Department of Traditional Chinese Medicine, Chang Gung Memorial Hospital, Keelung 204, Taiwan.
J Ethnopharmacol. 2013 Jan 30;145(2):614-20. doi: 10.1016/j.jep.2012.11.044. Epub 2012 Dec 7.
Indigo naturalis is used in traditional Chinese medicine to treat various dermatoses. Our previous clinical studies showed that indigo naturalis is an effective treatment for psoriasis. Herein, the capabilities of indigo naturalis extract and its derivatives to increase claudin-1 expression and tight junction (TJ) function in human keratinocytes and psoriatic lesions were further studied.
Claudin-1 expression in psoriatic plaques with or without indigo naturalis treatment was analyzed by immunohistochemical methods. In primary human keratinocytes, the expression of claudin-1 was analyzed by fluorescent immunostaining, a real-time RT-PCR, and Western blot analysis. The effect of indigo naturalis on TJs was evaluated by measuring the transepithelial electrical resistance (TEER) and paracellular tracer flux.
The indigo naturalis extract upregulated mRNA and protein expressions of claudin-1 and function of TJs in primary human keratinocytes in concentration-dependent manners. Its main components, indirubin, indigo, and tryptanthrin, exerted synergistic effects on upregulating TJ functions in primary human keratinocytes. In addition, indigo naturalis increased the activity of protein kinase C (PKC), and a known potent PKC inhibitor, Ro318220, attenuated the indigo naturalis-induced claudin-1 expression. Significantly, restoration of claudin-1 was observed in healed psoriatic lesions after indigo naturalis treatment.
Indigo naturalis upregulates claudin-1 expression and restores TJ function in keratinocytes. Our data also suggest that indirubin, indigo, and tryptanthrin have a synergistic effect on TJ function.
青黛在传统中医中用于治疗各种皮肤病。我们之前的临床研究表明，青黛是治疗银屑病的有效方法。在此，进一步研究了青黛提取物及其衍生物在增加人角质形成细胞和银屑病病变中 Claudin-1 表达和紧密连接 (TJ) 功能的能力。
通过免疫组织化学方法分析有或没有青黛治疗的银屑病斑块中 Claudin-1 的表达。在原代人角质形成细胞中，通过荧光免疫染色、实时 RT-PCR 和 Western blot 分析分析 Claudin-1 的表达。通过测量跨上皮电阻 (TEER) 和细胞旁示踪剂通量来评估青黛对 TJ 的影响。
青黛提取物以浓度依赖的方式上调原代人角质形成细胞中 Claudin-1 的 mRNA 和蛋白表达及其 TJ 功能。其主要成分靛玉红、靛蓝和色胺，协同上调原代人角质形成细胞中的 TJ 功能。此外，青黛增加蛋白激酶 C (PKC) 的活性，已知有效的 PKC 抑制剂 Ro318220 可减弱青黛诱导的 Claudin-1 表达。重要的是，青黛治疗后愈合的银屑病病变中观察到 Claudin-1 的恢复。
青黛上调角质形成细胞中 Claudin-1 的表达并恢复 TJ 功能。我们的数据还表明，靛玉红、靛蓝和色胺对 TJ 功能具有协同作用。
