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Objective: To explore the antagonistic effect of quercetin on fine particulate matter (PM2.5)-induced embryonic developmental toxicity in vitro.Methods: PM2.5 was collected on glass fiber filters by PM2.5 samplers during the heating period of Dec.2015 to Mar.2016 in an area of Haidian District, Beijing City.The sampled filters were cut into 1 cm×3 cm pieces followed by sonication.The PM2.5 suspension was filtered into a 10 cm glass dish through 8 layers of sterile carbasus and stored at-80 ℃ until freeze drying.Frozen PM2.5 suspension was dried by vacuum freeze-drying.In vitro post-implantation whole embryo culture was used in this study.Pregnant rats with 9.5 gestation days (GD) were killed by cervical dislocation and the uteri were removed into sterile Hank's solution.The embryos with intact yolk sacs and ecto placental cones were induced by PM2.5, and then subjected to intervention of quercetin at the doses of 0.1 μmol/L, 0.5 μmol/L, 1.0 μmol/L and 5.0 μmol/L, respectively.At the end of the 48 h culture period, the cultures were terminated, and all embryos were removed from the culture bottles and placed in prewarmed Hank's solution for evaluation.Morphological evaluation of the embryos was conducted under a stereomicroscope using the morphologic scoring system by Brown and Fabro.The mitochondrial reactive oxygen species (ROS) level was detected by FACSCalibur flow cyto-metry using MitoSOXTM Red staining.Results: An obvious antagonistic effect was achieved through querce-tin at the dose of 1.0 μmol/L, which could result in an increase of visceral yolk sac (VYS) diameter, crown-rump length and head length, somite number, and the differentiation of visceral yolk sac vascular vessels.The scores of allantois, flexion, heart, hind brain, midbrain, forebrain, auditory system, visual system, olfactory system, branchialarch, maxillary process, forelimb bud and hindlimb bud also revealed a significant increase and the relative mitochondrial ROS level of embryonic cells was significantly decreased when compared with PM2.5 group.Although quercetin at the doses of 0.1 μmol/L, 0.5 μmol/L, 5.0 μmol/L also exhibited protective effects against PM2.5-induced embryonic developmental toxicity, the protective effect was weaker when compared with the dose of 1.0 μmol/L.Conclusion: Quercetin at proper dose may be of great benefit for the development of embryos exposed to PM2.5 in the uterus of the rats.Quercetin provides an effective strategy for the prevention of PM2.5-induced embryonic developmental toxicity.Clearance of mitochondrial ROS may be one of its mechanisms.
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Traditional drug development and pre-clinical tests are based on animals and involve large numbers of animals,costs and long periods. Meanwhile,inter-species differences are difficult to overcome. Human embryonic stem cells (hESCs),which can self-renew and directly differentiate to types of cells,have become a new tool for toxicity alternative testing. hESC-Based alternative testing models,such as the reproductive toxicity test system,neuro development toxicity test system and metabolic model,can be used to predict target organ toxicity and toxic mechanisms of chemicals, analyze metabolic pathways and to search for potential toxicity biomarkers, when combined with omics such techiniques as metabonomics , proteomics and genomics. Therefore, hESC-based alternative testing models have extensive application to toxicology.
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Objective To observe the effects of fluoride on testicular cell cycle and cell apoptosis of male rats.Methods Thirty-two healthy male Wistar rats,weighting 150-180 g,were randomly divided into 4 groups by body weight using random number table,normal sodium (control),the low-dose,medium-dose and high-dose groups(100,200,300 mg· kg-1· d-1 NaF,respectively) by intragastric administration for 90 days,and bodyweight was observed daily.After the last intragastric administration,all rats were killed by cervical dislocation.The testicular cell cycle and cell apoptosis were measured by flow cytometry.Results After 30 days exposure,the difference of body weight between groups was statistically significant(F =3.884,P ＜ 0.05).The body weights in low-and medium-dose groups[(235.00 ± 14.56),(235.44 ± 24.99)g] were significantly increased than that of high-dose group [(206.00 ± 18.16)g,all P ＜ 0.05].There was no significant difference of body weight between the groups at 0,60 and 90 days(F =0.501,0.578,1.893,all P ＞ 0.05).Compared with the control group[(43.10 ± 3.62)％],the percentages of G0/G1 stage cells were significantly increased in all the NaF-treated groups [(57.60 ± 7.26) ％,(52.80 ± 3.20) ％,(73.13 ± 4.08) ％] and the percentages of S stage cells were significantly decreased in all the NaF-treated groups [(10.58 ± 2.58)％,(9.35 ± 0.35)％,(9.55 ± 0.50)％] compared to the control group[(19.23 ± 0.61)％,all P ＜ 0.05].On the other hand,the percentage of G2/M stage cells decreased significantly in high-dose group[(17.18 ± 2.21)％] compared with the control group[(36.34 ± 5.05)％,P ＜ 0.05].The testicular cell apoptosis ratios in all the NaF-treated groups were higher than that in the control group,but only in medium-and high-dose groups[(71.03 ± 2.30)％,(71.90 ± 2.16)％],the difference was statistically significant compared with the control group [(60.80 ± 2.34)％,all P ＜ 0.05].Conclusion Chronic fluorosis can change testicular cell cycle and cell apoptosis and damage the reproductive system.
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BACKGROUND:At present, the copper-bearing intrauterine device, a kind of class III medical devices, is commonly used in China. However, there is no clear conclusion about whether it has impact on the embryo or fetus in some cases, such as unexpected pregnancy during long-term implantation and pregnancy in a short time after removing it. OBJECTIVE: To evaluate the safety of copper-bearing intrauterine device by observing the influence of copper-bearing intrauterine device extracts on pregnant rats and rat fetuses by tail vein injection in the sensitive period of teratogenesis. METHODS: A total of 60 fertilized rats were divided into control group, high dosage group, middle dosage group, and low dosage group. The copper-bearing intrauterine device extracts were prepared by the continuous extraction method. Different concentrations (0.2, 0.1, 0.05 g/mL) of copper-bearing intrauterine device extracts were injected by the tail vein at the 1st day of pregnancy in the latter three groups at a dosage of 0.01 mL/g per day. The control group was given the same amount of normal saline. The injection lasted for 20 days. Then, the pregnant rats were sacrificed to measure body mass, check both sides of the uterus and internal organs, isolate fetal rats, as wel as record the quality of uterus and fetal rats, corpus luteum, implantation numbers, the number of stilbirths, then number of live births and the number of fetal absorption. The fetal rats were determined in the folowing aspects: body mass, body height, tail length, the ossification degree and appearance of the occipital bone, bone and visceral anomalies. RESULTS AND CONCLUSION: The number of births, implantation numbers, the number of live births, the number of corpus luteum, the percentages of live births and stilbirths, the number of resorbed fetuses, and the weight of uterus and fetal rats in the control group showed no difference from those in the other three groups (P > 0.05). No malformation in the internal organs occurred. Compared with the control group, the high, middle and low dosage groups showed no difference in the height, tail length, body mass, and ossification degree of the occipital bone of fetal rats (P > 0.05). No malformation in the appearance, skeleton and internal organs occurred in the fetal rats. These findings indicate that there were no maternal toxicity, abnormal embryonic growth or rat fetus anomalies after injecting copper-bearing intrauterine device extracts into pregnant rats in sensitive period of teratogenesis.
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Objective To probe into the effects of fluoride on metal elements in the testis tissue of male rats, and provide experimental basis to further research for reproductive toxicity of fluoride. Methods Thirty-two healthy male Wistar rats, weighting 150 - 180 g, were randomly divided into 4 groups, normal sodium(control) by intragastrie administration for 90 days, and body weight was observed daily. After the last intragastric administration, all rats were killed by cervical dislocation. The contents of calcium(Ca), ferri(Fe), zincum(Zn),cuprum(Cu ) and magnesium(Mg) in the testis tissue were measured by atomic absorption speetrophotometry.Results After 30 days exposure, the difference of body weight between groups was statistically significant(F=3.884, P 0.05). The difference of Ca, Zn and Mg levels among four groups was statistically significant(F = 6.630, 6.844, 5.333, all P 0.05). Conclusion Chronic fluorosis can affect the levels of metal elements in rat testis and damage the reproductive system.