Recently, hepatic sinusoidal obstruction syndrome (HSOS) caused by herbal preparations containing pyrrolizidine alkaloids (PAs), such as Gynura Rhizoma (Tusanqi), has gained global attention. However, the lack of a reliable and reproducible animal model has greatly hampered mechanistic studies. Therefore, we aimed to establish a reproducible HSOS mouse model and investigate the hepatotoxic mechanism. The model was established by intragastrical administration of Gynura Rhizoma extract, i.e., 1.0 g extract/kg per day (equal to 16.7 g crude drug/kg per day based on extraction rate and 49.1 mg PA/kg per day based on the total PA content in the extract determined) for 40 successive days. Then, the mice were sacrificed, and their blood samples and livers were collected for analyses. Using hematoxylin-eosin (HE) and Masson staining, scanning electron microscopy imaging, clinical biomarkers, and other assays, we showed that the HSOS was successfully induced in our mouse model. Furthermore, we detected the key factors involved in liver fibrosis in the mice, revealing significantly increased hydroxyproline concentration; elevated expression of α-smooth muscle actin (α-SMA) and fibrosis-related genes such as Collagen-1, Collagen-3, Mmp2, Mmp13, Timp1, Timp3, and Activin, upregulated Smad3 phosphorylation, and increased serum TGF-β levels. Moreover, pro-inflammatory cytokines, including Tnf-α, Il-1β, and Il-6, were also increased in the model. All these results demonstrate the key roles of the TGF-β-Smad3 and inflammatory signaling pathways in this Gynura Rhizoma-induced HSOS mouse model, suggesting that blockade of fibrosis and/or inflammation should be an effective treatment for HSOS.

中文翻译：

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含有吡咯烷定生物碱的绞股蓝可通过上调与纤维化相关的因子来诱导小鼠肝正弦梗阻综合征。

近来，由含有吡咯并核苷生物碱（PAs）的草药制剂引起的肝窦窦阻塞综合征（HSOS），已被全球关注。但是，缺乏可靠且可复制的动物模型极大地妨碍了机械学研究。因此，我们旨在建立可重现的HSOS小鼠模型并研究其肝毒性机制。通过胃内注射绞股蓝提取物建立模型，即每天1.0 g提取物/ kg（基于提取率等于16.7 g原料药/ kg /天，基于总PA含量计算为49.1 mg PA / kg /天）连续40天。然后，处死小鼠，并收集其血液样本和肝脏进行分析。使用苏木精-曙红（HE）和Masson染色，扫描电子显微镜成像，临床生物标志物和其他测定方法，我们表明在我们的小鼠模型中成功诱导了HSOS。此外，我们检测到了小鼠肝纤维化的关键因素，发现羟脯氨酸浓度显着增加。α-平滑肌肌动蛋白（α-SMA）和与纤维化相关的基因（如Collagen-1，Collagen-3，Mmp2，Mmp13，Timp1，Timp3和Activin）的表达升高，Smad3磷酸化上调和血清TGF-β水平升高。此外，模型中还增加了促炎细胞因子，包括Tnf-α，Il-1β和Il-6。所有这些结果证明了TGF-β-Smad3和炎症信号通路在此Gynura Rhizoma诱导的HSOS小鼠模型中的关键作用，