Evaluation On The Toxicological Safety And Anti-Oxidative Effects Of Tea Pholyphenols

Tea pholyphenols(TP) is the collective extract out of tea.Large studies show that TP has the effect of anti-oxidation,anti-tumor,hypo-lipidemic and others.The studies about TP current focus on its functions and less on security.Reactive oxygen species play an important role in the strat and development in cancer,cardiovascular diseases,aging-related diseases and other more than 100 kinds of diseases.Therefore, the search for efficient,low-cost,low toxicity of anti-oxidants and the corresponding screening and evaluation methods is particularly important.The purpose of this study is to evaluate the antioxidant ability of TP,to evaluate oxidants screening and evaluation models and their indicators,to modify the models;to evaluate the safety of TP,to provide the scientific basis for TP' safety usage in health food.â… .Toxicological safety evaluation of TPObjective:1.Acute toxicity test:To obtained the LD50 of TP,to assess the acute toxicity of TP preliminarily,and to provide the base for dose design in its sub-chronic toxicity test.2.Sub-chronic toxicity test:To assess the toxicity might coursed by TP and the potential target organ,to identify the NOAEL and provide basis for human usage.Method:1.An acute toxicity test:The LD₅₀ of TP was estimated by Horns assay.SD rats,40, 180-220g,half male and half female,randomized into four groups by weight,the subjects were given a one-time gavage solution.Female animals designed 0.464,1.0, 2.15,4.64g/kg.bw four dose groups;Males animals designed 1.0,2.15,4.64 and 10.0 g/kg.bw four dose groups;observe animals clinical symptoms and death for 14 days and calculated the LD₅₀ of TP.2.Sub-chronic toxicity test:SD rats,80,60-80g,half female and half male, randomized into four groups by gender and weight.TP given by gavage,and designed a blank control and 400,600,800 mg/kg.bw/ day three dose groups,detection indexes including the weight,food utilization,blood biochemical test,blood routine test,PT and APTT,urine routine test,organs-body ratios and the pathological examination.Results:1.Acute toxicity test:female LD50 =1.71 g / kg;male LD50 =2.33g/kg,TP belongs to low toxic substances.2.Sub-chronic toxicity test:Compared with the control group,weight,food utilization, hematology,blood biochemistry,urine routine and histopathology indicators had no meaningful changes. Conclusion:1.Acute toxicity test:TP belongs to low toxic substances.2.Sub-chronic toxicity test:In this experiment,TP 400,600 and 800 mg/ kg.bw/day gavage for 90 days,found no apparent toxic effects to animals.So the NOAEL for both female and male is 800 mg / kg.bw.â…¡.Evaluation on the anti-oxidative effect of TP.A:In vitroObjective:The purpose of this study is to determine TP's total antioxidant capacity, and verify whether the DPPH method can be used as antioxidants rapid screening methods.Methods:Establish DPPH experimental system,use VC and VE as reference,design five dose groups:0.025,0.050,0.100,0.150,0.200 g / L,to determine the antioxidant capacity of TP.Results:Compared with V_c and V_E at the same concentrations,TP has more ability to remove DPPH radical.Conclusion:TP has a strong antioxidant capacity,and its total antioxidant capacity stronger than V_c and V_E.B:In vivoObjective:To study the mechanism and dose-effect relationship of TP's anti-oxidative function.To establish anti-oxidation substance evaluation model and find the corresponding indicators.Methods:Male mice were divided into five groups,namely the control group, benzene bromide-induced oxidative damage model group and 25,50,100 mg / kg.bw three TP dose group,gavaged for 30 days,With the exception of the control group, the groups irrigation bromide benzene oil 30 mg / kg.bw,take the blood and liver for the determination of all relevant indicators.Results:Compared with the control group,the positive control group liver tissue MDA content,NOS activity,CAT activity,liver cells OLIVE comet tail moments were increased,liver SOD,TAOC,GSH-Px and serum GSH-Px activity decreased; compared with the positive control group,25,50,100 mg / kg.bw three TP dose groups liver tissue MDA content,NOS activity,CAT activity,liver cells OLIVE comet tail moments were decreased in varying degrees,liver tissue SOD,TAOC, GSH-Px and serum GSH-Px activity increased in varying degrees.Conclusion:This study has successfully established bromide benzene-induced acute liver tissue oxidative damage model;Both liver tissue SOD,GSH-PX,TOAC,NOS,MDA,liver tissue DNA strand breaks caused by oxidative stress and serum GSH-Px can used as the biological markers for anti-oxidants' anti-oxidation effect.TP,at 25 mg / kg.bw / day,can enhance the capability of body's antioxidant defense system through increase the activity of antioxidant enzymes.