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Objective: To evaluate the acute toxicity of 10% LDS, a new molluscicide, to non-target organisms., Methods: Based on "Chemical pesticide environmental safety test evaluation standard", an acute toxicity test was carried out with Coturnix coturnix japonica (quail), Apis mellifera L (bee), Bombyx mori (silkworm), and Brachydonio rerio (zebra fish) , and the skin stimulus test was also performed with guinea pig., Results: The quails had no toxic symptoms while the maximum poisoning concentration of LDS was 200 mg/kg (no toxicity). LC₅₀ of bees was 2.68 x 10³ mg/L (low toxicity). After 96 hours, no silkworms died in each group of different concentrations of LDS while the most concentration was 6.00 x 10² mg/kg, but there were some toxic symptoms such as inappetence and inactive in the high concentration group as compared to the blank control group (low toxic). LC₅₀ (96 h) of zebra fish was 6.16 mg/L (medium toxicity)., Conclusions: LDS has no toxicity to Coturnix coturnix japonica, low toxicity to Apis mellifera L and Bombyx mori, and medium toxicity to Brachydonio rerio. Compared with niclosamide ethanolamine salt, the toxicity to the fish is lower, and therefore, it is more suitable for the field application.

Zebrafish has unique advantages over other animal models in the aspect of drug screens for active ingredients and gains more and more attentions in drug research and development recently. Thus, this article reviews the recent advance of zebrafish-based drug screens in Chinese traditional medicine (TCM) effective part research, monomer drug screening, activity evaluation of natural products, discovery of new uses for old drugs, and toxicity assessment in early-phase drug discovery.

The zebra fish model, as an integral animal model, features small volume, high throughput, low cost, short cycle and reliable experimental results, thus has been widely used in medical studies. Traditional Chinese medicines (TCM) constitute a complex system, their active ingredients and action mechanisms are among study hotspots in during the development of modern TCMs. Along with the constant improvement of advanced technologies and methods, zebra fishes have been increasingly applied in studies on TCMs and shown advantages in active screening, and toxicity and metabolism studies. In this paper, TCM studies by using zebra fishes in recent years are summarized to provide new ideas and methods for basic studies on TCMs.

To explore adaptive changes of the Zebrafish (Danio rerio) to anaerobic exercise training as well as to collect basic data of molecular mechanisms of adaption to anaerobic exercise training among this fish, we investigated the influences of 4 weeks of anaerobic exercise training on the behavior, morphology, growth, muscle biochemical components and metabolic enzyme activities of the Zebrafish. Our results indicated that individual's daily activity level declined after 4 weeks training and they preferred to swim together more frequently. Both body length and weight gain decreased, allowing the fish to adapt to the increased locomotion. Similarly, glycogen in muscles increased and exercise endurance also strengthened due to the enhancement of energy storage. Moreover, although the activity of lactate dehydrogenase (LDH) in muscle has increased, the activity of citrate synthase (CS) decreased. Taken together, these results suggest that both the ability of anaerobic exercise and anaerobic metabolism of Zebrafish can in fact be enhanced by training, and the tangible changes that we could measure were retained, but only for a limited time.

Acute toxicity of PFOS/PFOA to zebrafish (Danio rerio) and development effects to zebrafish embryo were examined using a zebrafish embryo test. PFOS/PFOA showed remarkably toxicity effects on zebrafish. The LC50 (48 h) values are 1 005 mg/L for PFOA, 107 mg/L for PFOS, while the LC50 (96 h) values are 499 mg/L for PFOA, 71 mg/L for PFOS. Moreover PFOS/PFOA inhibited embryo development, and caused embryo abnormality and death. After exposure to high concentration of PFOS (> 240 mg/L), cells in animal pole of embryos autolyzed to coagulate, which indicated PFOS caused cell membranes damage. The most sensitive endpoints for PFOS exposure is spinal column malformation, and the EC50 values is 9.14 mg/L. While for PFOA hatching (96 h) is the most sensitive, and the EC50 values is 328.0 mg/L. Both PFOS and PFOA retarded embryo development which indicates their development toxicity.

Objective: To study the expression pattern of Polycomb gene Nspc1 at the early developmental stage in zebrafish., Methods: In situ hybridization probe for Nspc1 was designed according to the GenBank information. Collecting zebrafish embryos at different stages including one cell stage, two-cell stage, bud stage, and somites stage, we hybridized them with the prepared probe. Then the hybridization signals at different intervals were observed and photographed at the right time., Results: Nspc1 was expressed globally at the early stage. Its expression specificity began at the somites stage, mainly in the nervous system of the head., Conclusion: Nspc1 may play essential roles in the early stage development of zebrafish, especially in the nervous system.

Acute toxicity of BPA and TBBPA to Daphnia magna, zebrafish (Brachydanio rerio) and development effects of zebrafish embryo and zebrafish. The tested chemicals remarkably restrained the were studied, and safety assessment was also made to Daphnia magna mobilization of Daphnia magna, which may cause them death. 48 h EC50 values for D. magna were 8.91 and 0.69 mg x L(-1) respectively. In addition, the chemicals showed the toxicity effects on zebrafish, and 96 h LC50 values were 9.06 and 1.78 mg x L(-1) respectively. BPA and TBBPA remarkably retarded the development of zebrafish embryos, which may cause embryo abnormality and death. And the most sensitive toxicological endpoints to BPA and TBBPA were found, 72 h EC50 (malformation and embryo do not hatch) values were 2.90 and 0.14 mg x L(-1) respectively. The results showed that zebrafish embryo should be the most sensitive to the tested chemicals. The results indicated that BPA and TBBPA were the pollutants with high toxicity, in which TBBPA had the higher toxicity. BPA is a potential teratogen to zebrafish embryos, while TBBPA restrains embryo from hatch.

Objective: To observe the molluscicidal activity and the fish acute toxicity of the molluscicides extracted from Ginkgo biloba sarcotesta by benzinum (EGSB) (with major component of ginkgolic acid), arecoline (ARE) and their combination., Methods: Oncomelania hupensis snails were immersed in different concentrations of dry powder sarcotesta of Ginkgo biloba (DPGB), extract of Ginkgo biloba sarcotesta by water (EGSW) and EGSB by WHO recommended method for molluscicide screening to observe the molluscicidal activity, and also the inhibiting effect on the snails' climbing-up as well as acute toxicity to Brachydanio rerio. Niclosamide was used as control., Results: The three extractions from Ginkgo biloba all showed molluscicidal activity, with EGSB as the best. Its 24 h LC50 and LC90 were 0.65 mg/L and 5.50 mg/L, and the 48 h LC50 and LC90 were 0.07 mg/L and 0.85 mg/L, respectively. The combination of EGSB and ARE showed better effect than EGSB alone. Its 24 h LC50 and LC90 were 0.26 mg/L and 0.56 mg/L respectively, a sharp decrease by 60% and 90% compared to EGSB (P<0.05). Under the concentration of 2.50 mg/L of EGSB, the rate of snails' climbing-up was 10%, while under the concentration of 0.16 mg/L of the EGSB+ARE combination, the rate was 8%. The inhibition on the snails' climbing-up of the combination was stronger than EGSB. The fish survived for 24 h and 10th respectively at the concentration of 1 x LC90 and 2 x LC90 of EGSB. Under the concentration of 2 x LC90 of the combination, only 50% of the fish died and no fish died at the concentration of 1 x LC90. The toxicity of the combination was lower than EGSB alone., Conclusion: EGSB shows an adequate molluscicidal activity and it is worth of further investigation.

Using in situ hybridization on tissue sections with DIG antisense RNA probe, the distribution of zebrafish (Danio rerio) nanos1 mRNA during oogenesis and spermatogenesis was detected, and the expression and function of nanos 1 during zebrafish gametogenesis was preliminarily studied. The results were as follows: nanos 1 mRNA uniformly dispersed throughout the cytoplasm of oocytes at all stages. Strong expression of nanos1 mRNA was observed in oogonia and stage I, II oocytes, but the signal became weaker in later stage oocytes. Strong expression of nanos 1 mRNA was detected in spermatogonia and relatively weaker signal was found in primary spermatocytes but no nanos 1 mRNA expression was observed in spermatids. The results suggested that nanos 1 may play an important role in maintenance and functioning of the germline stem cell-oogonia and spermatogonia.