Effect of glibenclamide on viability and acid-base equilibrium of glioblastoma cells

AIM: To investigate the effect of glibenclamide (Glib) on the viability and acid-base equilibrium of glioblastoma cells. METHODS: U251 cells and U87 cells were treated with Glib at different concentrations. The inhibitory rates were detected by CCK-8 assay. The effective dose was screened and the experiment was divided into control group and drug treatment groups. The migration ability was monitored by wound healing assay, and intracellular pH was detected by pH indicator fluorescent probe. The protein expression levels of inwardly-rectifying potassium channel 4.1 (Kir4.1) and monocarboxylate transport protein 1 (MCT1) were determined by Western blot. RESULTS: The half maximal inhibitory concentrations (IC₅₀) of Glib for 48 h exposure of U251 cells and U87 cells were 400.20 μmol/L and 553.70 μmol/L, respectively. The effective inhibition doses of Glib for U251 cells were from the ranges of 100 μmol/L to 1 600 μmol/L, and those for U87 cells were from 50 μmol/L to 1 600 μmol/L in a concentration-dependent manner (P<0.05). Glib not only inhibited the migration (P<0.05) of U251 cells and U87 cells, which was negatively correlated with drug concentration (P<0.05), but also reduced the intracellular fluorescence intensity in experimental group (P<0.05), suggesting that with the increase in drug concentration, the intracellular pH decreased gradually (P<0.05). The protein expression of Kir4.1 and MCT1 was down-regulated by treatment with Glib, and was negatively correlated with concentration of Glib. CONCLUSION: Glib, a kind of potassium channel blocker, induces intracellular acidification via down-regulating the expression of Kir4.1 and MCT1, thus inhibiting the growth of glioblastoma in a certain dose range.     

薄层色谱扫描法测定茯苓山药片中格列本脲的含量

[目的]建立薄层扫描测定茯苓山药片中格列本脲含量。[方法]采用薄层扫描色谱法,氯仿-环己烷-乙醇-冰醋酸(8∶13∶1∶1)为展开剂,双波长扫描法(λS=300 nm,λR=350 nm)测定茯苓山药片中格列本脲的含量。[结果]格列本脲点样量在1.4～8.4μg范围内与峰面积呈良好线性关系(r=0.994 5),同板精密度RSD为0.81%(n=5),异板精密度RSD为6.05%(n=5),平均回收率分别为101.7%、100.1%、98.85%,RSD分别为4.10%、3.10%、3.96%(n=15)。[结论]薄层色谱扫描法简便、快速、重现性好,可作为茯苓山药片中格列本脲的含量测定方法。