Protective mechanism of tea polyphenols in potassium dichromate-induced acute renal injury in mice / 中国职业医学

ABSTRACT

OBJECTIVE: To explore the protective effect of tea polyphenols and its mechanism in potassium dichromate(PD)-induced acute renal injury in mice. METHODS: The specific pathogen free weaned Kunming mice were divided into control group, model group and low-, middle-and high-dose tea polyphenols groups, with 12 mice in each group. Mice in the control group were given 0.9% sodium chloride solution, and mice in other four groups were given PD solution with 4.275 mg/kg body weight every morning by intragastric administration. Then, mice in the control group and model group were given 0.9% sodium chloride solution in the afternoon, while mice in the low-, middle-and high-dose tea polyphenols groups were given 0.3 mL tea polyphenols solution with a dose of 200, 400 or 600 mg/kg body weight, respectively by gavage, once a day for two consecutive weeks. The body mass of mice was weighed during the experiment. At the end of the experiment, the mice were sacrificed. The kidneys were removed and weighed. The kidney organ coefficients were calculated. The levels of urea nitrogen and creatinine in serum were determined by two-point method, the activities of catalase(CAT) and glutathione peroxidase(GSH-Px) in serum of mice were detected by colorimetry. The pathological change of kidney in mice was observed. RESULTS: The body weight of mice in the model group decreased(P<0.05), while the kidney mass, renal organ coefficient, serum levels of urea nitrogen and creatinine increased(all P<0.05), and the serum activities of CAT and GSH-Px decreased(all P<0.05) compared with the control group. The body weight of mice in the three tea polyphenols groups increased(all P<0.05), while the kidney mass, renal organ coefficient, urea nitrogen and creatinine levels in serum decreased(all P<0.05), and the activities of CAT and GSH-Px in serum increased with the increasing intervention dose of tea polyphenols(all P<0.05) compared with the model group. The change of acute renal injury was mainly caused by renal tubular injury in the model group. The pathological changes of renal tissue in the three tea polyphenols intervention groups were improved compared to that in the model group, and the improvement showed a dose-effect relationship with the intervention of tea polyphenols. CONCLUSION: Tea polyphenols have a protective effect on PD-induced acute renal injury with a dose-effect relationship. Its mechanism of action is related to the fact that tea polyphenols can reduce or reverse oxidative stress and inflammation in the kidney.