ABSTRACT
Objective:To explore the absorption and transport properties of flavanomarein in the Madin-Darby canine kidney(MDCK) monolayer cell model. Method:Methyl thiazolyl tetrazolium(MTT) assay was used to investigate the toxicity of flavanomarein in MDCK cells. The resistance value of MDCK monolayer cell model was detected by Millicell-ERS-2 cell resistometer. The effects of mass concentration of flavanomarein,administration time,sodium-glucose cotransporter(SGLTs) inhibitor and glucose transporter 2(GLUT2) inhibitor on the transmembrane transport of flavanomarein were investigated. The concentration of flavanomarein was determined by UPLC-MS/MS, and the apparent permeability coefficient(Papp) and the efflux ratio(ER) were calculated. Result:When the concentration of flavanomarein was 5.625-120 mg·L-1, there was no significant toxic effect on MDCK cells. The transport of flavanomarein in MDCK monolayer cell model was time-dependent and concentration-dependent. The Papp values of flavanomarein were basically between 1×10-6 cm·s-1 to 10×10-6 cm·s-1. Compared with the blank group, the phlorizin group significantly reduced the transport of flavanomarein on the MDCK monolayer cell model at 60 min and 90 min. Conclusion:Flavanomarein is a moderately absorbed drug in the intestine, its transmembrane transport mechanism is dominated by passive transport along with active transport. SGLTs may be involved in mediating the transport of flavanomarein on the MDCK monolayer cell model.
ABSTRACT
Purpose Proteins constitute a major portion of the organic matrix of human calcium oxalate (CaOx) renal stones and the matrix is considered to be important in stone formation and growth. The present study evaluates the effect of these proteins on oxalate injured renal epithelial cells accompanied by a 2D map of these proteins. Materials and Methods Proteins were isolated from the matrix of kidney stones containing CaOx as the major constituent using EGTA as a demineralizing agent. The effect of more than 3kDa proteins from matrix of human renal (calcium oxalate) CaOx stones was investigated on oxalate induced cell injury of MDCK renal tubular epithelial cells. A 2D map of >3kDa proteins was also generated followed by protein identification using MALDI-TOF MS. Results The >3kDa proteins enhanced the injury caused by oxalate on MDCK cells. Also, the 2D map of proteins having MW more than 3kDa suggested the abundance of proteins in the matrix of renal stone. Conclusion Studies indicate that the mixture of >3kDa proteins in the matrix of human renal stones acts as promoter of calcium oxalate crystal nucleation and growth as it augments the renal epithelial cell injury induced by oxalate. The effect of promoters masks the inhibitors in the protein mixture thereby leading to enhanced renal cell injury. 2D map throws light on the nature of proteins present in the kidney stones. .