洛神花萃取物抑制糖尿病眼病變之研究

The study of Hibiscus Sabdariffa Linnaeus Extracts on inhibiting Diabetic Ophthalmopathy

簡哲鴻(Jhe-Hong Jian)

指導教授 ： 李彗禎

中山醫學大學/醫學院/生化暨生物科技研究所/碩士(2008年)

摘要

依據世界衛生組織統計，大多數失明的主要原因肇始於糖尿病眼病變。這是因為糖尿病患者在長期高血糖的環境下，產生許多不正常代謝產物影響眼睛正常功能，並造成體內抗氧化系統效力降低且產生大量自由基進而造成眼睛損傷。洛神花萃取物已經證實具有抗氧化、抗發炎及抗癌等功效。因此本實驗利用洛神花水萃物(HSE)及多酚(HPE)觀察降低糖尿病誘導眼病變之功效，並進一步研究其機轉。
在Sprague-Dawley (SD) Rat實驗中，以腹腔注射streptozotocin (STZ) 65mg/kg誘發糖尿病後，每日依體重給予洛神花水萃物及多酚100、200、300mg/kg，九週後犧牲取眼睛做分析。實驗結果發現，每日管餵HSE及HPE 100、200、300 mg/mL後，在血糖的分析中，並不能對血糖有抑制的情形，而在抗氧化酵素或分子當中，如catalase分別增加13.2%、10.1%、13.8%，並在給予HPE 200、300mg/kg 分別增加4.4%及3.3%；而GSH分別增加9.2%、8.2%、8.4%，並在給予HPE 200、300mg/kg 分別增加28%及78%；在水晶體外觀上，發現HSE能減緩白內障的情形，並且在視網膜病理切片中，發現能降低糖尿病引起視網膜的損害。進一步分析蛋白表現，經給予洛神花萃取物後，不能有效影響Akt磷酸化的情形，但是能抑制ERK、p38、JNK磷酸化的程度使細胞死亡程度下降。
在retinal pigement epithelial cell的細胞實驗中，加入H2O2 200μM誘導細胞受損並合併處理不同濃度的HSE及HPE(0.5、1、2、3mg/mL)，來探討洛神花萃取物的影響。在觀察細胞外觀以及存活程度上得知HPE能保護H2O2對於細胞造成的損傷。進一步分析蛋白表現，經給予洛神花萃取物(HPE)後，不能有效影響Akt磷酸化的情形，但是能抑制ERK磷酸化的程度使細胞死亡程度下降。
由實驗結果，我們推測洛神花水萃物(HSE)及多酚(HPE)能降低糖尿病造成的眼病變。

關鍵字

糖尿病眼病變 ； 洛神花萃取物

並列摘要

Diabetic ophthalmopathy is the leading cause of acquired blindness in the world. Diabetes sustained hyperglycemia circumstances, produced abnormal metabolism products to influence eye normal function, besides decreased antioxidant system, and furthermore produced free radical to damage eye.
It was demonstrated that Hibisus Sabdariffa potentiated antioxidative effect in previous studies. In this study, we further examined the effect of HSE or HPE on anti-ophthalmopathy. In Sprague-Dawley (SD) Rat experiment, after diabetes induction completed, HSE (100,200 and 300mg/kg), HPE (100,200 and 300 mg/kg) were fed by oral tube for nine weeks to observe the effects on diabetic rats. The results showed that treatment of HSE&HPE (100, 200 and 300 mg/kg) did not restrain the blood glucose. However, 100, 200 and 300mg/kg of HSE increased catalase activity to 13.2%, 10.1%, 13.8% ; and glutathione was increased to 9.2%, 8.2%, 8.4%. In the groups treated with 200 and 300mg/kg of HPE, catalase activity was increased to 4.4%, 3.3%; and glutathione was increased to 28%, 78%. In lens, HSE could decelerate the development of diabetic cataract by empiricism. In histopathological evalution of retina, HSE and HPE decreased diabetes induced retinal injury. We also found that in eye tissues, HSE or HPE cannot affect phosphorylation of Akt, but downregulate phosphorylation of extracellular signal-regulated kinase (ERK), p38 and JNK to reduce apoptosis. In retinal pigment epithelial (RPE) cell experiment, cell was pretreated with 200 μM of H2O2 accompanied with HSE or HPE (0.5, 1, 2, 3 mg/mL) for 6 hrs. The results showed that HPE could protect RPE cell from H2O2 induced damage . We also found HPE cannot affect phosphorylation of Akt, but downregulate phosphorylation of extracellular signal-regulated kinase (ERK) to reduce apoptosis.
In conclusion, we have demonstrated that HPE or HSE could have potential benefits in inhibiting diabetes induced ophthalmopathy.

並列關鍵字

Diabetic Ophthalmopathy ； Hibiscus Sabdariffa Linnaeus Extracts

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