ABSTRACT
Objective To understand the developmental effects induced by CdSe /ZnS quantum dots(QDs)on zebrafish embryos.Methods Zebrafish embryos were exposed to 0,0.5,1,2,4,8 and 16 nmol/L of CdSe /ZnS QDs,and the typical toxicological indexes were recorded at five time points respectively (24 hours post fertilization (hpf),48 hpf, 72 hpf,96 hpf,120 hpf).Results The results showed that the median lethal concentration (LC50 )for zebrafish embryos after 120 hpf was 21.38 nmol/L(95% CI =17.21 -26.57).The frequency of spontaneous movement in 60 seconds after 24 hpf,the frequency of heart beat in 60 seconds after 48 hpf,the hatching rate and the mortality rate were obviously affected by CdSe /ZnS QDs.Several abnormalities and toxic symptoms caused by CdSe /ZnS QDs at 8 nmol/L and 16 nmol/L were observed including pericardial edema,liver atrophy,non -depleted yolk,intestinal abnormal development and muscle degeneration after 120 hpf.Conclusion High level of CdSe /ZnS QDs (more than 8 nmol/L)could induce toxic effects on zebrafish embryonic development.
ABSTRACT
This study examined the mutagenic activity of genistein after a nitrite treatment under acidic conditions. Nitrite-treated genistein exhibited mutagenic activity toward Salmonella typhimurium strains TA 100 and TA 98 with or without S9 mix. Nitrite-treated genistein was demonstrated by electron spin resonance to generate radicals. An instrumental analysis showed 3'-nitro-genistein to have been formed in the reaction mixture. However, 3'-nitro-genistein did not exhibit mutagenic activity toward the S. typhimurium strains, suggesting that other mutagens might also have been formed in the reaction mixture. The clastogenic properties of nitrite-treated genistein and 3'-nitro-genistein were examined by a micronucleus test with male ICR mice. Nitrite-treated genistein and 3'-nitro-genistein showed a significantly higher frequency of micronucleated reticulocytes in mice than in the control group. These results suggest that a daily oral intake of genistein and nitrite through foodstuffs might induce the formation of various mutagenic compounds in the body.
