente, como vasoprotetora. Seu principal marcador é a rutina. Este estudo teve como objetivo avaliar a segurança da utilização do extrato seco de D. mollis em roedores. O extrato foi extraído, padronizado e quantificado apresentando teor de 76,0±3 por cento de rutina. Nos parâmetros bioquímicos e hematológicos avaliados, não se observou alterações nos grupos de machos e fêmeas que receberam a dose de 1000 e 2000 mg/kg de D. mollis, mas observou-se um aumento de eosinófilos. Nos estudos histopatológicos detectou-se hiperreatividade da polpa branca esplênica, no grupo que recebeu a dose de 2000 mg/kg de D. mollis. Na avaliação da resposta linfoproliferativa, com 1000 e 2000 mg/kg não foram observadas alterações, e somente nos estudos com a dose de 2000 mg/kg se observou diminuição de IgG. Os resultados obtidos, utilizando roedores, sugerem que nenhuma toxicidade existe na administração de extrato seco de D. mollis na dose de 1000 mg/kg.

Influence of the preparation method on the low efficacy of multi-herb commercial products: the example of João da Costa e Associações / Influência do método de preparação na baixa eficácia de produtos fitoterápicos: o exemplo do João da Costa e Associações

Native medicinal plants have been used for decades by Brazilian pharmaceutical companies to create commercial products. In this study, we have investigated the herb-combined product João da Costa e Associações® (JCA) commercialized for thirty years to treat dysmenorrhoea. JCA is prepared by decoction of Himatanthus lancifolius (Muell. Arg.) Woodson (Apocynaceae), Chondodendron platyphyllum Miers (Menispermaceae), Gossypium herbaceum L. (Malvaceae), Rosmarinus officinalis L. (Lamiaceae) and Echites peltata (Apocynaceae), followed by addition of sugar. The efficacy of JCA was verified by antinociceptive studies. The chemical composition was determined by fingerprint analysis in HPLC/ DAD. A weak inhibition of the second phase of the nociceptive effect induced by formalin indicated an activity similar to those steroids and not-steroids anti-inflammatories. Despite being prepared by decoction of five plants, the fingerprint analysis showed only two peaks. None of them corresponds to the chemical compounds observed in ethanol extracts prepared with the same plant material. We argue that the methods of preparation of the formulas should be considered in studies of multi-herbs products, since they can be the responsible for inefficacy or low activity of such products.

Plantas medicinais nativas do Brasil foram usadas por décadas pelas indústrias farmacêuticas nacionais para criar seus produtos. Neste estudo, foi investigado o produto João da Costa e Associações® (JCA) comercializado por mais de trinta anos para o tratamento de dismenorréia e outros problemas relacionados à saúde da mulher. JCA é preparado pela decocção de Himatanthus lancifolius (Muell. Arg.) Woodson (Apocynaceae), Chondodendron platyphyllum Miers (Menispermaceae), Gossypium herbaceum L. (Malvaceae), Rosmarinus officinalis L. (Lamiaceae) e Echites peltata (Apocynaceae), seguido de adição de açúcar. A eficácia de JCA foi verificada por meio da avaliação da atividade antinociceptiva. Já a composição química foi determinada por analises em HPLC/ DAD. Uma fraca inibição da segunda fase da nocicepção foi observada no teste da formalina, indicando uma ação semelhante aos antiinflamatórios esteroidais e não esteroidais. Apesar de ser preparado pela decocção de cinco plantas, a análise no HPLC apresentou somente dois picos, e nenhum deles correspondeu aos componentes observados nos extratos etanólicos preparados com as mesmas plantas. Os resultados sugerem que o método de preparação de JCA promove a perda dos componentes químicos das plantas e interfere consideravelmente na eficácia do produto.

Acute and chronic toxicological studies of the Brazilian phytopharmaceutical product Ierobina / Estudos de toxicidade aguda e crônica do produto fitoterápico brasileiro Ierobina

Ierobina® is a Brazilian phytopharmaceutical product employed for the treatment of dyspepsia (280 mg/kg/day). Despite its widespread use in the country for over 75 years, only recently its therapeutic efficacy has been attested in animals; however, no toxicological investigations have been carried out for the product to date. In this paper we evaluated the acute toxicity of Ierobina® administrated by gavage in mice (single doses of 2100 mg/kg, 6300 mg/kg and 12600 mg/kg), along with its chronic effects in rats, after product administration per os daily, at the doses of 2800 mg/kg and 5600 mg/kg, for 180 days. The product had low acute toxicity; all observed alterations were reversible and no animal died during the experiments. In chronic toxicological studies, Ierobina® administration for 180 days did not cause any changes in hematological and biochemical parameters, with the exception of decreasing the levels of alanine transaminase, aspartate transaminase and creatinine. However, histological evaluation of kidney, liver and other selected organs showed normal architecture, suggesting no morphological disturbances. Hence, considering the obtained results and the fact that Ierobina® has been commercialized for decades in Brazil, without any notified case of toxicity, it seems that the product is safe for human use.

A Ierobina® é um produto utilizado popularmente, no Brasil, para tratamento de dispepsia, na dose de 280 mg/kg/dia. Apesar de seu largo uso nos últimos 75 anos, recentemente foi comprovada sua eficácia em animais; porém, nenhuma avaliação de seu perfil toxicológico foi realizada. O objetivo do presente estudo foi avaliar a toxicidade aguda (doses únicas de 2100 mg/kg, 6300 mg/kg ou 12600 mg/kg), em camundongos, e crônica (doses de 2800 mg/kg ou 5600 mg/kg, por 180 dias), em ratos, após administração per os de Ierobina®. No teste de toxicidade aguda, as doses administradas não produziram nenhuma mortalidade e os sinais observados foram todos reversíveis. No teste de toxicidade crônica, não foram verificadas diferenças significativas nas análises hematológicas, macroscópicas e microscópicas. Nos exames de bioquímica sérica, diferença significativa foi observada somente na avaliação da alanina transaminase, aspartato transaminase e creatinina, porém, sem importância clínica. Assim, considerando os resultados obtidos e o fato de ser a Ierobina® um produto comercializado há décadas, sem qualquer notificação de casos de toxicidade, podemos concluir que o produto parece ser de segurança adequada para uso humano.

Anti-inflammatory activity and gastric lesions induced by zinc-tenoxicam.

Oral administration of tenoxicam or zinc-tenoxicam complex inhibited to a similar extent carrageenin-induced paw oedema and granulomatous tissue formation in rats as well as the acetic acid induced writhing response in mice. Gastric lesions induced by oral administration of zinc-tenoxicam were reduced in number and severity when compared with those induced by tenoxicam or the co-administration of tenoxicam and zinc acetate. However, after intraperitoneal administration, both zinc-tenoxicam and tenoxicam plus zinc acetate induced a reduced number of gastric lesions as compared with tenoxicam.