Effect of tea polyphenols on neurotoxicity induced by methylmercury in rats

Objective To examine the effect of tea polyphenols on toxic effect induced by methylmercury. Methods Thirty-six Wistar rats were randomly divided into 3 groups by weight.The first group was control group;the second group was treated with 12μmol/kg CH₃HgCl;the third group was the tea polyphenols pretreatment group.The pretreatment and CH₃HgCl treatment lasted for 4 weeks.Twenty four hours after the last treatment,the activities of Na⁺-K⁺-ATPase and Ca²⁺-ATPase,the contents of Ca²⁺ and reactive oxygen species,the levels of apoptosis in pallium were determined. Results Compared with the control group,the activities of Na⁺-K⁺-ATPase(2.72±0.46μmol/h·mg) and Ca²⁺-ATPase(1.52±0.26μmol/h·mg)decreased significantly(P<0.01)and the content of Ca²⁺ (239.52±44.84 nmol/L),the content of reactive oxygen species(313.86±35.11 fluorescence intensity),and the level of apoptosis(40.84±6.26%)increased significantly(P<0.01 for all)in CH₃HgCl treatment group.Compared with CH₃HgCl treatment group,the activities of Na⁺-K⁺-ATPase(3.58±0.71μmol/h·mg)and Ca²⁺-ATPase (1.98±0.29μmol/h·mg)increased significantly(P<0.05,P<0.01)and the content of Ca²⁺(188.39±7.43 nmol/L),the content of reactive oxygen species(238.03±22.99 fluorescence intensity)and the level of apoptosis (28.31±4.34%)decreased obviously in the tea polyphenols pretreatment group(P<0.05,P<0.01,and P<0.01). Conclusion Tea polyphenols has a protective effect on the neurotoxicity induced by methylmercury in rats.