salvianolic-acid-B and thiazolyl-blue

Radix Salvia miltiorrhiza (RSM), a traditional Chinese medicinal herb, has been alleged to possess therapeutic effects against senile dementia, also known as Alzheimer's disease (AD). However, the effects of the major components in RSM on cytotoxicity induced by amyloid-β peptide (Aβ) and on acetylcholinesterase activity have not been studied in depth to date. In this report, the effects of RSM aqueous/ethanol extracts, total polyphenols, total tanshinones and 3 phenolic compounds against toxicity mediated by Aβ(25-35) were tested with PC-12 cells. The results showed that Aβ(25-35)-induced cytotoxicity was revised by RSM aqueous/ethanol extracts and total polyphenols and that danshensu and salvianolic acid B could protect PC-12 cells by blocking Aβ(25-35)-induced Ca(2+)-intake, lactate dehydrogenase release, cell viability decrease and apoptosis. In addition, the activities of RSM extracts and relevant constituents in their inhibition of acetylcholinesterase were investigated using rat brain homogenates as an enzyme resource. Galanthamine hydrobromide, an accepted acetylcholinesterase inhibitor, was employed as a positive control agent. Our preliminary studies demonstrated that RSM ethanol extract, total tanshinones, tanshinone I and dihydrotanshinone I had remarkable inhibition effects on acetylcholinesterase in vitro. These findings suggest that both tanshinones and polyphenols in RSM are the active constituents responsible for the beneficial effects of this herb in AD treatment.

Topics: Abietanes; Amyloid beta-Peptides; Animals; Antioxidants; Apoptosis; Benzofurans; Calcium; Cell Survival; Cholinesterase Inhibitors; Hydroxybenzoates; L-Lactate Dehydrogenase; Male; Neuroprotective Agents; PC12 Cells; Phosphatidylinositols; Plant Extracts; Polyphenols; Rats; Rats, Sprague-Dawley; Salvia miltiorrhiza; Tetrazolium Salts; Thiazoles

Salvianolic acid B (Sal B) is one of the major water-soluble compounds isolated from Radix Salviae Miltiorrhizae (Danshen in Chinese) that has been reported to be beneficial to treatment of diabetic complications. However, the mechanisms involved in these effects are not discussed in relation to mesangial proliferation via modulation of NF-kappaB. To explain this, human mesangial cells were pretreated with or without Sal B (0.1, 1, 10 microM) for 24 h and stimulated with high glucose (30 mM). Then the effects of Sal B on mesangial cells proliferation, extracellular matrix production and the possible mechanisms were evaluated by methylthiazoletetrazolium assay, flow cytometry assay, enzyme-linked immunosorbent assay, gelatin zymography assay and western blot assay. These results indicated that Sal B could inhibit high glucose-induced mesangial cells proliferation and extracellular matrix production in a dose-dependent manner, partially through modulating the cell-cycle progress and MMP-2 and MMP-9 activities via suppressing NF-kappaB activation, suggesting that Sal B may be a promising agent for treating diabetic nephropathy.

Topics: Antioxidants; Benzofurans; Blotting, Western; Cell Cycle; Cell Nucleus; Cell Proliferation; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Fibronectins; Flow Cytometry; Glucose; Humans; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mesangial Cells; NF-kappa B; Signal Transduction; Tetrazolium Salts; Thiazoles

Danshensu (3-(3,4-dihydroxyphenyl) lactic acid) and salvianolic acid B, two natural phenolic acids of caffeic acid derivatives isolated from Salvia miltiorrhiza root of the most widely used traditional Chinese medicine for the treatment of various cardiovascular diseases, have been reported to have potential protective effects from oxidative injury. To better understand their biological functions, the in vitro radical scavenging and antioxidant activities of danshensu and salvianolic acid B were evaluated along with vitamin C. Both danshensu and salvianolic acid B exhibited higher scavenging activities against free hydroxyl radicals (HO()), superoxide anion radicals (O(2)(-)), 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals and 2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals than vitamin C. In contrary, danshensu and salvianolic acid B showed weaker iron chelating and hydrogen peroxide (H(2)O(2)) scavenging activities than vitamin C. As expressed as vitamin C equivalent capacity (VCEAC), the relative VCEAC values (mg/100ml) were in the order of salvianolic acid B (18.59) > danshensu (12.89) > vitamin C (10.00) by ABTS radical assay. The protective efficiencies against hydrogen peroxide induced human vein vascular endothelial cell damage were correlated with their antioxidant activities. Analysis of structure-activity relationship of these two compounds showed that the condensation and conjugation of danshensu and caffeic acid appears important for antioxidant activity. These results indicated that danshensu and salvianolic acid B are efficient radical scavengers and antioxidants, and salvianolic acid B is superior to danshensu. Their radical scavenging and antioxidant properties might have potential applications in food and healthcare industry.

Topics: Antioxidants; Ascorbic Acid; Benzofurans; Benzothiazoles; Biphenyl Compounds; Cell Survival; Chelating Agents; Endothelial Cells; Ferrous Compounds; Free Radical Scavengers; Humans; Hydrogen Peroxide; Hydroxyl Radical; Lactates; Oxidants; Picrates; Plant Roots; Salvia; Sulfonic Acids; Tetrazolium Salts; Thiazoles