Estudios de Seguridad Preclínica del extracto hidroalcohólico de semillas de Opuntia soehrensii, una especie alto-andina con actividad anti-Herpes Virus, en ratas Sprague Dawley / Preclinical safety of the hydroalcoholic extract of Opuntia soehrensii seeds with anti-herpes virus activity, in SD rats

Introducción. Alrededor de 3700 millones menores de 50 años con infección por VHS-1 y 491 millones de personas de 15 a 49 años cursan con infección por VHS-2 en el mundo; sus síntomas, vesículas o ulceras dolorosas reaparecen periódicamente. El tratamiento convencional disminuyó su efectividad en cepas resistentes e inmunodeprimidos. Alternativas terapéuticas con extractos de plantas medicinales y potencial antiviral, como Opuntia soehrensii Brito conocida como "ayrampù" en Bolivia, utiliza infusión de sus semillas como analgésico, antidiabético, hipotensor y febrífugo. En vapores por inhalación para afecciones respiratorias; como tintura tópica en lesiones dérmicas de viruela, sarampión y herpes labial. Objetivo. Evaluar la seguridad preclínica de un gel que contiene el extracto hidro-alcohólico de semillas de Opuntia soehrensii en diferentes dosis, aplicado en la mucosa vaginal de ratas Sprague Dawley. Material y métodos. Se ejecutaron protocolos de toxicidad aguda y subaguda para evaluar la respuesta sistémica, a través de marcadores bioquímicos y de comportamiento, y la respuesta local en mucosa vaginal, mediante estudios histopatológicos, en grupos de animales a los que se aplicó el gel con diferentes concentraciones del extracto de Opuntia soehrensii, comparados con un grupo control y otro que recibió solo el vehículo. Resultados. Se encontró que los indicadores sistémicos de comportamiento y ganancia de peso no mostraron diferencias entre grupos. Los indicadores hematológicos y bioquímicos mostraron resultados fisiológicamente esperados y sin cambios en los grupos de estudio. La citología expuso conservación del fenotipo celular para las fases del ciclo estral en todos los grupos. Los indicadores histológicos de reacción local e integridad celular se distribuyeron de igual manera en los todos los grupos. Conclusión. La aplicación de un gel de Opuntia soehrensii no muestra niveles apreciables de toxicidad local y sistémica, lo que permite recomendar la iniciación de estudios de aplicación clínica.

Introduction. Around 3.7 billion people under 50 years of age are infected with HSV-1 and 491 million people between the ages of 15 and 49 are infected with HSV-2 in the world; his symptoms, vesicles or painful ulcers recur periodically. Conventional treatment decreased its effectiveness in resistant and immunosuppressed strains. Therapeutic alternatives with extracts of medicinal plants and antiviral potential, such as Opuntia soehrensii Brito known as "ayrampù" in Bolivia, uses infusion of its seeds as an analgesic, antidiabetic, hypotensive and febrifuge. In vapors by inhalation for respiratory conditions; as a topical tincture in skin lesions of smallpox, measles and cold sores. Objectives . To evaluate the preclinical safety of a gel containing the hydroalcoholic extract of Opuntia soehrensii seeds in different doses, applied to the vaginal mucosa of Sprague Dawley rats. Material and Methods. Acute and sub-acute toxicity protocols were carried out to evaluate local response in the vaginal mucosa, through histo pathological studies, and systemic responses, through biochemical and behavioral markers, in groups of animals to which the gel with different concentrations of the extract of Opuntia soehrensii was applied, compared with a control group and another that received only the vehicle. Results. It was found that the histological indicators of local reaction and cell integrity were equally distributed in all groups. Cytology showed conservation of the cell phenotype for the phases of the estrous cycle in all groups. The systemic indicators of behavior and weight gain did not show differences between groups. Hematological and biochemical indicators showed results ranged in physiologic parameters, without changes in the study groups. Conclusion. The application of a gel from Opuntia soehrensii does not show appreciable levels of local and systemic toxicity, which makes it possible to recommend the initiation of clinical application studies.

Effects of Intermediate Frequency (150 kHz) Electromagnetic Radiation on the Vital Organs of Female Sprague Dawley Rats.

Exposure to electromagnetic radiation (EMR) from intermediate frequency sources has increased exponentially in recent years. The consequences of this exposure on biological systems are prompting scientists to study the effects on human health. This current study aimed to determine the effects of intermediate frequency (150 kHz) EMR exposure on the vital organs of female Sprague Dawley rats. The EMR group (n = 10 animals) was exposed to a frequency of 150 kHz with an intensity of 65 ± 15 µW/cm2 for two months. The control group (n = 10 animals) was exposed to an intensity of 35 ± 15 nW/cm2. Haematological, histochemical, gross, and histopathological profiles of all major organs of all animals were then performed using standard procedures. All major organs generally showed no significant detectable effects in either the control or EMR groups. However, gross and histopathological examinations revealed the effects of EMR on the liver and lungs, which showed inflammatory changes without significant biochemical/haematological manifestations. In addition, a significant increase in serum sodium level and a decrease in serum urea level were also observed in the EMR group. It can be concluded that the current frequency and duration of exposure trigger the changes in the liver and lungs but are not sufficient to cause clinical and functional manifestations. Therefore, a long-term exposure study might be helpful to determine the effects of 150 kHz IF EMR on these organs.

Moderate Toxicity of Potential Boron-containing Therapeutic, Dipotassium-trioxohydroxytetrafl uorotriborate - K2 (B3 O3 F4 OH) in Rats and Mice

Abstract Biological activity of boron-containing compounds (BCCs) has been well-known. Growing interest and numerous applications for BCCs have been reported. Boron and boron-containing acids show low acute toxicity in mammals but data on halogenated boroxine (HB) - dipotassium-trioxohydroxytetrafluorotriborate, K2(B3O3F4OH) acute toxicity have not been reported before. This compound, characterized as a potential therapeutic for skin changes, exhibits no observable genotoxicity in doses lower that 0.1 mg/ml in vitro and 55 mg/kg in vivo. It has also been confirmed as an antitumour agent both in vitro and in vivo as well as an inhibitor of enzymes involved in antioxidant mechanisms. The aim of this study was to assess the acute toxicity of HB and to determine the maximum tolerated dose as well as a dose free of any signs of toxicity in different test organisms. Acute toxicity of HB was tested in Sprague-Dawley and Wistar rats and BALB/c mice after single parenteral application of different doses. We determined doses free of any sign of toxicity and LD50 after single dose administration. LD50 of HB ranges from 63 to 75 mg/kg in different test models, meaning that HB shows moderate toxicity

MicroRNA-124a Protects the Myocardium Against Ischemia Reperfusion Injury Through Regulation of the Notch Signaling Pathway

Abstract Introduction: This study's objective is to investigate the effect of downregulation of micro ribonucleic acid (miR)-124a on myocardial injury after ischemia reperfusion (I/R) in rats. Methods: Sprague Dawley (SD) rats (n=20) were divided into four groups - sham, I/R, I/R+miR-124a antagomir (I/R+ant-miR-124a), and I/R+ant-normal control (NC). The pathomorphological and infarct size variance of injured myocardial tissues with IR were conducted with hematoxylin (HE) and triphenyltetrazolium chloride (TTC) staining. The expression levels of miR-124a, BAX, nuclear factor kappa B (NF-KB), Notch1, and Hes1 were examined by quantitative real-time polymerase chain reaction or Western blot in myocardium. The inflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α) were detected by the enzyme-linked immunosorbent assay, as well as the activity of lactate dehydrogenase (LDH) and creatine kinase (CK) in serum by colorimetry. Results: The expression of miR-124a was increased in the I/R group. Compared with I/R and I/R+ant-NC groups, after downregulating miR-124a, the expression of IL-6, IL-1β, TNF-α, BAX, NF-KB, LDH, and CK were decreased, but the expression of Notch1 and Hes1 were increased. In HE staining, myocardial tissue edema, red blood cell exudation, and myocardial fiber arrangement disorder were accompanied by inflammatory cell infiltration and local necrosis in the I/R group. However, the pathological injury of myocardial tissue was alleviated after downregulating miR-124a. Additionally, TTC results showed that the myocardial infarction area was decreased in the I/R+ant-miR-124a group. Conclusion: Downregulation of miR-124a expression through Notch pathway can significantly reduce myocardial damage after 24 hours of I/R in SD rats. Therefore, miR-124a may become a potential therapeutic target for I/R injury.

Hematologic evaluation of peripheral blood in Sprague Dawley rats by chronic exposure to aluminum chloride (AlCl3).

This study aimed to evaluate whether aluminum chloride (AlCl3) causes hematological changes in the peripheral blood of Sprague-Dawley (SD) rats. Five groups of female SD rats were intragastrically administered with 4 different concentrations of AlCl3 for 5 days a week for a total of 90 days. The aluminum concentration was determined via graphite furnace atomic absorption spectroscopy. Analysis of serum iron-kinetic profiles, blood cytometry outcomes, and blood smears of the blood samples. Scanning electron microscopy (SEM) and Raman spectroscopy were used to search for structural and ultrastructural changes, respectively. Blood aluminum concentration ranged 12.38-16.24 µg/L with no significant difference between experimental treatments. At the AlCl3 concentration of 40 mg Al/kg bw of rats/day, the mean ferritin value in the serum iron kinetic profile was 29.81±6.1 ng/mL, and this value showed a significant difference between experimental treatments. Blood cytometry revealed that there were 6.45-7.11×106 cells/µL erythrocytes, 8.91-9.32×103 cells/µL leukocytes, and 477.2-736.3×103 cells/µL platelets along with a hemoglobin of 37.38-41.93 g/dL and hematocrit level of 37.38-41.93%; the experimental treatments showed no significant differences. Erythrocyte structural analysis using SEM showed no differences between experimental treatments, whereas ultrastructural evaluation using Raman spectroscopy made it possible to identify the following bands: 741, 1123, 1350, 1578, and 1618 cm-1, which were respectively associated with the following vibrational modes and compounds: vibration of the tryptophan ring, asymmetric C-O-C stretching of glucose, C-H curve of tryptophan, C=C stretching of the heme group, and C-N stretching of the heme group, with no significant differences between experimental treatments. Therefore, AlCl3 administration does not induce ultrastructural changes in the erythrocyte membrane. This study revealed that serum ferritin concentration was the only parameter affected by AlCl3 exposure at 40 mg of Al/kg bw of rats/day.

MicroRNA-124a Protects the Myocardium Against Ischemia Reperfusion Injury Through Regulation of the Notch Signaling Pathway.

INTRODUCTION: This study's objective is to investigate the effect of downregulation of micro ribonucleic acid (miR)-124a on myocardial injury after ischemia reperfusion (I/R) in rats. METHODS: Sprague Dawley (SD) rats (n=20) were divided into four groups - sham, I/R, I/R+miR-124a antagomir (I/R+ant-miR-124a), and I/R+ant-normal control (NC). The pathomorphological and infarct size variance of injured myocardial tissues with IR were conducted with hematoxylin (HE) and triphenyltetrazolium chloride (TTC) staining. The expression levels of miR-124a, BAX, nuclear factor kappa B (NF-KB), Notch1, and Hes1 were examined by quantitative real-time polymerase chain reaction or Western blot in myocardium. The inflammatory cytokines interleukin (IL)-6, IL-1ß, and tumor necrosis factor alpha (TNF-α) were detected by the enzyme-linked immunosorbent assay, as well as the activity of lactate dehydrogenase (LDH) and creatine kinase (CK) in serum by colorimetry. RESULTS: The expression of miR-124a was increased in the I/R group. Compared with I/R and I/R+ant-NC groups, after downregulating miR-124a, the expression of IL-6, IL-1ß, TNF-α, BAX, NF-KB, LDH, and CK were decreased, but the expression of Notch1 and Hes1 were increased. In HE staining, myocardial tissue edema, red blood cell exudation, and myocardial fiber arrangement disorder were accompanied by inflammatory cell infiltration and local necrosis in the I/R group. However, the pathological injury of myocardial tissue was alleviated after downregulating miR-124a. Additionally, TTC results showed that the myocardial infarction area was decreased in the I/R+ant-miR-124a group. CONCLUSION: Downregulation of miR-124a expression through Notch pathway can significantly reduce myocardial damage after 24 hours of I/R in SD rats. Therefore, miR-124a may become a potential therapeutic target for I/R injury.

Bio-efficacy of iron and zinc fortified wheat flour along with bio-assessment of its hepatic and renal toxic potential / Bioeficácia da farinha de trigo fortificada com ferro e zinco e bioavaliação do seu potencial tóxico hepático e renal

Study was planned to assess the bio-efficiency along with toxicity of iron and zinc fortified whole wheat flour in Sprague dawley albino rats. Whole wheat flour was fortified with different dosage of sodium iron EDTA (NaFeEDTA), ferrous sulphate (FeSO4), zinc oxide (ZnO) and zinc sulphate (ZnSO4). The rats (n=3) in each group were fed on fortified wheat flour for 2 months. Liver biomarkers including alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate aminotransferase (AST) and bilirubin were recorded from serum samples. Increased concentration of ZnSO4 affected the liver biomarkers to be highest among all whereas, bilirubin levels were less than the rats fed on control diet. The above mentioned fortificants have negligible effect on renal biomarkers including creatinine and urea. Moreover, hematological parameters were also checked and reportedly, sodium iron EDTA fed rats presented highest amount of hemoglobin, iron and total iron binding capacity. Highest zinc level was observed in rats fed on whole wheat flour fortified with 60mg/Kg Zinc oxide. Microscopic observation of liver tissue depicted that rats fed on iron and zinc fortified wheat flour have more toxic effects whereas, histopathology presentation of kidney tissue has least toxic impact. It has been concluded that mandatory fortification of wheat flour with iron and zinc may cause increased serum biomarkers along with toxicity of vital organs like liver, hence fraction of wheat flour may be fortified to fulfill the requirements of deprived and vulnerable group.

O estudo foi planejado para avaliar a bioeficiência juntamente com a toxicidade da farinha de trigo integral fortificada com ferro e zinco em ratos albinos Sprague dawley. A farinha de trigo integral foi fortificada com diferentes dosagens de ferro sódico EDTA (NaFeEDTA), sulfato ferroso (FeSO4), óxido de zinco (ZnO) e sulfato de zinco (ZnSO4). Os ratos (n = 3) de cada grupo foram alimentados com farinha de trigo fortificada por 2 meses. Biomarcadores hepáticos incluindo fosfatase alcalina (ALP), alanina transaminase (ALT), aspartato aminotransferase (AST) e bilirrubina foram registrados a partir de amostras de soro. O aumento da concentração de ZnSO4 afetou os biomarcadores hepáticos como sendo os mais altos entre todos, enquanto os níveis de bilirrubina foram menores do que os ratos alimentados com dieta controle. Os fortificantes mencionados acima têm efeito insignificante nos biomarcadores renais, incluindo creatinina e ureia. Além disso, os parâmetros hematológicos também foram verificados e, segundo relatos, os ratos alimentados com EDTA de sódio e ferro apresentaram maior quantidade de hemoglobina, ferro e capacidade total de ligação de ferro. O maior nível de zinco foi observado em ratos alimentados com farinha de trigo integral fortificada com 60 mg/Kg de óxido de zinco. A observação microscópica do tecido hepático mostrou que ratos alimentados com farinha de trigo fortificada com ferro e zinco têm mais efeitos tóxicos, enquanto a apresentação histopatológica do tecido renal tem menos impacto tóxico. Concluiu-se que a fortificação obrigatória da farinha de trigo com ferro e zinco pode causar aumento dos biomarcadores séricos juntamente com toxicidade de órgãos vitais como o fígado, portanto a fração da farinha de trigo pode ser fortificada para atender os requisitos do grupo carente e vulnerável.

Maternal Low-Protein Diet Deregulates DNA Repair and DNA Replication Pathways in Female Offspring Mammary Gland Leading to Increased Chemically Induced Rat Carcinogenesis in Adulthood.

Studies have shown that maternal malnutrition, especially a low-protein diet (LPD), plays a key role in the developmental mechanisms underlying mammary cancer programming in female offspring. However, the molecular pathways associated with this higher susceptibility are still poorly understood. Thus, this study investigated the adverse effects of gestational and lactational low protein intake on gene expression of key pathways involved in mammary tumor initiation after a single dose of N-methyl-N-nitrosourea (MNU) in female offspring rats. Pregnant Sprague-Dawley rats were fed a normal-protein diet (NPD) (17% protein) or LPD (6% protein) from gestational day 1 to postnatal day (PND) 21. After weaning (PND 21), female offspring (n = 5, each diet) were euthanized for histological analysis or received NPD (n = 56 each diet). At PND 28 or 35, female offspring received a single dose of MNU (25 mg/kg body weight) (n = 28 each diet/timepoint). After 24 h, some females (n = 10 each diet/timepoint) were euthanized for histological, immunohistochemical, and molecular analyses at PDN 29 or 36. The remaining animals (n = 18 each diet/timepoint) were euthanized when tumors reached ≥2 cm or at PND 250. Besides the mammary gland development delay observed in LPD 21 and 28 groups, the gene expression profile demonstrated that maternal LPD deregulated 21 genes related to DNA repair and DNA replication pathways in the mammary gland of LPD 35 group after MNU. We further confirmed an increased γ-H2AX (DNA damage biomarker) and in ER-α immunoreactivity in mammary epithelial cells in the LPD group at PND 36. Furthermore, these early postnatal events were followed by significantly higher mammary carcinogenesis susceptibility in offspring at adulthood. Thus, the results indicate that maternal LPD influenced the programming of chemically induced mammary carcinogenesis in female offspring through increase in DNA damage and deregulation of DNA repair and DNA replication pathways. Also, Cidea upregulation gene in the LPD 35 group may suggest that maternal LPD could deregulate genes possibly leading to increased risk of mammary cancer development and/or poor prognosis. These findings increase the body of evidence of early-transcriptional mammary gland changes influenced by maternal LPD, resulting in differential response to breast tumor initiation and susceptibility and may raise discussions about lifelong prevention of breast cancer risk.

Species-Specific in vitro and in vivo Evaluation of Toxicity of Silver Nanoparticles Stabilized with Gum Arabic Protein.

INTRODUCTION: We report, herein, in vitro, and in vivo toxicity evaluation of silver nanoparticles stabilized with gum arabic protein (AgNP-GP) in Daphnia similis, Danio rerio embryos and in Sprague Dawley rats. PURPOSE: The objective of this investigation was to evaluate in vitro and in vivo toxicity of silver nanoparticles stabilized with gum arabic protein (AgNP-GP), in multispecies due to the recognition that toxicity evaluations beyond a single species reflect the environmental realism. In the present study, AgNP-GP was synthesized through the reduction of silver salt using the tri-alanine-phosphine peptide (commonly referred to as "Katti Peptide") and stabilized using gum arabic protein. METHODS: In vitro cytotoxicity tests were performed according to ISO 10993-5 protocols to assess cytotoxicity index (IC50) values. Acute ecotoxicity (EC50) studies were performed using Daphnia similis, according to the ABNT NBR 15088 protocols. In vivo toxicity also included evaluation of acute embryotoxicity using Danio rerio (zebrafish) embryos following the OECD No. 236 guidelines. We also used Sprague Dawley rats to assess the toxicity of AgNP-GP in doses from 2.5 to 10.0 mg kg-1 body weight. RESULTS: AgNP-GP nanoparticles were characterized through UV (405 nm), core size (20±5 nm through TEM), hydrodynamic size (70-80 nm), Zeta (ζ) potential (- 26 mV) using DLS and Powder X ray diffraction (PXRD) and EDS. PXRD showed pattern consistent with the Ag (1 1 1) peak. EC50 in Daphnia similis was 4.40 (3.59-5.40) µg L-1. In the zebrafish species, LC50 was 177 µg L-1. Oral administration of AgNP-GP in Sprague Dawley rats for a period of 28 days revealed no adverse effects in doses of up to 10.0 mg kg-1 b.w. in both male and female animals. CONCLUSION: The non-toxicity of AgNP-GP in rats offers a myriad of applications of AgNP-GP in health and hygiene for use as antibiotics, antimicrobial and antifungal agents.

Creatine Supply Attenuates Ischemia-Reperfusion Injury in Lung Transplantation in Rats.

Ischemia-reperfusion injury (IRI) is one of the factors limiting the success of lung transplantation (LTx). IRI increases death risk after transplantation through innate immune system activation and inflammation induction. Some studies have shown that creatine (Cr) protects tissues from ischemic damage by its antioxidant action. We evaluated the effects of Cr supplementation on IRI after unilateral LTx in rats. Sixty-four rats were divided into four groups: water + 90 min of ischemia; Cr + 90 min of ischemia; water + 180 min of ischemia; and Cr + 180 min of ischemia. Donor animals received oral Cr supplementation (0.5 g/kg/day) or vehicle (water) for five days prior to LTx. The left lung was exposed to cold ischemia for 90 or 180 min, followed by reperfusion for 2 h. We evaluated the ventilatory mechanics and inflammatory responses of the graft. Cr-treated animals showed a significant decrease in exhaled nitric oxide levels and inflammatory cells in blood, bronchoalveolar lavage fluid and lung tissue. Moreover, edema, cell proliferation and apoptosis in lung parenchyma were reduced in Cr groups. Finally, TLR-4, IL-6 and CINC-1 levels were lower in Cr-treated animals. We concluded that Cr caused a significant decrease in the majority of inflammation parameters evaluated and had a protective effect on the IRI after LTx in rats.

Quercetina Melhora o Perfil Lipídico e Apolipoproteico em Ratos Tratados com Glicocorticóides em Altas Doses / Quercetin Ameliorates Lipid and Apolipoprotein Profile in High-Dose Glucocorticoid Treated Rats

Resumo Fundamento Os glicocorticóides (GCs) são amplamente prescritos para o tratamento de numerosos distúrbios clínicos devido às suas propriedades anti-inflamatórias e imunomoduladoras, e um dos efeitos indesejáveis mais comuns desses medicamentos é a dislipidemia. Objetivo Avaliar o efeito da quercetina, um flavonoide derivado de plantas, no perfil lipídico de ratos tratados com glicocorticóides em altas doses. Métodos Um total de 32 ratos Sprague-Dawley foram distribuídos aleatoriamente entre quatro grupos (8 ratos por grupo) e tratados por 6 semanas com uma das seguintes opções : (i) solução salina normal; (ii) 40 mg/kg de succinato sódico de metilprednisolona (MP); (iii) MP + 50 mg/kg de quercetina; (iv) MP + 150 mg/kg de quercetina. O MP foi injetado por via subcutânea e a quercetina foi administrada por gavagem oral 3 dias por semana. No final do estudo, o perfil lipídico dos animais foi medido através de kits enzimáticos. Os dados foram analisados e a significância estatística foi estabelecida em p <0,05. Resultados Os níveis séricos médios de colesterol total (CT), triglicerídeos (TG) e LDL aumentaram drasticamente em animais tratados com GC em comparação com o grupo controle. Ambas as doses de quercetina (50 e 150 mg/kg) melhoraram o CT (43% e 45%), LDL (56% e 56%) e TG (46% e 55%, respectivamente). A razão Apo B/A1 diminuiu mais de 20% após a ingestão de Anti-Inflamatory Agents. Conclusões Esses dados sugerem que a ingestão de quercetina Quercetin; induzida por glicocorticóides. (Arq Bras Cardiol. 2020; 115(1):102-108)

Abstract Background Glucocorticoids (GCs) are widely prescribed for the treatment of numerous clinical disorders due to their anti-inflammatory and immune-modulatory properties and one of the most common untoward effects of these drugs is dyslipidemia. Objective To evaluate the effect of quercetin, a plant-derived flavonoid, on the lipid profile of high-dose glucocorticoid treated rats. Methods A total of 32 Sprague-Dawley rats, were randomly distributed among four groups (8 rats per group) and treated for 6 weeks with one of the following: (i) normal saline; (ii) 40 mg/kg methylprednisolone sodium succinate (MP); (iii) MP + 50 mg/kg quercetin; (iv) MP + 150 mg/kg quercetin. MP was injected subcutaneously, and quercetin was administered by oral gavage 3 days a week. At the end of the study, the animals' lipid profile was measured by enzymatic kits. Data were analyzed and statistical significance was set at p<0.05. Results The mean serum total cholesterol (TC), triglyceride (TG) and LDL levels were drastically increased in GC-treated animals compared with the control group. Both doses of quercetin (50 and 150 mg/kg) ameliorated TC (43% and 45%), LDL (56% and 56%) and TG (46% and 55% respectively). Apo B/A1 ratio decreased more than 20% following quercetin intake and the decline in TC/HDL, TG/HL, LDL/HDL ratios were significant. Conclusions These data suggest that quercetin intake with both doses of 50 and 150 mg/kg could be considered as a protective agent for glucocorticoid-induced dyslipidemia. (Arq Bras Cardiol. 2020; 115(1):102-108.)

Ensayo de inmunogenicidad y toxicidad aguda del candidato vacunal contra el cólera vax-COLER® / Immunogenicity and acute toxicity assay of the vaccine candidate against cholera vax-COLER®

Para el control y prevención del cólera humano se han llevado a cabo diferentes estrategias, entre las cuales, la vacunación es una de las medidas más eficaces. La evaluación preclínica de candidatos vacunales requiere de la demostración de la seguridad de los mismos, para lo cual los estudios toxicológicos son determinantes, al ser obligatorios y altamente regulados. Este estudio tuvo como objetivo demostrar la relevancia de las ratas Sprague Dawley como biomodelo a través de su respuesta inmunológica al candidato vacunal contra el cólera, vax-COLER®, utilizando la técnica de determinación de anticuerpos vibriocidas. Además, evaluar los efectos toxicológicos locales y sistémicos por la administración de una dosis de vax-COLER® a través de la evaluación de síntomas, del consumo de agua y alimentos, el peso corporal y estudios anatomopatológicos. La vacuna vax-COLER® resultó inmunogénica y no evidenció síntomas ni muertes, no hubo cambios en el peso corporal y los consumos de agua y alimentos se comportaron de forma similar entre todos los grupos. Los estudios anatomopatológicos solo mostraron cambios a nivel histológico en los ganglios linfáticos mesentéricos y placas de Peyer de los animales vacunados, con presencia de hiperplasia de los folículos secundarios subcapsulares, hallazgo que difirió significativamente con el resto de los grupos. Se concluye que la vacuna vax-COLER® es inmunogénica en ratas Sprague Dawley, demostrando la relevancia del biomodelo para la evaluación de la seguridad preclínica y que la aplicación de una dosis no produjo efectos tóxicos agudos generales ni locales(AU)

Different strategies have been carried out for the control and prevention of human cholera. Vaccination is one of the most effective strategies. Preclinical evaluation of vaccines needs to prove their safety; whereby toxicological studies are decisive. They are mandatory and highly regulated. This study was aimed to demonstrate the relevance of Sprague Dawley rats as a biomodel, through the immunological response to vax-COLER® cholera vaccine, using the technique of determination of vibriocidal antibodies. In addition, local and systemic toxicological effects were evaluated after administration of a dose of vax-COLER®; through the evaluation of symptoms, water and food consumption, body weight and anatomopathological studies. The vax-COLER® vaccine was immunogenic and showed no symptoms or deaths. No changes in body weight were detected, and food and water consumption were similar among all groups. The anatomopathological studies showed histological changes in the mesenteric lymph nodes and Peyer's patches of the vaccinated animals, with hyperplasia of the subcapsular secondary follicles, finding that differed significantly from the rest of the groups. It is concluded that vax-COLER® vaccine is immunogenic in Sprague-Dawley rats, demonstrating the relevance of the biomodel for the evaluation of preclinical safety, as well as that the application of a single dose did not produce acute general or local toxic effects(AU)

Efecto del ultrasonido de baja intensidad (USBI) sobre el movimiento dentario ortodóncico: estudio in vivo en ratas Sprague-Dawley / Effect of low intensity ultrasound (USBI) in the orthodontic dental movement: in vivo study in Sprague-Dawley rats

Este estudio se realizó con el propósito de analizar el efecto de la aplicación de ondas de USBI sobre la velocidad y distancia de movimiento dentario, y su efecto a nivel histológico en ratas Sprague-Dawley. Veintitrés ratas macho Sprague-Dawley fueron parte del experimento, las que fueron divididas aleatoriamente en tres grupos. Cinco ratas fueron utilizadas como control sin movimiento dentario ortodóncico (MDO), nueve ratas fueron sometidas a una aplicación de fuerza ortodóncica sin aplicación de USBI y nueve fueron sometidas a una aplicación de fuerza ortodóncica con USBI. Estas fuerzas ortodóncicas fueron realizadas entre el aspecto mesio vestibular del primer molar superior izquierdo y el incisivo central superior, traccionando el molar hacia mesial, aplicando una fuerza aproximada de 50 gramos durante 21 días, debido a problemas con la sedación estos dos últimos grupos quedaron compuestos de seis y ocho ratas respectivamente. En el grupo MDO sin USBI, se registró una reducción del espacio entre molares e incisivos de 2 mm. En el grupo MDO con USBI dicha reducción fue de 3.4 mm, siendo esta diferencia estadísticamente significativa. Histológicamente el grupo MDO c/USBI mostró un perímetro vascular y espacios medulares aumentados respecto de los otros grupos, no obstante, no se encontraron diferencias significativas en la cantidad de osteoclastos. Fue posible observar y demostrar cuantitativamente que el USBI es una forma de estimulación mecánica eficiente para la aceleración del MDO sobre un período experimental de 21 días, donde se observaron diferencias significativas entre el grupo control, el grupo MDO sin USBI y el grupo MDO con USBI en la magnitud del movimiento dentario. Se observó una mayor vascularidad en el grupo con USBI, expresando perímetros vasculares de mayor tamaño, esto pudo deberse al efecto estimulatorio del ultrasonido sobre la angiogénesis.

The objective of this study was to analyze the effect of USBI wave application on the speed and distance of dental movement, and its effect at histological level in SpragueDawley rats. In this study twenty-three male Sprague-Dawley rats were randomly divided into three groups. Five rats were used as control without orthodontic tooth movement (MDO), nine rats were subjected to an orthodontic force application without USBI application, and nine were subjected to an orthodontic force application with USBI. The orthodontic forces were performed between the vestibular mesio aspect of the first upper left molar and upper central incisor, pulling the molar mesially, applying an approximate force of 50 grams for 21 days. In light of sedation problems these last two groups were composed of six and eight rats respectively. In the MDO group without USBI, there was a reduction in the space between molars and incisors of 2 mm. In the MDO group with USBI this reduction was 3.4mm, this difference being statistically significant. Histologically, the MDO c / USBI group showed a vascular perimeter and enlarged spinal spaces with respect to the other groups, however, no significant differences were found in the amount of osteoclasts. It was possible to quantitatively demonstrate that USBI is a form of efficient mechanical stimulation for MDO acceleration over an experimental 21-day period, where significant differences were observed in tooth movement between the control group, the group without USBI and the group with USBI. A greater vascularity was observed in the group with USBI, expressing larger vascular perimeters, which could be due to the stimulatory effect of ultrasound on angiogenesis.

Reactogenicity of Bordetella pertussis vaccines formulations using aluminum adjuvants in Sprague Dawley rats / Reactogenicidad de formulaciones de vacunas de Bordetella pertussis utilizando adyuvantes de aluminio en ratas Sprague Dawley

Combined vaccines for childhood are a strategy in the prevention of several diseases. These can maximize protection and decrease immunization schedules in children. New candidates are getting closer to being able to meet these needs, but they raise numerous strategic questions related to formulation and regulatory aspects. In addition to being immunogenic and protective must have low reactogenicity when combined with other antigens. Adjuvants are important components in achieving these combinations. Therefore, a reactogenicity study was designed for two Bordetella pertussis formulations containing hydroxide or aluminum phosphate in Sprague Dawley rats. Both formulations dose were administered in 0.2 mL intramuscularly. Clinical evaluations, body weight, water consumption, food, temperature, muscle volume, dermal irritability and pathological studies with special interest at the inoculation site were carried out. Only differences in body temperature and muscle volume were found with a slight increase in values with return to normal. The macroscopic study showed lesions at the site of inoculation, consid­ered characteristics of aluminum adjuvants, such as granulomatous abscesses and the increase in regional lymph nodes near the inoculation site. As conclusion, there are no differences between the formulations of B. pertussis with hydroxide or aluminum phosphate resulted in low reactogenicity.

Las vacunas combinadas resultan una estrategia importante en la obtención de vacunas múltiples para la infancia y el uso de adyuvantes es un componente de gran valor en lograr estas combinaciones, además de ser inmunogénicas y protectoras deben tener baja reactogenicidad, cuando se combinan con diferentes antígenos. Por esta razón, se diseñó un estudio de reactogenicidad a dos formulaciones que contenían hidróxido y fosfato de aluminio con antígenos de Bordetella pertussis en ratas Sprague Dawley. Se administró a cada grupo de ensayo una dosis correspondiente de ambas formulaciones en 0,2 mL por vía intramuscular. Se realizaron observaciones clínicas, comportamiento del peso corporal, consumo de agua, alimentos, temperatura corporal, volumen muscular, irritabilidad dérmica y estudios anatomopatológicos macroscópicos, con especial interés en el sitio de inoculación. No se observaron síntomas, ni muertes en los animales durante el estudio. Tampoco se encontraron diferencias entre los grupos experimentales en cuanto al peso corporal, el consumo de agua y de alimentos; los estudios de temperatura corporal y volumetría muscular evidenciaron un ligero incremento en los valores, los cuales involucionaron rápidamente a la normalidad. En el estudio anatomopatológico macroscópico se observaron lesiones a nivel del punto de inoculación, consideradas propias de los adyuvantes que contienen aluminio, tales como formaciones abscedadas de tipo granulomatosas y el aumento de los ganglios linfáticos regionales cercanos al punto de inoculación. Se concluye que las formulaciones en hidróxido y fosfato de aluminio con antígenos de B.pertussis resultaron ser de baja reactogenicidad.

Case Reports of Situs Inversus Totalis and Dextrocardia in Sprague Dawley Rats.

Situs inversus totalis is a condition where there is a transposition of all internal organs from their normal anatomical location. This infrequent and rare congenital condition has been described in several species of mammals. Dextorcardia is a series of conditions associated with an abnormal congenital positioning of the heart, and is often associated with situs inversus totalis. Here we report a case of situs inversus totalis and two cases of dextrocardia identified in Sprague Dawley rats during gross necropsy evaluations at both the Health Sciences North Research Institute (HSNRI) in Canada and Finlay Institute of Vaccine Research and Production in Cuba. The intent of this report is to share our findings and aid in the accumulation of data on these rare conditions.

Estudio de tolerancia local de la vacuna antimeningocóccica VA-MENGOC-BC® en ratas Sprague Dawley. Evaluación a los 24 y 36 meses en estante / Local tolerance study of the VA-MENGOC-BC® antimeningococcal vaccine in Sprague Dawley rats. Evaluation at 24 and 36 months of shelf

La meningitis meningocóccica continua siendo un problema de salud en diferentes países y para la prevención de esta enfermedad se han obtenido diferentes vacunas. La vacuna VA-MENGOC-BC® ha constituido ser eficaz y segura en la prevención de la meningitis meningocóccica contra los serogrupos B y C. Esta ha demostrado buena estabilidad en el tiempo sin cambiar su calidad como producto; fue conservada a estante durante 24 y 36 meses a temperaturas de 4 a 8 °C. Se evaluó su posible potencial toxicológico a través de un estudio de tolerancia local en ratas Sprague Dawley para extender su vida útil. Los animales inmunizados se observaron diariamente para evaluar síntomas locales y sistémicos de toxicidad. Se realizaron evaluaciones del peso corporal, consumo de agua y alimento, termometría, musculometría e irritabilidad dérmica por el método de Draize. Se realizaron estudios anatomopatológicos periódicos para observar posibles efectos adversos. No se observaron síntomas de toxicidad ni muertes. No se encontraron diferencias entre los grupos experimentales en cuanto al peso corporal, el consumo de agua y de alimentos, no se evidenció fiebre, ni irritabilidad local. Anatomopatológicamente a nivel del punto de inoculación se observaron procesos granulomatosos de tipo macrofágicos característicos en las vacunas que contienen hidróxido de aluminio. Estos resultados permitieron concluir que la vacuna VA-MENGOC-BC® que permaneció en estante durante 24 y 36 meses no evidenció efectos adversos locales, ni sistémicos en las ratas(AU)

Meningococcal meningitis continues to be a health problem in different countries and different vaccines have been obtained for the prevention of this disease. VA-MENGOC-BC® vaccine has been effective and safe in the prevention of meningococcal meningitis against serogroups B and C. This has shown good stability over time without changing its quality as a product; it was stored on a shelf for 24 and 36 months at temperatures of 4 to 8 °C. Their possible toxicological potential was evaluated through a local tolerance study in Sprague Dawley rats. Immunized animals were observed daily to evaluate local and systemic toxicity symptoms. Body weight, water and feed intake, thermometry, musculometry were performed and dermal irritability by the Draize method. Anatomopathological studies to observe possible adverse effects were made. No symptoms of toxicity or deaths were observed. No differences were found between the experimental groups in terms of body weight, water and food consumption, no fever or local irritability was evident. Anatomopathologically no lesions of diagnostic value were observed, at the site of inoculation, granulomatous processes of macrophagic type characteristic in vaccines containing aluminum hydroxide were observed. These results allowed us to conclude that the VA-MENGOC-BC® vaccine that remained on the shelf for 24 and 36 months did not show any local or systemic effects in rats(AU)

aPKC-Mediated Persistent Increase in AMPA/NMDA Ratio in the VTA Participates in the Neuroadaptive Signal Necessary to Induce NAc Synaptic Plasticity After Cocaine Administration.

Chronic cocaine exposure produces enduring neuroadaptations in the brain's reward system. Persistence of early cocaine-evoked neuroadaptations in the ventral tegmental area (VTA) is necessary for later synaptic alterations in the nucleus accumbens (NAc), suggesting a temporal sequence of neuroplastic changes between these two areas. However, the molecular nature of the signal that mediates this sequential event is unknown. Here we used the behavioral sensitization model and the aPKC inhibitor of late-phase LTP maintenance, ZIP, to investigate if a persistent increase in AMPA/NMDA ratio plays a role in the molecular mechanism that allows VTA neuroadaptations to induce changes in the NAc. Results showed that intra-VTA ZIP microinfusion successfully blocked cocaine-evoked synaptic enhancement in the VTA and the expected AMPA/NMDA ratio decrease in the NAc following cocaine sensitization. ZIP microinfusions also blocked the expected AMPA/NMDA ratio increase in the NAc following cocaine withdrawal. These results suggest that a persistent increase in AMPA/NMDA ratio, mediated by aPKCs, could be the molecular signal that enables the VTA to elicit synaptic alterations in the NAc following cocaine administration.

Long-Term Dietary Intake of Chia Seed Is Associated with Increased Bone Mineral Content and Improved Hepatic and Intestinal Morphology in Sprague-Dawley Rats.

Chia seeds (Salvia hispanica) provide an unusually high content of α-linolenic acid with several potential health benefits, but few studies have examined the long-term intake of n-3 fatty acid-rich plant foods such as chia. In this work, we investigated some of the effects of a diet containing 10% chia seeds versus a conventional isocaloric diet for 10 and 13 months on body measurements, musculoskeletal system, the liver, and the intestines of 20 male Sprague-Dawley rats assigned into two groups. The n-6/n-3 ratios for the control and chia diets were 7.46 and 1.07, respectively. For the first 10 months of the diet, the body parameters and weights were similar, but at 13 months, the bone mineral content (BMC) of the chia-fed rats was significantly higher than that of the controls whether in total or proximal areas of the left tibia. Also, significant positive correlations were found between the age of the chia group and the bone mineral density, BMC, weight of the musculoskeletal system, final body weight, and skin weight. Liver and intestinal examinations showed improved morphology associated with lower lipid deposit in hepatocytes and increased intestinal muscle layers and crypt size in the chia group. This study provides new data suggesting the potential benefits associated with the long-term intake of chia seeds.

Effect of D-ribose-L-cysteine on aluminum induced testicular damage in male Sprague-Dawley rats.

OBJECTIVE: This study investigated the effects of D-ribose and L-cysteine on aluminum-induced testicular damage in male Sprague-Dawley rats. METHOD: A total number of thirty-five (35) adult male Sprague-Dawley rats were divided into four groups (AD). Group A (comprised five (5) rats) was designated the Control Group that received Physiological Saline; while groups B, C, and D (comprised ten (10) rats) were given 75 mg/kg, 150 mg/kg and 300 mg/kg of body weight of aluminum chloride respectively for 39 days. At day 40, the aluminum-treated groups were subdivided into sub-groups (B1, C1, D1) comprising of five (5) rats each, and 30 mg/kg body weight of Riboceine were administered for twenty (20) days. Groups B, C and D remained on the normal dosage of aluminum chloride for three more weeks (59 days). RESULTS: Andrological parameters (Sperm count, motility, morphology and testosterone) in the aluminum-treated Groups B and C showed no significant difference in their mean values when compared with their control counterparts, whereas there was a significant reduction in the andrological parameters in Group D rats when compared with the Control animals. Histoarchitecture of the testes "stain with H&E" of Group A, B and C rats appeared normal while Group D rats showed testicular damages with several abnormal seminiferous tubules with incomplete maturation of germinal cell layers and absence of spermatozoa in their lumen; Leydig cells appear hyperplastic. Group B1, C1 and D1 andrological and histological parameters appeared normal. CONCLUSION: Riboceine treatment significantly attenuates aluminum-induced testicular toxicity in male Sprague-Dawley in rats.

Early-in-life dietary zinc deficiency and supplementation and mammary tumor development in adulthood female rats.

Zinc deficiency during pregnancy and postnatal life can adversely increase risk of developing human diseases at adulthood. The present study was designed to evaluate whether dietary zinc deficiency or supplementation during the pregnancy, lactation and juvenile stages interferes in the development of mammary tumors induced by 7,12-dimethylbenzanthracene (DMBA) in female Sprague-Dawley (SD) rats. Pregnant female SD rats were allocated into three groups: zinc-adequate diet (ZnA - 35-mg/kg chow), zinc-deficient diet (ZnD - 3-mg/kg chow) or zinc-supplemented diet (ZnS - 180-mg/kg chow) during gestational day 10 (GD 10) until the litters' weaning. Female offspring received the same diets as their dams until postnatal day (PND) 51. At PND 51, the animals received a single dose of DMBA (50 mg/kg, ig) and zinc-adequate diets. At PND 180, female were euthanized, and tumor samples were processed for histological evaluation and gene expression microarray analysis. The ZnD induced a significant reduction in female offspring body weight evolution and in mammary gland development. At late in life, the ZnD or ZnS did not alter the latency, incidence, multiplicity, volume or histological types of mammary tumors in relation to the ZnA group. However, the total tumor number in ZnS group was higher than in ZnA group, accompanied by distinct expression of 4 genes up- and 15 genes down-regulated. The present findings indicate that early-in-life dietary zinc supplementation, differently to zinc deficiency, has a potential to modify the susceptibility to the development of mammary tumors induced by DMBA.