Study On Male Reproductive Toxicity Induced By Organic Extracts In Tap Water Of Chongqing City And Green Tea's Antagonism

With the development of industry and agriculture, more and more organic pollutants were detected in water. In early studies we found that source water and treated water from five waterworks was seriously polluted by organic pollutants, and they had high detected rate and detected concentration of DBP. DBP is well known as male reproductive toxicity. There are some new pollutants in tap water beacause of storage and flow. In recent research, Chongqing Diseases Control Center found that the concentration of common organic pollutants in tap water, such as DBP, was higher than that in treated water. Similar findings were shown in other cities. Therefore, it is very important to study on the kind and level of organic pollutants in tap water and their harm to human health (especially male reproductive toxicity). Organic pollutants in tap water in Chongqing city was analyzed by Gas Chromatography coupled with Mass Spectrometry (GC/MS), and the reproductive toxicity of them was detected in Kunming mouse. Thought of the antioxidation and antimutagenicity of green tea, we also studied whether green tea reduces the reproductive toxicity of organic pollutants of tap water in Kunming mouse. Method 2100 liters of tap water with the source of Jialing River water was sampled in December 2003. Solid phase extraction was used to concentrate the organic compounds with GDX-102 resin. The kind of organic extracts (OE) and the quantity of DBP were analyzed by GC/MS. We observed the reproductive effects of organic extracts in mice. We also studied the antagonistic effect of green tea on the male reproductive impairment induced by OE. Animal test: 100 male mice of Kunming mice were randomly divided into seven groups. GroupⅠ(Dimethyl sulfoxide,DMSO solvent control, 0.005 L/kg b.w) ,GroupⅡ(OEl12.5 L/kg b.w), GroupⅢ(OEm,25.0L/kg b.w), GroupⅣ(OEh,50.0L/kg b.w), GroupⅤ(OEh,50L/kg+Green Tea,2g/L b.w), GroupⅥ(OEh,50L/kg+Green Tea,12g/L b.w) and GroupⅦ(Cyclophosphamide ,CP ,positive control ,40mg/kg b.w) were intraperitoneally injected for five days. GroupⅤand GroupⅥwas feed respective with 2g/L (GTl)and 12g/L (GTh) aqueous solution of green tea for two weeks before treatment. Mice were killed at 15th and 35th day after injection. Spermid counting of the epididymis was done with light microscope. Testosterone (T) and follicle-stimulating hormone (FSH) were detected with radioimmunoassay (RIA). Activity of acid phosphates (ACP), γ-glutamyl transpeptidase (γ-GT )of testicular interstitial fluid was detected using chemical colorimetric method. Malondialdehyde (MDA) activity was tested with thibabituric acid (TBA) method. Pathohistological change was observed with light microscope and electron microscope. Results 1.A total of 17 kinds of organic pollutants were detected in the tap water sample, PAEs were accounted 44.23% of the total peak area. The concentration of DBP was found to be 1.9μg/L in the sample. 2.Epididymal sperm counts of OEh and CP groups had significantly reduced compared with the DMSO group (P<0.05). Spermid concentration of OEh+GTl, OEh+GTh groups increased compared to OEh group. 3.After treated 15 day, frequency of abnormal sperm in OEh and CP groups significantly increased compared to DMSO group (P<0.01). After treated 35 days, percentages of abnormal sperm in OEh and CP groups significantly increased compared to DMSO group (P<0.01), OEh+GTh group significantly reduced compared to OEh group ( P<0.05). 4.Testosterone of OEl and OEm significantly decreased compared to DMSO group (P<0.01) after treated 15 days. As to FSH tended to increase, but there was no significant difference between the groups (P >0.05). T reascended obviously in OEh+GTh group. All FSH decreased significantly compared with DMSO group except OEl ( P<0.05) after treated 35 days. 5.ACP activity of treated groups significantly descended compared with DMSO (P<0.05) after treated 15 days. They were reascended at 35th day. But OEh and CP groups were still significantly reduced compared to DMSO (P<0.05). γ-GT activity of OEh and CP group significantly increased compared with DMSO (P<0.05) after treated 15 days. 6.Pathological changes as seen with the light microscope included detachment,rarefaction and decrease of germ cell, and vacuolar degeneration of the Sertoli cell. Hyperplasy of leydig cell was found at 35 day. Pathological changes of OEh+GTl group were slighter than OEh group. Ultrastructural changes were found in germ cell such as cell membrane dissolved, nucelus pycnosis; Sertoli cells endochylema swelled, dilated SER and Leydig cell mitochondrial cristae appeared swelling, collapse, increased numbers lipid droplets at 15th day. These changes were found to be slighter and the function of the cells was more active at 35th day. Conclusion 1.PAEs were found to be the main organic pollutants in tap water in Chongqing. The DBP, which was reproductively toxicant, were detected in relatively high concentration. 2.To some extent, OE has damaged reproductive system of male mice. The mechanism probably is that OE has some direct toxicity to leydig cell,Sertoli cell. 3.OE of tap water can reduce sperm counts and increase of frequency of abnormal sperm. 4.The T decreased at 15th day after OE exposure; FSH decreased at 35th day. The decrease of T could be related to the damage of Leydig cell. Hypothalamic-pituitary-gonadal axis negative feedback adjustment was thought to be the main factor of the FSH reduced. 5.OE can cause the decline of the activity of testicular ACP that maybe caused by the degeneration of seminiferous epithelium and increase of γ-GT activity that caused the damage of Sertoli cells. 6.The histopathology changes were induced by the OE included detachment of spermatogenic cells, vacuolization degeneration of the Sertoli cell; hyperplasia of interstitial cell was observed with the light microscope. Ultrastructural changes were found in germ cell such as cell membrane dissolved, nucelus pycnosis; Sertoli cell endochylema swelled, SER dilated and Leydig cell mitochondrial cristae appeared swelling, collapse, increased numbers lipid droplets at 15th day. 7.The male reproductive toxicity incuced by OE can be antagonised with green tea. In summary, the organic extracts from the tap water in Chongqing can cause male reproductive toxicity. But the results have some limitation because the water samplecollected at a single time. Dynamic observation of the level of organic contaminant in tap water, further research of the mechanism of male reproductive toxicity caused by OE and explorate the optimized protective dose of green tea will be significnt to protect the reproductive health of human beings.