Inhibitory Effects of Garlic Oil on Human Low Density Lipoprotein Oxidation

Growing evidence indicates that oxidized low density lipoprotein (LDL) may promote atherogenesis. Therefore, inhibition of LDL oxidation may impede this process. The inhibitory effected on the susceptibility of human LDL to $Cu^{2+}$ or macrophages induced oxidation was investigated by monitoring thiobarbituric acid reactive substances(TBARS). Organosulfur compounds of garlic oil contains diallyldisulfide, diallyltrisulfide, diallyltetrasulfide, and diallyl pentasulfide in order. Garlic oil inhibited LDL oxidation by $Cu^{2+}$, or macrophages in a dose dependently, with a 20~60 ${\mu}g$, as increased TBARS assay. Garlic oil, at 60 ${\mu}M$, almost completely inhibited macrophages induced increase in electrophoretic mobility of LDL. When compared with several other antioxidants, probucol showed highest ability, and then garlic oil showed a much higher ability than natural occurring antioxidants, ${\alpha}$-tocopherol and ascorbic acid. The results suggested that garlic oil might play the inhibitory effects in the process of LDL oxidation.

본 연구에서는 동맥경화의 원인으로 알려진 사람 low density lipoprotein (LDL)에 대한 garlic oil의 산화억제 효과에 대하여 실험하였다. Garlic oil을 HPLC로 분석한 결과 diallyl disulfide, diallyltrisulfide, diallyltetrasulfide and diallyl pentasulfide 등의 유황화합물이 많이 들어 있었다. 사람 LDL을 $Cu^{2+}$ 및 macrophages 유도 oxidized LDL로 산화시킬 때 garlic oil을 20~60${\mu}g$/mL 범위에서 첨가하며 실험하였을 때 용량 의존형으로 억제되었고, garlic oil을 60 ${\mu}g$/mL 첨가하였을 때 LDL의 산화가 거의 억제되었으며, 산화 LDL의 전기영동에 의한 이동거리도 60 ${\mu}g$/mL 농도에서 거의 억제되었다. 그리고 garlic oil은 동맥의 내피세포에서도 용량 의존형으로 억제효과를 나타내었다. 또한 garlic oil은 tocopherol, ascorbic acid 보다 약간 높은 억제효과를 나타내었다. 이상의 결과에 따르면 garlic oil은 macrophage 및 내피세포에서 LDL의 항산화 효과가 있어 LDL의 산화 억제효과가 있는 것으로 나타났다.