Catalpolaglycone disrupts mitochondrial thermogenesis by specifically binding to a conserved lysine residue of UCP2 on the proton leak tunnel.

BACKGROUND: Catalpol (CAT), a naturally occurring iridoid glycoside sourced from the root of Rehmannia glutinosa, affects mitochondrial metabolic functions. However, the mechanism of action of CAT against pyrexia and its plausible targets remain to be fully elucidated. PURPOSE: This study aimed to identify the specific targets of CAT for blocking mitochondrial thermogenesis and to unveil the unique biological mechanism of action of the orthogonal binding mode between the hemiacetal group and lysine residue on the target protein in vivo. METHODS: Lipopolysaccharide (LPS)/ carbonyl cyanide 3-chlorophenylhydrazone (CCCP)-induced fever models were established to evaluate the potential antipyretic effects of CAT. An alkenyl-modified CAT probe was designed to identify and capture potential targets. Binding capacity was tested using in-gel imaging and a cellular thermal shift assay. The underlying antipyretic mechanisms were explored using biochemical and molecular biological methods. Catalpolaglycone (CA) was coupled with protein profile identification and molecular docking analysis to evaluate and identify its binding mode to UCP2. RESULTS: After deglycation of CAT in vivo, the hemiacetal group in CA covalently binds to Lys239 of UCP2 in the mitochondria of the liver via an ɛ-amine nucleophilic addition. This irreversible binding affects proton leakage and improves mitochondrial membrane potential and ADP/ATP transformation efficiency, leading to an antipyretic effect. CONCLUSION: Our findings highlight the potential role of CA in modulating UCP2 activity or function within the mitochondria and open new avenues for investigating the therapeutic effects of CA on mitochondrial homeostasis.

Fuziline Ameliorates Glucose and Lipid Metabolism by Activating Beta Adrenergic Receptors to Stimulate Thermogenesis.

Radix aconiti carmichaeli is a widely used traditional Chinese medicine that has been found to be effective in treating cardiovascular diseases and metabolic disorders. Patients with these diseases often experience a heat generation disorder, which is characterized by chilliness and can worsen the progression of the disease. This study established an in vitro screening model combining the examination of cellular mitochondrial membrane potential and mitochondrial temperature to screen drugs with thermogenic activity. After differentiation and determination of the content of characteristic metabolites of the drug-containing serum blood components, it was found that Fuziline (FZL) is the key thermogenic property in Radix aconiti carmichaeli, responsible for its thermogenic effects with a high relative importance of 33%. Experiments were conducted to evaluate the thermogenic activity of Radix aconiti carmichaeli and FZL in vivo by assessing temperature changes in various organs, including the rectum, liver, and brown adipose tissue. Moreover, the effects of intracellular ß3-adrenergic receptor (ß3-AR) agonistic effects were evaluated using transient ß3-AR transfection and dual-luciferase assay systems. The molecular mechanism by which FZL promotes thermogenesis and improves mitochondrial function was investigated by verifying the ß-adrenergic receptors (ß-AR) downstream signaling pathway. The results suggest that FZL activates ß-AR nonselectively, which in turn activates the downstream cAMP-PKA signaling pathway and leads to an increase in liver glycogenolysis and triglyceride hydrolysis, accompanied by enhancing mitochondrial energy metabolism. Consequently, the liver and brown adipose tissue receive energy to generate heat. In summary, these findings provide insight into the therapeutic application of Radix aconiti carmichaeli for metabolic disorders associated with heat generation disorders.

Ursolic acid alleviates tetrandrine-induced hepatotoxicity by competitively binding to the substrate-binding site of glutathione S-transferases.

BACKGROUND: Tetrandrine (TET), a bisbenzylisoquinoline alkaloid isolated from Stephania tetrandra S. Moore, is the only approved medicine in China for silicosis. However, TET-induced hepatotoxicity has raised safety concerns. The underlying toxic targets and mechanism induced by TET remain unclear; there are no targeted detoxification strategies developed for TET-induced hepatotoxicity. Ursolic acid (UA), a pentacyclic triterpene with liver protective effects, may have detoxification effects on TET-induced hepatotoxicity. PURPOSE: This study aims to explore toxic targets and mechanism of TET and present UA as a potential targeted therapy for alleviating TET-induced hepatotoxicity. METHODS: A TET-induced liver-injury model was established to evaluate TET toxicity and the potential UA detoxification effect. Alkenyl-modified TET and UA probes were designed to identify potential liver targets. Pharmacological and molecular biology methods were used to explore the underlying toxicity/detoxification mechanism. RESULTS: TET induced liver injury by covalently binding to the substrate-binding pocket (H-site) of glutathione S-transferases (GSTs) and inhibiting GST activity. The covalent binding led to toxic metabolite accumulation and caused redox imbalance and liver injury. UA protected the liver from TET-induced damage by competitively binding to the GST H-site. CONCLUSION: The mechanism of TET-induced hepatotoxicity is related to irreversible binding with the GST H-site and GST-activity inhibition. UA, a natural antidote, competed with TET on H-site binding and reversed the redox imbalance. This study revealed the hepatotoxic mechanism of TET and provided a targeted detoxifying agent, UA, to alleviate hepatotoxicity caused by GST inhibition.

Silencing c-Myc Enhances the Antitumor Activity of Bufalin by Suppressing the HIF-1α/SDF-1/CXCR4 Pathway in Pancreatic Cancer Cells.

BACKGROUND: Pancreatic cancer is one of the most aggressive malignancies. Bufalin, a traditional Chinese medicine, has been used to treat pancreatic cancer as an antitumor agent although the mechanism by which it exerts its effects is still unclear. c-Myc has been found to be overexpressed in more than half of human cancers including pancreatic cancer. However, the role of c-Myc in pancreatic cancer cells and its influence in bufalin-treated pancreatic cancer are yet to be clarified. The present study aimed to investigate the role of c-Myc in the antitumor activity of bufalin in pancreatic cancer. METHODS: c-Myc siRNA and overexpression plasmid were transfected into pancreatic cancer cells to construct the cell models. c-Myc expression was detected via quantitative real-time polymerase chain reaction and western blot. The effect of c-Myc on bufalin-induced inhibition of cell proliferation was detected via CCK-8 assay. Cell apoptosis and the cell cycle were analyzed via flow cytometry. Cell invasion and migration was detected via Transwell and wound healing assays, respectively. In addition, the effect of bufalin on the suppression of tumor growth in vivo was studied in nude mice model subcutaneously injected with PANC-1 and SW1990 cells. Hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling assay were used to evaluate pathological changes in vivo. The expression of HIF-1α/SDF-1/CXCR4 were detected via western blot. RESULTS: CCK-8 assay showed that bufalin could inhibit the proliferation of pancreatic cancer cell, and c-Myc downregulation enhanced this effect. Similarly, c-Myc downregulation enhanced the effect of bufalin on cell cycle arrest, apoptosis, and the invasion and migration of pancreatic cancer cell in vitro. Further mechanism assay showed that c-Myc enhances the effect by regulating the HIF-1α/SDF-1/CXCR4 signaling pathway. The in vivo studies verified the results that c-Myc enhances the effect of bufalin through regulation of the HIF-1α/SDF-1/CXCR4 pathway. CONCLUSIONS: Downregulation of c-Myc enhanced the antitumor activity of bufalin in pancreatic cancer cells by suppressing the HIF-1α/SDF-1/CXCR4 pathway. These findings indicate that c-Myc inhibitors could enhance the clinical therapeutic effect of bufalin and may expand the clinical application of bufalin accordingly.

A rapid integrated bioactivity evaluation system based on near-infrared spectroscopy for quality control of Flos Chrysanthemi.

For quality control of herbal medicines or functional foods, integral activity evaluation has become more popular in recent studies. The majority of researchers focus on the relationship between chromatography/mass spectroscopy and bioactivity, but the connection with spectrum-activity is easily ignored. In this paper, the near infrared reflection spectra (NIRS) of Flos Chrysanthemi samples were collected as a representative spectrum technology, and corresponding anti-inflammation activities were utilized to illustrate the spectrum-activity study. HPLC/Q-TOF-MS identification and heat map clustering were used to select the quality markers (Q-marker) from five cultivars of Flos Chrysanthemi. Using boxplot analysis and the interval limits of detection (LODs) theory, six crucial markers, namely, chlorogenic acid, 3,5-dicaffeoylquinic acid, 1,5-dicaffeoylquinic acid, luteoloside, apigenin-7-O-ß-d-glucoside, and luteolin-7-O-6-malonylglucoside were screened out. Then partial least squares regression (PLSR) calibration models combined with synergy interval partial least squares (siPLS) and 12 different spectral pretreatment methods were developed for the parameters optimization of these Q-markers in Flos Chrysanthemi powder. After comparing the relationship between Q-marker contents and anti-inflammation activity via three machine learning approaches and PLSR, back-propagation neural network (BP-ANN) displayed a more excellent non-linear fitting effect, as its R for new batches reached 0.89. These results indicated that the integrated NIRS and bioactive strategy was suitable for fast quality management in Flos Chrysanthemi, and also applied to other botanical food quality control.

Comparative evaluation of different cultivars of Flos Chrysanthemi by an anti-inflammatory-based NF-κB reporter gene assay coupled to UPLC-Q/TOF MS with PCA and ANN.

ETHNOPHARMACOLOGICAL RELEVANCE: Flos Chrysanthemi (FC), a commonly used traditional Chinese medicine, has five major cultivars ("Boju", "Chuju", "Gongju", "Hangbaiju" and "Huaiju") from different sources. However, the active constituents of these cultivars have not been studied or characterized with respect to their bioactivity, which is a serious problem when considering quality and safety. AIM OF THE STUDY: To evaluate the differences among the five cultivars of FC, and to establish a method for the standardization and quality control of FC related to its bioactivity. MATERIALS AND METHODS: In this study, the different ingredients in five cultivars of FC were identified by UPLC-Q/TOF and PCA, and the anti-inflammatory ingredients of FC were predicted and screened by artificial neural network (ANN) and an NF-κB luciferase reporter gene assay system. Using this comprehensive method, we successfully screened the anti-inflammatory markers of different cultivars of FC. RESULTS: Nineteen marker ingredients were confirmed to contribute strongly to the cluster, and eleven compounds in the five cultivars of FC were found to exert potential anti-inflammatory effects. Among these compounds, the NF-κB inhibitor activity of apigenin-7-O-6″-malonyl-glucoside, luteolin-7-O-rutinoside, quercetin-7-O-galactoside, quercetin-3-O-glucoside, apigenin-7-O-rutinoside and apigenin-7-O-glucoside were first reported here. Chlorogenic acid, luteolin-7-O-glucoside, 3,5-dicaffeoylquinic acid and luteolin were confirmed to be the most important anti-inflammatory marker ingredients useful for the quality control of FC. CONCLUSIONS: The proposed efficient and systematic method is helpful for the standardization and quality control of FC. Moreover, this comprehensive strategy may prove to be a powerful technique for the rapid establishment of quality control procedures related to bioactivity for other herbal samples and foods.

An integrated strategy of marker ingredients searching and near infrared spectroscopy rapid evaluation for the quality control of Chinese eaglewood.

The application of near infrared spectroscopy (NIRS) in traditional Chinese medicine (TCM) has usually been limited by its blindness to qualitative or quantitative multivariate analysis and because its chemical significance is easily ignored. Here, an integrated technology of ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-Q/Tof) and NIRS was proposed to set up a systematic quality control of Chinese Eaglewood (CE). UPLC-Q/Tof combined with principle compound analysis (PCA) was used to identify the marker ingredients of CE. Four types of highly oxidized 5,6,7,8-tetrahydro-2-(2-phenylethyl) chromones (THPECs) were then identified as potential markers to distinguish the authenticity of the CE. Based on the marker ingredients, the definite wavenumber intervals and spectral pretreatment pattern of NIRS were selected to act as an alternative evaluation technology directed against CE powder samples. Calibration equations were developed from the contents of the four markers, as detected by high performance liquid chromatography (HPLC) and NIRS data, using synergy interval partial least squares (siPLS) algorithm with Leave-One-Out (LOO) cross-validation. Using siPLS regression, satisfactory calibration statistics were obtained for the prediction of the marker ingredients. The correlation coefficient (r) between the predicted and reference results for the test set was used as an evaluation parameter for the models (r>0.9). Hierarchical cluster analysis and partial least squares-discriminant analysis (PLS-DA) were applied to further analyze the quantitative results from NIRS. From this systematic method, 50 CE samples were divided into superior, qualified, unqualified, and fake samples, displaying a more elaborate division than PLS-DA, which is only based on whole NIR spectra or HPLC. This tandem technique of UPLC-Q/Tof and NIRS assessment presented in this work can be used as a rapid evaluation approach for the quality control of complicated herbal medicines.

Dual-bioactivity-based liquid chromatography-coupled quadrupole time-of-flight mass spectrometry for NF-κB inhibitors and ß2AR agonists identification in Chinese Medicinal Preparation Qingfei Xiaoyan Wan.

Traditional Chinese medicine (TCM) preparations have been used as an effective multitarget strategy for the treatment of complex diseases; however, their bioactive constituents are undefined and difficult to identify. In this study, a simple and dual-target method based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry combined with dual-bioactive (NF-κB and ß(2)-adrenergic receptor) luciferase reporter assay systems was developed for the rapid determination of various bioactive compounds of TCM preparations. Qingfei Xiaoyan Wan, a TCM preparation used for the clinical therapy of asthma, was analyzed with this method. Potential anti-inflammatory and spasmolytic constituents were screened using NF-κB and ß(2)-adrenergic receptor activity luciferase reporter assay systems and simultaneously identified according to the time-of-flight mass spectrometry data. One ß(2)-adrenergic receptor agonist (ephedrine) and four structural types of NF-κB inhibitors (arctigenin derivatives, cholic acid derivatives, chlorogenic acid, and sinapic acid) were characterized. Tracheloside was considered a new NF-κB inhibitor. Further cytokine and chemokine detection confirmed the anti-inflammatory effects of the potential NF-κB inhibitors. The integration of ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry and dual-bioactive human cell functional evaluation systems proved to be a simple and effective strategy for the rapid screening of various bioactive compounds in TCM preparations used to treat complex diseases.

Pharmacokinetic study of salvianolic acid A in rat after intravenous administration of Danshen injection.

In order to research the pharmacokinetics of salvianolic acid A (SalA), a herbal ingredient isolated from Salvia miltiorrhiza Bunge, after intravenous administration to rats, a specific and accurate high-performance liquid chromatography (HPLC) was developed. The assay procedure involved simple liquid-liquid extraction of SalA and internal standard (IS, ethyl-p-hydroxybenzoate) from plasma into ethyl acetate. The organic layer was separated and evaporated under reduced pressure at 40 degrees C. The residue was reconstituted in the mobile phase and analyzed on an Inertsil C8 column, monitored at 285 nm. The mobile phase, which consisted of methanol-acetonitrile-water-formic acid (10:20:70:0.4, by vol), was used at a flow rate of 1.0 mL/min. The ratio of the peak area of the analyte to IS was applied to quantify the plasma samples. The standard curve for SalA was linear (r2 = 0.9999) in the concentration range of 0.75-150 microg/mL. The limit of quantitation (LOQ) of SalA was 0.75 microg/mL. The intra- and inter-day precisions (RSD) of the quality control (QC) samples were in the ranges of 2.17-3.29 and 1.24-5.28%, respectively. Accuracy in the measurement of QC samples ranged from 94.7 to 101.1%. This method was validated for specificity, accuracy and precision and was successfully applied to the pharmacokinetic study of SalA in rat plasma after intravenous administration of Danshen injection.