Author/Authors :
Kawakami، نويسنده , , Yuki and Hosokawa، نويسنده , , Tomoko and Morinaka، نويسنده , , Tomoko and Irino، نويسنده , , Shioka and Hirano، نويسنده , , Shiori and Kobayashi، نويسنده , , Hirokazu and Yoshioka، نويسنده , , Akiko and Suzuki-Yamamoto، نويسنده , , Toshiko and Yokoro، نويسنده , , Miyuki and Kimoto، نويسنده , , Masumi and Tsuji، نويسنده , , Hideaki and Yamashita، نويسنده , , Hiromi and Doi، نويسنده ,
Abstract :
Oxidative modification of low density lipoprotein (LDL) is one of the critical steps for the development of atherosclerosis and leucocyte-type 12-lipoxygenase, highly expressed in macrophages, has been suggested to play an essential role in this process. In the present study, we show that guava leaf extracts inhibited, not only the leucocyte-type 12-lipoxygenase activity, but also LDL oxidation, mediated by the enzyme-overexpressing macrophage-like J774A.1 cells. Oral administration of guava leaf extracts to apoE-knockout mice at 100 mg of dry extracts/kg of body weight, once a day for 16 weeks, significantly reduced the area of atherogenic lesions developed in the aorta and aortic sinus. The major components inhibiting leucocyte-type 12-lipoxygenase contained in guava leaf extracts were identified as ethyl gallate and quercetin. The inhibitory effects of guava leaf extracts on the leucocyte-type 12-lipoxygenase activity, as well as on cell-mediated LDL oxidation, might be involved in the antiatherogenic effect of the extracts.
Keywords :
Arachidonic acid , LDL oxidation , Psidium guajava , Leucocyte-type 12-lipoxygenase , atherosclerosis , macrophages
