Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, Guangdong, China.
Key Laboratory of Hunan Province for Traditional Chinese Medicine in Obstetrics & Gynecology Research, Hunan Provincial Maternal and Child Health Care Hospital, Changsha 410008, Hunan, China.
Phytomedicine. 2019 Feb;53:274-285. doi: 10.1016/j.phymed.2018.09.009. Epub 2018 Sep 5.
Renal fibrosis is the most common pathway leading to end-stage renal disease. It is characterized by excess extracellular matrix (ECM) accumulation and renal tissue damage, subsequently leading to kidney failure. Asperulosidic acid (ASPA), a bioactive iridoid glycoside, exerts anti-tumor, anti-oxidant, and anti-inflammatory activities, but its effects on renal fibrosis induced by unilateral ureteral obstruction (UUO) have not yet been investigated.
This study aimed to investigate the protective effect of ASPA on renal fibrosis induced by UUO, and to explore its pharmacological mechanism.
Thirty-six Sprague-Dawley (SD) rats were randomly divided into six groups: sham group, UUO model group, three ASPA treatment groups (10, 20, and 40 mg/kg), and captopril group (20 mg/kg). Rats were administered vehicle, ASPA or captopril intraperitoneally once a day for 14 consecutive days. Urea nitrogen (BUN), uric acid (UA) and inflammatory factors in serum samples were evaluated on the 7th, 10th, and 14th day after renal fibrosis induction. In addition, the 12 h urine was collected to test the content of urinary protein (upro) on the 14th day. The obstructive renal tissues were collected for pathological analysis (hematoxylin and eosion (H&E) staining and Masson's Trichrome staining) and immunohistochemical analysis on the 14th day after renal fibrosis induction. The mRNA expression of related factors and the protein levels of smad2, smad3, and smad4 were measured in UUO-induced rats by real time PCR and Western blot, respectively.
The levels of BUN, UA, and upro were elevated in UUO-induced rats, but ASPA treatment improved renal function by reducing the levels of BUN, UA, and upro. The protein levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6, as well as the mRNA levels of TNF-α, IL-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1) and interferon-γ (IFN-γ), were decreased after ASPA administration (10, 20 and 40 mg/kg) in a dose-dependent manner. The ASPA exerted an alleviation effect on the inflammatory response through inhibition of nuclear factor-kappa B (NF-κB) pathway. In addition, reductions in α-smooth muscle actin (α-SMA), collagen III, and fibronectin expression were observed after ASPA administration at doses of 20 and 40 mg/kg. Furthermore, the renal expression of transforming growth factor-β1 (TGF-β1), smad2, smad3, and smad4 was down-regulated by ASPA treatment at doses of 20 and 40 mg/kg.
ASPA possessed protective effects on renal interstitial fibrosis in UUO-induced rats. These effects may be through inhibition of the activation of NF-κB and TGF-β1/smad2/smad3 signaling pathways.
肾纤维化是导致终末期肾病的最常见途径。其特征为细胞外基质（ECM）过度积累和肾组织损伤，随后导致肾功能衰竭。獐牙菜苦苷（ASPA）是一种生物活性环烯醚萜糖苷，具有抗肿瘤、抗氧化和抗炎作用，但它对单侧输尿管梗阻（UUO）诱导的肾纤维化的影响尚未得到研究。
本研究旨在探讨 ASPA 对 UUO 诱导的肾纤维化的保护作用，并探讨其药理学机制。
36 只 Sprague-Dawley（SD）大鼠随机分为 6 组：假手术组、UUO 模型组、ASPA 治疗组（10、20 和 40mg/kg）和卡托普利组（20mg/kg）。大鼠每天腹膜内注射载体、ASPA 或卡托普利，连续 14 天。在肾纤维化诱导后第 7、10 和 14 天评估血清尿素氮（BUN）、尿酸（UA）和炎症因子。此外，在肾纤维化诱导后第 14 天收集 12h 尿液以检测尿蛋白（upro）含量。在肾纤维化诱导后第 14 天收集梗阻性肾组织进行病理分析（苏木精和伊红（H&E）染色和 Masson 三色染色）和免疫组织化学分析。通过实时 PCR 和 Western blot 分别检测 UUO 诱导大鼠相关因子的 mRNA 表达和 smad2、smad3 和 smad4 蛋白水平。
UUO 诱导的大鼠 BUN、UA 和 upro 水平升高，但 ASPA 治疗通过降低 BUN、UA 和 upro 水平改善了肾功能。ASPA 以剂量依赖性方式降低 TNF-α、IL-1β 和 IL-6 的蛋白水平以及 TNF-α、IL-1β、IL-6、单核细胞趋化蛋白-1（MCP-1）和干扰素-γ（IFN-γ）的 mRNA 水平。ASPA 通过抑制核因子-κB（NF-κB）通路发挥抗炎作用。此外，在 20 和 40mg/kg ASPA 给药后观察到 α-平滑肌肌动蛋白（α-SMA）、胶原 III 和纤连蛋白表达减少。此外，在 20 和 40mg/kg ASPA 治疗时，肾转化生长因子-β1（TGF-β1）、smad2、smad3 和 smad4 的表达下调。
ASPA 对 UUO 诱导的大鼠肾间质纤维化具有保护作用。这些作用可能是通过抑制 NF-κB 和 TGF-β1/smad2/smad3 信号通路的激活来实现的。
