Differential toxicity and teratogenic effects of the hot water and cold water extracts of Lignosusrhinocerus (Cooke) Ryvarden sclerotium on zebrafish (Danio rerio) embryos.

ETHNOPHARMACOLOGICAL RELEVANCE: The sclerotium of Lignosusrhinocerus (Cooke) Ryvarden is highly valued for its purported medicinal properties. The decoction and macerated materials prepared from the sclerotium are used for treating cancer and other ailments based on extensive traditional knowledge. Scientific evidence from in vitro cytototoxicity, anti-inflammatory and immunomodulatory analyses showed the effectiveness of sclerotial water extracts but toxicity assessment of such preparations has not been reported. AIM OF THE STUDY: This study aimed to compare the differential toxicity and teratogenicity (if any) of the hot water (HW) and cold water (CW) extracts of both wild and cultivated sclerotium on zebrafish (Danio rerio) embryos. MATERIALS AND METHODS: Zebrafish embryos were treated with varying concentrations of the sclerotial HW and CW extracts (0.3-500 µg/mL) for 72 h until hatching. The hatching, mortality and heartbeat rate of the embryos as well as the potential teratogenic effect of the extracts were assessed in embryos post-treatment with the extracts. RESULTS: While the sclerotial HW extracts were nontoxic (LC50 > 500 µg/mL), the sclerotial CW extracts delayed the hatching of the embryos up to 48 h and showed slight toxicity with LC50 values of 398.4 µg/mL and 428.3 µg/mL for the cultivated and wild sclerotium, respectively. The sclerotial CW extracts also induced minor tachycardia in zebrafish larvae. Phenotypic assessment revealed that, while yolk sac edema was observed at high concentrations (300 and 500 µg/mL) of all extracts, curved trunk and bent tail were only observed in the embryos treated with CW extracts of wild sclerotium (300 and 500 µg/mL) but not for CW extracts of cultivated sclerotium at similar concentrations. CONCLUSION: The sclerotial water extracts of L.rhinocerus prepared using different methods have varying degree of toxicity and teratogenicity in zebrafish embryos with the sclerotial CW extracts showed higher toxicity than the HW extracts.

Endopleura uchi (Huber) Cuatrec.: A medicinal plant for gynecological treatments - A reproductive toxicity assessment in zebrafish (Danio rerio).

ETHNOPHARMACOLOGICAL RELEVANCE: Endopleura uchi (Huber) Cuatrec is a plant species from the Brazilian Amazon. The barks of this tree are used in folk medicine - mainly as a decoction - for dyslipidemia, uterine infection, fibroids, polycystic ovary, menstrual disorders, as a contraceptive and abortive agent, among others. However, the data available about its developmental toxicity are still insufficient. AIM OF THE STUDY: This study aimed to evaluate the reproductive toxicity and teratogenic effects in embryos from zebrafish treated with the hydroethanolic extract from the barks of Endopleura uchi (EEu). MATERIALS AND METHODS: Both sexes of zebrafish (Danio rerio) were treated with EEu either through immersion (1.2, 2.5, and 5 mg/L) or orally (75, 200, and 500 mg/kg) over 21 consecutive days. Next, we assessed their fertility and gonads' histopathology; in their embryos were assessed teratogenesis, lethalities, and heart rate during daily observations (24, 48, 72, and 96 hpf). RESULTS: The phytochemical analysis of EEu through HPLC/MS shows bergenin as the major compounds. After 21 days of treatment were detected minor histopathological changes in parental fishes, such as atretic oocytes, interstitial fibrosis, and decreased the percentage of early vitellogenic oocytes, but without impairing the reproduction of treated animals. However, in the embryos was observed significantly increased frequency of malformation in all the groups treated through immersion, and in the group treated orally with the highest concentration (500 mg/kg). CONCLUSION: Based on the results, EEu caused no adverse effects in the progenitors on both treatments (immersion and oral). However, it was observed that the concentrations 1.2, 2.5, and 5 mg/L (immersion), and the dose 500 mg/kg (oral) caused malformations in the offspring (F1 generation). These results emphasize the need for attention when using preparations from E. uchi, mainly for pregnant women. Further studies are needed to compare its effects with the extract's primary compound (bergenin).

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.

Evaluation of Tanshinone IIA Developmental Toxicity in Zebrafish Embryos.

Tanshinone IIA (Tan-IIA) is derived from the dried roots of Salvia miltiorrhiza Bunge, a traditional Chinese medicine. Although Salvia miltiorrhiza has been applied for many years, the toxicity of the mono-constituent of Salvia miltiorrhiza, tanshinone IIA, is still understudied. This study evaluated the cardiotoxicity and developmental malformations of Tan-IIA by using zebrafish normal embryos and dechorionated embryos. After treatment with Tan-IIA in different concentrations for four-day periods, obvious pericardial edema, spinal curvature, and even missing tails were observed in zebrafish embryos. The LC50 values in the dechorionated embryo group at 72 h post-fertilization (hpf) and 96 hpf were 18.5 µM and 12.8 µM, respectively, and the teratogenicity was manifested at a concentration of about 1 µM. The main endpoints of teratogenicity were scoliosis, malformation of tail, and pericardium edema. Our findings displayed the potential cardiotoxicity and severe impact on the abnormal development of Tan-IIA in zebrafish embryo at high concentrations, which may help avoid the risk of its clinical application.

Design and Comparative Evaluation of the Anticonvulsant Profile, Carbonic-Anhydrate Inhibition and Teratogenicity of Novel Carbamate Derivatives of Branched Aliphatic Carboxylic Acids with 4-Aminobenzensulfonamide.

Epilepsy is one of the most common neurological diseases, with between 34 and 76 per 100,000 people developing epilepsy annually. Epilepsy therapy for the past 100+ years is based on the use of antiepileptic drugs (AEDs). Despite the availability of more than twenty old and new AEDs, approximately 30% of patients with epilepsy are not seizure-free with the existing medications. In addition, the clinical use of the existing AEDs is restricted by their side-effects, including the teratogenicity associated with valproic acid that restricts its use in women of child-bearing age. Thus, there is an unmet clinical need to develop new, effective AEDs. In the present study, a novel class of carbamates incorporating phenethyl or branched aliphatic chains with 6-9 carbons in their side-chain, and 4-benzenesulfonamide-carbamate moieties were synthesized and evaluated for their anticonvulsant activity, teratogenicity and carbonic anhydrase (CA) inhibition. Three of the ten newly synthesized carbamates showed anticonvulsant activity in the maximal-electroshock (MES) and 6 Hz tests in rodents. In mice, 3-methyl-2-propylpentyl(4-sulfamoylphenyl)carbamate(1), 3-methyl-pentan-2-yl-(4-sulfamoylphenyl)carbamate (9) and 3-methylpentyl, (4-sulfamoylphenyl)carbamate (10) had ED50 values of 136, 31 and 14 mg/kg (MES) and 74, 53, and 80 mg/kg (6 Hz), respectively. Compound (10) had rat-MES-ED50 = 13 mg/kg and ED50 of 59 mg/kg at the mouse-corneal-kindling test. These potent carbamates (1,9,10) induced neural tube defects only at doses markedly exceeding their anticonvuslnat-ED50 values. None of these compounds were potent inhibitors of CA IV, but inhibited CA isoforms I, II and VII. The anticonvulsant properties of these compounds and particularly compound 10 make them potential candidates for further evaluation and development as new AEDs.

Developmental toxicity in flounder embryos exposed to crude oils derived from different geographical regions.

Crude oils from distinct geographical regions have distinct chemical compositions, and, as a result, their toxicity may be different. However, developmental toxicity of crude oils derived from different geographical regions has not been extensively characterized. In this study, flounder embryos were separately exposed to effluents contaminated by three crude oils including: Basrah Light (BLO), Pyrenees (PCO), and Sakhalin Vityaz (SVO), in addition to a processed fuel oil (MFO-380), to measure developmental toxicity and for gene expressions. Each oil possessed a distinct chemical composition. Edema defect was highest in embryos exposed to PCO and MFO-380 that both have a greater fraction of three-ring PAHs (33% and 22%, respectively) compared to BLO and SVO. Observed caudal fin defects were higher in embryos exposed to SVO and MFO-380, which are both dominated by naphthalenes (81% and 52%, respectively). CYP1A gene expressions were also highest in embryos exposed to SVO and MFO-380. Higher incidence of cardiotoxicity and lower nkx 2.5 expression were detected in embryos exposed to PCO. Unique gene expression profiles were observed in embryos exposed to crude oils with distinct compositions. This study demonstrates that crude oils of different geographical origins with different compositional characteristics induce developmental toxicity to different degrees.

Influence of the antimicrobial compound allyl isothiocyanate against the Aspergillus parasiticus growth and its aflatoxins production in pizza crust.

Aflatoxins (AFs) are secondary metabolites produced by different species of Aspergillus, such as Aspergillus flavus and Aspergillus parasiticus, which possess mutagenic, teratogenic and carcinogenic activities in humans. In this study, active packaging devices containing allyl isothiocyanate (AITC) or oriental mustard flour (OMF) + water were tested to inhibit the growth of A. parasiticus and AFs production in fresh pizza crust after 30 d. The antimicrobial and anti-aflatoxin activities were compared to a control group (no antimicrobial treatment) and to a group added with commercial preservatives (sorbic acid + sodium propionate). A. parasiticus growth was only inhibited after 30 d by AITC in filter paper at 5 µL/L and 10 µL/L, AITC sachet at 5 µL/L and 10 µL/L and OMF sachet at 850 mg + 850 µL of water. However, AFs production was inhibited by all antimicrobial treatments in a dose-dependent manner. More importantly, AITC in a filter paper at 10 µL/L, AITC sachet at 10 µL/L, OMF sachet at 850 mg + 850 µL of water and sorbic acid + sodium propionate at 0.5-2.0 g/Kg completely inhibited AFs formation. The use of AITC in active packaging devices could be a natural alternative to avoid the growth of mycotoxinogenic fungi in refrigerated bakery products in substitution of common commercial preservatives.

Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans.

Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

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.

A paradoxical teratogenic mechanism for retinoic acid.

Retinoic acid, an active metabolite of vitamin A, plays essential signaling roles in mammalian embryogenesis. Nevertheless, it has long been recognized that overexposure to vitamin A or retinoic acid causes widespread teratogenesis in rodents as well as humans. Although it has a short half-life, exposure to high levels of retinoic acid can disrupt development of yet-to-be formed organs, including the metanephros, the embryonic organ which normally differentiates into the mature kidney. Paradoxically, it is known that either an excess or a deficiency of retinoic acid results in similar malformations in some organs, including the mammalian kidney. Accordingly, we hypothesized that excess retinoic acid is teratogenic by inducing a longer lasting, local retinoic acid deficiency. This idea was tested in an established in vivo mouse model in which exposure to excess retinoic acid well before metanephric rudiments exist leads to failure of kidney formation several days later. Results showed that teratogen exposure was followed by decreased levels of Raldh transcripts encoding retinoic acid-synthesizing enzymes and increased levels of Cyp26a1 and Cyp26b1 mRNAs encoding enzymes that catabolize retinoic acid. Concomitantly, there was significant reduction in retinoic acid levels in whole embryos and kidney rudiments. Restoration of retinoic acid levels by maternal supplementation with low doses of retinoic acid following the teratogenic insult rescued metanephric kidney development and abrogated several extrarenal developmental defects. This previously undescribed and unsuspected mechanism provides insight into the molecular pathway of retinoic acid-induced teratogenesis.

Teratogenic and toxic effects of Lingzhi or Reishi medicinal mushroom, Ganoderma lucidum (W.Curt.:Fr.) P. Karst. (higher Basidiomycetes), on zebrafish embryo as model.

This paper highlights the teratogenic and toxic effects of Ganoderma lucidum (Lingzhi or Reishi mushroom) extract on zebrafish embryos. Hatchability, malformations, and lethality rate of zebrafish embryos were assessed to provide valuable information regarding the potential teratogenic activity of G. lucidum. Hatching was completed 48 h post treatment application (hpta) at 1% or lower concentrations of extract and embryo water. The hatching rate of embryos treated with 5% or higher concentrations was significantly lower (p> 0.05) than the control. Tail malformation was the most marked morphological abnormality in embryos at 72 hpta, which was obviously caused by 1% extract (55.56% tail malformation) and was observed in all embryos exposed to 5% of extract. Growth retardation was evident in embryos exposed to 5%, 10%, and 20%. However, lethal effect of extract of G. lucidum was dependent on dose and time of exposure. Mortality rates of embryos treated with 5% (44.44%) or higher concentrations of the extract was significantly higher (p > 0.05) than that of the control embryos at 72 hpta. These results suggest that G. lucidum extract has lethal and sub-lethal effects on zebrafish embryos.

Comparative embryotoxicity of different antimalarial peroxides: in vitro study using the rat whole embryo culture model (WEC).

Three groups of compounds: (i) active peroxides (artemisinin and arterolene), (ii) inactive non-peroxidic derivatives (deoxyartemisinin and carbaOZ277) and (iii) inactive peroxide (OZ381) were tested by WEC system to provide insights into the relationship between chemical structure and embryotoxic potential, and to assess the relationship between embryotoxicity and antimalarial activity. Deoxyartemisinin, OZ381 and carbaOZ277 did not affect rat embryonic development. Artemisinin and arterolane affected primarily nucleated red blood cells (RBCs), inducing anemia and subsequent tissue damage in rat embryos, with NOELs for RBC damage at 0.1 and 0.175µg/mL, respectively. These data support the idea that only active antimalarial peroxides are able to interfere with normal embryonic development. In an attempt to establish whether and to what extent activity as antimalarials and embryotoxicity can be divorced, IC(50)s for activity in Plasmodium falciparum strains and the NOELs for RBCs were compared. From this comparison, arterolane showed a better safety margin than artemisinin.

Antifertility and fetotoxic activities of Acanthus montanus aqueous extract in Wistar rats.

Acanthus montanus T. Anderson (Acanthaceae) possesses several medicinal properties; it is used in Cameroon as a folk medicine to treat pain, inflammation and threatened abortion. The aim of this study was to determine the effect of A. montanus aqueous extract on the estrous cycle pre- and postimplantation in rats and its mechanism of action. The estrous cycles of Wistar rats were monitored before, during and after oral administration of distilled water (control) or aqueous extract (62.5, 125, 250, 500, 1000 mg/kg/day). Furthermore, pregnant rats received the above doses of aqueous extract on days 1-6 (preimplantation) or 6-15 (postimplantation) of gestation and were sacrificed on day 8 or 20 of pregnancy, respectively. Moreover, aqueous extract (500 and 1000 mg/kg/day) was given to ovariectomized rats in the presence or absence of exogenously administered estrogen and/or progesterone and uterine weight and deciduoma count were evaluated. The extract, irrespective of dose, reversibly prolonged the metestrous and occasionally the diestrous stages of the estrous cycle. The extract did not alter the uterine wet weight or deciduoma count, suggesting a lack of estrogenic and progestational effects. At 1000 mg/kg/day, the extract caused appreciable preimplantation losses of 36.8 +/- 6.5% (P < 0.05), while none of the doses caused postimplantation losses. The extract also caused delayed fetal growth.

Maternal and developmental toxicity evaluation of Acanthus montanus leaves extract administered orally to Wistar pregnant rats during organogenesis.

Acanthus montanus is a plant used in Cameroon to treat pains and threatened abortion. The aim of this study was to evaluate the influence of methanol/methylene chlorides leaves extract from Acanthus montanus on Wistar pregnant rats and identify the substance(s) essential for these actions. Dams were treated orally from days 6 to 15 of the pregnancy at the dose levels of 0, 250, 500 and 1000 mg/(kgday). They were sacrificed on day 20 or allowed to deliver and wean. Various parameters were assessed. The F(1) generation offsprings were allowed to give birth to F(2) generation and a number of parameters assessed. The results showed that there was no maternal or organs toxicity. Embryotoxicity was observed during organogenesis manifested by reduction in foetal body weight, crown-rump and tail lengths and reduced ossification of extremities bones. However after delivery, these signs of growth retardation were seen before day 5, and henceforth, the treated pups regained all their parameters to normality. All others parameters for F(1) and F(2) generations were insignificant. beta-Sitosterol was the major chemical component of the extract and its role on these results could not be ignored. The MeOH/CH(2)Cl(2) extract of this plant is embryotoxic peri-natally at high doses but this failed to manifest after 5 days of post-natal survival. beta-Sitosterol may be central in the observed effects of the extract. This extract can be tolerated by pregnant patients.

Azetidine-2-carboxylic acid in garden beets (Beta vulgaris).

Azetidine-2-carboxylic acid (L-Aze) is a toxic and teratogenic non-protein amino acid. In many species, including man, L-Aze is misincorporated into protein in place of proline, altering collagen, keratin, hemoglobin, and protein folding. In animal models of teratogenesis, it causes a wide range of malformations. The role of L-Aze in human disease has been unexplored, probably because the compound has not been associated with foods consumed by humans. Herein we report the presence of L-Aze in the garden or table beet (Beta vulgaris).

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.

Rapid oxidation of arsenite in a hot spring ecosystem, Yellowstone National Park.

Geothermal springs within Yellowstone National Park (YNP) often contain arsenic (As) at concentrations of 10-40 microM, levels that are considered toxic to many organisms. Arsenite (As(III)) is often the predominant valence state at the point of discharge but is rapidly oxidized to arsenate (As(V)) during transport in shallow surface water. The current study was designed to establish rates and possible mechanisms of As(III) oxidation and to characterize the geochemical environment associated with predominant microbial mats in a representative acid-sulfate-chloride (pH 3.1) thermal (58-62 degrees C) spring in Norris Basin, YNP. At the spring origin, total soluble As was predominantly As(III) at concentrations of 33 microM. No oxidation of As(III) was detected over the first 2.7 m downstream from the spring source, corresponding to an area dominated by a yellow filamentous S0-rich microbial mat However, rapid oxidation of As(III) to As(V) was observed between 2.7 and 5.6 m, corresponding to termination of the S0-rich mats, decreases in dissolved sulfide, and commencement of a brown Fe/As-rich mat. Rates of As(II) oxidation were estimated, yielding an apparent first-order rate constant of 1.2 min(-1) (half-life = 0.58 min). The oxidation of As(III) was shown to require live organisms present just prior to and within the Fe/As-rich mat. Complementary analytical tools used to characterize the brown mat revealed an As:Fe molar ratio of 0.7 and suggested that this filamentous microbial mat contains iron(III) oxyhydroxide coprecipitated with As(V). Results from the current work are the first to provide a comprehensive characterization of microbially mediated As(III) oxidation and the geochemical environments associated with microbial mats in acid-sulfate-chloride springs of YNP.

Prediction of embryotoxic effects of valproic acid-derivatives with molecular in vitro methods.

Therapy with the antiepileptic drug valproic acid (2-propylpentanoic acid, VPA) during early pregnancy can cause similar teratogenic effects (neural tube defects) in human and mice. In this study a new molecular bioassay is presented using following endpoints: differentiation of F9 teratocarcinoma cells, altered cell morphology, induction of possible targeted genes, and the induction of viral RSV-promoter. The induction of a transiently transfected viral (RSV) promoter driven luciferase gene by VPA was used to screen a set of VPA-derivatives. Structure-activity investigations showed: the longer the aliphatic side chain the more the induction of the RSV-reporter gene. The specific induction was stereoseletive. The teratogenic enantiomer S-4-yn-VPA (2-propyl-4-pentynoic acid) induced the RSV-driven reporter gene while the non teratogenic R-4-yn-VPA does not. Heptyl-4-yn-VPA was the most potent teratogen in vitro and in vivo. Non teratogenic VPA-derivatives like R-4-yn-VPA and 2-en-VPA (2-propyl-2-pentenoic acid) were ineffective in this system. Thus, the teratogenic effect of VPA and VPA-derivatives in the mouse correlated with the specific induction of the viral RSV-promoter controlled reporter in F9-cells. Acid compounds such as fatty acids are known to interact with peroxisome proliferator-activated receptors (PPARs). To test structure-activity relationships by VPA or its derivatives we used CHO cells stably expressing hybrid proteins of the ligand-binding domain of either of the PPARs. The teratogen VPA and the teratogenic derivatives of VPA activated the PPAR-delta construct in a very specific structure- and stereoselective way which correlated well with the activities in the reporter gene assay (bioassay) and those in vivo. No such correlation was found with respect to activation of PPAR-alpha or PPAR-gamma. These structure-activity relationships indicate that PPAR-delta may be a potential mediator of VPA-induced differentiation of F9 cells and may possibly be involved in the mechanism of teratogenicity of VPA in vivo. Furthermore two bioassays were designed with clearly defined endoints, amenable to automation and screening of great number of compounds. The test system allows to replace animal experiments in the preclinical development of new antiepileptics drugs with reduced teratogenic risk. Supported by BgVV-ZEBET (Berlin).

Detecting potential teratogenic alkaloids from blue cohosh rhizomes using an in vitro rat embryo culture.

The novel alkaloid thalictroidine (1), as well as the known alkaloids taspine (2), magnoflorine (3), anagyrine (4), baptifoline (5), 5,6-dehydro-alpha-isolupanine (6), alpha-isolupanine (7), lupanine (8), N-methylcytisine (9), and sparteine (10), were identified from an extract of Caulophyllum thalictroides rhizomes. N-Methylcytisine exhibited teratogenic activity in the rat embryo culture (REC), an in vitro method to detect potential teratogens. The structure of 1 was elucidated using various spectroscopic methods, primarily by NMR techniques. Thalictroidine, anagyrine, and alpha-isolupanine were not teratogenic in the REC at tested concentrations. Taspine (2) showed high embryotoxicity, but no teratogenic activity, in the REC.