Li Dan, Lyu Yuanfeng, Song Qianbo, Lai Yuen Sze, Zuo Zhong
School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
Front Pharmacol. 2022 Sep 26;13:1017741. doi: 10.3389/fphar.2022.1017741. eCollection 2022.
Polygoni Multiflori Radix (PMR) is a commonly used traditional Chinese medicine in clinical practice, while adverse effects of hepatotoxicity related to PMR have been frequently reported. The clinical case reports indicated that PMR hepatotoxicity could occur under both overdose medication/long-term exposure and low doses with short-duration (idiosyncratic) conditions. The combination treatment with emodin and 2,3,5,4'-tetrahydroxystilbene-2---D-glucopyranoside (TSG), two major PMR components, was reported to contribute to PMR hepatotoxicity after long-term treatment. However, the role of the combination treatment of these two components in PMR-induced idiosyncratic liver injury has not been clearly clarified. In this study, the LPS-mediated inflammatory stress model rats were adopted to explore the idiosyncratic liver injury induced by the bolus combination treatment with emodin and TSG. After a bolus oral administration with TSG (165 mg/kg), emodin (5 mg/kg) or their combination in both normal and LPS-mediated inflammatory stress model rats, the systemic/hepatic concentrations of emodin, emodin glucuronides and bile acids were determined; the hepatotoxicity assessments were conducted monitoring histopathological changes and liver injury biomarkers (ALT and AST). Moreover, the protein expressions of bile acid homeostasis- and apoptosis-related proteins were examined. No liver damage was observed in the normal rats after a bolus dose with the individual or combination treatment, while the bolus combination treatment with emodin and TSG induced liver injury in the LPS-mediated inflammatory stress model rats, evidenced by the elevated plasma levels of alanine aminotransferase (∼66%) and aspartate aminotransferase (∼72%) accompanied by severe inflammatory cell infiltration and apoptotic hepatocytes in liver tissue. Moreover, such combination treatment at a bolus dose in the LPS-mediated inflammatory stress model rats could significantly elevate the hepatic TBA levels by about 45% up-regulating the hepatic protein expression levels of bile acid synthesis enzymes and inhibiting that of bile acid efflux transporters and the expression levels of apoptosis-related proteins. Our study for the first time proved the major contribution of the combination treatment with emodin and TSG in PMR-induced idiosyncratic liver injury.
何首乌是临床常用的一味中药，然而，与何首乌相关的肝毒性不良反应屡有报道。临床病例报告表明，何首乌肝毒性在过量用药/长期接触以及低剂量短期（特异质性）情况下均可能发生。据报道，大黄素与2,3,5,4'-四羟基二苯乙烯-2-O-β-D-葡萄糖苷（TSG）这两种何首乌的主要成分联合治疗，长期治疗后会导致何首乌肝毒性。然而，这两种成分联合治疗在何首乌诱导的特异质性肝损伤中的作用尚未明确阐明。在本研究中，采用脂多糖（LPS）介导的炎性应激模型大鼠，以探究大黄素与TSG联合大剂量给药诱导的特异质性肝损伤。在正常大鼠和LPS介导的炎性应激模型大鼠中，分别单次口服给予TSG（165 mg/kg）、大黄素（5 mg/kg）或二者的组合后，测定大黄素、大黄素葡萄糖醛酸苷和胆汁酸的全身/肝脏浓度；通过监测组织病理学变化和肝损伤生物标志物（谷丙转氨酶和谷草转氨酶）进行肝毒性评估。此外，检测胆汁酸稳态和凋亡相关蛋白的表达。正常大鼠单次给予单独药物或联合用药后未观察到肝损伤，而大黄素与TSG联合大剂量给药在LPS介导的炎性应激模型大鼠中诱导了肝损伤，表现为血浆丙氨酸转氨酶（约66%）和天冬氨酸转氨酶（约72%）水平升高，同时伴有肝组织中严重的炎性细胞浸润和凋亡肝细胞。此外，在LPS介导的炎性应激模型大鼠中，这种联合大剂量给药可使肝脏总胆汁酸水平显著升高约45%，上调胆汁酸合成酶的肝脏蛋白表达水平，抑制胆汁酸外流转运蛋白的表达水平以及凋亡相关蛋白的表达水平。我们的研究首次证明了大黄素与TSG联合治疗在何首乌诱导的特异质性肝损伤中起主要作用。
