Saffron supplement maintains morphology and function after exposure to damaging light in mammalian retina
Saffron supplement maintains morphology and function after exposure to damaging light in mammalian retina
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DOI：
10.1167/iovs.07-0438
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发表时间：
2008-03-01
影响因子：
4.4
通讯作者：
Bisti, Silvia
中科院分区：
文献类型：
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作者：
Maccarone, Rita;Di Marco, Stefano;Bisti, Silvia
目的.为了验证番红花提取物（Crocus sativus L.）作为膳食补充剂给予抵消连续光照对白化病大鼠视网膜的影响。使用三个实验组的Sprague-Dawley大鼠。实验动物在暴露于明亮的连续光（BCL）24小时之前，预先喂饲马诺龙或β-胡萝卜素（1 mg提取物/kg/d）。在光暴露前一天和光暴露后1周，在对照组和给药组大鼠中记录闪光视网膜电图（fERG）。在第二次记录结束时，处死动物，并快速取出视网膜，固定，冷冻切片，并标记，以便可以分析外核层（ONL）的厚度。用Western blot和免疫组织化学方法分别检测成纤维细胞生长因子（FGF）2蛋白水平和细胞定位的变化。在第二系列实验中，在光暴露结束时处死大鼠，并通过末端转移酶介导的脱氧尿苷三磷酸（d-UTP）-生物素缺口末端标记（TUNEL）评估ONL中的凋亡数字的量。BCL诱导的DNA片段，死亡细胞的特征，几乎完全在感光层。由BCL诱导的光感受器死亡的速率表示为每毫米的TUNEL阳性分布的频率。光感受器层在很大程度上保留在经曲马多龙处理的动物中，因为它是fERG反应。此外，BCL诱导的光感受器死亡率在治疗的动物中显著降低。在β-胡萝卜素预喂养实验中，形态学分析显示ONL的保存与用Escherichron预喂养获得的相似，而fERG反应是不可记录的。Western blot分析显示，光照诱导对照组和β-胡萝卜素处理组大鼠的FGF 2表达显著上调，而β-胡萝卜素处理组大鼠的FGF 2表达无明显变化。这些结果表明，光感受器保护蛋白可能保护光感受器免受视网膜应激，维持形态和功能，并可能作为程序性细胞死亡的调节剂。
PURPOSE. To test whether the saffron extract ( Crocus sativus L.) given as a dietary supplement counteracts the effects of continuous light exposure in the albino rat retina.METHODS. Three experimental groups of Sprague-Dawley rats were used. Experimental animals were prefed either saffron or beta-carotene (1 mg extract/kg/d) before they were exposed to bright continuous light (BCL) for 24 hours. Flash electroretinograms (fERGs) were recorded in control and treated rats the day before and 1 week after light exposure. At the end of the second recording session, the animals were killed and the retinas were quickly removed, fixed, cryosectioned, and labeled so that the thickness of the outer nuclear layer (ONL) could be analyzed. Changes in protein level and cellular localization of fibroblast growth factor (FGF) 2 were determined by Western blot analysis and retinal immunohistochemistry, respectively. In a second series of experiments, rats were killed at the end of light exposure, and the amount of apoptotic figures in the ONL was assessed by terminal transferase-mediated deoxyuridine triphosphate (d-UTP)-biotin nick-end labeling ( TUNEL). BCL induced DNA fragmentation, characteristic of dying cells, almost exclusively in the photoreceptor layer. The rate of photoreceptor death induced by BCL is expressed as the frequency of TUNEL-positive profiles per millimeter.RESULTS. The photoreceptor layer was largely preserved in saffron-treated animals because it was the fERG response. In addition, the rate of photoreceptor death induced by BCL appeared drastically reduced in treated animals. In beta-carotene prefeeding experiments, morphologic analysis showed preservation of the ONL similar to that obtained with saffron prefeeding, whereas the fERG response was unrecordable. Western blot analysis showed that exposure to light induced a strong upregulation of FGF2 in control and beta-carotene-treated rats, but s no change was noted in saffron-treated rats.CONCLUSIONS. These results show that saffron may protect photoreceptors from retinal stress, maintaining both morphology and function and probably acting as a regulator of programmed cell death.