AL0671, a new potassium channel opener, inhibits nonenzymatic glycation of protein and LDL oxidation.

1. The effects of AL0671, a novel potassium channel opener, on protein glycation and low-density lipoprotein (LDL) oxidation were tested. 2. AL0671 dose-dependently inhibited both fluorescence development of bovine serum albumin and cross-linking of lysozyme. These inhibitory effects for glycation were no less potent than aminoguanidine. 3. AL0671 dose-dependently inhibited both increase in negative charge and apo B-100 fragmentation during incubation of LDL with Cu2+. In addition, AL0671 significantly decreased the LDL degradation in rat peritoneal macrophages. 4. Neither pinacidil nor levcromakalim inhibited protein glycation and LDL oxidation. 5. Antioxidant properties of AL0671 might be due to its potent electron-donating ability, and this agent is expected to be useful for hypertensive diabetes.