This study was designed to determine whether low-density lipoporoteins (LDL) extracted from egg yolk in extender improve the function of Korean Jeju Black Bull semen. The semen was cryopreserved with 5% ethylene glycol (EG) or 7% glycerol (G) extenders containing 10% egg yolk (EY), 4% LDL and 5% EY or 8% LDL. Frozen-thawed sperm were evaluated sperm motility, viability, membrane integrity and acrosome integrity. Post-thawed sperm motility has been significantly higher (p<0.05) in 4% LDL + 5% EY (; EG and ; 7% G) than 8% LDL (; EG and ;G). Treatment of 4% LDL + 5% EY-EG () has been significantly improved sperm viability compared to other treatments except 10% EY - EG. Moreover, in membrane integrity, swollen sperm ratio has been only significantly increased (p<0.05) in 4% LDL + 5% EY - EG () among all treatments. In assess to detect acrosome integrity, especially, AR pattern ratio has been significantly decreased (p<0.05) in 4% LDL + 5% EY - EG among all treatments. In sperm viability as time passes, between 4% LDL + 5% EY and 10% EY, there was no significant difference, but 8% LDL was significantly decreased sperm viability in EG (1 and 2 hrs) and G (30 min, 1, 2, 5 and 12 hrs) extender. However, there were no significant differences among all treatments except 8% LDL-G in sperm membrane integrity. 8% LDL-G has been significantly decreased swollen sperm ratio at 5 hrs after thawed. It is concluded from these results that 4% LDL + 5% EY to the freezing extender showed more positive effect on the frozen-thawed spermatozoa in Korean Jeju Black bull.

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 Cu²+ 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 Cu²+, or macrophages in a dose dependently, with a 20~60 μg, as increased TBARS assay. Garlic oil, at 60 μM, 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, α-tocopherol and ascorbic acid. The results suggested that garlic oil might play the inhibitory effects in the process of LDL oxidation.

Growing evidence indicates that oxidized low density Iipoprotein (LDL) may promote atherogenesis. Therefore, inhibition of LDL oxidation may impede this process. The effect of chitin sulfate on the susceptibility of human low density lipoprotein (LDL) to macrophages-induced oxidation was investigated by monitoring a thiobarbituric acid reactive substance (TBARS). Chitin sulfate inhibited LDL oxidation by macro phages in a dose dependent manner, with a 50-100μM, as assessed by TBARS assay. Chitin sulfate, at 100 μM, almost completely inhibited the macrophage-induced increase in electrophoretic mobility of LDL. Also, chitin sulfate almost completely inhibit O₂^- at concentration of 100 μM. These observations suggest that chitin sulfate might be an effective in prevention of atherosclerosis.

This study was undertaken to evaluate antioxidative activities of substances isolated from marine resources against human low density lipoprotein (LDL). Methanol-water extract (80:20, v/v) of Sargassum ringgoldianum had the highest antioxidant activity and the active substance was purified by silica gel column chromatography by eluting chlorform : methanol mixture (80:20, v/v). The active fraction was separated to several spots on the TLC in chloroform : methanol (10:1, v/v) mixture. Antioxidative activity of band 4 of fraction 2 on TLC was highest than that of a-tocopherol against human LDL oxidation by the method of thiobarbituric acid reactive substance (TBARS). The band 4 of fraction 2 inhibited the copper mediated oxidation of human LDL with almost completely at 1 or 2 mg/ml.

해양 미생물로부터 사람 Low Density Lipoprotein(LDL)에 대한 항산화 활성 균주를 검색 하였든 바 부산 인근연안에서 항산화 활성이 높은 Bacillus sp. RH-5를 분리 동정하였다. Bacillus sp. RH-5의 항산화 활성물질의 생산 거 배지는 1.0% glucose, 0.25% polypeptone, 0.25% yeast extract, 0.01% FeSO_4?7H_2O, 50% sea water이였다. 이때 최적 조건은 pH 7.0, 배양 온도는 30℃ 및 배양 시간은 48시간에서 항산화 활성이 가장 높았다. 사람 LDL을 1~5 μM CuSO_4 존재하에서 산화 시킨 결과 Bacillus sp. RH-5 배양액의 ethyl acetate 추출물의 500 및 1,000 ㎍/ml에서 산화가 억제되었으며 또 5 μM CuSO_4 존재하에서 산화시킨 LDL의 전기영동거리는 native LDL보다 다소 높았으나 LDL에 ethyl acetate추출물을 첨가한 경우 그 이동거리는 native LDL과 거의 비슷하였다.