Study On The Genotoxicity Of Organic Extracts In Fishpond Water Containing Sewage And Its Toxic Effects On The Genital Organs Of Male Mice

Objective: Because of the shortage of the water resource, many areas in china utilize municipal sewage for agriculture irrigation and aquaculture. Domestic and overseas studies showed that there were a large number of hazardous chemicals in the sewage, including some kinds of Persistent Organic Pollutants (POPs). Because it is hard for POPs to degrade and easy to bioaccumulate, once POPs enter human body through the food chains, potential harms can be imposed to human health. To evaluate the possibility of the potential hazardous health effects on the human beings induced by the organic pollutants in the fishpond water, the genotoxicity of the organic extracts (OEs) in the fishpond water containing the sewage were detected. To primarily study the reproduction-endocrine disrupting effects of POPs in the fishpond water, the genital organs' coefficients of male mice exposed to the OEs were determined and the histopathological changes were observed using the optics microscope. Methods: Fishpond water containing sewage from Xiqing District in Tianjin was collected in spring (sample A) and autumn (sample B) respectively, organic pollutants in the water samples were extracted using XAD-2 resins, 150L water for each water sample was extracted. After being K-D condensed and vacuum dried, the OEs were dissolved into 30ml dimethylsulfoxide (DMSO). ①Healthy Kunming mice were randomly divided into 6 groups according to the body weight, 8 mice each group. Themice were administrated through peritoneal injection with OEs at the doses of equivalent to 2517kg, 12.5L/kg, 6.25L/kg, 3.125L/kg water sample respectively, continuously for 3 days. The negative and positive control groups were administrated with DMSO and cyclophosphamide (CP) respectively. The effects of chromosome damage and DNA damage induced by the OEs were detected using mice bone marrow micronudeus test and un-fluorescent staining comet assay of mice peripheral blood lymphocytes. ?Separated mouse spleen cells were respectively treated by OEs at doses of equivalent to 2.5ml, 1.25ml, 0.625ml water sample per 2ml soliquid of the spleen cells for 2h at 37 °C. The negative and positive control groups were treated with DMSO and potassium dichromate (0.2mmol/L) respectively. The DNA damage effects of the mice spleen cells induced by the OEs were detected using un-fluorescent staining comet assay. (3) The testis of male mice in the mice bone marrow micronudeus test were taken and the testicular cells were separated . The DNA damage effects on the germ cells induced by the OEs were determined using un-fluorescent staining comet assay. ?Healthy sexual mature Kunming male mice were randomly divided into 6 groups according to the body weight, 6 mice each group. The mice were respectively administrated by peritoneal injection with OEs at the doses of equivalent to 25L/kg, 12.5L/kg, 6.25L/kg, 3.125L/kg water sample, continuously for 5 days. The negative and positive control groups were administrated with DMSO and CP respectively. On the thirtieth day after the last administration, the mice were sacrificed and the frequencies of malformed sperm in the mice were determined. The genital organs' coefficients of the testis, foreskin gland and spermatophore were calculated and the histopathological changes of testis and prostate were observed using optics microscope. Results: (1) The frequencies of the micronuclei in PCE cells of mice in the 25L/kgand 12.5L/kg groups of the sample A and sample B were significantly higher than those of the negative control group (P<0.01 and P <0.05) and significant dose-response relationships were obtained between the frequencies of the micronuclei and the doses of the OEs (P<0.01), which indicated that some organic mutagens existed in the fishpond water containing sewage. (2) The results of comet assay of mice peripheral blood lymphocytes showed that the tailed-cells rates of each exposure group and the tail's length of 25L/kg and 12.5L/kg groups of sample A were significantly higher than those of the negative control group (P<0.01). Significant dose-response relationships were obtained between the tailed-cells rates, tail's length and the doses of sample A (P<0.01). The results of comet assay of mice peripheral blood lymphocytes showed that the tailed-cells rates and tail's length of 25L/kg and 12.5I7kg groups of sample B were significantly higher than those of the negative control group (iM).Ol). Significant dose-response relationships were obtained between the tailed-cells rates, tail's length and the doses of sample B (P <0.01). The results indicated that the OEs of sample A and sample B could induce DNA damage on mice peripheral blood lymphocytes. (3) In comparison with the negative control group, there were significant differences in the tailed-cells rates and tail's length at each OEs treated group of sample A and sample B (P <0.01) . Significant dose-response relationships were obtained between the tailed-cells rates, tail's length and the doses of sample A and sample B (P <0.01). The results of the comet assay showed that OEs of sample A and sample B could induce DNA damage on mice spleen cells in vitro. (4) The results of comet assay of mice testicular cells showed that the tailed-cells rates and tail's length of each OEs treated group of sample A and sample B were significantly higher than those of the negative control group (P<0.01). There were significant dose-response relationships between the tailed-cells rates, tail's...