Study On The Toxicity And Mechanism Of 8:2 Fluorotelomer Alcohol

Fluoroteloer alcohols?FTOHs?is fluorocarbon oligomers,which has been widely applied in food packaging,home furnishing,fire resistant foam,surfactants,textiles,adhesives,waxes,polishing agents and leather.Fluorotelomers occupy a leading position in global consumption.8:2 Fluorotelomer alcohol is the most widely used FTOH homologues,which is widespread,long-term and persistent in the environment.It has been reported at home and abroad that 8:2 FTOH is a kind of persistent environmental pollutant with carcinogenicity,reproductive toxicity,mutagenic toxicity,developmental toxicity,neurotoxicity,immunotoxicity and other toxicity,but its toxicity mechanism is not clear.In this study,it has obtained the median lethal dose(LD₅₀)on ICR mice for oral acute toxicity,the no observed adverse effect level?NOAEL?and the target organs on Wistar rats for oral subacute toxicity through traditional toxicology research of 8:2 FTOH.On this basis,we have identified the toxicity biomarkers,analyzed metabolic pathways affected and toxic mechanism of 8:2 FTOH.1. Acute toxicity test of 8:2 FTOH in miceWe adopted korbor method to study the acute oral toxicity of 8:2 FTOH in ICR mice.The dose range of LD₅₀of 8:2 FTOH was found through the preliminary results.And then selected the dose series of acute toxicity test.Recorded the number of animal deaths during the 14 day observation period and calculation formula to calculated the LD₅₀,95%confidence limit and standard error.We obtained the acute oral LD₅₀of female ICR mice was 9270 mg/kg,the 95%confidence limit was1640-1740 and the standard error was 0.07.The acute oral LD₅₀of male ICR mice was 4780 mg/kg,the 95%confidence limit was 1570-1790 and the standard error was0.06.The above results showed that oral acute toxicity was lower and significant gender difference of 8:2 FTOH.2.28 day oral toxicity test of 8:2 FTOH in ratsThe 25%of acute oral LD₅₀of mice exposed to 8:2 FTOH was designed as the high dose group.Due to the great difference of toxicity between male and female mice,male and female Wistar rats were divided into two groups for 28 day oral subacute toxicity study.Three doses of 600 mg/kg/d,1200 mg/kg/d and 2400 mg/kg/d were given to female rats,and three doses of 300 mg/kg/d,600 mg/kg/d and 1200mg/kg/d were given to male rats.The blank control group was set up in female and male rats.The blank control group was given 0.5%CMC sodium suspension of equal volume.The rats were administrated by gavage for 28 days,and then observed for 14days.The daily performance of the rats was observed during the experiment.At the end of the experiment,determining the blood routine and biochemical indexes,conducting autopsy and histopathological observation,and calculating organ coefficient.Compared with the blank control group,the level of RBC was significantly reduced in the middle and high-dose groups of females?p<0.05,p<0.05?.The level of HGB and HCT were significantly reduced in the females middle and high-dose group?p<0.05,p<0.05,p<0.01,p<0.01?.The level of RDW was significantly increased in the high-dose group of females?p<0.01?.The level of MPV was significantly increased in the low-dose group of females?p<0.05?.The level of PLT were significantly decreased in the females low,middle and high-dose group?all were p<0.05?.The level of RBC was significantly decreased in the males middle and high-dose group?all were p<0.05?.The level of PLT was significantly decreased in the males low,middle and high-dose group?all were p<0.05?.Compared with the blank control group,the levels of TB,ALB,ALT,AST and CREA were significantly increased?p<0.05,p<0.05,p<0.05,p<0.05?in females low-dose group.The levels of TG was significantly decreased in low-dose group?p<0.01?.The levels of ALB,ALT,AST and CREA were significantly increased?p<0.05,p<0.05,p<0.01?and TG was significantly decreased?p<0.01?in females middle-dose group.The level of ALB,AST,AST,CREA and UREA were significantly increased?p<0.05,p<0.01,p<0.05,p<0.01,p<0.01?.The levels of TG and TC were significantly decreased?p<0.01,p<0.01?in females high-dose group.The level of ALT was significantly increased?p<0.01?and TG and TC significantly reduced?p<0.01,p<0.01?in males low-dose group.The level of TB,ALB,ALT and AST were significantly increased?p<0.05,p<0.05,p<0.01,p<0.05?,and the level of TG and TC significantly decreased?p<0.01,p<0.01?in males middle-dose group.The level of ALB,ALT,AST and CREA were significantly increased?p<0.05,p<0.01,p<0.05?and TG and TC were significantly decreased?p<0.01,p<0.01?in males high-dose group.Compared with the control group,the organ coefficients and weight of liver and kidney in low,middle and high group were significantly increased?all were p<0.01?.The organ coefficient and weight of uterus in the low and middle dose group was significantly increased?p<0.01,p<0.05,p<0.01,p<0.05?.However,the organ coefficient and weight of uterus in the high-dose group was decreased significantly?p<0.01,p<0.01?.The rat heart caused by 8:2 FTOH were necrosis and rupture of muscle cells,dissolution and edema of muscle fibers,increase of tissue space,hyperemia and expansion of blood vessels,and infiltration of inflammatory cells.Which were hepatic edema,inflammatory cell infiltration,dilatation and congestion of hepatic sinuses.The brush border of epithelial cells in renal proximal convoluted tubules were injured.The epithelial cells of renal tubules were swollen and necrotic,and the space of glomerular capsule was enlarged.The structure of splenic nodule was scattered,even disappeared of high-dose group on females and males.The uterine epithelial cells occured dropsy,necrosis and abscission.The neutrophils was diffuse infiltrated and it is mild lesions in uterus.The granulosa cell was necrosis and inflammatory cell was diffuse infiltration in ovary,which showed moderate lesions.The spermatocytes in testis decreased and necrotized.The interstitium of seminiferous tubules occured edema.According to the oral toxicity test results of rats exposed to 8:2 FTOH for 28days,the NOAEL of 8:2 FTOH to female rats is lower than 600 mg/kg/d and to male rats is lower than 300 mg/kg/d.The toxic of 8:2 FTOH to males is more serious than females and is reversible.8:2 FTOH has many kinds of toxicity,such as cardiotoxicity,hepatotoxicity,nephrotoxicity,immunotoxicity,endocrine interference,reproductive toxicity and so on.It is a kind of environmental pollutant with systemic multi organ toxicity.3. Toxic metabonomics of 8:2 FTOH on rat plasmaFinally,the mechanism of multiple organ toxicity in Wistar rats exposed to 8:2FTOH?female:2400mg/kg;male:1200mg/kg?was explored at the level of metabolites.In this study,The LC/MS-Q-TOF technique was used to analyze the plasma samples from Wistar rats by extensive target toxicity.Through multivariate statistical analysis showed that the 30 and 35 differential metabolites were screened out in female and male rats separately,mainly including in amino acid metabolites and lipid metabolites,such as glycine?Gly?,glutamic acid?Glu?,pyroglutamic acid?p Glu?,N-Propionylglycine,Hexanoyl glycine,?-Ketoglutaric Acid??-KG?,phosphatidylcholine?PC?,lysophosphatidylcholine?LPC?,phosphatidyl ethanolamine?PE?,lysophosphatidyl ethanolamine?LPE?,diacylglycerol?DG?and triglyceride?TG?and Free fatty acids?FFA?.According to KEGG analysis,these differential metabolites are mainly involved in the metabolic pathways of glutathione metabolism,glycerophosphatidylcholine metabolism,glyceride metabolism,arachidonic acid metabolism,linoleic acid metabolism,fatty acid prolongation,fatty acid degradation and phosphoinositol metabolism.It is suggested that 8:2 FTOH may cause oxidative stress and multiple organ toxicity mainly through lipid metabolism disorder,and may resist oxidative stress through glutathione metabolism.