AIM:To investigate the effect of tea polyphenols(TP)on the sensitivity of human gastric cancer cells to oxaliplatin(L-OHP)in vitro and its mechanism.METHODS:Human gastric cancer HGC-27 and N87 cells,and human gastric mucosal GES-1 cells were used in this study.The HGC-27 and N87 cells were randomly assigned into con-trol group,TP(5 μmol/L)group,L-OHP(5.2 μmol/L for HGC-27 cells,7.7 μmol/L for N87 cells)group,and TP(5 μmol/L)combined with L-OHP(5.2 μmol/L for HGC-27 cells,7.7 μmol/L for N87 cells)group,with 3 replicate wells per group.The cell viability was detected by CCK-8 assay,and the IC50 value of L-OHP was calculated.The proliferation of the cells was assessed by colony formation assay.The migration and invasion abilities of the cells were evaluated by scratch test and Transwell assay.Flow cytometry was performed to evaluate the antiapoptotic effect of the treatments.Ade-novirus infection was conducted to evaluate cell autophagy.The levels of intracellular reactive oxygen species(ROS)were assessed using a ROS assay kit.Western blot analysis was performed to evaluate the protein expression levels of microtu-bule-associated protein 1 light chain 3(LC3),nuclear factor E2-related factor 2(Nrf2),heme oxygenase-1(HO-1)and superoxide dismutase 1(SOD1).RESULTS:Combination of TP and L-OHP significantly reduced the viability of HGC-27 and N87 cells,and markedly inhibited cell proliferation and migration compared with L-OHP alone.Significant increas-es in autophagosomes and ROS levels were observed in combination group compared with L-OHP alone group.The ratio of LC3-II/LC3-I significantly increased in combination group,whereas the expression of Nrf2,HO-1 and SOD1 significantly decreased compared with L-OHP alone group(P<0.05).CONCLUSION:Treatment with TP enhanced the sensitivity of HGC-27 and N87 cells to L-OHP by inhibiting the Nrf2 pathway,promoting the production of intracellular ROS,and in-ducing cell autophagy.

Objective:A gas chromatography analysis system for fatty acid compositions of hydrogenated palm glycerides was established to provide a reference for quality standards of hydrogenated palm glycerides.Methods:In this test,a DB-WAX(30 m ×0.53 mm,1.0 μm)strong polarity gas chromatographic column was employed with an injection volume of 1 μL and a split ratio of 120∶1.The initial column temperature was 70℃,sustained for 2 min,ramped up to 230 ℃ at a rate of 5 ℃ per minute,and maintained for 10 min,with the inlet temperature of 250 ℃ and the detector temperature of 250 ℃.Results:In this experiment,the gas chromatograph-ic method was established successfully to determine fatty acid compositions of hydrogenated palm glycerides.The validated results indicated that the method exhibited well-suited system applicability,specificity and precision,and the RSD(％)fulfilled the requirements.The limit of detection(LOD)and limit of quantification(LOQ)values of nine fatty acid methyl esters were defined,and fatty acid compositions of seven batches of samples were checked successfully.Conclusion:The GC methodology developed in this study is suitable for the analysis and determina-tion of fatty acid compositions in hydrogenated palm glycerides,which can serve as a reference for the quality control of this pharmaceutical excipient and the establishment of quality standards.