探討褐藻素對傷害性紫外線B誘發角膜內皮傷害之保護作用

To explore protective effects of Fucoxanthin on ultraviolet-B induced corneal endothelial diaorders

陳佳增(Jia-Zeng Chen)

指導教授 ： 黃宣瑜 ； 曾廣文

中山醫學大學/醫學科技學院/生物醫學科學學系碩士班/碩士(2017年)

摘要

人體與動物實驗均證實，過度曝曬於光線中會造成各種不同程度的眼球傷害。環境中，大約有九成的紫外線會被角膜所吸收阻擋，而角膜組織也對紫外線傷害也最立即且顯著，造成的影響包括角膜炎、視力模糊與強烈的疼痛感。在東方亞洲國家以褐藻用藥的歷史發長久遠，在古書均有紀載褐藻治療器官炎症與安神鎮痛的功效；現今研究也證實褐藻當中萃取的褐藻素，尤其對細胞有抗發炎與抗氧化等保護作用。然而眼角膜組織受傷害過程中，褐藻素處理使用是否能具抑制白血球浸潤以及維持角膜內皮細胞的完整性等等的保護作用，相關機制目前仍不清楚。角膜部分的實驗，以紫外線誘發角膜炎傷害模式中，觀察到同時施予褐藻素處理之組別確實對於角膜的完整度均有顯著的提升，對於角膜水腫以及白血球浸潤的現象亦有顯著的改善效果。褐藻素處理後，並可維持角膜內皮接合(tight junction)蛋白Zonula occludens-1 (ZO-1)的整度性。綜合以上實驗結果，以褐藻素處理確實對於紫外線誘導傷害後的角膜組織的完整與發炎疼痛的緩解是有正向的生理性幫助。現行的結果是褐藻素對於角膜內皮細胞的完整度性具有正向功效，並可減少角膜水腫程度或角膜內白血球浸潤的產生。此研究計畫的證實對褐藻素處理對於紫外線誘發角膜炎傷害有抑制效果，並對於角膜疾病提供未來有效的治療方向的選擇。

關鍵字

角膜炎 ； 紫外線B

並列摘要

Light-induced ocular discords have been demonstrated by the results of human and animal studies. Ultraviolet B (UVB) irradiation is the most common cause of radiation damage to the eyeball and is a risk factor for corneal disorder. The absorption properties of the cornea contribute to the protection of the retina against the hazards of UV light exposure. The cornea absorbs about 90% of UVB radiation and is most sensitive to UVB damage. UV-induced keratitis is often marked by moderate to intense pain and decrease visual acuity. In response to UVB, corneal tissue recruited neutrophils and produced inflammatory cytokines. Brown seeweeds are used in traditional Chinese medicine to regulate the energy imbalance, either in the form of an excess or a deficiency of the body’s elemental energies in Asia. However, Fucoxanthin, an orange-colored pigment, along with chlorophylls a and c and β-carotene, present in brown seaweeds, such as Hijikia fusiformis, Laminaria japonica and Sargassum fulvellum, have not been extensively examined on neutrophil recruitment to the cornea. To clarify the protective roles and underlying mechanisms of Fucoxanthin of ocular lesions, we investigate the beneficial effect and mechanisms of Fucoxanthin ameliorates UV keratitis. Inhibitions of typical edema and myeloperoxidase (MPO) positive-cells recruitment were observed in groups of treatment with Fucoxanthin following UV-induced corneal disorders.We observed protected from destruction the barrier properties of endothelial cells by blocking the degradation of tight junction protein ZO-1 after Fucoxanthin treatment. The findings may propose target choices for potential therapeutic regimes in the future.

並列關鍵字

keratitis ； Ultraviolet B

參考文獻

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