Studies On The Cytotoxicity And Genotoxicity Of KF And Tea Soaks Containing High Fluoride

Objective: Fluorine is the essential microelement for organism, which is not only disease etiology of natural geochemical disease, but also the important pollutants of industrial production and livelihood coal-fired.There was a close relation between fluoride and metabolism of calcium and phosphorus.Excessive fluoride intaken can affect different organs and tissue of the body, such as bones and teeth. With the development of industrial production, the opportunities exposed to fluoride are increased more and more, the safety problem about fluoride attracte people's attention, especially the potential genetic toxicity studies have begun to be taken notes seriously. The KF and two kinds of tea that have a stronger concentration to fluoride in the environment were choosed as research subjects.We attempts to explore the genotoxicity of fluoride by understanding the cytotoxicity, mutagenicity and DNA damage of KF and two kinds of tea containing high fluoride, which may provide some experimental for the safety of drinking tea.Methods: The fluoride concentration of green tea A,green tea B and the control tea soaks were determined by using fluoride ion-selective electrode analysis. The viability of the V79 cells which were treated by different dosage of two tea soaks containg high fluoride and KF was detected by trypan blue stain assay and MTT method, and the dose-effect and time-effect relation coule be definited. Salmonella typhimurium microsoml enzyme test (Ames test) was used to detect the mutagenicity of two tea soaks containg high fluoride and KF. The single cell gel electrophoresis (SCGE) was used to detect the DNA damage of two tea soaks containg high fluoride and KF,the difference of DNA damage caused by tea soaks containing different fluoride was compared.Results: The fluoride content of green tea A,B and the control tea were 2330mg/kg,1390mg/kg and 7.5mg/kg, respectively,and exceed the agriculture profession standard. Tea soaks containing high fluoride and KF could induce viability inhibition with significant dose-effect and time-effect relationship; In trypan blue stain assay test, the median proliferation inhibition concentrations(IC50)of KF was significantly lower than that of three kinds of tea,and the IC50 of the control tea >that of green tea B>that of green tea A from the median proliferation inhibition concentrations at 4h and 24h . The cell survival rate of the green tea A,B and KF were significantly less than the control tea(p<0.05),the cell survival rate of the green tea B was significantly higher than the green tea A ( p<0.05 ) at the concentration of 2.50mg/mL~10.00mg/mL for 4h and 0.63~10.00mg/mLfor 24h. In MTT test, the cell survival rates of the green tea A,B and KF were significantly less than the control tea(p<0.05),The cell survival rate of the green tea B was significantly higher than that of the green tea A(p<0.05)for 4~24h. Analysing the median lethal concentrations(IC50) of KF and three tea soaks, there are significant differences between the three tea groups and KF(p<0.05), The average IC50 of green tea A,green tea B,control tea and KF were 20.36,23.24,28.18,0.93mg/ml respectively . There was no mutagenicity about these two kinds of tea soaks and KF in Ames test. The colonies of TA98, TA100 and TA102 strains were less than that of the corresponding negative control group (p<0.01) at the concentration of 5000μg/dish in the fluoride control group (KF). In single cell gel electrophoresis (SCGE) assay, KF,green tea A and green tea B could induce DNA damage in V79 cells. DNA damage of KF was larger than that of green tea A,B(p<0.05),and the DNA damage of green tea A was larger than that of green tea B(p<0.05), There was no significant difference between the control tea and negative group.Conclusions: The fluoride content of green tea A,B exceed the agriculture profession standard。KF and two tea soaks containg high fluoride could induce viability inhibition with significant dose-effect relationship in V79 cells, Cytotoxicity of green tea A,B were larger than that of the control tea(p<0.05), Cytotoxicity of KF were larger than that of tea soaks containing high fluoride at at the low concentrations on V79 cells. There was no mutagenicity about these two kinds of tea soaks and KF in Ames test. KF,green tea A and green tea B could induce DNA damage in V79 cells. DNA damage of KF was larger than that of green tea A,B(p<0.05),and the DNA damage of green tea A was larger than that of green tea B(p<0.05).