Toxicity Study Of Chiral Indoxacarb To Zebrafish

Indoxacarb is a new efficient broad-spectrum chiral pesticide, belonged to oxadiazines. And its unique insecticidal mechanism is different from most of the nerve agents. As the patents expired, indoxacarb is in the increase of dosage and has got more attention about effects on aquatic organisms and water quality. The results are showed as follows:1. Indoxacarb(DPX-MP062),(-)-stereoisomer and (+)-stereoisomer were used to take the acute toxicity test, embryo acute toxicity test and the genetic toxicity of Brachydanio rerio.2. The study of genetic toxicity. The results indicated that indoxacarb,(+)-stereoisomer and (-)-stereoisomer could cause B. rerio cell apoptosis, DNA damage and genetic toxicity after a short-term infected.2.1The study of DNA damage. Micronucleus test, comet assay and DNA Laddering were used to text DNA damage of B.rerio larvae liver and peripheral blood cells could be caused by chiral pesticides indoxacarb or not. The results of micronucleus test showed that when the concentrations of indoxacarb were1.98mg·L-1and2.16mg·L-1, compared to the control group, the extremely significant difference could be found in the micronucleus rate of B.rerio larvae peripheral blood cells after exposed for96h (P<0.01). In comet assay, after exposed in indoxacarb for48h, compared with the contrast group, each concentration group’s comet tail length, comet tail moment and the percentage of DNA in comet tail appeared the extremely significant difference and reached a maximum within96h. The DNA Laddering results showed that strip breakages on DNA were appeared when tested Brachydanio rerio larvaes exposed in both indoxacarb and (+)-stereoisomer for24hours. The results revealed that indoxacarb and stereoisomers could cause DNA damage and genetic toxicity within96hours.2.2The study of cytotoxicity. Annexin V-FITC/PI double staining was used to test indoxacarb and stereoisomers caused cell apoptosis of B. rerio larvaes liver cells. The results suggested that after exposed in indoxacarb for24h, the apoptpsis rates of1.65mg·L-1,1.81mg·L-1,1.98mg·L’1and2.16mg·L-1were18.30%22.50%.27.00%and 30.40%respectively. Compared with apoptpsis rates of contrast groups, the extremely significant difference were found after exposed in indoxacarb for24h. After using (+)-stereoisomer treated for24h, the apoptosis rate of groups O.1mg-L-1,0.18mg·L-1,0.32mg·L-1were0.56mg·L-1were24.30%,16.80,23.40%and12.20%respectively, and the extremely significant differences were also found. After B. rerio larvaes exposed in (-)-stereoisomer for24h, the apoptosis rates of groups0.74mg·L-11.00mg·L-1,1.36mg·L-1.and1.85mg·L-1turned out to be24.30%,19.40%,27.00%,18.10%and8.20%respectively, and the extremely significant differences were also found.3. The results of embryo acute toxicity. The resluts of embryo acute toxicity of indoxacarb and stereoisomers reealed that (+)-stereoisomer and (-)-stereoisomer had some degree impact on voluntary movement frequency of embryos, yolk cyst rate, pericardial cyst rate, Heart rate and hatchability. It showed that96h-LCso of (+)-stereoisomer was100mg·L-1and96h-LCso of (-)-stereoisomer was8.67mg·L-1.And (+)-stereoisomer caused the apoptosis of nerve cells by staining of acridine orange. And by the same methold, it revealed that (-)-stereoisomer caused heart cell apoptosis.