Toxicidad a dosis repetida e inmunogenicidad en Cercopithecus aethiops, del candidato vacunal SOBERANA 01 (FINLAY-FR-01) contra el coronavirus de tipo 2 causante del síndrome respiratorio agudo severo / Repeated dose toxicity and immunogenicity in Cercopithecus aethiops of SARS-CoV-2 SOBERANA 01 (FINLAY-FR-01) vaccine candidate

En el Instituto Finlay de Vacunas se desarrolló el candidato vacunal SOBERANA 01 (FINLAY-FR-01) contra el coronavirus de tipo 2 causante del síndrome respiratorio agudo severo. Este trabajo tuvo como objetivo evaluar la inmunogenicidad y posibles efectos toxicológicos del candidato vacunal SOBERANA 01 (FINLAY-FR-01 en Cercopithecus aethiops. Se utilizaron cinco primates no humanos (hembras), de 1-3 años de edad y 1-4 kg de peso corporal, distribuidos en dos grupos experimentales: Control (Solución Salina Fisiológica) y Tratado SOBERANA 01 (FINLAY-FR-01). El estudio se extendió por 84 días, en un esquema a dosis repetida de cuatro inmunizaciones los días 0, 28, 56 y 70. Se realizaron observaciones clínicas diarias, peso corporal, signos vitales (temperatura rectal, frecuencia respiratoria, y frecuencia cardíaca), exámenes electrocardiográficos, toma de la temperatura del sitio de inyección, musculometría e irritabilidad dérmica. Fueron realizados exámenes de hematología, bioquímica sanguínea, así como estudios inmunológicos. El ensayo concluyó con una supervivencia del 100por ciento, no se manifestaron signos de toxicidad, no hubo variaciones hematológicas, ni de la bioquímica sanguínea asociadas a la sustancia de ensayo. Además, no se observaron efectos locales en el sitio de administración. Por último, el candidato vacunal resultó inmunogénico, ya que se indujeron títulos altos de IgG anti-RBD, así como de la inhibición de la unión de RBD a ACE2(AU)

At Finlay Vaccine Institute has been developed the vaccine candidate SOBERANA 01 (FINLAY-FR-01) against SARS-CoV-2 virus, causing COVID-19. This work aims to evaluate the immunogenicity and possible toxicological effects of the SOBERANA 01 (FINLAY-FR-01) vaccine candidate in Cercopithecus aethiops. Five non-human primates (females) from 1-3 years old and 1-4 kg of body weight were distributed in two experimental groups: Control (Physiological Saline Solution) and Treated (SOBERANA 01 FINLAY-FR-01). The study extended through 84 days, in a repeated dose schedule of four immunizations on days 0, 28, 56, and 70. Daily clinical observations, body weight, vital signs (rectal temperature, respiratory rate, and heart rate), electrocardiographic examinations, temperature of the injection site, musculometry and dermic irritability, were performed. Hematological and blood biochemistry tests, as well as immunological studies were assessed. At the end of the assay 100percent survival was obtained, there were no signs of toxicity neither hematological or blood biochemistry variations associated with the test substance. In addition, no local effects were observed at the administration site. Finally, the vaccine candidate was immunogenic, since high titers of anti-RBD IgG, as well as inhibition of the RBD to ACE2 binding were induced(AU)

The efficacy of 2-nitrovinylfuran derivatives against Leishmania in vitro and in vivo.

Despite recent advances in the treatment of some forms of leishmaniasis, the available drugs are still far from ideal due to inefficacy, parasite resistance, toxicity and cost. The wide-spectrum antimicrobial activity of 2-nitrovinylfuran compounds has been described, as has their activity against Trichomonas vaginalis and other protozoa. Thus, the aim of this study was to test the antileishmanial activities of six 2-nitrovinylfurans in vitro and in a murine model of leishmaniasis. Minimum parasiticide concentration (MPC) and 50% inhibitory concentration (IC50) values for these compounds against the promastigotes of Leishmania amazonensis, Leishmania infantum and Leishmania braziliensis were determined, as were the efficacies of two selected compounds in an experimental model of cutaneous leishmaniasis (CL) caused by L. amazonensis in BALB/c mice. All of the compounds were active against the promastigotes of the three Leishmania species tested. IC50 and MPC values were in the ranges of 0.8-4.7 µM and 1.7-32 µM, respectively. The compounds 2-bromo-5-(2-bromo-2-nitrovinyl)-furan (furvina) and 2-bromo-5-(2-methyl-2-nitrovinyl)-furan (UC245) also reduced lesion growth in vivo at a magnitude comparable to or higher than that achieved by amphotericin B treatment. The results demonstrate the potential of this class of compounds as antileishmanial agents and support the clinical testing of Dermofural(r) (a furvina-containing antifungal ointment) for the treatment of CL.

The efficacy of 2-nitrovinylfuran derivatives against Leishmania in vitro and in vivo

Despite recent advances in the treatment of some forms of leishmaniasis, the available drugs are still far from ideal due to inefficacy, parasite resistance, toxicity and cost. The wide-spectrum antimicrobial activity of 2-nitrovinylfuran compounds has been described, as has their activity against Trichomonas vaginalis and other protozoa. Thus, the aim of this study was to test the antileishmanial activities of six 2-nitrovinylfurans in vitro and in a murine model of leishmaniasis. Minimum parasiticide concentration (MPC) and 50% inhibitory concentration (IC50) values for these compounds against the promastigotes of Leishmania amazonensis, Leishmania infantum and Leishmania braziliensis were determined, as were the efficacies of two selected compounds in an experimental model of cutaneous leishmaniasis (CL) caused by L. amazonensis in BALB/c mice. All of the compounds were active against the promastigotes of the three Leishmania species tested. IC50 and MPC values were in the ranges of 0.8-4.7 µM and 1.7-32 µM, respectively. The compounds 2-bromo-5-(2-bromo-2-nitrovinyl)-furan (furvina) and 2-bromo-5-(2-methyl-2-nitrovinyl)-furan (UC245) also reduced lesion growth in vivo at a magnitude comparable to or higher than that achieved by amphotericin B treatment. The results demonstrate the potential of this class of compounds as antileishmanial agents and support the clinical testing of Dermofural(r) (a furvina-containing antifungal ointment) for the treatment of CL.

Evaluación genotóxica del extracto oleoso de la semilla de Carapa guianensis Aublet en el ensayo de aberraciones cromosómicas en ratones Balb/c / Genotoxic assessment of the Carapa guianensis Aublet seed oil extract in the chromosomal aberrations assay performed in Balb/c mice

Introducción: el extracto oleoso de la semilla de Carapa guianensis Aublet ha tenido diversos usos biomédicos. Recientemente fue evaluado este extracto, el cual manifestó grandes potencialidades como antioxidante en ensayos in vivo; pero poco se conoce de su efecto sobre el ADN en biomodelos experimentales. Objetivo: evaluar el potencial genotóxico del extracto oleoso de la semilla de Carapa guianensis en el ensayo de aberraciones cromosómicas de células de la médula ósea de ratones Balb/c. Métodos: se formaron cinco grupos experimentales: un grupo placebo (Tween 65 al 2 por ciento), tres tratados con niveles de dosis del extracto (400, 1 000 y 2 000 mg/kg), administrados por vía oral durante 14 días; por último, un grupo control positivo tratado con ciclofosfamida, en dosis de 50 mg/kg por vía intraperitoneal 48 y 24 h antes de la eutanasia. Se administraron cinco animales/sexo/grupo. Después de los 14 días de administración se les efectuó la eutanasia por dislocación cervical y se les extrajo la médula ósea del fémur para proceder a realizar la técnica citogenética de aberraciones cromosómicas. Resultados: los resultados entre controles y tratados con el extracto no difirieron para los dos sexos en las variables índice mitótico, Gaps, células con poliploidías, número de células con aberraciones cromosómicas y cromatídicas y el porcentaje de células con aberraciones. Sin embargo, sí difirieron controles y tratados contra el grupo tratado con ciclofosfamida, lo que valida nuestros resultados. Conclusiones: el extracto oleoso de la semilla de la Carapa guianensis no posee potencialidades genotóxicas en la formación de aberraciones cromosómicas, sobre todo estructurales en células de la médula ósea de ratones Balb/c de ambos sexos(AU)

Introduction: the oil extract from Carapa guianensis seed has various biomedical applications. It was recently evaluated and revealed great potentialities as antioxidant in in vivo assays, but little is known about its effect on DNA in experimental biomodels. Objective: to evaluate the genotoxic potential of the oil extract from Carapa guianensis seed in the chromosomal aberration of the bone marrow cells test performed in Balb/c mice. Methods: five experimental groups were created: one placebo group (Tween 65, 2 percent), three treated with different extract doses (400, 1000 and 2000 mg/kg) orally administered for 14 days and one positive control group treated with cyclophosphamide at a dose of 50 mg/kg intraperitoneally at 48 and 24 h before euthanasia. Five animals per sex from each group were administered the set dose. After 14 days of treatment, the animals were euthanized through cervical dislocation and their femoral bone marrow was taken out to perform the cytogenetic chromosomal aberration technique. Results: the results between the control group and the groups treated with the extract did not differ between the two sexes in terms of the mitotic index variables, Gaps, polyploidy cells, number of cells with chromosome and chromatic aberrations and the percentage of aberration cells. However, the results of controls and of treated groups were different from those of the group treated with cyclophosphamide, which proved the validation of our results. Conclusions: the oil extract from Carapa guianensis seeds does not have genotoxic potential for the formation of chromosome aberrations, mainly structural, in Balb/c mice bone marrow of both sexes(AU)

Evaluación genotóxica del extracto oleoso de la semilla de Carapa guianensis Aublet en el ensayo de aberraciones cromosómicas en ratones Balb/c / Genotoxic assessment of the Carapa guianensis Aublet seed oil extract in the chromosomal aberrations assay performed in Balb/c mice

Introducción: el extracto oleoso de la semilla de Carapa guianensis Aublet ha tenido diversos usos biomédicos. Recientemente fue evaluado este extracto, el cual manifestó grandes potencialidades como antioxidante en ensayos in vivo; pero poco se conoce de su efecto sobre el ADN en biomodelos experimentales. Objetivo: evaluar el potencial genotóxico del extracto oleoso de la semilla de Carapa guianensis en el ensayo de aberraciones cromosómicas de células de la médula ósea de ratones Balb/c. Métodos: se formaron cinco grupos experimentales: un grupo placebo (Tween 65 al 2 por ciento), tres tratados con niveles de dosis del extracto (400, 1 000 y 2 000 mg/kg), administrados por vía oral durante 14 días; por último, un grupo control positivo tratado con ciclofosfamida, en dosis de 50 mg/kg por vía intraperitoneal 48 y 24 h antes de la eutanasia. Se administraron cinco animales/sexo/grupo. Después de los 14 días de administración se les efectuó la eutanasia por dislocación cervical y se les extrajo la médula ósea del fémur para proceder a realizar la técnica citogenética de aberraciones cromosómicas. Resultados: los resultados entre controles y tratados con el extracto no difirieron para los dos sexos en las variables índice mitótico, Gaps, células con poliploidías, número de células con aberraciones cromosómicas y cromatídicas y el porcentaje de células con aberraciones. Sin embargo, sí difirieron controles y tratados contra el grupo tratado con ciclofosfamida, lo que valida nuestros resultados. Conclusiones: el extracto oleoso de la semilla de la Carapa guianensis no posee potencialidades genotóxicas en la formación de aberraciones cromosómicas, sobre todo estructurales en células de la médula ósea de ratones Balb/c de ambos sexos(AU)

Introduction: the oil extract from Carapa guianensis seed has various biomedical applications. It was recently evaluated and revealed great potentialities as antioxidant in in vivo assays, but little is known about its effect on DNA in experimental biomodels. Objective: to evaluate the genotoxic potential of the oil extract from Carapa guianensis seed in the chromosomal aberration of the bone marrow cells test performed in Balb/c mice. Methods: five experimental groups were created: one placebo group (Tween 65, 2 percent), three treated with different extract doses (400, 1000 and 2000 mg/kg) orally administered for 14 days and one positive control group treated with cyclophosphamide at a dose of 50 mg/kg intraperitoneally at 48 and 24 h before euthanasia. Five animals per sex from each group were administered the set dose. After 14 days of treatment, the animals were euthanized through cervical dislocation and their femoral bone marrow was taken out to perform the cytogenetic chromosomal aberration technique. Results: the results between the control group and the groups treated with the extract did not differ between the two sexes in terms of the mitotic index variables, Gaps, polyploidy cells, number of cells with chromosome and chromatic aberrations and the percentage of aberration cells. However, the results of controls and of treated groups were different from those of the group treated with cyclophosphamide, which proved the validation of our results. Conclusions: the oil extract from Carapa guianensis seeds does not have genotoxic potential for the formation of chromosome aberrations, mainly structural, in Balb/c mice bone marrow of both sexes(AU)

Toxicological Assessment of the Cochleate Derived from Neisseria meningitidis Proteoliposome in Sprague Dawley Rats.

BACKGROUND: The AFCo1 cochleate is a potential novel adjuvant derived from Neisseria meningitidis B proteoliposome. AIM: The aim was to assessing the safety of AFCo1 by single and repeated doses in Sprague Dawley rats. MATERIALS AND METHODS: Rats were grouped for treatment with AFCo1, placebo formulation or control. The first study was a single intranasal dose of 100 µl and monitoring body weight, water, and food intakes as well as clinical symptoms. Fourteen days later the rats were killed and anatomopathological studies were conducted. In a second study, four similar doses of the test substance were instilled every 5 days. Clinical observations were carried out as for the single dose study and a number of rats from each group were killed 3 and 14 days after the last dose in order to conduct hematological, hemochemical, and anatomopathological studies. RESULTS: No variable showed differences of toxicological relevance; the histological changes found were mild and similarly frequently in the three groups. According to the irritability index calculated form histology of the nasal region, AFCo1 was also classified as nonirritating. CONCLUSION: AFCo1 is potentially safe for human use by nasal route as evidenced by the absence of local and systemic signs of toxicity in Sprague Dawley rats.

Repeated dose toxicity study of a live attenuated oral cholera vaccine in Sprague Dawley rats.

BACKGROUND AND AIMS: A live attenuated vaccine candidate against human cholera has been developed from the genetically modified Vibrio cholerae O1, biotype El Tor, serotype Ogawa, 638 strain. Previous single dose toxicity and local tolerance studies have demonstrated that the product is innocuous in Sprague Dawley rats by oral route and single dose. The present paper describes a repeated dose toxicity study using a further dose compared to the proposed clinical schedule. METHODS: Sprague Dawley rats (140-180g) were treated with two doses of the vaccine candidate with a dedicated placebo formulation or were not treated at all (controls). The test products were inoculated at a 21-day interval. Animals were observed daily, body weight was determined weekly and food and water intakes were measured every other day. Three and 14 days after the last inoculation, groups of rats were humanely sacrificed, bled and macroscopically examined. Blood samples were taken for hematology, serum biochemistry and to determine the vibriocide antibody titers. A comprehensive list of tissue and organ samples was taken for microscopic studies. RESULTS: There was no mortality and no animal showed any clinical symptoms. Food and water intake, body weight, and hematological and biochemical variables did not show differences of toxicological and/or statistical relevance among the experimental groups. Macroscopic examination did not demonstrate any alterations and there were no histological findings of toxicological significance. CONCLUSIONS: The vaccine was considered potentially safe for human use as indicated by the results in Sprague Dawley rats.

Immunization of mice with a Mycobacterium tuberculosis genomic expression library results in lower bacterial load in lungs after challenge with BCG.

Tuberculosis is a serious infectious disease in many developing countries. The lack of an effective vaccine for preventing this disease has stimulated the search for new vaccine candidates against Mycobacterium tuberculosis. In the present work, the construction of a genomic expression library of M. tuberculosis in a eukaryotic expression vector was carried out. Immunization of Balb/c mice with a plasmid DNA pool from this library (containing 8360 clones) induced a significant IgG antibody response. Immunized mice were challenged by intratracheal route with 10(5) cfu of non-pathogenic Mycobacterium bovis BCG and were sacrificed 21 days post-challenge. Mice immunized with the genomic expression library showed a significant reduction of viable bacteria in lungs and less pulmonary tissue damage. Granulomas were not observed and the lungs had a more discrete perivascular inflammatory cell infiltrate compared to control mice. Results suggest that the genomic expression library contains genes encoding proteins that are protective against M. tuberculosis infection.

Prueba toxicológica de dosis única para la vacuna antileptospirósica vax-SPIRAL en ratones / Single-dose toxicological test for leptospirosis vaccine vax-SPIRAL in rats

Se realizó la prueba toxicológica de dosis única para la vacuna antileptospirósica vax-SPIRAL en ratones. No se encontraron síntomas clínicos de toxicidad y las diferencias entre las variables evaluadas no fueron importantes desde el punto de vista biológico

Prueba toxicológica de dosis única para la vacuna antileptospirósica vax-SPIRAL en ratones / Single-dose toxicological test for leptospirosis vaccine vax-SPIRAL in rats

Se realizó la prueba toxicológica de dosis única para la vacuna antileptospirósica vax-SPIRAL en ratones. No se encontraron síntomas clínicos de toxicidad y las diferencias entre las variables evaluadas no fueron importantes desde el punto de vista biológico(AU)