ABSTRACT
In this study, bovine serum albumin (BSA)/methylglyoxal (MGO) non-enzymatic glycosylation reaction system was used for the evaluation of the inhibitory effects of Moutan Cortex extracts on the formation of AGEs. The HPLC-LC-ESI-MS/MS technology was adopted to test and indentify active components in Moutan Cortex against AGEs formation. The different concentrations of extracts (crude herb concentration 50, 100, 150, 200, 250 g•L⁻¹) from Moutan Cortexwas determined by fluorospectrophotometry, indicating an activity against AGEs formation in different concentrations of extracts, the inhibition ratio were (36.2±5.3)%, (43.5±6.2)%, (55.4±7.8)%, (68.6±6.7)%, (70.4±8.2)%, respectively after 6-day reaction in a dose dependent manner. Besides, the forming speed of AGEs tended to be steady after 24 h reaction. The HPLC technology was used to analyze chromatograms before and after the incubation of Moutan Cortex and methylglyoxal, identify changes in five chromatographic peaks and show decrease or increase in chromatographic peaks. These substances were trigalloyl glucose, tetragalloyl glucose, galloylpaeoniflorin, hexagalloyl glucose and benzoylpaeoniflorin after LC-ESI-MS/MS identification. Extracts from Moutan Cortex showed the remarkable inhibitory effects against formation of AGEs in BSA/glucose system. Furthermore, these potential active components might be associated with the efficacy of Moutan Cortex on treatment of diabetic nephropathy, which enriches basic studies for Moutan Cortex and provides ideas and reference basis for subsequent studies.
ABSTRACT
Objective To observe the effect of Vitamin E on advanced glycosylation end-products(AGEs) and their receptors in renal tissue of diabetic rats.Methods Rat diabetic nephropathy was induced by intraperitoneal injection of STZ.Rats were allocated to normal control group(NC group),diabetes mellitus group(DM group),and Vitamin E group(VE group).All rats were treated with corresponding drugs for 8 weeks.During and after the treatment,the general state,blood glucose level(BGL),blood urea nitrogen(BUN),serum creatinine(Scr),urinary albumin excretion rate(UAER),glycosylated hemoglobin(HbA1C),clearance rate of creatinine(Ccr) and kidney weight/body weight ratio were determined in different groups.The fluorescence microscope was used to observe advanced glycosylation end-products fluorescence intensity in iced slices.The expression of RAGE in rats' renal tissue slices was measured by immunohistochemistry.Results ① Compared with those in NC group,GLU,HbA1C,BUN,UAER,kidney weight/body weight ratio,contents of AGEs,and RAGE increased significantly(P