Vera Maria Peters

Fetal toxicity of Solanum lycocarpum (Solanaceae) in rats.

Lobeira (Solanum lycocarpum) is a Brazilian plant used as a hypoglycemic agent. In this study, the toxic effects of lobeira were evaluated during the fetogenesis period. Twenty pregnant Wistar rats were randomly allocated into two groups: control and treated, which received, via oral gavage, 0.5 ml of distilled water or 100 mg of the lobeira powder/kg of body weight, respectively, during days 17-20 of pregnancy. Maternal toxicity was evaluated by body weight, food intake, piloerection, locomotor activity, diarrhoea and vaginal bleeding. Euthanasia was done on 21st day, when ovaries, fetuses and their respective placentas were removed. Resorptions, live and dead fetuses were recorded. External malformations and fetal body, brain, liver, lung and kidneys were also weighed. No clinical signs of maternal toxicity were observed. The placenta weights of the treated rats were lower than those of the control (P<0.01). Lungs (P<0.01) and kidneys (P<0.02) of the fetuses treated with lobeira were also significantly reduced, suggesting a fetotoxic effect of this plant.

Molecular imaging, biodistribution and efficacy of mesenchymal bone marrow cell therapy in a mouse model of Chagas disease

Chagasic cardiomyopathy, resulting from infection with the parasite Trypanosoma cruzi, was discovered more than a century ago and remains an incurable disease. Due to the unique properties of mesenchymal stem cells (MSC) we hypothesized that these cells could have therapeutic potential for chagasic cardiomyopathy. Recently, our group pioneered use of nanoparticle-labeled MSC to correlate migration with its effect in an acute Chagas disease model. We expanded our investigation into a chronic model and performed more comprehensive assays. Infected mice were treated with nanoparticle-labeled MSC and their migration was correlated with alterations in heart morphology, metalloproteinase activity, and expression of several proteins. The vast majority of labeled MSC migrated to liver, lungs and spleen whereas a small number of cells migrated to chagasic hearts. Magnetic resonance imaging demonstrated that MSC therapy reduced heart dilatation. Additionally metalloproteinase activity was higher in heart and other organs of infected mice. Protein expression analyses revealed that connexin 43, laminin γ1, IL-10 and INF-γ were affected by the disease and recovered after cell therapy. Interestingly, MSC therapy led to upregulation of SDF-1 and c-kit in the hearts. The beneficial effect of MSC therapy in Chagas disease is likely due to an indirect action of the cells of the heart, rather than the incorporation of large numbers of stem cells into working myocardium.

Toxicology of Lapachol in rats: embryolethality

Lapachol is a naphtoquinone with therapeutic potential against enterovirus, Chagas disease and is also used as an antimalarial and antiinflamatory agent. In order to study teratogenic potential of Lapachol, pregnant Wistar rats were treated with 0.5 ml of distilled water (control group); 0.5 ml of hydroalcoholic solution (vehicle group) and 10 mg of Lapachol in 0.5 ml of hydroalcoholic solution (treated group) by oral gavage from the 8th to the 12th day of pregnancy. The following variables were observed: maternal body weight on days 1, 6, l5 and 21 and food intake on days 2, 6, 15 and 21 of pregnancy. The number of live and dead fetuses and the sites of resorptions were counted. The ovaries were weighed and the corpora lutea were counted. Data were analyzed by ANOVA-one way, Dunnett test and the chi square test. Significance level test alpha = 0.05. Results have shown that mothers were unaffected but there were a 99.2% of fetus mortality, indicative of a strong abortifacient effect of Lapachol in rats.

Interceptive effect of Lapachol in rats.

Lapachol is a naphtoquinone with therapeutic potential against Chagas disease and is also used as an antimalarial agent. To study the reproductive toxicity potential of Lapachol, pregnant Wistar rats were treated with 0.5 mL of distilled water (control group), 0.5 mL of hydroalcoholic solution (vehicle group), or 20 mg of Lapachol in 0.5 mL of hydroalcoholic solution (treated group) by oral gavage from the 8th to the 12th day of pregnancy. The following variables were observed: maternal body weight on days 1, 6, 15, and 21; food intake on days 2, 6, 15, and 21 of pregnancy. The number of live and dead fetuses and the sites of resorptions were counted. The ovaries were weighed and the corpora lutea were counted. Data were analyzed by ANOVA one-way Dunnett test and chi 2 test. Results showed that mothers were uneffected but there was 100% fetal/embryo mortality, indicative of a strong interceptive effect of Lapachol in rats.

Post-biopsy bovine embryo viability and whole genome amplification in preimplantation genetic diagnosis.

OBJECTIVE To evaluate the effect of the biopsy of 8-cell to 16-cell bovine embryos on their subsequent development and the effect of whole genome amplification (WGA) on removed blastomeres. DESIGN Randomized study. SETTING Molecular genetics and animal reproduction laboratories. PATIENT(S) Cow ovaries obtained from slaughterhouses. INTERVENTION(S) The ovaries were punctured, and the oocytes were matured and fertilized in vitro. On the fourth day after fertilization, 8-cell to 16-cell bovine embryos were biopsied, one quarter of each embryo being removed. The blastomeres were submitted to WGA followed by polymerase chain reaction (PCR). The embryos were returned to culture for evaluation of their development. MAIN OUTCOME MEASURE(S) Subsequent rate of blastocyst development, embryo cell number, WGA efficiency, and sex determination. RESULT(S) A total of 92 embryos were submitted to biopsy. The blastocyst production was 53.3%, with 44.9% of hatching rate. These results were similar to those of the control group (66.0% and 42.6%) of 103 embryos. Overall, no impact was detected on embryo quality in blastocyst cell number between the two groups. Removed blastomeres were submitted to WGA, resulting in 98.2% of efficiency. However, only 59% of the samples were sexed by PCR. CONCLUSION(S) Biopsy of 8-cell to 16-cell bovine embryos did not affect their subsequent development. WGA was successful in removed blastomeres.

Radiographic evidence of mandibular osteoporosis improvement in Wistar rats treated with Ginkgo biloba

Objective: Evaluate the effects of the extract of Ginkgo biloba (EGb) on the rat mandibular glucocorticoid‐induced‐osteoporosis. Method: 36 female rats were divided into six groups (n=6): control, osteoporosis, positive control and EGb1 (14mg/kg/day), EGb2 (28mg/kg/day), and EGb3 (56mg/kg/day) treatment. Treatments were conducted for 30 days after osteoporosis induction. The animals were euthanized and their left mandibles were removed and radiographed to evaluate the cortical and the periodontal bone support. The control group was compared with the osteoporosis group (Students t‐test). The other groups were analyzed by ANOVA test followed by Tukey post‐hoc test (p < 0.05). Results: There was a significant reduction in periodontal bone support in the osteoporosis group. The positive control group showed a significant increase in the mesial periodontal bone support, as well as the EGb group treated with 28 and 56 mg/Kg, which showed a significant increase in the mesial and distal periodontal bone support. The mandibular cortical was not affected by osteoporosis; however, the group treated with EGb using 56 mg/Kg showed a significant increase in the thickness of the mandibular cortical. Conclusions: The EGb recovered the periodontal bone support and increased the mandibular cortical thickness. The EGb may be effective in the treatment of osteoporosis. Copyright

Absence of interceptive effect in rats treated with Solanum lycocarpum (St. Hil)

The interceptive effect of the powder of Solanum lycocarpum (St. Hil) (Solanaceae) fruit, used as a hypoglycemic agent by diabetic patients in Minas Gerais state (Brazil), was evaluated to observe possible effects upon zygote and pre-embryo transport in rats, since it contains solamargine and solasonine from which a 3beta-acetoxipregna-5,16-dien-20-one is obtained as well as an alkaloid with stereospecific configuration to the synthesis of steroid hormones. Inseminated rats received an aqueous suspension of 100 mg of the lobeira powder/kg of body weight, by oral gavage, from the 1st to the 4th day of pregnancy. A control group received 5 mL of distilled water in the same schedule. The pregnant rats were weighed at the beginning of treatment and on sacrifice day. Animals were killed on the 5th day of pregnancy. The oviducts and uterine horns were removed and flushed with saline solution to count expanded blastocysts. It was concluded that administration of lobeira did not cause maternal toxicity, alteration of the pre-embryo transport or reduction of the number of expanded blastocysts.

Efficacy of Morus nigra L. on reproduction in female Wistar rats

Morus nigra L. is a plant employed as a substitute for the conventional hormonal replacement therapy. This work analyzes the estrogenic effect of M. nigra on the reproductive system and embryonic development of Wistar rats. Female rats were orally treated with M. nigra hydroalcoholic extract (MnHE) at the dose levels of 25, 50, 75, 350 and 700 mg/kg of body weight over 15 days, and continued through mating until the 14th day of gestation. Vaginal smears were performed daily and the body weight of the females was recorded at 5 days intervals. On day 15 of gestation, the females were killed and their kidneys, liver, spleen and ovaries were removed and weighed. The number of implants, resorptions, and live and dead fetuses were evaluated. Histological sections of ovaries, measurement of the height of the uterine epithelium and vaginal smears were performed to assess the estrogenic activity. The results showed that the administration of MnHE did not significantly alter the analyzed variables. Therefore, considering the experimental model used in this study, the data obtained indicate that M. nigra did not exhibit any estrogenic activity nor did exert a toxic effect on the female reproductive system and on the embryonic development of rats.

Desenvolvimento embrionário em ratas tratadas com Hypericum perforatum durante o período de implantação

Hypericum perforatum is used as an alternative treatment of depression, which is a disease that has been affecting women during post-partum or gestation. There is little information in experimental studies regarding the reproductive toxicity of hiperic. The present paper aims at assessing Hypericum perforatums embryotoxic potential. Pregnant Wistar rats were treated with 36 or 360 mg/kg body weight of Jarsin dried extract, via oral gavage on days 5 and 7 post-insemination. Animals from the control group received 0.5 mL of distilled water through the same via and days. The animals were killed on the 15th day and the following variables were analyzed: maternal and fetal body weight, food intake, clinical signs of toxicity, weight of ovaries and placenta, number of corpora lutea, resorptions, live and dead fetuses, and the proportion of implantation and resorption. No significant differences were observed in any of these variables, leading to the conclusion that in the experimental model used, Hypericum perforatum does not seem to be toxic to the mother, does not interfere with blastocyst implantation nor does it seem to be toxic to the embryo.

A toxicidade do Hypericum perforatum administrado a ratas prenhes

BACKGROUND: Saint Johns wort (Hypericum perforatum) is a medicinal plant used in the treatment of depression and other psychiatric disorders. OBJECTIVE: In the present paper, the toxicity of H. perforatum administered to female rats during organogenesis (9th to 15th day of pregnancy) was evaluated. METHODS: Thirty inseminated Wistar rats were randomly distributed into Control and Treated groups, which received by gavage, respectively, 0.5 ml of saline and 36 mg/Kg body weight of Jarsin dried extract diluted into 0.5 ml of saline. Maternal toxicity was evaluated by means of: water and food intake, body weight, piloerection, walking activity, diarrhea and death. Animals were killed on the 21st day of pregnancy, when kidneys, liver and ovaries were weighed. Implantation and reabsorption indices were calculated, as well as the average number of fetuses per mother. RESULTS: Clinical signs of maternal toxicity were not observed and none of the variables analyzed showed statistically significant differences. CONCLUSION: At the dose administered in the experimental model used, H. perforatum does not seem to be toxic to the mother.