The excessive intake of fluoride, one of the trace elements required to maintain health, leads to liver injury. Tetramethylpyrazine (TMP) is a kind of traditional Chinese medicine monomer with a good antioxidant and hepatoprotective function. The aim of this study was to investigate the effect of TMP on liver injury induced by acute fluorosis. A total of 60 1-month-old male ICR mice were selected. All mice were randomly divided into five groups: a control (K) group, a model (F) group, a low-dose (LT) group, a medium-dose (MT) group, and a high-dose (HT) group. The control and model groups were given distilled water, while 40 mg/kg (LT), 80 mg/kg (MT), or 160 mg/kg (HT) of TMP was fed by gavage for two weeks, with a maximum gavage volume for the mice of 0.2 mL/10 g/d. Except for the control group, all groups were given fluoride (35 mg/kg) by an intraperitoneal injection on the last day of the experiment. The results of this study showed that, compared with the model group, TMP alleviated the pathological changes in the liver induced by the fluoride and improved the ultrastructure of liver cells; TMP significantly decreased the levels of ALT, AST, and MDA (p < 0.05) and increased the levels of T-AOC, T-SOD, and GSH (p < 0.05). The results of mRNA detection showed that TMP significantly increased the mRNA expression levels of Nrf2, HO-1, CAT, GSH-Px, and SOD in the liver compared with the model group (p < 0.05). In conclusion, TMP can inhibit oxidative stress by activating the Nrf2 pathway and alleviate the liver injury induced by fluoride.

Hepatic oxidative stress is an important mechanism of Cd-induced hepatotoxicity, and it is ameliorated by TMP. However, this underlying mechanism remains to be elucidated. To investigate the mechanism of the protective effect of TMP on liver injuries in mice induced by subchronic cadmium exposure, 60 healthy male ICR mice were randomly divided into five groups of 12 mice each, namely, control (CON), Cd (2 mg/kg of CdCl₂), Cd + 100 mg/kg of TMP, Cd + 150 mg/kg of TMP, and Cd + 200 mg/kg of TMP, and were acclimatized and fed for 7 d. The five groups of mice were gavaged for 28 consecutive days with a maximum dose of 0.2 mL/10 g/day. Except for the control group, all groups were given fluoride (35 mg/kg) by an intraperitoneal injection on the last day of the experiment. The results of this study show that compared with the Cd group, TMP attenuated CdCl₂-induced pathological changes in the liver and improved the ultrastructure of liver cells, and TMP significantly decreased the MDA level (p < 0.05) and increased the levels of T-AOC, T-SOD, and GSH (p < 0.05). The results of mRNA detection show that TMP significantly increased the levels of Nrf2 in the liver compared with the Cd group as well as the HO-1 and mRNA expression levels in the liver (p < 0.05). In conclusion, TMP could inhibit oxidative stress and attenuate Cd group-induced liver injuries by activating the Nrf2 pathway.

Excessive intake of fluoride, one of the trace elements to maintain health, leads to liver injury. Tetramethylpyrazine (TMP) is a kind of traditional Chinese medicine monomer with good antioxidant and hepatoprotective function. The aim of this study was to investigate the effect of TMP on liver injury induced by acute fluorosis. A total of 60 1-month-old male Institute of Cancer Research mice without carriage of pathogenic bacteria were selected. All mice were fed adaptively for one week, and then randomly divided into 5 groups: control (K) group, model (F) group, low-dose (LT) group, medium-dose (MT) group and high-dose (HT) group. The control and model group were given distilled water, while 40 mg/kg (LT), 80 mg/kg (MT) and 160 mg/kg (HT) TMP were fed by gavage for two weeks with the maximum gavage volume of mice is 0.2ml/10g/d. Except for the control group, all groups were given fluoride (35 mg/kg) by intraperitoneal injection on the last day of the experiment. The results of this study showed that compared with the model group, TMP alleviated the pathological changes of liver induced by fluoride and improved the ultrastructure of liver cells; TMP significantly decreased the levels of ALT, AST and MDA (P <0.05), and increased the levels of T-AOC, T-SOD and GSH (P <0.05). The results of mRNA detection showed that TMP significantly increased the mRNA expression levels of Nrf2, HO-1, CAT, GSH-Px and SOD in liver compared with model group (P <0.05). In conclusion, TMP can inhibit oxidative stress by activating Nrf2 pathway and alleviate liver injury induced by fluoride.