Hepatic Effect of 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside, the Signature Component of Traditional Chinese Medicine Heshouwu: Advances and Prospects.

Traditional Chinese medicine Heshouwu, named Polygoni Multiflori Radix in Pharmacopoeia of the People's Republic of China (PPRC, 2020), is derived from the root tuber of Polygonum multiflorum Thunb., Heshouwu or processed Heshouwu is well known for its function in reducing lipids and nourishing the liver. However, increasing cases of Heshouwu-induced hepatotoxicity were reported in recent years. Researchers have begun to study the paradoxical effects of Heshouwu on the liver. 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside (TSG), an abundant functional component of Heshouwu, shows various biological activities, among which its effect on the liver is worthy of attention. This paper reviews the current studies of TSG on hepatoprotection and hepatotoxicity, and summarizes the doses, experimental models, effects, and mechanisms of action involved in TSG's hepatoprotection and hepatotoxicity, aiming to provide insight for future study of TSG and understanding the effects of Heshouwu on the liver. Emerging evidence suggests that TSG ameliorates both pathological liver injury and chemical-induced liver injury by modulating lipid metabolism, inhibiting the inflammatory response and oxidative stress in the liver. However, with the reports of clinical cases of Heshouwu induced liver injury, it has been found that long-term exposure to a high dose of TSG cause hepatocyte or hepatic tissue damage. Moreover, TSG may cause hepatotoxicity by affecting the transport and metabolism of other possible hepatoxic compounds in Heshouwu. Studies indicate that trans-TSG can be isomerized into cis-TSG under illumination, and cis-TSG had a less detrimental dose to liver function than trans- TSG in LPS-treated rats. In brief, TSG has protective effects on the liver, but liver injury usually occurs under highdose TSG or is idiosyncratic TSG-induced liver injury.

Inhibition of CYP3A4 enhances aloe-emodin induced hepatocyte injury.

Aloe-emodin (AE) is a natural hydroxyanthraquinone derivative that was found in many medicinal plants and ethnic medicines. AE showed a wide array of pharmacological activities including anticancer, antifungal, laxative, antiviral, and antibacterial effects. However, increasing number of published studies have shown that AE may have some hepatotoxicity effects but the mechanism is not fully understood. Studies have shown that the liver injury induced by some free hydroxyanthraquinone compounds is associated with the inhibition of some metabolic enzymes. In this study, the CYP3A4 and CYP3A1 were found to be the main metabolic enzymes of AE in human and rat liver microsomes respectively. And AE was metabolized by liver microsomes to produce hydroxyl metabolites and rhein. When CYP3A4 was knocked down in L02 and HepaRG cells, the cytotoxicity of AE was increased significantly. Furthermore, AE increased the rates of apoptosis of L02 and HepaRG cells, accompanied by Ca2+ elevation, mitochondrial membrane potential (MMP) loss and reactive oxygen species (ROS) overproduction. The mRNA expression of heme oxygenase-1 in L02 and HepaRG cells increased significantly in the high-dose of AE (40 µmol/L) group, and the mRNA expression of quinone oxidoreductase-1 was activated by AE in all concentrations. Taken together, the inhibition of CYP3A4 enhances the hepatocyte injury of AE. AE can induce mitochondrial injury and the imbalance of oxidative stress of hepatocytes, which results in hepatocyte apoptosis.

Exploration of components and mechanisms of Polygoni Multiflori Radix-induced hepatotoxicity using siRNA -mediated CYP3A4 or UGT1A1 knockdown liver cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Polygoni Multiflori Radix, the dried root of Polygonum multiflorum Thunb., and its processed products have been used as restoratives for centuries in China. However, the reports of Polygoni Multiflori Radix-induced liver injury (PMR-ILI) have received wide attention in recent years, and the components and mechanism of PMR-ILI are not completely clear yet. Our previous studies found that the PMR-ILI was related to the down-regulation of some drug metabolism enzymes (DME). AIM OF THE STUDY: To explore the effect of the inhibition of CYP3A4 or UGT1A1 on PMR-ILI, screen the relevant hepatotoxic components and unveil its mechanism. METHODS: RT-qPCR was used to detect the effects of water extract of Polygoni Multiflori Radix (PMR) and its main components on the mRNA expression of CYP3A4 and UGT1A1 in human hepatic parenchyma cell line L02. High-performance liquid chromatography (HPLC) was employed to detect the content of major components in the PMR. And then, the stable CYP3A4 or UGT1A1 knockdown cells were generated using short hairpin RNAs (shRNA) in L02 and HepaRG cells. Hepatotoxic components were identified by cell viability assay when PMR and its four representative components, 2,3,5,4'-tetrahydroxy stilbene glycoside (TSG), emodin (EM), emodin-8-O-ß-D-glucoside (EG), and gallic acid (GA), acted on CYP3A4 or UGT1A1 knockdown cell lines. The PMR-ILI mechanism of oxidative stress injury and apoptosis in L02 and HepaRG cells were detected by flow cytometry. Finally, the network toxicology prediction analysis was employed to excavate the targets of its possible toxic components and the influence on the metabolic pathway. RESULTS: PMR and EM significantly inhibited the mRNA expression of CYP3A4 and UGT1A1 in L02 cells, while TSG and GA activated the mRNA expression of CYP3A4 and UGT1A1, and EG activated CYP3A4 expression while inhibited UGT1A1 expression. The contents of TSG, EG, EM and GA were 34.93 mg/g, 1.39 mg/g, 0.43 mg/g and 0.44 mg/g, respectively. The CYP3A4 or UGT1A1 knockdown cells were successfully constructed in both L02 and HepaRG cells. Low expression of CYP3A4 or UGT1A1 increased PMR cytotoxicity remarkably. Same as PMR, the toxicity of EM and GA increased in shCYP3A4 and shUGT1A1 cells, which suggested EM and GA may be the main components of hepatotoxicity in PMR. Besides, EM not only inhibited the expression of metabolic enzymes but also reduced the cytotoxicity threshold. EM and GA affected the level of ROS, mitochondrial membrane potential, Ca2+ concentration, and dose-dependent induced hepatocyte apoptosis in L02 and HepaRG cells. The network toxicology analysis showed that PMR-ILI was related to drug metabolism-cytochrome P450, glutathione metabolism, and steroid hormone biosynthesis. CONCLUSION: The inhibition of mRNA expression of CYP3A4 or UGT1A1 enhanced hepatotoxicity of PMR. EM and GA, especially EM, may be the main hepatotoxic components in PMR. The mechanism of PMR, EM and GA induced hepatotoxicity was proved to be related to elevated levels of ROS, mitochondrial membrane potential, Ca2+ concentration, and induction of apoptosis in liver cells.

[Risk analysis for cerebral hyperperfusion syndrome after carotid endarterectomy].

OBJECTIVE: To analyze risk factors for cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy (CEA). METHODS: From September 2010 to September 2012, 183 consecutive patients with carotid artery stenosis who had indications for CEA entered the study. There were 149 male and 34 female patients, aged from 38 to 83 years with an average of (66 ± 9) years. Intracranial blood flow changes were monitored through transcranial Doppler routinely. Pre- and post-operative middle cerebral artery velocity (VMCA) were recorded. CHS was diagnosed by the combination of hyperperfusion syndrome and 100% increase of VMCA after operation compared with pre-operative baseline values. The patients who had CHS during hospitalization were recorded. Pre-operative and operative related factors were analyzed by univariate analysis, followed by Logistic regression model, to identify the risk factors of CHS. RESULTS: Overall, CHS occurred in 15 patients (8.2%) after CEA. The average onset time was (2.6 ± 0.2) days after surgery. By decreasing blood pressure and using dehydration medicine, all the patients with CHS recovered before discharge. None of them developed to intracranial hemorrhage. On univariate analysis, significant risk factors for CHS were history of stoke, symptomatic carotid artery stenosis and shunting during operation. On Logistic regression model, independent risk factor was symptomatic carotid artery stenosis (OR = 6.733, 95%CI: 1.455-31.155, P = 0.015), while shunting during operation (OR = 0.252, 95%CI: 0.067-0.945, P = 0.041) was a protective factor. CONCLUSIONS: Symptomatic carotid artery stenosis is an independent risk factor for CHS after CEA and shunting during operation is a protective factor. Using shunt may be an effective method of preventing CHS after CEA.

Supine-to-standing transcranial Doppler test in patients with multiple system atrophy.

BACKGROUND: Supine-to-standing test, a transcranial Doppler (TCD) based technique, has been recently developed to evaluate cardiovascular dysautonomia. We explored the value of supine-to-standing TCD test in predicting the course of multiple system atrophy (MSA) with orthostatic hypotension (OH). METHODS: By monitoring the signals of middle cerebral artery during supine-to-standing posture changes, the trend curves of cerebral blood flow velocities, pulsatility index and resistance index were obtained from 38 MSA patients with OH and 31 healthy subjects. The correlation between TCD findings and the clinical outcome of the patients, which was determined by follow-up structured phone interview, was analyzed. Adverse outcome was defined if a patient died, was in bed-ridden state or had recurrent syncope (>1 per month). RESULTS: Two characteristic TCD findings were revealed in the MSA patients but not in the controls, i.e. a blunted cerebral blood flow velocity rebound after standing and/or sustained higher pulsatility index upon standing than supine baseline. Structured phone interview was completed in 31 of the 38 patients (mean follow-up time, 20 ± 11 months). While no subject had recurrent syncope before enrollment, 12 patients developed an adverse outcome during follow-up. The coexistence of two characteristic TCD findings predicted adverse outcomes with positive predictive value 66.7% and negative predictive value 87.5%. CONCLUSIONS: Supine-to-standing TCD test is valuable in predicting the course of MSA with OH at early stage. We hypothesize baroreflex failure effects and paradoxical cerebral vasoconstriction in response to OH may account for the TCD findings in MSA patients.

[The prevalence of combined extra- and intra-cranial artery stenosis in patients with extracranial internal carotid artery occlusive disease.].

OBJECTIVE: The intra-cranial arteries are more affected in Asian ischemic stroke patients. We thought that tandem or diffuse arterial occlusive disease may be more common among patients with extracranial internal carotid artery (ICAex) occlusive disease. In the current study, the frequency of other co-existing extracranial artery (EA) or intracranial artery (IA) stenosis in patients with ICAex occlusive disease and its risk factors were studied. METHOD: One hundred and ninety-eight consecutive patients with ischemic stroke or TIA who were admitted to our hospital from Jan 2001 to May 2008 and who had stenosis (70%) or occlusion of ICAex were enrolled in the study. All the patients were examined with carotid duplex and transcranial Doppler (TCD). Among them, 75 patients were also examined with DSA, 52 patients with intracranial MRA and 25 patients with extra- and intra-cranial CTA. Extracranial artery stenosis or occlusion were diagnosed with DSA/CTA in 93 patients, and with carotid duplex only in 105 patients. Intracranial artery stenosis was diagnosed with DSA/MRA/CTA in 118 patients, and with TCD only in 80 patients. Patients with presumably cardioembolism such as atrial fibrillation were excluded. RESULTS: Among the 198 patients, 172 (86.8%) had other combined EA or IA stenosis. One hundred and thirty-five patients (135/198, 68.2%) had other combined EA stenosis, which were more frequently found in the contralateral ICAex (71/198, 35.9%). One hundred and twenty-three patients (123/198, 62.1%) had combined IA stenosis, which were more frequently found in MCA (75/198, 37.9%). 52 (52/198, 26.3%) had ipsilateral terminal ICA and/or middle cerebral artery stenosis. CONCLUSION: Tandem or diffuse arterial occlusive disease is common among patients with steno-occlusion of ICAex. Therefore, it is important to evaluate other EA and IA stenosis before CEA or CAS in Chinese patients.