ABSTRACT
Objective To explore the effects of humulon on kinetic parameters of N-acetyltransferase-1(NAT1) of human gastric cancer SGC-7901.Methods Employing HPLC,using para-aminobenzoic acid(PABA) as substrate,in intact SGC-7901 cells and their cytoplasm,taking the speed of PABA being acetylated to Ac-PABA by NAT1 as the rate of NAT1,using double reciprocal plot,taking the reciprocal of concentration of PABA and reaction rate of NAT1 as coordinates,regression equation was obtainied and the Michaelis constant(Km) and maximum reaction velocity(Vmax) were calculated.Results Study on enzyme kinetics demonstrated,as for intact SGC-7901 cells,Km and Vmax of control group were(3.910?0.087) ?mol/L and(0.306 0?0.006 7) pmol/L(1?106 cells),respectively,Km and Vmax of the humulon group were(3.830?0.123) ?mol/L and(0.275 0?0.005 8) pmol(1?106 cells),respectively.As for the cytoplasm of SGC-7901 cells,Km and Vmax of control group were(760.2?210.2) ?mol/L and(0.191 0?0.043 7) pmol/(mg?min),Km and Vmax of the humulon group were(449.0?72.9) ?mol/L and(0.094 0?0.010 4) pmol/(mg?min).Statistically,as for intact SGC-7901 cells or their cytoplasm,there was no difference of the Km between control group and humulon group,but there was remarkable difference of Vmax between control group and humulon group,P
ABSTRACT
Objective To study the anti-tumor effects of humulon on arylamine N-acetyltransferase-1(NAT1)activity.Methods Employing HPLC,using PABA as substrate,in intact SGC-7901 cells and their cytoplasm,making PABA being acetylated to Ac-PABA by NAT1 as the activity of NAT1.Reverse transcriptase polymerase chain reaction(RT-PCR)assay was used to study the expression of the NAT1 mRNA.Results The results show that humulon could inhibit the production of Ac-PABA in intact SGC-7901 cell and the cytoplasm,the production of Ac-PABA was gradually increased with the interaction time increasing.But comparing with corresponding negative control group's,the production of Ac-PABA was decreased evidently and the humulone could inhibit the expression of NAT1 mRNA.Conclusion Humulon could prevent the occurrence and deterioration of cancer.Its mechanisms can be attributed to its effect on decreasing the production of acetylation of carcinogenic aromatic amines,which is acetylated from aromatic amines,and inhibiting the NAT1 activity and expression of NAT1 mRNA.
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Objective To study the effects of Qinglongyi polysaccharide on sialic acid (SA) content, Na+, K+-ATP and Ca2+, Mg2+-ATPase activity, and membrane potential in erythrocytes of S180 mice. Methods Using Kit to determine the SA content and Na+, K+-ATPase, Ca2+, Mg2+-ATPase activity, using flow cytometry to determine the membrane potential of erythrocytes of S180 mice. Results In the treated groups with three doses, it showed Qinglongyi polysaccharide could make the SA content increased (P
ABSTRACT
Object To observe antitumor effects of different extract fractions from Qinglongyi (DEQ). Methods S180-mice and H22-mice were given by ip as model. Antitumor effects of DEQ on S180-mice were observed, and also the effect on indexes of thymus and spleen, sialic acid (SA) content in cancer cell membrane and erythrocyte membrane in S180-mice and H22-mice. Results The two extract fractions by cold and hot alcohol have obvious antitumor effects in a dose-effect manner to S180-mice, and can prolong H22-mice life. The two extract fractions from Qinlongyi can significantly decrease SA in cancer cell membrane and increase SA in erythrocyte membrane. Conclusion The two extract fractions from Qinglongyi have antitumor effects.