RP-HPLC method for rhein quantification in Cassia fistula L. (Fabaceae) leaves

Objectives@#The aim of this study is to establish a Reversed Phase – High Performance Liquid Chromatographic (RP-HPLC) method for the quantification of Rhein from Cassia fistula L. leaves.@*Methods@#A Shimadzu system equipped with a C18 Column (150 x 4.6 mm, 5 μm) with an isocratic elution of Acetonitrile (solvent A) and 0.1% trifluoroacetic acid aqueous solution (solvent B) (Merck, 1.08178.0050) with a 55:45 ratio, respectively and a flow rate of 1.0 mL/min and sample injection of 10 μL detection was done at 230 nm. Standard solution of Rhein (Chengdu Biopurify) was prepared for method development. This study was validated using the guidelines set under “ICH Topic Q2 R2 or the Validation of Analytical Procedures”. Procedures for linearity, precision, accuracy, limit of detection, and limit of quantitation were performed.@*Results@#The retention time of Rhein standard was determined at 5.10 minutes. LOD and LOQ were determined to be 1.278 mcg/mL and 3.872 mcg/mL, respectively with good linearity (R2 ≥0.996) with a linear range of 2.5-20 ug/mL of the Rhein standard. The accuracy of the method was determined based on % recovery method and ranged from 94.75%-100.32% (intraday, n=3) with %RSD of 0.71. The intraday precision %RSD was 2.92 (n=6) while interday precision %RSD was 3.75 (n=3). The method was able to check the Rhein quantity among 10 samples of Cassia fistula L. leaves from different locations in the Philippines.@*Conclusion@#The method was found to be sensitive and accurate for the quantification of Rhein. The method was found to be useful for the quantification of the amount of Rhein and can be used as a Quality Control tool for the assessment of Cassia fistula.

Research progress in epigenetic pharmacological effects of rhein / 中国中药杂志

Rhein, which is one of the main active components of Rheum palmatum, has a range of pharmacological activities such as the regulation of the metabolism of glucose and lipids, anti-inflammatory, anti-tumor, anti-fibrosis, etc. Epigenetics refers to the heritable variation of gene expression without altering the DNA sequence. It is involved in the emergence and development of inflammation, renal fibrosis, diabetes, cancer, atherosclerosis, and other diseases, thus becoming a new strategy for the treatment of many di-seases. A series of studies have shown that epigenetic modification may be a common molecular mechanism of various pharmacological effects of rhein. This paper summarized the effects of rhein on the regulation of epigenetic modification and its underlying mechanisms, which involve the regulation of DNA methylation, protein acetylation, and RNA methylation, so as to provide a basis for the development and application of rhein.

Study on improvement effects and mechanism of rhein on immunoglobulin A nephropathy / 中国药房

OBJECTIVE To study the improvement effects and mechanism of rhein on immunoglobulin A nephropathy （IgAN） model rat based on signal transducer and activator of transcription 3 （STAT3） signaling pathway. METHODS Rats were randomly divided into normal control group， IgAN model group and rhein treatment group， with 10 rats in each group. IgAN model group and rhein treatment group were given combination of bovine serum albumin+lipopolysaccharide+carbon tetrachloride to induce IgAN model. Since the 7th week， rhein treatment group rats were intragastrically given relevant medicine， and normal control group and model group rats were given equal amount of normal saline intragastrically， for consecutive 4 weeks. After the last administration， the count of urine sediment erythrocyte， 24 h-urine total protein （UTP）， the levels of immunoglobulin A （IgA） in serum and secretory immunoglobulin A （sIgA） in intestinal mucosa were detected. The pathological changes of Peyer’s patch in renal cortex and intestinal mucosa and IgA deposition in renal cortex were observed. The expressions of interleukin-17 （IL-17）， IL- 6 and transforming growth factor β （TGF-β） in Peyer’s patch of intestinal mucosa in rats were detected. The expressions of STAT3 and related orphan receptor γt （RORγt） mRNA in Peyer’s patch were detected. The expressions of p-STAT3 and RORγt proteins in Peyer’s patch were detected. RESULTS Compared with normal control group， the count of urine sediment erythrocyte， 24 h-UTP， the levels of IgA in serum and sIgA in intestinal mucosa were increased significantly in IgAN model group （P＜0.01）； enlarged renal corpuscles， dilated renal sacs， obvious intratubular mesangial hyperplasia and fibrosis were observed in renal cortex； the volume and germinal center of Peyer’s patch in intestinal mucosa increased； IgA deposition of renal cortex zxyylxk20220103） was obvious； the expressions of IL-17， IL-6 and TGF-β in Peyer’s patch， mRNA expressions of STAT3 and RORγt， protein expressions of p-STAT3 and RORγt were increased significantly （P＜0.01）. Compared with IgAN model group，above indexes were decreased significantly in rhein treatment group （P＜0.01）， pathological damage of renal cortex was improved， the volume of Peyer’s patch and germinal center of intestinal mucosa were reduced， and IgA deposition in renal cortex was weakened. CONCLUSIONS Rhein can improve IgAN model rats， the mechanism of which may be associated with inhibiting STAT3 signaling pathway and regulating immune function of Peyer’s patch in intestinal mucosa.

Potential Medicinal Value of Rhein for Diabetic Kidney Disease / 中国结合医学杂志

Diabetic kidney disease (DKD) is the primary cause of mortality among diabetic patients. With the increasing prevalence of diabetes, it has become a major concern around the world. The therapeutic effect of clinical use of drugs is far from expected, and therapy choices to slow the progression of DKD remain restricted. Therefore, research on new drugs and treatments for DKD has been a hot topic in the medical field. It has been found that rhein has the potential to target the pathogenesis of DKD and has a wide range of pharmacological effects on DKD, such as anti-nephritis, decreasing blood glucose, controlling blood lipids and renal protection. In recent years, the medical value of rhein in the treatment of diabetes, DKD and renal disease has gradually attracted worldwide attention, especially its potential in the treatment of DKD. Currently, DKD can only be treated with medications from a single symptom and are accompanied by adverse effects, while rhein improves DKD with a multi-pathway and multi-target approach. Therefore, this paper reviews the therapeutic effects of rhein on DKD, and proposes solutions to the limitations of rhein itself, in order to provide valuable references for the clinical application of rhein in DKD and the development of new drugs.

Mechanism of rhein inhibition of colorectal cancer through arginine metabolism based on protein chip / 药学学报

Rhein is an anthraquinone compound extracted from rhubarb, aloe vera, Polygonum multiflorum. In this study, we screened the potential targets of rhein through protein chip technology and investigated the underlying mechanism of its inhibition of colorectal cancer. Colony formation assay and scratch assay were used to examine the effect of rhein on the proliferation and migration abilities of HCT116 cell; KEGG and protein interaction analyses of rhein specific binding proteins by screening rhein binding proteins using protein chip; qRT-PCR and Western blot assays were used to determine the effect of rhein on the expression levels of BCL-2-associated X protein (BAX), B-cell lymphoma-2 (BCL-2) and argininosuccinate synthetase 1 (ASS1) in HCT116 cell. The antitumor effect of rhein was verified by azoxymethane combined with dextran sodium sulfate (AOM/DSS) induced colorectal cancer model. Experimental animal procedures were performed in accordance with animal welfare and the standards of the Laboratory Animal Ethics Committee of South China Agricultural University, with approval from the ethics committee. In vivo and in vitro results indicate that rhein specific binding proteins are mainly involved in amino acid anabolism, especially the arginine anabolic signaling pathway. Rhein inhibited the proliferation and migration of HCT116 cell in a concentration-dependent manner. Treated with rhein for 24 h significantly enhanced the expression of BAX and ASS1 in HCT116 cells, as well as the level of nitric oxide (NO) metabolism. In a mouse model of colorectal cancer, rhein significantly alleviated AOM/DSS induced weight loss and reduced fecal occult blood score. Meanwhile, rhein enhanced BAX and ASS1 expression in colon tumor tissue, as well as increased arginine and NO in serum. IHC and HE stain indicated that rhein alleviated Ki67 expression and macrophage infiltration in the colonic tissue of mice with AOM/DSS and delayed tumor formation. In conclusion, rhein can exert antitumor activity by regulating arginine and NO metabolism through ASS1.

Rhein inhibits hydrogen peroxide-induced apoptosis of human umbilical vein endothelial cells and its mechanism / 中国中药杂志

This study investigated the effect of rhein(RH) on the apoptosis and autophagy of human umbilical vein endothelial cells(HUVECs) induced by hydrogen peroxide(H_2O_2) and its underlying mechanism. The oxidative damage model in HUVECs was established and the cells were divided into different treatment groups. Cell survival rate was detected by MTT assay, apoptosis by Annexin V-FITC/PI double staining and Hoechst 33258 fluorescence staining, autophagy by Ad-mCherry-GFP-LC3 B adenovirus transfection, and protein expression by Western blot. The results showed that RH could protect cells by increasing the cell survival rate in a dose-dependent manner, decreasing the expression of apoptosis-related proteins(Bax and cleaved caspase-3) and the ratio of Bax/Bcl-2, elevating the expression of Bcl-2, up-regulating the expression of microtubule-associated protein 1 light chain 3(LC3)-Ⅱ, and down-regulating the expression of p62. Adenovirus transfection results showed that RH could increase the green and red spots, as well as the yellow spots. However, after the addition of autophagy inhibitor 3-MA, autophagy was reduced and apoptosis was increased. RH could enhance the expression of silent information regulator 2 related enzyme 1(SIRT1). The addition of SIRT1 inhibitor EX-527 reduced the protective effect of RH and cell viability. The addition of 3-MA had no effect on the expression of SIRT1 protein, but the expression of SIRT1 and LC3-Ⅱ proteins decreased and the expression of p62 increased after the addition of EX-527. After RH treatment, the phosphorylation of adenosine monophosphate-activated protein kinase(AMPK) increased, while that of the mechanistic target of rapamycin(mTOR) decreased in a dose-dependent manner. Moreover, this effect could be weakened by the AMPK inhibitor compound C. RH may enhance autophagy through SIRT1/AMPK/mTOR pathway to reduce H_2O_2-induced apoptosis of HUVECs.

Synthesis and antitumor activities of NO-donating rhein derivatives / 中国药科大学学报

@#Seven target compounds coupled by rhein and furoxan were synthesized and their chemical structures were confirmed by 1H NMR, IR, and MS. All target compounds were evaluated for anti-proliferative activity against human hepatoma cells HepG2 and Bel-7402, human colon cancer cells HCT116, human osteosarcoma cells U2OS, drug-resistant cells Bel-7402/5-FU and normal hepatocytes cells LO2 in vitro by thiazolyl blue(MTT) colorimetry. The results indicated that all target compounds had more potent anti-proliferative activity than their parent compound rhein. Additionally, compound 4g had stronger proliferation inhibitory activity on HepG2, Bel-7402, U2OS and Bel-7402/5-FU,with little effect on the proliferation of normal cells, exhibiting selective inhibitory activity. Griess assay was used to measure the release of nitric oxide in vitro. Results showed that compound 4g could increase the releases NO in HepG2 cells, which may be associated with its antitumor effects. Furthermore, the antitumor activity of compound 4g was attenuated by NO scavenger (hemoglobin), which indicates that the antitumor activity of compound 4g may be partly related to the release of NO.

Research progress of effect of Rhei Radix et Rhizoma and its anthraquinone in treatment of autoimmune diseases / 中国中药杂志

Rhei Radix et Rhizoma was first recorded in Shennong Ben Cao Jing, with a wide range of pharmacological activities. Autoimmune disease is a kind of disease that damages the tissue structure and function of immune cells and their components due to the impairment of immune tolerance function, including atherosclerosis, multiple sclerosis, gout, rheumatoid arthritis, autoimmune thyroiditis, ulcerative colitis, type 1 diabetes and IgA nephropathy. In recent years, clinical and experimental studies show that Rhei Radix et Rhizoma has potential therapeutic effects on autoimmune diseases. Under the guidance of the theory of traditional Chinese medicine, this paper reviews therapeutic and intervening effects of Rhei Radix et Rhizoma and its main active ingredient anthraquinone on autoimmune diseases. It also puts forward new study directions in view of the existing problems in studies of rhubarb and its anthraquinone, with the aim to provide reference for clinical treatment and scientific studies of effect of Rhei Radix et Rhizomaon autoimmune diseases.

Simultaneous determination of five ingredients in Taohe-Chengqi Decoction by UPLC-MS/MS / 国际中医中药杂志

Objective:To develop the UPLC-MS/MS method for the determination of amygdalin, cinnamic acid, rhein, emodin and glycyrrhizic acid in Taohe-Chengqi Decoction simutaneously. Methods:The separation was performed on Supelco Discovery C18, and isocratic elution was carried out with mobile phase consisting of acetonitrile - 4 mmol/L ammonium formate. The mass spectrometer was operated in the positive and negative ionization electrospray (ESI) mode using multiple monitoring (MRM) to analize of five ingredients. The precursor to product ion transitions monitored for amygdalin, cinnamic acid, rhein, emodin and glycyrrhizic acid were m/z 458.2→296.0, 146.8→103.1, 283.7→239.9, 269.7→226.1 and 821.4→350.9, respectively. Results:Amygdalin, cinnamic acid, rhein, emodin and glycyrrhizic acid were analyzed, the linear ranges were 0.001 6-0.102 4, 0.001 6-0.102 4, 0.001 6-0.102 4, 0.000 8-0.051 2 and 0.000 4-0.256 0 ng, respectively. The r were 0.998 7, 0.999 1, 0.999 5, 0.998 9 and 0.998 6, respectively. The recovery of five analytes ranges from 97.33% to 105.33% and the Relative Standard Deviations were all below 2.69%. Conclusion:This UPLC-MS/MS method is exclusive, rapid and sensitivewhich could be applied for the determination of amygdalin, cinnamic acid, rhein, emodin and glycyrrhizic acid in Taohe-Chengqi Decoction.

Effect of Rhein on AQP4 and Microglia Mediated Inflammatory Response in Cerebral Ischemia Rats / 中国实验方剂学杂志

Objective:To investigate the effect of rhein on aquaporin 4 （AQP4） and brain edema after cerebral ischemia and the role of microglia-mediated inflammation in this process. Method:The modified thread embolization method was selected to establish the cerebral ischemia model of the right middle cerebral artery embolism （MCAO） in rats. The rats were divided into sham operation group， model group， minocycline group， and high， medium and low-dose rhein groups （3.46，1.73，0.865 mg·kg^-1）. The neurobehavioral function was measured by a modified neurobehavioral score. Wet and dry weight methods were used to measure the changes of water content in brain tissue of rats with cerebral ischemic injury. Western blot was used to detect the expressions of interferon-<italic>γ</italic> （IFN-<italic>γ</italic>） and interleukin-2 （IL-2） in the peripheral ischemic area of rats in each group. Immunofluorescence double labeling method was used to detect the expressions and localization of microglia fine markers Iba-1 and AQP4. Result:Compared with the sham operation group， neurological function score and water content on the side of brain tissue injury of the model group were significantly increased （<italic>P</italic><0.05）. Compared with the model group， the neurological function score and the water content of the brain tissue of each drug group were reduced （<italic>P</italic><0.05， <italic>P</italic><0.01）. Compared with sham operation group， the protein expressions of IFN-<italic>γ</italic> and IL-2 in the model group increased significantly （<italic>P</italic><0.05）. Compared with the model group， the protein expressions of IFN-<italic>γ</italic> and IL-2 in the peripheral area of cerebral ischemia of each drug group were significantly improved （<italic>P</italic><0.05， <italic>P</italic><0.01）. Immunofluorescence double staining results showed that compared with the sham operation group， the model group showed significant increase in the fluorescence expression of AQP4 protein on activated microglia， while each drug group could reduce the fluorescence expression of AQP4 protein on activated microglia， different levels of activated microglia markers Iba-1 and AQP4 were co-localized in the peripheral area of cerebral ischemia in each group. Conclusion:Rhein could reduce the degree of brain edema caused by cerebral ischemic injury， and its mechanism may be related to the inhibition of microglia-mediated neuroinflammation and the down-regulation of AQP4 expression.

Hepatotoxicity of Main Components of Polygonum multiflorum and Its Effects on Drug Metabolism Enzyme / 中国药房

OBJECTIVE：To study the hepatotoxicity of main components of Polygonum multiflorum ，and investigate its toxic mechanism based on metabolic enzymes. METHODS ：ADMETlab 2.0 platform was used to forecast the toxic or carcinogenic effects of emodin ，physcion，rhein，stilbene glycoside and gallic acid on liver ，skin and heart. The effects of those components on cytochrome P 450 enzyme system （CYP1A2，CYP2C9，CYP2C19，CYP2D6，CYP3A4）were evaluated. The effects of different concentrations of emodin ，rhein，stilbene glycoside and gallic acid （10，20，40，80 μmol/L）on the survival rate of normal hepatocyte L 02 were detected. The effects of major components of P. multiflorum on the activity of UGT 1A1 enzyme were studied by in vitro reaction system ，using bilirubin as substrate. RESULTS ：Main components of P. multiflorum ，ie. emodin ，physcion， rhein and gallic acid ，showed strong toxic effects on the liver ，while stilbene glycosides possessed weak toxic effects on the liver. Emodin and physcion had strong inhibitory effects on CYP 1A2 and medium inhibitory effects on CYP 2C9，CYP2D6 and CYP3A4；rhein showed medium inhibitory effects on CYP 1A2 and CYP 2C9，while stilbene glycoside and gallic acid possessed weak inhibitory effects on the above enzymes. Emodin （40，80 μmol/L）and gallic acid （40，80 μmol/L）could significantly reduce the survival rate of L 02 cells（P＜0.01）. The inhibition rate of 5，10，20，40，80 μmol/L emodin and gallic acid（except for 5 μmol/L emodin）on UGT 1A1 enzyme increased significantly （P＜0.01），and the inhibition effect of emodin on UGT 1A1 enzyme was reversible competitive inhibition. CONCLUSIONS ：The main components of P. multiflorum ，ie. emodin ，rhein and physcion ， are hepatotoxic ；the mechanism of it may be associated with inhibiting the activity of CYP 1A2 and CYP 2C9 and competitively blocking rate-limiting enzyme UGT 1A1 in the process of bilirubin metabolism.

Study on potential hepatotoxicity of rhein in Rhei Radix et Rhizoma based on liver metabolism / 中国中药杂志

The bilirubin metabolism mediated by the phase Ⅱ metabolizing enzyme UGT1A1 in the liver was evaluated to study the potential hepatotoxicity risk based on investigation on the inhibitory effect of rhein and its metabolites on the UGT1A1 enzyme in Rhei Radix et Rhizoma. Firstly, in vitro liver microsomes incubation was used to initiate the phase Ⅱ metabolic reaction to investigate the inhibitory effect of rheinon UGT1A1 enzyme. Secondly, the phase Ⅰ and phase Ⅱ metabolic reactions were initiated to investigate the hepatotoxicity risk of rhein metabolites. It was found that the rhein and its phase Ⅱ metabolites had no significant inhibitory effect on UGT1A1 enzyme, but its phase Ⅰ metabolites significantly reduced UGT1A1 enzyme activity. Based on the metabolites analysis, it is speculated that the rhein phase Ⅰ metabolite rheinhydroxylate and its tautomers have certain hepatotoxicity risks, while the toxicity risk induced by the prototype and phase Ⅱ metabolites of rheinglucoside, rheinglucuronic acid and rhein sulfate is small.

Selective phytochemicals targeting pancreatic stellate cells as new anti-fibrotic agents for chronic pancreatitis and pancreatic cancer

Activated pancreatic stellate cells (PSCs) have been widely accepted as a key precursor of excessive pancreatic fibrosis, which is a crucial hallmark of chronic pancreatitis (CP) and its formidable associated disease, pancreatic cancer (PC). Hence, anti-fibrotic therapy has been identified as a novel therapeutic strategy for treating CP and PC by targeting PSCs. Most of the anti-fibrotic agents have been limited to phase I/II clinical trials involving vitamin analogs, which are abundant in medicinal plants and have proved to be promising for clinical application. The use of phytomedicines, as new anti-fibrotic agents, has been applied to a variety of complementary and alternative approaches. The aim of this review was to present a focused update on the selective new potential anti-fibrotic agents, including curcumin, resveratrol, rhein, emodin, green tea catechin derivatives, metformin, eruberin A, and ellagic acid, in combating PSC in CP and PC models. It aimed to describe the mechanism(s) of the phytochemicals used, either alone or in combination, and the associated molecular targets. Most of them were tested in PC models with similar mechanism of actions, and curcumin was tested intensively. Future research may explore the issues of bioavailability, drug design, and nano-formulation, in order to achieve successful clinical outcomes with promising activity and tolerability.

Simultaneous and Rapid Detection of Concentrated Liquid of Compound Dahuang Decoction Based on Near Infrared Spectroscopy / 中国实验方剂学杂志

Objective::Near infrared spectroscopy was used to detect the concentration density (25 ℃), solid-containing content, rhein content and glycyrrhizic acid content of compound Dahuang decoction. Method::The concentrated liquid of compound Dahuang decoction was determined by near infrared optical fiber transmission spectrometry. The contents of rhein and glycyrrhizic acid were determined by HPLC. Fifty-one samples were used for internal cross-validation, and partial least square regression was used to establish correction models between near-infrared spectrum and density, solid-containing content, rhein content and glycyrrhizic acid content, respectively. Ten unknown concentrated liquid samples were collected for external validation and prediction. Result::The external validation complex correlation coefficients between near-infrared spectra and density, solid-containing content, rhein content and glycyrrhizic acid content of the concentrated liquid of compound Dahuang decoction were 0.995 9, 0.999 6, 0.997 0 and 0.992 2, and the root mean square error of prediction (RMSEP) values were 2.50×10-3, 0.17, 7.57 and 67.10, respectively. Conclusion::The near infrared spectroscopy is suitable for the determination of evaluation indexes of the concentrated liquid index of compound Dahuang decoction, and has the characteristics of rapid, simple, stable and reliable.

Preparation and Preliminary Evaluation of Paclitaxel-loaded TPGS-CR Polymeric Micelles / 中国药学杂志

OBJECTIVE: To prepare paclitaxel loaded D-α-tocopheryl polyethylene glycol 1000 succinate(TPGS)-modified carboxymethyl chitosan-rhein polymeric micelles (PTX/TPGS-CR PMs) and preliminarily evaluate their performance. METHODS: PTX/TPGS-CR PMs was prepared by dialysis method, and the preparation procedure of PTX/TPGS-CR PMs was optimized by single factor with the drug loading, encapsulation rate and particle size as the indicators, then the optimized preparation procedure was verified. The safety of PTX/TPGS-CR PMs was initially investigated by the hemolysis test and the vascular irritation test. The cytotoxicity of PTX/TPGS-CR PMs in Hela cells was studied by MTT assay. Cell uptake experiments were performed by laser confocal microscopy and flow cytometry to investigate the uptake of PTX/TPGS-CR PMs by Hela cells. RESULTS: The particle size and PDI of PTX/TPGS-CR PMs prepared by the optimized preparation were (197.3±4.4) nm and (0.131±0.021), respectively. The Zeta potential was (-31.8±0.5) mV. The drug loading and encapsulation efficiency were (48.20±3.03)% and (87.26±4.91)%, respectively. The hemolytic test results showed that the hemolysis rate was less than 1.71%. No obvious irritation was observed after intravenous injection. The cytotoxicity of PTX/TPGS-CR PMs in Hela cells was concentration-and time-dependent. Cell uptake experiments showed that PTX/TPGS-CR PMs could be efficiently uptake by Hela cells. CONCLUSION: The PTX/TPGS-CR PMs has high drug loading and encapsulation efficiency, good safety. And they exhibite slightly better antitumor activity in vitro than Taxol®.

Effects of rhein derivatives 4 a containing amide structure on migration and invasion in ovarian cancer cells / 中国药理学通报

Aim To investigate the effect of Rhein derivative 4a containing amide structure on migration and invasion in ovarian cancer SKOV3 cells and its possible mechanism. Methods Ovarian cancer SK0V3 cells were used as target cells. Molecular docking and West-em blot were used to detect the regulatory effect of derivative 4a on Racl protein. CCK8, HE staining, Scratch and Transwell assay were used to detect the effects of derivative 4a on the proliferation, morphology , migration and invasion of SK0V3 cells, respectively. Western blot was employed to determine the expression of matrix metalloproteinases and EMT-related proteins. Results Derivative 4a could effectively bind to Racl protein, and the binding energy was-29. 10 kcal • mol"1, which was significantly lower than that of Rhein; it also could down-regulate the expression of Racl protein in SK0V3 cells. Derivative 4a could significantly inhibit the proliferation, invasion and migra tion of SKOV3 cells, and induce a large amount of cellular vacuolation; derivative 4a could also down-regu-\ late the expression of MMP-2 and MMP-9, up-regulate the expression of EMT epithelial marker protein E-ca-derin but down-regulate the expression of vimentin and j3-cantenin. Conclusions Derivative 4 a can inhibit the proliferation, migration and invasion of ovarian cancer SK0V3 cells. The mechanism may relate to its targeted regulation of Racl, thereby inhibiting the secretion of matrix metalloproteinases, up-regulating the expression of key molecule E-caderin and down-regula-ting the expression of Vimentin and (3-cantenin in EMT i process.•.

Protective effects of Rhein on cardiomyocyte induced with H2O2 / 医学研究生学报

ObjectiveThe effect of Rhein on myocardial cell injury and its possible mechanism of action remains unknown. This study aims to explore the effect and mechanism of rhein on cardiomyocyte injury induced by hydrogen peroxide (H2O2).MethodsRat cardiomyocyte H9c2 was stimulated using H2O2 to establish the myocardial cell injury model. The experiment was divided into three groups including a control group, H2O2 induced group, and Rhein treated group. Fluorescence probe and biochemical methods were used to detect the oxidative stress level of H9c2 cells. RT-qPCR and immunofluorescence tests were adapted to determine the apoptosis of H9c2 cells. Besides, RT-qPCR was carried out to evaluate the inflammatory response of H9c2 cells. Finally, western blot assay was performed to evaluate the expression of MAPK and NF-κB signaling pathways.ResultsThe results of fluorescence probe showed that the expression of ROS of H9c2 cells induced by H2O2 was decreased significantly after Rhein intervention. Besides, the biochemical test showed that the expressions of GSK-Px and CAT of H9c2 cells induced by H2O2 were increased significantly after Rhein treatment. RT-qPCR data suggested that Rhein could significantly decrease the mRNA expressions of Bax, caspase-3 and caspase-9, and upregulate the mRNA expression of Bcl-2 of H9c2 cells induced by H2O2. Moreover, immunofluorescence experiments showed that Rhein could significantly inhibit the expression of caspase-3 of H9c2 cells induced with H2O2. Further, the results of RT-qPCR indicated that the mRNA expressions of IL-6, TNF-α、IL-1β and IL-1α of H9c2 cells induced by H2O2 was decreased significantly after Rhein intervention. Finally, western blot showed that Rhein can significantly inhibit the expressions of MAPK and NF-κB signaling pathways.ConclusionRhein can reduce the injury of cardiomyocytes induced by H2O2, which may be achieved by inhibiting the expressions of MAPK and NF-κB signaling pathways.

Effect of celastrol combined medication on the inhibition of HepG2 cell proliferation / 中国药科大学学报

@#To study the inhibitory effect of celastrol respectively combined with glycyrrhetic acid, paclitaxel, and rhein on the proliferation of human hepatoma cell line HepG2. The MTT method was used to detect the survival rate of HepG2 cells. The cooperativity index(CI)and Jin′s formula method were used to determine the synergistic effect. Apoptosis and cell cycle arrest were detected, too. The results show that celastrol, glycyrrhetinic acid, rhein, and paclitaxel alone can inhibit the proliferation of HepG2 cells, respectively. Combination with glycyrrhetic acid, paclitaxel, and rhein, respectively, the inhibitory effect of celastrol on the proliferation of HepG2 cells was significantly enhanced. And the synergistic effect on the proliferation inhibition of HepG2 cells in some concentrations was displayed in the experiment. The cell apoptosis rate was improved(P< 0. 01)and more cells were arrested in G2/M phase. Celastrol respectively combined with glycyrrhetic acid, paclitaxel, and rhein displayed a synergistic inhibitory effect on the proliferation of HepG2 cells, and the effect was related to inducing cell apoptosis and increasing the cell cycle arrest in G2/M phase.

Cytotoxicity and cellular uptake of paclitaxel-loaded carboxymethyl chitosan-rhein polymeric micelles in MCF-7 cells / 中国药科大学学报

@#In this study, in vitro cytotoxicity of carboxymethyl chitosan-rhein conjugate(CR conjugate)and paclitaxel-loaded carboxymethyl chitosan-rhein polymeric micelles(PTX/CR PMs)was evaluated by MTT method in MCF-7 cells. The results showed that CR conjugate displayed good security; PTX/CR PMs in 24 h showed better antitumor activity than Taxol® . Environment-responsive fluorescent probe P4 was used to determine the cellular uptake of PTX/CR PMs in MCF-7 cells. The results also showed that P4 and PTX co-loaded carboxymethyl chitosan-rhein polymeric micelles ［(P4+PTX)/CR PMs］ could be taken up by MCF-7 cells. There was no difference between(P4+PTX)/CR PMs group and(P4+PTX)/CR PMs with verapamil group, suggesting that CR PMs could protect fluorescent probe and/or drugs in their cores avoiding efflux by P-glycoprotein. These results will contribute to in vivo study of CR conjugate and PTX/CR PMs in the future.

Mechanism of Xiahuang Granules in treating opioid-induced constipation based on network pharmacology / 中草药

Objective: To explore the potential mechanism of Xiahuang Granules in the treatment of opioid-induced constipation. Methods: Various medicinal ingredients and targets information of Xiahuang Granules were found in TCMSP database. In Genecards database, "opiod constipation", "opioid-induced bowel dysfunction" and "opioid-induced constipation" were used as keywords to search for targets related to opioid-induced constipation, and the active targets mapping of Xiahuang Granules were selected as the research targets. The common targets were imported into the STRING database to build the targets interaction network diagram, and Cytoscape 3.3.0 software was used for visual processing to screen out the core targets. The OmicsBean analysis platform and STRING database were used to conduct GO function enrichment and KEGG pathway enrichment analysis on the targets. Results: A total of 55 chemical constituents, 158 candidate target genes, 86 common targets after mapping Venny, 49 corresponding chemical components, 12 core targets and 19 main chemical components of Xiahuang Granules were obtained by screening. GO functional enrichment analysis showed 4 150 biological process items, involving chemical stimulus cell reactions, chemical reactions, biological quality control and other processes; A total of 302 cell composition items, involving voxel projection, extracellular space, and whole membrane processes; A total of 459 molecules function items, involving processes such as protein binding, molecular transduction activity, and enzyme binding were obtained. KEGG enrichment analysis revealed 149 signaling pathways related to the effect of Xiahuang Granules, involving the AGE-RAGE signaling pathway in diabetic complications and tumor necrosis factor signaling pathway, etc. The network of "medicinal herb-component-target-pathway" of Xiahuang Granules was established. Conclusion: The main chemical components of Xiahuang Granules including naringenin, nobiletin, aloe emodin, rhein may regulate endocrine resistance and tumor necrosis factor signaling pathways by acting on key proteins such as TNF, MAPK3, IL-6, VEGFA, and PTGS2, thus play a role in laxative, antispasmodic, and promoting gastrointestinal motility, which provides theoretical basis for Xiahuang Granules to treat opioid-induced constipation and is consistent with the preliminary verification results of Xiahuang granules.