Bioactive Fatty Acids Reduce Development of Gastric Cancer Following Duodenogastric Reflux in Rats

Background: Bioactive fatty acids such as the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the modified fatty acid analogue, tetradecylthioacetic acid (TTA), are known to influence inflammatory processes in the body. Our aim was to investigate if diets containing fish oil (FO) enriched with bioactive fatty acids could affect inflammation and development of glandular stomach carcinogenesis in a duodenogastric reflux (DGR) animal model. We also wanted to evaluate if a high-fat diet might increase the risk of developing gastric cancer compared to a low-fat diet. Methods: 185 rats operated on with a gastroenterostomy were randomly allocated to 5 different treatment groups given: low-fat, high-fat, high-fat + FO, high-fat + TTA or high-fat + FO + TTA. The stomachs were removed after 50 weeks and examined by light microscopy with hematoxylin and eosin staining (HE). Immunohistochemical staining against COX-2, PCNA and p53 was performed when adenocarcinomas were found. The plasma fatty acid profile was determined. Results: Adenocarcinomas developed in 21% of animals fed the low-fat diet, 35% in the high-fat group, 16% in the high-fat + TTA group, 21% in the high-fat + FO group and 8.6% in the high-fat + FO + TTA treatment group. COX-2 and PCNA were positive whereas p53 was negative in the majority of the samples. The anti-inflammatory fatty acid index increased after treatment with FO and in combination with FO and TTA. Conclusion: FO and TTA in combination with a high-fat diet significantly lower the risk of developing adenocarcinomas in rats subjected to duodenogastric reflux. This is most likely due to a selective modulation of inflammation.

Effect of bile salts and bile acids on human gastric mucosal epithelial cells

Objective：To explore the effect of bile salt and bile acid on cultured eternalized human gastric mucosa epithelium GES-1 cells. Methods：Cultured eternalized human gastric mucosa epithelium GES-1 cells were treated with media containing 6 different kinds of bile salts and 3 different kinds of bile acids and their mixture with different concentrations： GCDC（glycochenodeoxychoμte）, GDC （glycodeoxychoμte）, GC（glycochoμte）, TCDC（taurochenodeoxychoμte）, TDC（taurodeoxychoμte）, TC （taurochoμte）, LCA （lithocholicacid）, CA（cholic acid）, DCA（deoxycholic acid）（50 μ mol/L,250 μ mol/L,500 μ mol/L,1000 μ mol/L）, DY（mixture of bile salts） and DS（mixture of bile acids）（250 μ mol/L,500 μ mol/L,1000 μ mol/L,1500 μ mol/L, 2000 μ mol/L）, in comparison with the control group（in normal media without bile salts and bile acids）. Cell proliferation was assessed by MTT（3-[4,5-Dimethylthiaolyl]-2,5- diphenyl-tetrazolium bromide） assay for 72 hours with different concentrations and the apoptotic cells were assayed by flow cytometry （FCM） with Annex V-FITC conjugated with propidium iodide（PI） staining for 24 hours with different concentrations（1500,2000 μt mol/L）. Results：There was no significant difference in morphology and cell proliferation in GC group after 24-72 h. Low concentration（50 μ mol/L） of GCDC, GDC, TCDC, TDC and TC accelerated gastric epithelial cell growth in a dosage-time dependent manner. At middle concentration （250-500 μ mol/L）, it showed positive effect after 24-48 h, while negative effect after 72 h. At high concentration（1000 μ mol/L）, it accelerated gastric epithelial cell growth after 24h and show consistent inhibition even leading to necrosis after 48-72 h. LCA and CA showed a positive effect on the concentration of 50 μ mol/L after 24-72 h, while 250-1000 μ mol/L showed a trend towards apoptosis after 24-72 h. At 50-500 μmol/L, DCA showed proliferation after 24 h and apoptosis after 48-72 h, but showed necrosis after 24-72 h at 1000 μmol/L. DY and DS could facilitate normal gastric mucosa epithelial cell growth at low concentration （250-500 μ mol/L）, however at 1000-2000 μ mol/L the trend shifted from apoptosis to necrosis. FCM with Annexin-V conjugated with PI staining revealed that GCDC, GDC, GC, TCDC, TDC, TC, LCA, CA, DCA, DY and DS induced apoptosis of human gastric mucosal epithelial cells. They were all significantly higher than that of the control（P 〈 0.05）, but there was no significant difference in GC group （P 〉 0.05）. The bile salts induced apoptosis in a time-dose-dependent manner. Conclusion：Our results suggested that bile acid and bile salt is the trigger of injury in human gastric mucosal epithelial cells.

Effect of domperidone therapy on nocturnal dyspeptic symptoms of functional dyspepsia patients

AIM:To investigate the incidence of nocturnal dyspeptic symptoms in patients with functional dyspepsia(FD) and whether prokinetic drugs can alleviate them. METHODS:Eighty-five consecutive Chinese patients with FD were included in this study.One week after single-blinded placebo run-in treatment,baseline nocturnal intragastric pH,bile reflux and nocturnal dyspeptic symptoms of eligible patients,including epigastric pain or discomfort,abdominal distention and belching, were investigated with questionnaires.Patients exhibiting nocturnal dyspeptic symptoms were randomly and double-blindly assigned to domperidone group or placebo group.Nocturnal intragastric pH and percentage of duodenogastric bile reflux time were determined after treatment. RESULTS:Of the 85 FD patients,2 females withoutnocturnal symptoms,who responded to placebo run-in treatment,were excluded from the study,30(36.1%) exhibited nocturnal dyspeptic symptoms with increased duodenogastric bile reflux time(intragastric bilirubin absorbance>0.14)and mean gastric pH(confirming the existence of bile reflux)(P=0.021,0.023) at night were included in the study.Of these 30 patients,21(70%)had overt nocturnal duodenogastric bile reflux,which was significantly higher than that of those without nocturnal symptoms(P=0.026).The 30 patients were allocated to domperidone group or placebo group(n=15).The nocturnal duodenogastric bile reflux and gastric pH were significantly decreased after domperidone treatment(P=0.015,0.021).The severity score of nocturnal dyspeptic symptoms was also significantly decreased after domperidone treatment (P=0.010,0.015,0.026),which was positively correlated with the reduced nocturnal bile reflux or gastric pH(r=0.736,0.784,0.753 or r=0.679,0.715,0.697, P=0.039,0.036,0.037 or P=0.043,0.039,0.040). CONCLUSION:A subgroup of Chinese FD patients show overt nocturnal dyspeptic symptoms,which may be correlated with the excessive nocturnal duodenogastric bile reflux.Domperidone therapy can alleviate these symptoms.