Teratogenic and anticonvulsant effects of zinc and copper valproate complexes in zebrafish.

Valproic acid (VPA) is an antiepileptic drug (AED) that has the broadest spectrum across all types of seizures and epileptic syndromes. Unfortunately, approximately 30% of epileptic patients are refractory to the classical AED. Metal ions have been frequently incorporated into pharmaceuticals for therapeutic or diagnostic purposes and research. In this preliminary study, we assess the embryo toxicity and the anticonvulsant activity of 4 novel metallodrugs, with Zn+2 and Cu+2, a derivative of valproic acid and the N-donor ligand in an adult zebrafish epileptic seizure model induced by pentylenetetrazole. The most toxic complex was [Cu(Valp)2Bipy], in which the LC50 was 0.22 µM at 48 h post fertilization (HPF) and 0.12 µM at 96 HPF, followed by [Zn(Valp)2Bipy] (LC50 = 10 µM). These same metallodrugs ([Cu(Valp)2Bipy] 10 mM/kg and [Zn(Valp)2Bipy] 30 mM and 100 mM/kg) displayed superior activity, thus reducing the seizure intensity by approximately 20 times compared to sodium valproate (175 mM/kg). Overall, [Cu(Valp)2Bipy] showed the best anticonvulsant effects. However, because of the toxicity of copper, [Zn(Valp)2Bipy] is considered the most promising anticonvulsant for future studies.

Effects of diphenyl diselenide and diphenyl ditellurite on chicken embryo development.

Studies of our group has demonstrated that (PhSe)2 plays some pharmacologic activities. In addition, it is possible that this compound would be an alternative source of organic selenium in animal foods. However, previous works showed that diphenyl diselenide (PhSe)2 and diphenyl ditelluride (PhTe)2 are toxic for mammals, but their undesirable effects were never tested in avian models. Then, the present study was carried to examine the possible teratogenic effects of (PhSe)2 and (PhTe)2 on chicken embryo development. The eggs were injected with (PhSe)2 at 0, 1 and 10 nmol or with (PhTe)2 at 4 nmol. The control was injected with 10 µl of soya bean oil (vehicle). In order to determine the possible toxic effect of these chemicals, we measure the embryo dimensions, the encephalon, heart and liver weight, thiobarturic acid reactive species (TBARS) level and the δ-aminonevulinate dehydratase (ALA-D) activity. (PhSe)2 and (PhTe)2 did not affect the embryo dimensions. Treatment with (PhSe)2 at 10 nmol per egg caused a increase on TBARS level and on ALA-D activity of the liver tissue, whereas (PhTe)2 decreased encephalon weight, had a tendency to increase to increase TBARS level but did not affect ALA-D activity. Taken together, these results indicate that (PhSe)2 and (PhTe)2 are slightly toxic for chicken embryos. Furthermore, (PhTe)2 caused a decrease in encephalon, which indicates its neurotoxicity. Finally, these results indicate that (PhTe)2 seems not be promissory for therapeutic applications, whereas (PhSe)2 could be of clinical and/or nutritional concern, which will be target for further researches.

Assessment of cytotoxicity, fetotoxicity, and teratogenicity of Plathymenia reticulata Benth Barks aqueous extract.

Scientific assessment of harmful interactions of chemicals over the entire reproductive cycle are divided into three segments based on the period: from premating and mating to implantation (I), from implantation to major organogenesis (II), and late pregnancy and postnatal development (III). We combined the segments I and II to assess Plathymenia reticulata aqueous extract safety. In order to investigate reproductive toxicity (segment I), pregnant rats received orally 0.5 or 1.0 g/kg of extract, daily, during 18 days. These concentrations were determined by a preliminary in vitro LD50 test in CHO-k1 cells. A control group received deionized water. The offspring was removed at the 19th day, by caesarean, and a teratology study (segment II) was carried out. The corpora lutea, implants, resorptions, live, and dead fetuses were then counted. Placenta and fetuses were weighted. External and visceral morphology were provided by the fixation of fetuses in Bouin, whereas skeletal analysis was carried out on the diaphanizated ones. The increase in the weights of placenta and fetuses was the only abnormality observed. Since there was no sign of alteration on reproduction parameters at our experimental conditions, we conclude that P. reticulata aqueous extract is safe at 0.5 to 1.0 g/kg and is not considered teratogenic.

The cytotoxic and embryotoxic effects of kaurenoic acid, a diterpene isolated from Copaifera langsdorffii oleo-resin.

In this work, we studied the effects of kaurenoic acid, a diterpene isolated from the oleo-resin of Copaifera langsdorffii in developing sea urchin (Lytechinus variegatus) embryos, on tumor cell growth in microculture tetrazolium (MTT) test and on mouse and human erythrocytes in hemolysis assay. Continuous exposure of embryos to kaurenoic acid starting immediately after fertilization inhibited the first cleavage (IC(50): 84.2 microM) and progressively induced embryo destruction (IC(50): 44.7 microM and < 10 microM for blastulae and larvae stages, respectively). In MTT assay, kaurenoic acid at a concentration of 78 microM produced growth inhibition of CEM leukemic cells by 95%, MCF-7 breast and HCT-8 colon cancer cells by 45% each. Further, kaurenoic acid induced a dose-dependent hemolysis of mouse and human erythrocytes with an EC(50) of 74.0 and 56.4 microM, respectively. The destruction of sea urchin embryos, the inhibition of tumor cell growth and the hemolysis of mouse and human erythrocytes indicate the potential cytotoxicity of kaurenoic acid.

Embriofetopatías por abuso de drogas que producen dependencia / Embryofetuspathies by drugs abuse that produced dependencies

A través de los siglos, las sociedades han sentido temor por los efectos adversos que puede tener el entorno en el desarrollo del feto. Se conocen como teratógenos los agentes farmacológicos, químicos, físicos o infecciosos que actúan sobre el embrión o el feto ocasionando daño estructural o funcional. En este sentido, hemos hecho una revisión sobre los daños ocasionados al embrión y al feto por las drogas ilícitas a fin de ayudar a los pediatras en el reconocimiento de las anomalías producidas por ellas, entender el curso de dichos trastornos y así poder orientar al niño, a su familia y a la comunidad. Igualmente alertar a los adolescentes sobre el riesgo a que está sometida su descendencia en caso de consumirlas durante el embarazo . El efecto teratogénico de algunas de ellas es bien conocido como el de el alcohol y la cocaina, pero en otras está en estudio, de allí nuestro interés en investigar el posible efecto teratogénico u otros efectos de la marihuana, ácido lisérico (LSD), nicotina y cafeína, anfetaminas y solventes inorgánicos. Es de hacer notar que no se conoce ninguna estadística en nuestro país sobre esta problemática