Shamsi Farrukh A, Chaudhry Imtiaz A, Boulton Mike E, Al-Rajhi Ali A
Research Department, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.
Curr Eye Res. 2007 Jun;32(6):575-84. doi: 10.1080/02713680701363833.
To determine the efficacy of L-carnitine (LC) against oxidative changes in human retinal pigment epithelium (RPE) cells.
The RPE cells from human donor eyes were cultured in Hams F-10 medium. The effect of LC on H2O2-induced morphologic changes in the RPE cells was analyzed by light microscopy. Reduction in cell death after the impact of LC treatment on H2O2-treated cells was analyzed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays. In addition, the effect of H2O2 on the activity of RPE-antioxidant enzymes, glutathione (GSH) and superoxide dismutase (SOD), and LC-induced protection was also determined.
LC protected the RPE cells by inhibiting the peroxide-induced cytopathic effect from 50% to 10%. Nuclear condensation observed in 40% of the H2O2-treated cells decreased to 20% after LC treatment. The MTT assays demonstrated that 100 microM oxidant caused appreciable cell death, which was reduced by LC treatment; however, 100% protection was not achieved. Significant peroxide-induced cell death was seen within 5 hr of H2O2 treatment, and a quantifiable reduction was observed after LC treatment for a similar time period. The change in the antioxidant potential of the RPE induced by oxidative stress was restored by LC treatment, as demonstrated by an increase in GSH and SOD activities.
LC is capable of protecting the RPE cells from H2O2-induced oxidative damage, implying that micronutrients can have a positive effect and can play an important role in the treatment of oxidation-induced ocular disorders. Further studies are needed to understand the mechanism of LC-induced protection to the RPE cells.
确定左旋肉碱（LC）对人视网膜色素上皮（RPE）细胞氧化变化的疗效。
将来自人类供体眼睛的RPE细胞在哈姆氏F-10培养基中培养。通过光学显微镜分析LC对H2O2诱导的RPE细胞形态变化的影响。通过MTT [3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐] 试验分析LC处理对H2O2处理细胞后的细胞死亡减少情况。此外，还确定了H2O2对RPE抗氧化酶、谷胱甘肽（GSH）和超氧化物歧化酶（SOD）活性的影响以及LC诱导的保护作用。
LC通过将过氧化物诱导的细胞病变效应从50%抑制到10%来保护RPE细胞。在40%的H2O2处理细胞中观察到的核浓缩在LC处理后降至20%。MTT试验表明，100 microM氧化剂导致明显的细胞死亡，而LC处理可减少这种死亡；然而，未实现100%的保护。在H2O2处理后5小时内可见明显的过氧化物诱导的细胞死亡，在类似时间段的LC处理后观察到可量化的减少。LC处理恢复了氧化应激诱导的RPE抗氧化潜能的变化，表现为GSH和SOD活性增加。
LC能够保护RPE细胞免受H2O2诱导的氧化损伤，这意味着微量营养素可以产生积极作用，并在氧化诱导的眼部疾病治疗中发挥重要作用。需要进一步研究以了解LC对RPE细胞诱导保护的机制。
