Study on the hepatotoxicity and potential mechanism of gefitinib based on CYP450 in mice and AML12 cells.

OBJECTIVES: Gefitinib is mainly used for the treatment of non-small-cell lung cancer. Hepatotoxicity is one of the main side effects of gefitinib, and seriously affects the treatment process of the disease. However, the hepatotoxicity mechanism of gefitinib remains unclear. METHODS: The hepatotoxicity of different doses of gefitinib was investigated in mice and AML-12 cells, and the possible correlation of hepatotoxicity with CYP450 was analysed. KEY FINDINGS: The toxic effects of gefitinib were confirmed by the increased liver index, decreased body weight and survival rate, injured liver function and histopathology followed 16 days of oral administration. Gefitinib (400 mg/kg) upregulated the hepatic mRNA expression of CYP1A1 and downregulated the CYP2D9 and CYP2D10 in mice. Furthermore, we verified that gefitinib produced cytotoxicity on AML-12 cells in a dose and time-dependent manner, and confirmed that gefitinib (20 µM) induced cell apoptosis, upregulated mRNA expression of CYP1A1 and downregulated CYP2D9 and CYP2D10. Pearson correlation analysis also showed that the hepatotoxicity of gefitinib was positively correlated with CYP1A1 and negatively correlated with CYP2D9 and CYP2D10. CONCLUSIONS: Our results suggested that the hepatotoxicity gefitinib may be associated with CYP1A1, CYP2D9 and CYP2D10. These findings will contribute to a better understanding of the mechanism of gefitinib hepatotoxicity.

Baicalin ameliorates CUMS-induced depression-like behaviors through activating AMPK/PGC-1α pathway and enhancing NIX-mediated mitophagy in mice.

Mitochondrial dysfunction has been reported to be involved in the pathogenesis of depression, and mitophagy is a key pathway for mitochondrial quality control. This study aimed to investigate the effect of baicalin on mitophagy in the hippocampus of mice exposed to chronic unpredictable mild stress (CUMS) and explore its potential mechanism. After exposure to CUMS for 6 weeks, mice were given baicalin (20 mg/kg) or fluoxetine (20 mg/kg) by oral gavage for 4 weeks, and HT22 cells were injured by corticosterone (CORT) in vitro. Depression-like behaviors were assessed by sucrose preference test and tail suspension test. The mitochondrial structure was observed by transmission electron microscopy. Detection of mitophagy and mitophagy-related protein by mitophagy kit and Western blot. The results showed that baicalin improved depressive-like behaviors in CUMS mice, and ameliorated mitochondrial structural impairment in the hippocampus neuron. Baicalin significantly down-regulated light chain 3(LC3)II/I, protein sequestosome 1 (P62), and translocase of the outer membrane 20 (TOM20), and up-regulated Nip-like protein (NIX), Adenylate activated protein kinase (AMPK), and Peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1α. Furthermore, molecular docking showed that baicalin interacts with AMPK through hydrogen bonding. Baicalin increased NIX and AMPK, and improved mitophagy level and mitochondrial function in HT22 cells. Treatment with Phorbol 12-Myristate 13-acetate demonstrated that up-regulation of NIX ameliorated CORT-induced mitochondrial dysfunction in HT22 cells. In conclusion, the present study suggested that the antidepressant effect of baicalin may be related to the enhancement of NIX-mediated mitophagy through activating the AMPK/PGC-1α pathway by directly binding to AMPK.

Baicalin improves the energy levels in the prefrontal cortex of mice exposed to chronic unpredictable mild stress.

Depression is gradually becoming a primary mental disease threatening human health. Therefore, there is an urgent need to clarify the pathogenesis of depression and identify new effective natural antidepressants. This study aimed to investigate the antidepressant effects of baicalin and explore its potential mechanism in a mouse model of depression induced by chronic unpredictable mild stress (CUMS). Following a 6-week exposure to CUMS, mice were treated with baicalin (10 mg/kg) or fluoxetine (10 mg/kg) for 4 weeks by oral gavage. A sucrose preference test and a forced swimming test were performed to evaluate depression-like behaviors, and the levels of adenosine triphosphate (ATP) in the prefrontal cortex were measured. Moreover, gene expression and enzyme activities related to ATP production, and mitochondrial function, were monitored. The results indicated that baicalin and fluoxetine could alleviate CUMS-induced depression-like behaviors of mice. In addition, baicalin significantly elevated the ATP content and the expression of genes hexokinase 1 (Hk1), pyruvate dehydrogenase E1 alpha 1 (Pdha-1), isocitrate dehydrogenase (Idh), peroxisome proliferator-activated receptor, gamma, coactivator 1 alpha (Pgc-1α), and sirtuin-1 (Sirt1) in the prefrontal cortex. Furthermore, baicalin increased the activity of the respiratory chain complexes I and V as well as the mitochondrial membrane potential. In conclusion, baicalin may exert its antidepressant effect partly by upregulating the expression of some genes coding for enzymes involved in the glycolysis and the tricarboxylic acid cycle, and improving the mitochondrial function to enhance the ATP level in the brain.

[Expression of P27 protein and cyclin E in colon cancer].

BACKGROUND & OBJECTIVE: P27 protein and cyclin E were negative cell cycle regulators. Until the present, the influence of P27 protein and cyclin E on progression of colon cancer was unclear. The aim of this study was to observe the expression features of P27 protein and cyclin E in the tissues of colon neoplasms, and to investigate the relationship between colon neoplasms and tumor special growth factor (TSGF). METHODS: Sixty-nine cases of samples included 23 normal tissues, 28 colon polyps (13 inflammatory polyps and 15 adenomatous polyps), and 18 colon carcinomas. The location and expression of P27 protein and cyclin E were determined using immunohistochemical method in all samples. These samples were diagnosed using formal pathological techniques simultaneously; the relationship between colon neoplasms and TSGF was also investigated. RESULTS: The positive signal of P27 and cyclin E was found mainly in the cytoplasm and extracellular matrix of normal colon tissues, inflammatory polyps, and adenomatous polyps. Less amount of positive expression product of P27 protein and cyclin E was observed in colon carcinoma cells; and the positive signal was only located in the cytoplasm of gland-like cells. The content of TSGF in colon carcinoma tissues was significantly higher than that in normal tissues (117.3+/-57.02 versus 64.16+/-27.5,P< 0.01), but there was no significant difference between colon carcinoma tissues and inflammatory polyp tissues (117.3+/-57.02 versus 92.5+/-47.9,P >0.05). CONCLUSION: P27 protein and cyclin E participate in the adjustment process of colon neoplasm occurrence and progression. The reduced expression of P27 protein and cyclin E may indicate the possibility of colon carcinoma.