ASPIRIN PROTECTS LOW-DENSITY-LIPOPROTEIN FROM OXIDATIVE MODIFICATION

Objective-To examine the effects of aspirin on the potential for oxida tive modification of low density lipoprotein (LDL). Design-Before and after trial. Setting-University department of medicine within a distri ct general hospital campus. Patients-Ten healthy normolipidaemic volun teers drawn from laboratory and medical staff. Interventions-Aspirin ( enteric coated) 300 mg daily for two weeks. Main outcome measures-In v itro oxidation of LDL following ultraviolet C (UVC) irradiation with m easurements made of malondialdehyde, conjugated dienes, and electropho retic mobility. Results-There was a significant decrease in malondiald ehyde production from LDL modified by aspirin in vivo following exposu re to WC irradiation for 90 minutes, culminating in a 30% decrease by 240 minutes (mean (SD) 64.2 (9.12) v 89.6 (11.6) nmol/mg LDL protein, P = 0.029). These observations were borne out using LDL modified by as pirin in vitro. The WC induced increase in relative electrophoretic mo bility of LDL was also significantly reduced following aspirin treatme nt (mean (SD) 2.17 (0.16) v 2.66 (0.24), P = 0.012). Conclusions-Aspir in, both in vivo and in vitro, protects LDL against subsequent oxidati ve modification, providing an additional mechanism whereby aspirin may protect against atherosclerosis.