Publications (4)10.22 Total impact
- [Show abstract] [Hide abstract] ABSTRACT: Background/Aims: Melatonin, synthesized by the pineal gland and released into the blood, appears to have antitumour properties; however, the mechanisms of its anti-cancer effects are largely unknown, especially in stomach cancer. Here, we explore the antitumour activity of melatonin in a gastric cancer cell line (AGS) and analyse its molecular mechanisms. Methods: AGS cells were treated with melatonin, and cell viability was assessed using a CCK-8 assay. Flow cytometry was performed to evaluate apoptosis, and protein expression was examined by Western blotting. Results: Melatonin significantly inhibited cell viability, clone formation, and cell migration and invasion and induced apoptosis in AGS cells. Moreover, MAPK pathways (p38, JNK and ERK) were activated by melatonin treatment, which also significantly increased caspase-3 cleavage and Bax protein expression and decreased Bcl-2 protein expression in a time-dependent manner. Our results demonstrate that p38 and JNK inhibitors (SB203580 and SP600125, respectively) prevented melatonin-induced apoptosis; thus, the propensity of p38 MAPK and JNK to promote apoptosis could be at least partly due to the inhibition of NF-κB p65 activation by p38 and JNK. Finally, melatonin was able to strengthen cisplatin-mediated antitumour effects in human gastric carcinoma cells by up-regulating the expression of Bax, down-regulating the expression of Bcl-2 and activating the caspase-dependent apoptotic pathway. Conclusion: Melatonin induced apoptosis in AGS cells by activating the caspase-dependent apoptotic pathway and by inhibiting the nuclear translocation of NF-κB p65, two processes that are regulated by p38 and JNK. Furthermore, melatonin significantly enhanced the anti-tumour effects of cisplatin, with low systemic toxicity. These new findings suggest that melatonin may act as a potent anti-tumour agent and may have great potential as an adjuvant therapy in the future.
- [Show abstract] [Hide abstract] ABSTRACT: With the rapid development of real-time elastography (RTE), a variety of measuring methods have been developed for the assessment of hepatic fibrosis. We evaluated the overall performance of four methods based on RTE by performing meta-analysis of published literature. Online journal databases and a manual search from April 2000 to April 2014 were used. Studies from different databases that meet inclusion criteria were enrolled. The statistical analysis was performed using a random-effects model and fixed-effects model for the overall effectiveness of RTE. The area under the receiver operating characteristic curve (AUROC) was calculated for various means. Fagan plot analysis was used to estimate the clinical utility of RTE, and the heterogeneity of the studies was explored with meta-regression analysis. Thirteen studies from published articles were enrolled and analyzed. The combined AUROC of the liver fibrosis index (LFI) for the evaluation of significant fibrosis (F≥2), advanced fibrosis (F≥3), and cirrhosis (F = 4) were 0.79, 0.94, and 0.85, respectively. The AUROC of the elasticity index (EI) ranged from 0.75 to 0.92 for F≥2 and 0.66 to 0.85 for F = 4. The overall AUROC of the elastic ratio of the liver for the intrahepatic venous vessels were 0.94, 0.93, and 0.96, respectively. The AUROC of the elastic ratio of the liver for the intercostal muscle in diagnosing advanced fibrosis and cirrhosis were 0.96 and 0.92, respectively. There was significant heterogeneity in the diagnostic odds ratio (DOR) for F≥2 of LFI mainly due to etiology (p<0.01). The elastic ratio of the liver for the intrahepatic vein has excellent precision in differentiating each stage of hepatic fibrosis and is recommend to be applied to the clinic.
- [Show abstract] [Hide abstract] ABSTRACT: Recent studies have demonstrated that melatonin significantly decreased all studied acute pancreatitis-associated inflammatory parameters, in addition to reducing apoptosis and necrosis associated with pancreatic injury. However, the effect of melatonin on gut barrier dysfunction and bacterial translocation has not been fully elucidated. This study aimed to investigate the protective effects of melatonin on intestinal integrity in a rat model of severe acute pancreatitis (SAP) to evaluate whether melatonin prevented intestine barrier dysfunction and reduced bacterial translocation. Forty male Sprague Dawley (SD) rats were randomly divided into three groups, with 8 rats in the sham operation (SO) group, 18 rats in the SAP group and 14 SAP rats in the melatonin treatment (MT) group. SAP was induced by retrograde injection of 4% taurocholate into the biliopancreatic duct. Melatonin was administered 30 min prior to taurocholate injection in the melatonin-treated rats. All rats were sacrificed 24 h subsequent to pancreatitis induction. Real-time fluorescence quantitative polymerase chain reaction was used to detect and quantify Escherichia coli (E. coli) O157 in postcava blood. The microvilli structure was also analyzed with transmission electron microscopy. The level of E. coli DNA in the MT group was significantly lower than in rats in the SAP group. No E. coli DNA was detected in the control group. Villus height and crypt depth in the ileum were significantly higher in the MT and control groups compared to the SAP group, and were significantly higher in the MT group than in the SAP group. These results suggested that melatonin prevented gut barrier dysfunction and reduced bacterial translocation, resulting in reduced pancreatic-associated infections and decreased early mortality rates.
- [Show abstract] [Hide abstract] ABSTRACT: This study aims to investigate the relationship between the protective effects of melatonin in pancreas and the expression of sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) and Na(+)/Ca(2+) exchanger (NCX) in rats with acute necrotizing pancreatitis (ANP), to verify whether melatonin ameliorates ANP by alleviating calcium overload. Ninety-six male Sprague-Dawley rats were randomly divided into four groups (sham operation group, ANP group, melatonin treatment group, melatonin contrast group). ANP was induced by the retrograde injection of 4% taurocholate (1 ml/kg body weight) into the biliopancreatic duct. Melatonin (50 mg/kg body weight) was administered 30 min before the induction of ANP in the melatonin treatment group. Rats in each group were euthanized at 1, 4, and 8 h after ANP induction. Pancreatic tissues were removed to measure SERCA and NCX levels and cytosolic calcium ion (Ca(2+)) concentration ([Ca(2+)](i)). At each time point, SERCA and NCX levels in the melatonin treatment group were significantly higher than that in the ANP group, and lower than that in the sham group and the melatonin contrast group. These levels did not differ between the 4- and 8-h time points in the ANP group. [Ca(2+)](i) in pancreatic acinar cells was higher in the melatonin treatment group than in the sham group and the melatonin contrast group, but lower than in the ANP group, at each time point. Melatonin can reduce pancreatic damage via the up-regulation of SERCA and NCX expression, which can alleviate calcium overload in pancreatic acinar cells.