The protective effect and mechanism of tea polyphenols on oral cancer in mice / 中国医师杂志

ABSTRACT

Objective:To explore the protective mechanism of tea polyphenols (TP) on mouse oral cancer.Methods:A total of 50 mice were divided into control group, model group, TP group, Selisistat group, TP+ Selisistat group, with 10 mice in each group. The control group was gavaged with physiological saline, while the model group, TP group, Selisistat group, and TP+ Selisistat group were gavaged with 300 mg/L 4-NQO to establish a mouse oral cancer model. Physiological saline, 200 mg/kg TP, 0.01 mg/kg Selisistat, and 200 mg/kg TP+ 0.01 mg/kg Selisistat were gavaged respectively. The weight changes of each group of mice were compared; HE staining was used to observe the morphology of mouse oral tumor tissue; Enzyme linked immunosorbent assay was used to detect the levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in serum; Immunoblotting and immunohistochemistry were used to detect the expression of silencing information regulatory factor (Sirt1) and nuclear factor E2 related factor 2 (Nrf2) proteins in mouse oral tissues.Results:Compared with the control group, the model group mice had a decrease in body weight [(23.19±1.36)g], a decrease in serum SOD level [(91.64±8.75)U/ml], an increase in MDA level [(5.18±0.46)nmol/ml], a decrease in Sirt1 (0.38±0.05) and Nrf2 (0.36±0.05) protein expression in oral tissue, and an increase in Nrf2 acetylation level (0.84±0.11) (all P<0.05). Compared with the model group, the TP group mice had an increase in body weight [(25.28±1.25)g], elevated serum SOD levels [(121.24±10.68)U/ml], decreased MDA levels [(3.89±0.42)nmol/ml], increased expression of Sirt1 (0.61±0.09) and Nrf2 (0.58±0.06) proteins in oral tissue, and decreased Nrf2 protein acetylation levels (0.39±0.05); The Selisistat group mice showed a decrease in body weight [(21.41±1.07)g], a decrease in serum SOD levels [(72.16±7.43)U/ml], an increase in MDA levels [(5.87±0.41)nmol/ml], a decrease in Sirt1 (0.23±0.04) and Nrf2 protein (0.24±0.03) expression in oral tissue, and an increase in Nrf2 acetylation levels (1.12±0.14) ( P<0.05). The body weight [(23.32±1.27)g], serum SOD levels [(92.58±8.13)U/ml], and oral Sirt1 (0.41±0.06) and Nrf2 (0.38±0.05) protein expression in the TP+ Selisistat group mice were higher than those in the Selisistat group, while MDA [(5.11±0.38)nmol/ml] and Nrf2 acetylation levels (0.82±0.09) were lower than those in the Selisistat group (all P<0.05). Conclusions:Tea polyphenols can alleviate oral tissue damage and alleviate oxidative stress in mice with oral cancer, and their mechanism may be related to the upregulation of the Sirt1/Nrf2 pathway.