Research progress of cystine/glutamate antiporter as drug targets / 药学学报

Cystine/glutamate antiporter [system Xc(-)] is a sodium independent amino acid transporter, which is a heterodimer composed of light chain subunit xCT and heavy chain subunit 4F2hc (CD98) through covalent disulfide bond. System Xc(-) typically mediates cystine uptake and glutamate output, helps to maintain the balance of glutamate, cystine and cysteine inside and outside the cell, regulates the level of glutamate inside and outside the membrane and the synthesis of intracellular glutathione, thus affecting oxidative stress and glutamate neurotoxicity. This review expounds the structure and function of system Xc(-), analyzes the role of the transporter in physiology and pathology, discusses the role and mechanism in different diseases, and discusses the specific research progress of system Xc(-) as a drug target. This review summarizes the research status of system Xc(-) and provides theoretical guidance for further research on system Xc(-) and drug discovery.

Chemical constituents from ripe fruit of Cornus officinalis / 中国中药杂志

To investigate the chemical compounds from the fruit of Cornus officinalis, six compounds were isolated and determined by extensive spectroscopic analysis as 6'-O-acetyl-7α-O-ethyl morroniside (1), (-)-isolariciresinol 3α-O-β-D-glucopyranoside(2), apigenin (3), cirsiumaldehyde(4), p-coumaric acid (5), caffeic acid (6). Compound 1 was a new iridoid glucoside,and compounds 2-4 were obtained from the Cornus genus for the first time. Compounds 2-6 were evaluated for the viability of PC12 cells when exposed in conditions of oxygen and glucose deprivation. The MTT results showed that compound 4 increased cell viability moderately in OGD/R treated PC12 cells at the concentration of 1.0 μmol•L⁻¹.

Antithrombotic effects of the effective components group of Xiaoshuantongluo formula in vivo and in vitro / 中国天然药物

The present study was designed to investigate the antithrombotic effects and underlying mechanisms of the effective components group (ECG) of Xiaoshuantongluo recipe (XECG) and to further verify the rationality and feasibility of ECG-guided methodology in traditional Chinese medicine (TCM) research. The arterial thrombosis model induced by ferric chloride (FeCl3) oxidation and the venous thrombosis model induced by inferior vena cava ligation were established to evaluate the antithrombotic potential of XECG. Our results indicated that XECG significantly prolonged the time to occlusion, activated partial thromboplastin time (APTT), and prothrombin time (PT), and markedly inhibited adenosine diphosphate (ADP)-induced platelet aggregation in the 20% FeCl3-induced arterial thrombosis model. The superoxide dismutase (SOD) activity was significantly increased and the levels of malondialdehyde (MDA) and nitric oxide (NO) were dramatically decreased in the plasma of arterial thrombosis rats after XECG treatment for 12 days. Furthermore, XECG markedly reduced the weight of thrombus formed by inferior vena cava ligation. Additionally, XECG exhibited 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and protective effect on mitochondrial lipid peroxidation. In summary, XECG played an important role in the prevention of thrombosis through interacting with multiple targets, including inhibition of platelet aggregation and coagulation and repression of oxidative stress. The ECG-guided methodology was validated as a feasible tool in TCM research.

Effects of paclitaxel loaded-drug micelles on cell proliferation and apoptosis of human lung cancer A549 cells / 药学学报

This study was conducted to investigate the paclitaxel loaded by hydrazone bonds in poly(ethylene glycol)-poly(caprolactone) micelles (mPEG-PCL-PTX) on proliferation and apoptosis of human lung cancer A549 cells and its possible mechanisms of anti-tumor activity. The cell proliferation was measured with MTT assay. Flow cytometry were used to analyze the cell cycle. The cell apoptosis was analyzed using Hoechst/P staining. The expression levels of apoptotic genes expression in the mitochondrial apoptosis pathway were detected by RT-PCR and Western blotting, respectively. The mPEG-PCL-PTX could inhibit the proliferation of A549 cells and promote the apoptosis. The Bax, caspase-3 protein expression were increased while Bcl-2 protein expression was decreased in A549 cells. Results showed that the polymer containing hydrazone bond is non-toxic in vitro, the mPEG-PCL-PTX micelles can inhibit the proliferation and induce the apoptosis of A549 cells. Key words: paclitaxel; micelle; A549 cell; proliferation; cell cycle; apoptosis

Effects of Aptamer-siRNA Nucleic Acid Compound on Growth and Apoptosis in Myeloid Leukemia Cell Line K562 / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the effects of aptamer-siRNA nucleic acid compound on growth and apoptosis in myeloid leukemia cell line K562.</p><p><b>METHODS</b>the changes of cellular morphology and structure were observed by using fluorescence microscope, laser confocal microscope, JEM-4000EX transmission electron microscopy; MTT assay were performed to evaluate the sensibility of K562 cells to aptamer-siRNA compound, the apoptosis was detected by DNA gel electro-phoresis.</p><p><b>RESULTS</b>The remarkably changes of morphology and structure of K562 cells treated with 200 µmol/L aptamer-siRNA were observed under fluorescence microscopy and electromicroscopy. As compared with control, the aptamer-siRNA compound showed more inhibitory effect on K562 cells and there was significant difference (P<0.05). The MTT assay showed that the IC50 value of aptamer-siRNA compound for K562 cells was 150 µmol/L. According to agarose gel electrophoresis observation, when the aptamer-siRNA compound showed effect on K562 cells, the typical DNA lader could be observed.</p><p><b>CONCLUSION</b>The aptamer-siRNA compound can significantly induce K562 cell apoptosis, and provide reference for gene therapy of patients with chronic myelocytic lenkemia.</p>

Effects of salidroside on cell proliferation and apoptosis of human hepatocellular carcinoma HepG2 cells / 中国药学杂志

OBJECTIVE: To investigate the salidroside on proliferation and apoptosis of human hepatocellular carcinoma HepG2 cells and its possible mechanisms of anti-tumor. METHODS: Cultured HepG2 cells in vitro were used as the research object and their cell morphology were observed by inverted microscope. The inhibitory rate of cell proliferation was measured by MTS assay. The cell apoptosis was determined by flow cytometry. The protein expressions of Bcl-2, Bax, caspase-3 and caspase-8 were detected by Western blot analysis. RESULTS: Salidroside could inhibit the proliferation of HepG2 cells and promote its apoptosis. The Bax, caspase-3 and caspase-8 protein expression were increased while Bcl-2 protein expression was decreased in HepG2 cells in a concentration-dependent manner. CONCLUSION: Salidroside can inhibit the proliferation and induce the apoptosis of HepG2 cells, and the mechanism may be associated with regulating protein expression of Bcl-2, Bax, caspase-3 and caspase-8.

Neuroprotective effects of the effective components group of xiaoshuantongluo against oxygen-glucose deprivation in primary cultured rat cortical neurons / 药学学报

This study is to investigate the effect of the effective components group of Xiaoshuantongluo (XECG) on neuronal injury induced by oxygen-glucose deprivation (OGD) in primary cortical cultures isolated from SD rat cortex at day 3 and the possible mechanism. Cells were divided into control group, OGD model group and XECG group (1, 3 and 10 mg x L(-1)). The cell viability was assessed with MTT assay and the LDH release rate was measured by enzyme label kit. The cell apoptosis was analyzed using Hoechst staining. RT-PCR was applied to detect the mRNA levels of JAK2 and STAT3. Western blotting was used to detect the expressions of Bcl-2, Bax, p-JAK2 and p-STAT3 proteins. Results showed that XECG resulted in an obvious resistance to oxygen-glucose deprivation-induced cell apoptosis and decrement of cell viability, decrease the cell LDH release rate. XECG could adjust the expression of Bcl-2 and Bax proteins and increase Bcl-2/Bax ratio, up-regulate the expression of p-JAK2 and p-STAT3. In conclusion, XECG could protect against the neuronal injury cells exposed to OGD, which may be relevant to the promotion of JAK2/STAT3 signaling pathway, and impact the expression of Bax and Bcl-2.

Protective effect of mailuoning injection on cerebral ischemia/reperfusion injury in rats and its mechanism / 中国中药杂志

<p><b>OBJECTIVE</b>To discuss the protective effect of Mailuoning injection on ischemia/reperfusion (I/R) injury in rats and its mechanism.</p><p><b>METHOD</b>Healthy male adult Sprague-Dawley (SD) rats were randomly divided into the sham operation group, the model group, the edaravone (3 mg x kg(-1)) control group, and Mailuoning high, middle and low-dose groups (4, 2, 1 mL x kg(-1)), with 10 rats in each group, and administered with drugs through tail intravenous injection. The middle cerebral artery occlusion (MCAO) was adopted to establish the rat ischemia/reperfusion model. After the ischemia for 2 h and reperfusion for 24 h, the pathological changes in neurovascular units (NVU) of brain tissues at the ischemia side was observed by HE staining. The expressions of glialfibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule 1 (Ibal) were detected by the immunohistochemical method. The expressions of tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta), vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) were detected by the western blotting technique.</p><p><b>RESULT</b>Mailuoning injection could significantly improve the pathological changes in cortical penumbra brain tissue UVN of (I/R) rats, reduce the number of GFAP and Ibal positive cells, and significantly decrease the expressions of TNF-alpha, IL-1beta, VCAM-1 and ICAM-1 of brain tissues of I/R rats.</p><p><b>CONCLUSION</b>Mailuoning injection shows an obvious protective effect on UVN of I/R rats. Its mechanism may involve the inhibition of the activation of astrocyte and microglia and the secretion and expression of various inflammatory factors.</p>

Pinocembrin protects rats against cerebral ischemic damage through soluble epoxide hydrolase and epoxyeicosatrienoic acids / 中国天然药物

AIM@#To investigate the relationship between cerebroprotection of pinocembrin and epoxyeicosatrienoic acids (EETs) and their regulating enzyme soluble epoxide hydrolase (sEH).@*METHODS@#Rats underwent middle cerebral artery occlusion (MCAO) to mimic permanent focal ischemia, and pinocembrin was administrated via tail vein injection at 10 min, 4 h, 8 h and 23 h after MCAO. After 24 MCAO, rats were re-anesthetized, and the blood and brain were harvested and analyzed.@*RESULTS@#Pinocembrin displayed significant protective effects on MCAO rats indicated by reduced neurological deficits and infarct volume. Importantly, co-administration of 0.2 mg·kg(-1) 14, 15-EEZE, a putative selective EET antagonist, weakened the beneficial effects of pinocembrin. 14, 15-EET levels in the blood and brain of rats after 24 h MCAO were elevated in the presence of pinocembrin. In an assay for hydrolase activity, pinocembrin significantly lowered brain sEH activity of MCAO rats and inhibited recombinant human sEH activity in a concentration-dependent manner (IC50, 2.58 μmol·L(-1)). In addition, Western blot and immunohistochemistry analysis showed that pinocembrin at doses of 10 mg·kg(-1) and 30 mg·kg(-1) significantly down-regulated sEH protein in rat brain, especially the hippocampus CA1 region of MCAO rats.@*CONCLUSION@#Inhibiting sEH and then increasing the potency of EETs may be one of the mechanisms through which pinocembrin provides cerebral protection.

High-throughput screening for hamster chymase 2 inhibitors / 药学学报

To screen potential hamster chymase 2 inhibitors, a high-throughput screening (HTS) model was established. Recombinant hamster chymase 2 with active form was cloned and expressed in E. coli. The HTS model with total volume of 50 microL in 384-well microplate was based on fluorescence analysis and was proved sensitive as well as specific (Z' = 0.84). A total of 40 080 samples (including 28 060 compounds and 12 020 natural products) were screened, and 613 samples with inhibition greater than 90% were selected for further rescreening. Finally, compounds J16647 and J16648 were identified with high inhibitory activity on chymase 2, and whose IC50 values were 0.823 and 0.690 micromol x L(-1), respectively.

High-throughput screening of human soluble protein tyrosine phosphatase 1B inhibitors / 药学学报

To screen potential human soluble protein tyrosine phosphatase 1B (PTP1B) inhibitors, a high-throughput screening (HTS) model in 384-well microplate with total volume of 50 microL was established. Recombinant PTP1B was cloned and expressed in E. coli. with its specific substrate 4-nitrophenyl phosphate disodium salt hexahydrate (PNPP). The HTS model was based on enzyme reaction rate with enhanced sensitivity and specificity (Z' = 0.78). A total of 24,240 samples were screened, among them 80 samples with inhibition greater than 70% were selected for further rescreening. Finally, six compounds with high inhibitory activity were identified, whose IC50 values were 21.58, 18.39, 15.37, 11.92, 37.27, and 36.61 microg x mL(-1), separately. The results indicated that the method was stable, sensitive, reproducible and also suitable for high-throughput screening.