Inhibitory Effects of Rosmarinic Acid on LDL Oxidation In vitro

Oxidation of low-density lipoprotein (LDL) has been strongly implicated in the pathogenesis of atherosclerosis. The use of antioxidant compounds in dietary food stuffs including vitamin E and rosmarinic acid may lead to the inhibition of production of oxidized LDL and may decrease both the development and the progression of atherosclerosis. The present work investigated the effects of Rosmarinic Acid (RA) on LDL oxidation induced-CuSO4 quantitatively in vitro. Fasting blood samples from normal people after an overnight fasting were collected and then LDL was isolated. LDL was incubated without CuSO4 as control and incubated with CuSO4 and several concentrations of RA (50، 100 and 200 µM); and measured the formation of conjugated dienes and Malondialdehyde (MDA). Inhibition of this Cu-induced oxidation was studied in the presence of several concentrations of RA (50، 100 and 200 µM). It was demonstrated that RA is able to decrease CuSO4-induced LDL oxidation. Rosmarinic acid showed a decrease in the formation of (MDA). Rates of 31. 8%، 36. 7% and 50. 3% were seen at concentrations ranging from 50، 100 and 200 µM، respectively، against oxidation in vitro. The inhibitory effects of the RA on LDL oxidation were dose-dependent at concentrations ranging from 50 to 200 µM. This study showed that RA at concentrations (50، 100 and 200 µM) prevented the oxidation of LDL in vitro and it may suggest that they have the similar effect in vivo.