In order to study the effects of Ca2+ in the biosynthesis of salvianolic acid B (Sal B) induced by salicylic acid (SA) in the young seedlings of Salvia miltiorrhiza, we used confocal laser scanning microscopy and high performance liquid chromatography to measure the change of relative fluorescence intensity of Ca2+ and the contents of Sal B induced by SA before and after the application of extracellular calcium channel inhibitors (VP and LaCl3), intracellular calcium channel inhibitor (LiCl), as well as intracellular calmodulin antagonist (TFP). SA could induce the calcium burst, and the Ca2+ peak could last to 2-3 min in the guard cells of S. miltiorrhiza, which prompted the biosynthesis of Sal B after the Ca2+ burst. Both Vp or LaCl3, and LiCl or TFP could inhibit the burst of Ca2+ and the biosynthesis of Sal B. The above results demonstrated that Ca2+ from the extracellular and the intracellular calcium store regulate the biosynthesis of Sal B elicited by salicylic acid in S. miltiorrhiz young seedlings.
Benzofurans ; metabolism ; Calcium ; metabolism ; Plant Leaves ; metabolism ; Salicylic Acid ; pharmacology ; Salvia miltiorrhiza ; metabolism ; Seedlings ; metabolism ; Signal Transduction

We studied the influence of the concentration of Ca2+ (0-50 mmol/L) in culture medium on the synthesis of rosmarinic acid (RA) and related enzymes in Salvia miltiorrhiza suspension cultures. Using verpamil (VP, a calcium channel antagonist) and ionophore A23187, we studied the mechanism of secondary metabolites of Salvia miltiorrhiza suspension cultures influenced by the concentration of Ca2+ in the culture medium. The synthesis of intracellular RA in 6-day incubation was significantly dependent on the medium Ca2+ concentration. At the optimal Ca2+ concentration of 10 mmol/L, a maximal RA content of 20.149 mg/g biomass dry weight was reached, which was about 37.3% and 20.4% higher than that at Ca2+ concentrations of 1 and 3 mmol/L, respectively. The variation of the activity of PAL and TAT, two key enzymes of the two branches of RA, could be affected by the concentration of Ca2+ in culture medium. The change of their activity occurred prior to the accumulation of RA, which suggested both of the key enzymes be involved in the synthesis of RA. Meanwhile, the enzymatic action of PAL was more distinct than TAT. The treatment of VP and A23187, respectively, indicated that the influence of RA affected by the concentration of Ca2+ in the culture medium was accomplished by the intracellular Ca2+, and the flow of Ca2+ from the extracellular to the intracellular environment could also participate in this process.
Calcium ; pharmacology ; Cinnamates ; metabolism ; Culture Media ; Culture Techniques ; methods ; Depsides ; metabolism ; Phenylalanine Ammonia-Lyase ; metabolism ; Salvia miltiorrhiza ; chemistry ; enzymology ; growth & development ; Tyrosine Transaminase ; metabolism

OBJECTIVETo investigate the role of ATP-binding cassette transporter G1 (ABCG1) in endothelial dysfunction induced by high glucose.

METHODSHuman aortic endothelial cells (HAECs) were incubated in the presence of 5.6 or 30 mmol/L glucose for 24-72 h with or without a 2-h pretreatment with the LXR agonist 22(R)-hydroxycholesterol. Real-time PCR and Western blotting were used to measure the mRNA and protein expressions of ABCG1; the intracellular cholesterol efflux and endothelial nitric oxide synthase (eNOS) activity were measured by scintillation counting.

RESULTSHigh glucose time-dependently suppressed ABCG1 expression and cholesterol efflux to HDL in HAECs. High glucose also decreased eNOS activity. ABCG1 down-regulation induced by high glucose, along with decreased cholesterol efflux and eNOS activity, was abolished by treatment of the cells with the LXR agonist.

CONCLUSIONEndothelial dysfunction induced by high glucose is associated with decreased ABCG1 expression.

ATP Binding Cassette Transporter, Sub-Family G, Member 1 ; ATP-Binding Cassette Transporters ; genetics ; metabolism ; Aorta ; cytology ; Cell Line ; Down-Regulation ; drug effects ; Endothelial Cells ; cytology ; metabolism ; physiology ; Glucose ; pharmacology ; Humans