Herbal Medicine Group, Faculty of Pharmacy, The University of Sydney, Sydney, NSW 2006, Australia.
Evid Based Complement Alternat Med. 2012;2012:323784. doi: 10.1155/2012/323784. Epub 2012 Apr 11.
Diabetic retinopathy is a preventable microvascular diabetic complication and a leading cause of vision loss. Retinal pigment epithelial cell apoptosis is an early event in diabetic retinopathy. Taurine is reportedly beneficial for diabetic retinopathy and is abundant in the fruit of Lycium barbarum (LB). We have investigated the effect of pure taurine and an extract of LB rich in taurine on a model of diabetic retinopathy, the retinal ARPE-19 cell line exposed to high glucose. We demonstrate for the first time that LB extract and the active ligand, taurine, dose dependently enhance cell viability following high glucose treatment in the ARPE-19 retinal epithelial cell line. This cytoprotective effect was associated with the attenuation of high glucose-induced apoptosis, which was shown by characteristic morphological staining and the dose-dependent decrease in the number of apoptotic cells, determined by flow cytometry. Moreover, we have shown that LB extract and taurine dose dependently downregulate caspase-3 protein expression and the enzymatic activity of caspase-3. We conclude that taurine, a major component of LB, and the LB extract, have a cytoprotective effect against glucose exposure in a human retinal epithelial cell line and may provide useful approaches to delaying diabetic retinopathy progression.
糖尿病性视网膜病变是一种可预防的微血管糖尿病并发症，也是导致视力丧失的主要原因。视网膜色素上皮细胞凋亡是糖尿病性视网膜病变的早期事件。据报道，牛磺酸对糖尿病性视网膜病变有益，并且在枸杞（LB）的果实中含量丰富。我们研究了纯牛磺酸和富含牛磺酸的 LB 提取物对糖尿病性视网膜病变模型（高糖暴露的视网膜 ARPE-19 细胞系）的影响。我们首次证明，LB 提取物和活性配体牛磺酸可在 ARPE-19 视网膜上皮细胞系中依赖于剂量依赖性增强高葡萄糖处理后的细胞活力。这种细胞保护作用与高葡萄糖诱导的细胞凋亡的减弱有关，通过特征性形态学染色和通过流式细胞术确定的凋亡细胞数量的剂量依赖性减少来显示。此外，我们已经表明，LB 提取物和牛磺酸可剂量依赖性地下调 caspase-3 蛋白表达和 caspase-3 的酶活性。我们得出的结论是，LB 的主要成分牛磺酸和 LB 提取物对人视网膜上皮细胞系中的葡萄糖暴露具有细胞保护作用，并且可能为延缓糖尿病性视网膜病变的进展提供有用的方法。
