ABSTRACT
We observed the effect of calcium dobesilate (CaD) on apoptosis induced by cisplatin in human proximal tubular epithelial cells (HK-2) and explored the possible mechanism. Based on HK-2 cells apoptosis model induced by cisplatin, CCK-8 method was used to detect the effect of CaD on the proliferation of HK-2. Apoptosis was detected by flow cytometry. Reactive oxygen species (ROS) assay was used to evaluate the level of oxidative stress. The mitochondrial membrane potential was measured by JC-1 method. The expression levels of p53, caspase-3, bcl-2 and bax in cisplatin-induced HK-2 were detected by Western blot. The expression of renal injury factor 1(KIM-1) and neutrophil gelatin-related apolipoprotein (NGAL), markers of acute kidney injury, were detected by ELISA. The results showed that CaD could reduce the oxidative stress level induced by cisplatin and inhibit apoptosis in renal tubular epithelial cells. Cisplatin can up-regulate the protein expressions of p53, caspase-3, bax, KIM-1 and NGAL, and reduce the expression of bcl-2. After using CaD, the protein levels of KIM-1, NGAL, p53, caspase-3 and bax were significantly reduced, while the levels of bcl-2 were increased. This study has shown that CaD can alleviate cisplatin-induced HK-2 injury and inhibit HK-2 apoptosis, which may be related to the regulation of bax/bcl-2/caspase-3 apoptosis signaling pathway.
ABSTRACT
OBJECTIVE: To investigate the mechanism of transmembrane transport of mycophenolate mofetil (MMF) and its active metabolite mycophenolic acid (MPA). METHODS: Caco-2 cell monolayer model was developed for MMF and MPA transport experiment, and the LC-MS/MS method was used for the determination of MMF and MPA concentration in transport medium. The apparent permeability coefficient (Papp) and efflux ratio (Pratio) were calculated and used for the evaluation of the ability of drug transport and drug efflux across Caco-2 cell monolayer. RESULTS: The Papp of MPA in two-way transport experiment (Papp,ab and Papp,ba) at 10, 50 and 100 μmol · L-1 were(9.70 ± 0.40) × 106 cm · s-1 [(13.52 ± 0.28) × 106 cm · s-1], (9.35 ± 0.62) × 106 cm · s-1 [(11.38 ± 0.59) × 106 cm · s-1], (8.69 ± 0.69) × 106 cm · s-1 [(10.53 ± 0.64) × 106 cm · s-1], respectively. Pratio were 1.39, 1.22 and 1.22, respectively. Pratio of MPA was reduced by verapamil, a well-known P-glycoprotein inhibitor. MMF was mostly hydrolyzed to MPA during the transport process across the Caco-2 cell monolayer. The amount of MPA transported increased with time, but the amount of MMF transported changed not significantly over time and no significant effect of verapamil was observed. CONCLUSION: The transmembrane transport of MPA is affected by active transport efflux mediated by transporter with P-gp involved. No effect of P-gp is found in MMF transmembrane transport, which is passive transport.
ABSTRACT
<p><b>AIM</b>To investigate the pharmacokinetics of mycophenolic acid (MPA), an active metabolite of mycophenolate mofetil (MMF) in Chinese adult liver transplant patients.</p><p><b>METHODS</b>Thirty-eight liver transplant patients (male 30, female 8) receiving MMF 1.0 g, twice daily in accordance with the recommended regimen were included in this study. Plasma MPA concentrations were measured by high performance liquid chromatography at 0.5, 1, 1.5, 2, 4, 6, 8, 10 and 12 h after the administration of a single dose. Pharmacokinetic parameters were calculated with 3P97 software.</p><p><b>RESULTS</b>The plasma MPA concentration-time curve was characterized with an early sharp peak reached at 0.5 - 6.0 h after oral administration. And in some patients there was a small second peak due to enterohepatic circulation of mycophenolic acid glucuronide (MPAG), which underwent deglucuronidation and re-absorption as MPA at 4 to 12 h postdose. The mean peak plasma concentration (C(max)) and area under concentration-time curve (AUC(0-12 h)) were (12 +/- 7) microg x mL(-1) and (44 +/- 16) microg x h x mL(-1), respectively. However, a large variability of pharmacokinetic parameters existed in these patients.</p><p><b>CONCLUSION</b>In view of the inter-individual variability of MMF pharmacokinetics, plasma MPA concentration should be monitored routinely after MMF administration for individual patient.</p>