Establishment of an in vitro method of rabbit embryo toxicity with toxicokinetics study.

This report introduces a novel method, rabbit whole embryo culture (WEC) combined with toxicokinetics (TK), for toxicity testing. Rodent WEC has been extensively used for in vitro screening of developmental toxicity. To improve the reliability of in vitro data, it is important to consider TK and species specificity. To test the utility and effectiveness of this method, we investigated the toxic effect of thalidomide on rabbit embryos and its behavior in test systems both in vitro and in vivo under the same experimental condition. The data showed that thalidomide induced embryo malformations such as embryonic brain hypoplasia, short limb buds, and declined embryonic growth both in vitro and in vivo. The toxic effect increased with the increasing exposure of the embryo to thalidomide. In addition, we observed similar toxic effects and exposure-effect relationships in vivo and in vitro. Therefore, we preliminarily conclude that this new method can effectively predict and explain thalidomide toxicity. Furthermore, we investigated the behavior of test compounds in the WEC system for the first time, and this method is expected to be an important technique for in vitro toxicity study after extensive verification.

[Chronic hepatotoxicity evaluation of Chinese medicinal herb Zishen Yutai pill prepared from Polygoni Multiflori Radix preparata in dogs].

To study the chronic hepatotoxicity of Chinese medicine Zishen Yutai pill (ZYP) prepared from Polygonum multiflorum with the recommended dosage in normal Beagle dogs. Low, middle and high doses of ZYP (1.5, 3.0, 6.0 g·kg⁻¹; i.e. 3×, 6× and 12× equivalent doses) were given orally to dogs for 39 consecutive weeks. At the same time, the same volume of deionized water was used as the solvent control group, one time a day. The general condition of the animals was observed every day during the period of administration, and the blood was collected before and 13, 26, 39, 43 weeks after administration to detect the biomarkers related to the hepatotoxicity of the dog serum. 2/7, 3/7 and 2/7 animals were dissected after 13, 39, and 43 weeks of administration to observe the pathological changes of the animal organs, weigh the mass of main organs and conduct pathological examination of the liver. As compared to the solvent control group, 11 liver hepatotoxicity traditional biomarkers such as ALT, AST were found no ZYP-related changes at month 3, 6, 9 of the administration and month 1 in recovery period; There was no significant difference in liver viscera index and liver pathology. Therefore, no obvious hepatotoxicity was shown by ZYP administered up to 6.0 g·kg⁻¹ for 9 months in normal dogs at doses of 1.5, 3.0, and 6.0 g·kg⁻¹.

Effects of oral cimetidine on the reproductive system of male rats.

Cimetidine is widely used for the treatment of digestive tract ulcers, but it induces testis injury. To explore the mechanisms underlying cimetidine-induced toxicity towards the testis, the effects of oral cimetidine on the reproductive system of male rats were assessed. Cimetidine was orally administered to male rats at 20, 40 or 120 mg/kg/day for 9 weeks. The rats were then euthanized, and serum, testis, epididymis, prostate gland, seminal vesicle, preputial gland, levator ani muscle and sphincter ani samples were collected. Sperm parameters were obtained by computer-assisted sperm analysis. Serum hormone levels were measured by ELISA. Protein expression levels were detected by immunohistochemistry. Apoptosis was assessed with the DeadEnd™ Colorimetric Apoptosis Detection System. The results indicated that the sperm average path velocity, straight line velocity and curvilinear velocity were significantly decreased in the 120 mg/kg cimetidine group compared with the control group, while luteinizing hormone and testosterone levels were significantly higher compared with the control group. Testicular lesions were observed by histopathology in the 120 mg/kg cimetidine group. The amounts of cells positive for cyclooxygenase-2 (COX-2) and nuclear factor κB (NF-κB) were increased in the 120 mg/kg cimetidine group compared with the control group. The amounts of cells positive for iNOS were increased in all cimetidine treatment groups. In addition, apoptotic cells were significantly more abundant in the 120 mg/kg cimetidine group compared with the control group, as indicated by terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling. Overall, 9 weeks of oral cimetidine induced pathological changes in the testicles and hormone secretion disorder in rats. COX-2, iNOS and NF-κB upregulation and induction of apoptosis may be associated with the reproductive toxicity caused by cimetidine.

Reproductive toxicity of ZishenYutai pill in rats: Perinatal and postnatal development study.

ZishenYutai pill (ZYP) is one of the most commonly used Chinese patent medicines for threatened miscarriage. Although ZYP is widely used, its toxic effects are rarely assessed. We aimed to investigate whether ZYP had reproductive toxicity during perinatal and postnatal period. Pregnant rats (F0) were continuously exposed to 6, 12 and 24 g/kg body weight/d of ZYP by intragastric administration from gestation day15 to post-natal day21. Vehicle and propylthiouracil (PTU, 15 mg/kg) were used as the negative control and positive control, respectively. The mating was done between the treatment (ZYP or PTU) group and negative control group when the F1 pups were born 63-70 days. Body weight, reproductive ability, physical development and neurodevelopment of F0, F1 and F2 pups were observed. The reproductive capacity of F0 and F1 generation decreased significantly after PTU exposure; however, the body weight and reproductive ability of F0, the physical development, weight, feed consumption and reproductive ability of F1, as well as the physical development and body weight of F2 rats were not significantly changed in the ZYP-treated group compared with the negative control group. ZYP exposure had no perinatal toxicity in 3 generations of rats and may be widely used for miscarriage.

Reproductive Toxicity of Zishen Yutai Pill in Rats: The Fertility and Early Embryonic Development Study (Segment I).

Purpose. This study was aimed to investigate the reproductive toxicity of Zishen Yutai Pill (ZYP) on fertility and early embryonic development in rats. Methods. SD rats were randomly divided into 5 groups: vehicle control group (distilled water, i.g.), positive control group (80 mg/kg of cyclophosphamide, i.p.), and three ZYP-treated groups (3, 6, and 12 g/kg/d, i.e., 12x, 24x, and 48x clinical doses, i.g.). The high dose was set as the maximum gavage dosage. Results. Cyclophosphamide showed diverse hazards, such as decreased weight of male reproductive organs and sperm density (P < 0.05). However, there were no obvious effects of ZYP on physical signs, animal behavior, and survival rate, as well as on weight and food intake during the premating and gestation periods. Importantly, there were no significant adverse effects of ZYP on indexes of copulation, fecundity and fertility indexes, weights and coefficients of male reproductive organs, epididymal sperm number and motility, estrous cycle, preimplantation loss rate, and implantation rate. Besides, the numbers of live and resorbed fetuses per litter were not significantly altered. Conclusions. ZYP had no reproductive toxicities on fertility and early embryonic development in rats at 48x equivalent clinical doses.

Development and application of an analytical method for curdione quantification in pregnant Sprague-Dawley rats by LC-MS/MS.

The vaginal administration route suffers from relatively low absorption efficiency, which may hinder the identification of the toxicokinetics of curdione in pregnant women. A sensitive analytical method for determining the plasma concentration of curdione was developed and applied in the determination of curdione in pregnant Sprague-Dawley rats as a simulated model. Glimepiride was used as an internal standard and chromatographic separation was achieved on a Capcell Pak C18 MGIII column. A gradient elution profile with 0.5% formic acid (A)-0.5% formic acid-acetonitrile (B) was selected as mobile phase. The selected reaction monitoring mode was used for quantification based on the target fragment ions m/z 237.2 to m/z 135.1 for curdione and m/z 491.3 to m/z 352.1 for the glimepiride. The standard curve was linear over the range of 0.5-500 ng/mL for curdione in rat plasma and yielded a consistent peak pattern, even at the lower limit of quantitation of 0.5 ng/mL. The retention times of curdione and IS were 6.55 and 6.59 min, respectively. The mean recovery of curdione in rat plasma was 95.5-101.1%. The intra-day and inter-day precisions were between 2.35 and 9.08%. This LC-MS/MS method provides a simple and sensitive means for determining the plasma concentration.

The alteration of inflammatory markers and apoptosis on chronic prostatitis induced by estrogen and androgen.

PURPOSE: The age-related decline of the testosterone-to-estrogen (T-to-E2) ratio in serum is associated with the increased prevalence of prostatic inflammation. The goal of the study was to induce prostatic inflammation with E2 and androgen treatment and to explore the inflammatory markers and apoptosis on prostatitis. METHODS: Castrated SD rats were treated with E2 and different doses of androgens to achieve an elevated concentration of E2 and a wide range of the androgen-to-E2 ratio in serum. Inflammatory markers TNF-α, COX-2 and MIP-1α were immunohistochemically stained. Apoptosis detection was evaluated by TUNEL staining. E2, T and DHT concentrations in serum were measured, and the relative weight of the prostate and seminal vesicles were determined. RESULTS: T was anti-inflammatory at the doses which normalized or over stimulated the growth of the prostate and seminal vesicles. Experimentally, prostatitis induced by E2 alone increased the prostatic levels of the inflammatory markers TNF-a, COX-2 and MIP-1a. As signs of anti-estrogenic actions, androgens dose-dependently decreased the expression of TNF-α, COX-2 and MIP-1α. Prostatitis induced by E2 alone caused extensive apoptosis in the castrate-resistant cells and E2-induced apoptosis occurred dependently of T manipulation. CONCLUSIONS: Estrogen-alone-induced inflammatory response could promote the expression of inflammatory markers; however, T supplementation reduces the expression of inflammatory markers and E2-induced apoptosis occurs dependently on T manipulation in prostatitis.

The toxicokinetic profile of curdione in pregnant SD rats and its transference in a placental barrier system detected by LC-MS/MS.

The objective of this study was to determine the toxicokinetic profile of curdione in pregnant SD rats as well as the transference of curdione into the fetus through the placental barrier system using LC-MS/MS. Thirteen pregnant SD rats were treated with 7, 21 and 63 mg/kg curdione once daily from gestational day 6 (GD6) to GD15. Blood samples were collected at different time points on GD6 and GD15. Maternal plasma, placental plasma, placenta tissue, amniotic fluid and fetal tissue were collected for concentration analysis after all the animals were sacrificed following one repeated dose on GD19. The results indicated that Cmax, AUC(0₋t) and AUC(0₋∞) increased in a dose-dependent manner both on GD6 and GD15. At 7 mg/kg group, the total serum clearance value on GD15 was reduced to approximately 16.4% of that on GD6, and the volume of distribution was also significantly decreased (p<0.05). Curdione could be detected in the maternal plasma, placental plasma, placenta tissue, amniotic fluid and fetal tissue, and its concentration in the fetal tissue reached saturation at 21 mg/kg. In conclusion, curdione presents with the risk of accumulation in pregnant SD rats and may affect the fetus via transference through the placental barrier system.