Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
J Ethnopharmacol. 2019 Oct 28;243:112078. doi: 10.1016/j.jep.2019.112078. Epub 2019 Jul 10.
Rhododendron molle G. Don (Ericaceae) (RM) is a natural medicinal plant. Its root extracts have been applied in clinic and proved to be effective in chronic glomerulonephritis and rheumatoid arthritis in China. Surprising, little is understood about the key compound of RM and the exact mechanisms underlying its treatment on kidney diseases. In this study, we will explore whether rhodojaponin II (R-II), as the important compound of RM, also exerts the major effect.
Mouse model of focal segmental glomerulosclerosis was induced by single dose of adriamycin injection. Induced adriamycin nephropathy (ADRN) mice were treated individually with RM root extract (5 mg/kg, n = 5), RM root extract (60 mg/kg, n = 5), R-II (0.04 mg/kg, n = 6) or captopril (30 mg/kg, n = 5) for five weeks. Podocyte marker (nephrin and podocin) expressions were examined by immunohistochemical staining and Western Blot analysis. Fibronectin level was evaluated by immunohistochemical staining and Western Blot analysis. Interstitial infiltrated inflammatory cells (CD4 T cells, CD8 T cells, and CD68 macrophages) were examined with immunohistochemical staining. The expressions of NF-ĸB p-p65 and TGF-β1/Smad pathway associated key proteins, such as TGF-β1, Smad3, phosphorylated-Smad3 (p-Smad3), and Smad7, were analyzed respectively by Western Blot analysis.
RM root extract (5 mg/kg) and its important compound R-II (0.04 mg/kg) significantly ameliorated proteinuria, podocyte injury, and glomerulosclerosis, meanwhile, they hampered interstitial fibrosis in mice with ADRN. R-II significantly reduced NF-ĸB p65 phosphorylation, interstitial infiltrated CD4 T cells, CD8 T cells, and CD68 macrophages, at the same time, down-regulated TGF-β1 and p-Smad3 protein expressions in mice with ADRN.
RM root extract, R-II, could effectively ameliorate proteinuria and kidney injury in ADRN, related to its anti-inflammatory effects, as well as suppression of TGF-β1/Smad signaling pathway.
密枝杜鹃（Rhododendron molle G. Don）（杜鹃花科）（RM）是一种天然药用植物。其根提取物已在临床上应用，并已证明对中国的慢性肾小球肾炎和类风湿性关节炎有效。令人惊讶的是，人们对 RM 的关键化合物知之甚少，也不清楚其治疗肾脏疾病的确切机制。在这项研究中，我们将探讨作为 RM 的重要化合物的罗托苷 II（R-II）是否也具有主要作用。
通过单次注射阿霉素诱导小鼠局灶节段性肾小球硬化模型。用 RM 根提取物（5mg/kg，n=5）、RM 根提取物（60mg/kg，n=5）、R-II（0.04mg/kg，n=6）或卡托普利（30mg/kg，n=5）分别对诱导的阿霉素肾病（ADRN）小鼠进行单独治疗，为期五周。通过免疫组织化学染色和 Western Blot 分析检测足细胞标记物（nephrin 和 podocin）的表达。通过免疫组织化学染色和 Western Blot 分析评估纤维连接蛋白水平。通过免疫组织化学染色检查间质浸润的炎症细胞（CD4 T 细胞、CD8 T 细胞和 CD68 巨噬细胞）。通过 Western Blot 分析分别分析 NF-κB p-p65 和 TGF-β1/Smad 通路相关关键蛋白的表达，如 TGF-β1、Smad3、磷酸化-Smad3（p-Smad3）和 Smad7。
RM 根提取物（5mg/kg）及其重要化合物 R-II（0.04mg/kg）显著改善了 ADRN 小鼠的蛋白尿、足细胞损伤和肾小球硬化，同时抑制了间质纤维化。R-II 显著降低了 NF-κB p65 的磷酸化、间质浸润的 CD4 T 细胞、CD8 T 细胞和 CD68 巨噬细胞，同时下调了 ADRN 小鼠中 TGF-β1 和 p-Smad3 蛋白的表达。
RM 根提取物和 R-II 可有效改善 ADRN 中的蛋白尿和肾脏损伤，这与其抗炎作用以及抑制 TGF-β1/Smad 信号通路有关。
