Inhibitory effect of walnut (Juglans regia L.) husk hydroalcoholic extract on LDL oxidation in Vitro

Introduction: Lipid oxidation, including LDL oxidation, plays a pivotal role in development of atherosclerosis. Supplementing diet with antioxidants, such as vitamin E and walnut husk hydroalcoholic extract, may prevent LDL oxidation. In the present study, we investigated the in vitro effects of walnut husk hydroalcoholic extract on serum LDL oxidation caused by copper sulfate. Method: Blood samples were obtained from healthy individuals after an overnight fasting. Serum LDL was isolated. A control group was created using the serum LDL alone, and experiment groups were created using serum LDL oxidized by CuSO4 and walnut husk hydroalcoholic extract at concentrations of 0.2, 2 and 20 μg/mL. LDL oxidation was assessed through measuring conjugate dienes, lag times and malonedialdehyde (MDA) to provide a basis for comparing the effects of different concentrations of walnut husk hydroalcoholic extract on serum LDL oxidation in the presence of copper. Results: Our findings indicate that walnut husk hydroalcoholic extract reduces serum LDL oxidation, with lag times equal to 87%, 178% and 202% for concentrations of 0.2, 2 and 20 μg/mL, respectively. In other words, the inhibitory properties of walnut husk hydroalcoholic extract on LDL oxidation are proportionate to the extract concentration. Conclusion: The findings of the present study indicate that walnut husk hydroalcoholic extract prevents LDL oxidation. This compound may have similar effects in vivo.