Balestrieri M L, De Prisco R, Nicolaus B, Pari P, Moriello V Schiano, Strazzullo G, Iorio E L, Servillo L, Balestrieri C
Department of Biochemistry and Biophysics, Second University of Naples, Italy.
Free Radic Biol Med. 2004 Apr 15;36(8):1058-67. doi: 10.1016/j.freeradbiomed.2004.01.014.
Lipophilic compounds contained in tomato can prevent cardiovascular diseases by modulating the atherogenic processes in vascular endothelium mediated by oxidized low-density lipoproteins (LDLs). We investigated the effects of lycopene on the metabolism of platelet-activating factor (PAF) and its much less biologically active acyl analog, acyl-PAF, known to prevent LDL oxidation. Lycopene, or lycopene in association with alpha-tocopherol, or whole tomato lipophilic extracts (containing more than 80% lycopene) were used in experiments in which endothelial cells (ECs) are known to synthesize PAF following H(2)O(2)-induced oxidative stress. The results indicated that in each case H(2)O(2)-stimulated PAF biosynthesis in ECs, which is catalyzed by acetyl-CoA acetyltransferase (AT), appeared strongly inhibited. However, acyl-PAF biosynthesis, which also occurs through the PAF-dependent transacetylase (TA), was significantly increased by lycopene only when it was in association with alpha-tocopherol or with the minor compounds present in the whole lipophilic tomato extract. These findings suggest that alpha-tocopherol or lipophilic compounds present in tomato juice potentiate the effects of lycopene on the modulation of PAF and acyl-PAF biosynthesis in ECs during oxidative stress.
番茄中含有的亲脂性化合物可通过调节由氧化型低密度脂蛋白（LDL）介导的血管内皮细胞致动脉粥样硬化过程来预防心血管疾病。我们研究了番茄红素对血小板活化因子（PAF）及其生物活性低得多的酰基类似物酰基 - PAF代谢的影响，已知酰基 - PAF可防止LDL氧化。在已知内皮细胞（ECs）在H₂O₂诱导的氧化应激后合成PAF的实验中，使用了番茄红素、与α - 生育酚结合的番茄红素或整个番茄亲脂提取物（含番茄红素超过80%）。结果表明，在每种情况下，由乙酰辅酶A乙酰转移酶（AT）催化的H₂O₂刺激的ECs中PAF生物合成均受到强烈抑制。然而，同样通过PAF依赖性转乙酰酶（TA）发生的酰基 - PAF生物合成，仅当番茄红素与α - 生育酚或整个亲脂性番茄提取物中存在的次要化合物结合时，才会因番茄红素而显著增加。这些发现表明，α - 生育酚或番茄汁中存在的亲脂性化合物可增强番茄红素在氧化应激期间对ECs中PAF和酰基 - PAF生物合成调节的作用。
