Virtual Screening Based on Ensemble Docking Targeting Wild-Type p53 for Anticancer Drug Discovery.

The tumor-suppressor function of p53 makes it an attractive drug target. Efforts were mostly put on stabilization of the functional p53 or reactivation of mutated p53. Previous studies have shown that small molecules targeting Loop1/Sheet3 (L1/S3) can reactivate the R175H-p53 and stabilize p53 in vitro. Since the L1/S3 pocket is shared by the mutate and the wild type (WT) p53, virtual screening is introduced to identify natural products targeting the L1/S3 of WT p53. Considering the high flexibility of Loop1, ensemble docking method is utilized for different clusters of the L1/S3. Seven conformations were chosen for docking. As one of the 181 selected candidates, torilin not only improved p53 activity, but also increased p21 protein expression level, which lies downstream of p53, therefore suppressing HCT116 cancer cell growth. Torilin may covalently bind to Cys124 of p53 by 2-methyl-2-butenal (2M2B) group, as torilin derivatives, which do not contain the 2M2B group, were not able to increase the p53 transcription activity. In conclusion, this study demonstrated that L1/S3 of WT-p53 is a druggable pocket, and torilin has a potential cytotoxicity through activating the p53 pathway.

[Application of affinity chromatography and its mathematical model in study of active components of traditional Chinese medicine].

Affinity chromatography is characterized by its high specificity,high recovery rate and sensitivity,and it has been widely used in the selection of active ingredients of traditional Chinese medicine,separation and enrichment of low molecular weight sugars and protein peptides,research on mechanism of action and discovery of targets.This paper reviewed the application of affinity chromatography and its adsorption isotherm model,kinetic model and adsorption thermodynamic mechanism in the field of traditional Chinese medicine.This summarizes and provides thinking for comprehensive applications of affinity chromatography theory in the field of active ingredient screening,purification and medicine interaction.

[Study on mechanism and structure-activity relationship of hypolipidemic polysaccharides: a review].

Hypolipidemic polysaccharides have notable activity and safety with a range of diverse sources. In this paper, the classification of hypolipidemic polysaccharides was carried out into polysaccharide sulfate, glycosaminoglycan, homopolysaccharide and heteropolysaccharide. The hypolipidemic activity mechanism and structure-activity relationship hypothesis of those polysaccharides in recent years were briefly reviewed therefore to provide references for the study and product development of polysaccharides.

Autophagic cell death induced by reactive oxygen species is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells.

AIM: To investigate whether autophagic cell death is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells, and to explore the underlying mechanism. METHODS: Human hepatocellular carcinoma cells were treated with hyperthermia and ionizing radiation. MTT and clonogenic assays were performed to determine cell survival. Cell autophagy was detected using acridine orange staining and flow cytometric analysis, and the expression of autophagy-associated proteins, LC3 and p62, was determined by Western blot analysis. Intracellular reactive oxygen species (ROS) were quantified using the fluorescent probe DCFH-DA. RESULTS: Treatment with hyperthermia and ionizing radiation significantly decreased cell viability and surviving fraction as compared with hyperthermia or ionizing radiation alone. Cell autophagy was significantly increased after ionizing radiation combined with hyperthermia treatment, as evidenced by increased formation of acidic vesicular organelles, increased expression of LC3II and decreased expression of p62. Intracellular ROS were also increased after combined treatment with hyperthermia and ionizing radiation. Pretreatment with N-acetylcysteine, an ROS scavenger, markedly inhibited the cytotoxicity and cell autophagy induced by hyperthermia and ionizing radiation. CONCLUSION: Autophagic cell death is involved in hyperthermic sensitization of cancer cells to ionizing radiation, and its induction may be due to the increased intracellular ROS.

[Progresses in screening active compounds from herbal medicine by affinity chromatography].

Affinity chromatography is a chromatographic method for separating molecules using the binding characteristics of the stationary phase with potential drug molecules. This method can be performed as a high throughput screening method and a chromatographic separation method to screen a variety of active drugs. This paper summarizes the history of affinity chromatography, screening technology of affinity chromatography, and application of affinity chromatography in screening bio-active compounds in herbal medicines, and then discusses its application prospects, in order to broaden applications of the affinity chromatography in drug screening.

[Advances in research of pharmacological effects and formulation studies of linalool].

Linalool, as a major volatile compound, is widely distributed in natural plant essential oil. In addition, it can also be artificially synthesized. Linalool is used frequently as an important ingredient of perfumes and household detergents. It is still employed in food flavor and industries. Besides, linalool has some positive effect on healthcare. Many studies have showed that linalool exhibited a variety of pharmacological activities, including analgesic, anxiolytic, sedative, anti-inflammatory, anti-tumor and anti-bacterial effects. Therefore, linalool will be a promising agent for clinical application. This article reviews the pharmacological effects and formulation studies of linalool so as to provide a theoretical basis for its further development and utilization.

[Advances in novel carrier systems of chemical constituents from spice volatile oils].

Recent years, chemical constituents from spice volatile oils have gained worldwide concern owing to its multiple pharmacological effects and safety for using as the natural antibacterial agents. However, their poor dissolution, strong volatility, serious irritation, weak stability, easy oxidation and low bioavailability characteristics are the major obstacle in the preparation of effective oral formulation and practical application. Therefore, there is an urgent need to select a novel carrier system that can delivery the chemical constituents from spice volatile oils more efficiently with improving their stability as well as alleviating the irritation, and develop the functional food, health products and even medicine for exerting their pharmacological effects, which also is the focus and nodus of the research on their application. This review presents recent systematic studies on their novel carrier systems, including cyclodextrin inclusion complex, liposomes, nanoemulsions, nanoparticles, solid dispersion and so on, and summarizes the characteristics, application range and problems of each novel carrier systems, in order to provide some beneficial thoughts in further developing new products of chemical constituents from spice volatile oils.

[Advanced in solubilization methods of water-insoluble natural drugs].

With the development of natural products, the research activities on the solubilization methods of water-insoluble natural products have been carried out worldwide. Big molecular weight and poor solubility of most natural active ingredients lead to a very poor oral absorption and low bioavailability, which has extremely limited their development in pharmaceutical fields and clinical application. As a result, it is necessary to find out a suitable technique to improve the solubility and enhance the oral bioavailability of insoluble natural drugs. Based on the related references published in these years, this review introduced some new techniques to improve the solubility and bioavailability of natural drugs, including prodrugs, inclusion complex, solid dispersion, cocrystals, osmotic pump, liquisolid compacts, micronization, self-microemulsifying, nanosuspensions, lipsomes, polymeric micelles and so on, and summarized the theory, characteristics, application range, application examples, problems and development direction of each technique.

[Research progress of in vitro and in vivo anti-tumor effects and formulation of bufalin].

Bufalin is an active compound of the traditional Chinese medicine Chansu, which exhibits significant anti-tumor activities in many solid tumors and leukemia cell lines. Bufalin could introduce apoptosis, reverse drug-resistance, and prevent migration and invasion of tumor cells. This paper reviewed the latest research progress of the in vitro and in vivo anti-tumor effect and mechanism of bufalin on a series of cancers, such as hepatocellular carcinoma, lung cancer, colon cancer, gastric cancer, leukemia, bladder cancer, and its formulation study is also summarized for the reference of its further study and application.

[Advances in research of chemical constituents and pharmacological activities of common used spices].

Spices have enjoyed a long history and a worldwide application. Of particular interest is the pharmaceutical value of spices in addition to its basic seasoning function in cooking. Concretely, equipped with complex chemical compositions, spices are of significant importance in pharmacologic actions, like antioxidant, antibacterial, antitumor, as well as therapeutical effects in gastrointestinal disorders and cardiovascular disease. Although increasing evidences in support of its distinct role in the medical field has recently reported, little information is available for substantive, thorough and sophisticated researches on its chemical constituents and pharmacological activities, especially mechanism of these actions. Therefore, in popular wave of studies directed at a single spice, this review presents systematic studies on the chemical constituents and pharmacological activities associated with common used spices, together with current typical individual studies on functional mechanism, in order to pave the way for the exploitation and development of new medicines derived from the chemical compounds of spice (such as, piperine, curcumin, geniposide, cinnamaldehyde, cinnamic acid, linalool, estragole, perillaldehyde, syringic acid, crocin).

Triggering effect of N-acetylglucosamine on retarded drug release from a lectin-anchored chitosan nanoparticles-in-microparticles system.

The aim of this study was to investigate the use of N-acetylglucosamine (NAG) to accelerate drug release from a lectin-modified carrier. A wheat germ agglutinin (WGA)-anchored salmeterol xinafoate (SalX)-loaded nanoparticles-in-microparticles system (NiMS) was prepared with an ionotropic gelation technique combined with a spray drying method. The formulated microparticles were spherical, with diameters ranging mainly from 2 to 8 µm; the drug entrapment efficiency was >70% (w/w), and the loading capacity was approximately 8% (w/w). Drug release from WGA-SalX-NiMS, within the first 4h, was approximately 30% less than that from SalX-NiMS, indicating an effect of lectin-modification to retard drug release from the NiMS. Due to "sugar-lectin" interactions, drug release from WGA-SalX-NiMS was substantially increased after the addition of NAG to the release medium. However, no significant influence of NAG was observed on the drug release profile of SalX-NiMS without WGA anchorage. The characteristics of NAG-WGA interaction may provide valuable insights into the "triggering-effects" of specific sugars on drug release from lectin-anchored carriers. These results suggest that it is possible to control drug release from a lectin-anchored drug delivery system using a specific sugar, and that the designed novel WGA-SalX-NiMS may be a suitable formulation for chronotherapy of asthma.

[Advance in studies on anti-tumor mechanism of matrine].

Matrine is one of the main active components extracted from Sophora flavescens, S. subprostrata and S. alopecuroides. In recent years, its anti-tumor activity has attracted wide attention. According to studies, matrine shows the anti-tumor effect through multiple channels such as inducing apoptosis and autophagy of cancer cells, arresting cell cycle, inhibiting tumor cell migration, angiogenesis and NF-kappaB, as well as the synergistic effect with chemotherapeutics. Along with the further studies on matrine's anti-tumor mechanism, it has a broad prospect for development and application in tumor clinical treatment.

Hyperthermia inhibits hypoxia-induced epithelial-mesenchymal transition in HepG2 hepatocellular carcinoma cells.

AIM: To investigate the effect of hyperthermia on hypoxia-induced epithelial-mesenchymal transition (EMT) in HepG2 hepatocellular carcinoma (HCC) cells, and its mechanism. METHODS: Cells were treated with hyperthermia at 43 °C for 0.5 h, followed by incubation under hypoxic or normoxic conditions for 72 h. Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by immunofluorescence assay or Western blot. The protein and mRNA expressions of Snail were also determined by Western blot and reverse transcription-polymerase chain reaction. Cell migratory capacity was evaluated. RESULTS: Hypoxia induced EMT in HepG2 cells, which was evidenced by morphological, molecular and functional changes, including the formation of a spindle shape and the loss of cell contact. The expression of E-cadherin was decreased but the expression of vimentin was increased; also, the migratory capability was increased by 2.2 ± 0.20-fold as compared with normoxia. However, those effects were inhibited by hyperthermia pretreatment. Furthermore, protein synthesis and mRNA expression of Snail in the cells were enhanced by hypoxia as compared with normoxia, and also significantly inhibited by hyperthermia pretreatment. CONCLUSION: Hyperthermia may inhibit hypoxia-induced EMT in HepG2 HCC cells, and the mechanism may involve inhibition of induced expression of Snail.

Hyperthermia inhibits transforming growth factor beta-induced epithelial-mesenchymal transition (EMT) in HepG2 hepatocellular carcinoma cells.

BACKGROUND/AIMS: EMT plays an essential role in tumor progression and metastasis. Hyperthermia is a potent approach for cancers with low side effects. However, the effect of hyperthermia on EMT of cancer cells is unknown. METHODOLOGY: Cells were treated with TGF-ß1 and epidermal growth factor for 96 h and then exposed to hyperthermia at 43°C for 0.5 h. Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by Western blot. The protein and mRNA expressions of Snail were detected with Western blot and RT-PCR. Cell migratory capacity was evaluated. RESULTS: TGF-ß1 induced EMT in HepG2 cells, which was evidenced by morphological, molecular and functional changes, including the formation of spindle shape and the loss of cell contact. The expression of E-cadherin was decreased but the expression of vimentin increased; also, the migratory capability was increased by 2.1±0.19-fold as compared with untreated cells. However, those effects were inhibited by the treatment of hyperthermia. Furthermore, the protein and mRNA expressions of Snail induced by TGF-ß1 were also significantly inhibited by hyperthermia treatment CONCLUSIONS: Hyperthermia can inhibit TGF-ß1-induced EMT in HepG2 cells, suggesting that hyperthermia may alter the properties of metastatic potential in cancer cells and inhibit tumor metastasis.

[Advance in hepatic protective formulations of traditional Chinese medicine and their quality control methods].

As many traditional Chinese medicines have been founded to have protective effect on liver damage in recent years, they have also got involved in increasingly wide clinical application. Meanwhile, with the development of new hepatic protective formulations of traditional Chinese medicines, we have set increasingly higher requirements for quality control methods and measures. This essay summarizes the advance in studies on hepatic protective formulations of traditional Chinese medicine and their quality control methods in the combination of relevant domestic and foreign literatures, looking into the future of the development of new hepatic protective formulations of traditional Chinese medicines.

Formulation and pharmacokinetic evaluation of tetracycline-loaded solid lipid nanoparticles for subcutaneous injection in mice.

The aim of this work was to prepare tetracycline-loaded solid lipid nanoparticles (Tet-SLN), and to evaluate the potential of these colloidal carriers for subcutaneous injection. Tet-SLN was prepared by microemulsion method and the preparation conditions were optimized by ternary phase diagram. At optimized process conditions, lyophilized Tet-SLN showed spherical particles with a mean diameter of 87.2±46.9 nm and a negative zeta potential of -6.69 mV, up to 1.7% tetracycline drug content was achieved after loading. In vitro release test showed a biphasic release profile for Tet-SLN and more than 80% of the drug was liberated from Tet-SLN in 48 h. After subcutaneous injection of Tet-SLN to mice, a considerable sustained release was observed; tetracycline in blood could be detected lasting 36 h, and lower concentrations of tetracycline in all tissues tested compared to the free tetracycline solution were observed. In conclusion, Tet-SLN can be prepared well by microemulsion method and subcutaneous injection of SLN provide a new perspective for drug sustained release.

[Carbon sequestration of young Robinia pseudoacacia plantation in Loess Plateau].

In order to understand the carbon sequestration of ecological forests in Loess Plateau, a comparative study was made on the organic carbon density (OCD) of soil, litter, and plant organs in an 8-year-old Robinia pseudoacacia plantation and nearby barren land. Comparing with the barren land, the young R. pseudoacacia plantation had a decrease (0.26 kg x m(-2)) of soil OCD, but the OCD in its litter, root system, and aboveground organs increased by 121.1%, 202.0%, and 656. 7%, respectively, with a total carbon sequestration increased by 3.3% annually, which illustrated that R. pseudoacacia afforestation on Loess Plateau had an obvious positive effect on carbon sequestration.

[Nanoscale drug carriers for traditional Chinese medicine research and development].

Nanocarriers generally made of natural or artificial polymers ranging in size from about 10-1 000 nm, possess versatile properties suitable for drug delivery, including good biocompatibility and biodegradability, potential capability of targeted delivery and controlled release of incorporated drugs, and have been extensively used in the development of new drug delivery systems (DDS). These types of nano-DDS have considerable potential to traditional Chinese medicine (TCM), and recently have attracted increasing efforts on the TCM research and development. In this review, the recently published literature worldwide is covered to describe the latest advances in the applications as TCM delivery carriers, and to highlight the characteristics and preparation methods of some selected examples of promising nanocarriers such as nanoparticles, lipid nanoparticles, nanoemulsions, nanomicelles and nanoliposomes.

Melatonin reduces inflammatory injury through inhibiting NF-kappaB activation in rats with colitis.

Proinflammatory mediators are important in the pathogenesis of IBD, which are regulated by activation of NF-kappaB. The aim of this study was to investigate whether melatonin reduces inflammatory injury and inhibits proinflammatory molecule and NF-kappaB in rats with colitis. Rat colitis model was established by TNBS enema. NF-kappaB p65, TNF-alpha, ICAM-1, and IkappaBalpha in colon tissue were examined by immunohistochemistry, EMSA, RT-PCR, and Western blot analysis. Expression of proinflammatory molecule and activation of NF-kappaB were upregulated and IkappaB level decreased in rats with colitis. Melatonin reduces colonic inflammatory injury through downregulating proinflammatory molecule mediated by NF-kappaB inhibition and blockade of IkappaBalpha degradation.

Effects of garlicin on apoptosis in rat model of colitis.

AIM: To investigate the effects of garlicin on apoptosis and expression of bcl-2 and bax in lymphocytes in rat model of ulcerative colitis (UC). METHODS: Healthy adult Sprague-Dawley rats of both sexes, weighing 180+/-30 g, were employed in the present study. The rat model of UC was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) enema. The experimental animals were randomly divided into garlicin treatment group (including high and low concentration), model control group, and normal control group. Rats in garlicin treatment group and model control group received intracolic garlicin daily at doses of 10.0 and 30.0 mg/kg and equal amount of saline respectively 24 h after colitis model was induced by alcohol and TNBS co-enema. Rats in normal control group received neither alcohol nor only TNBS but only saline enema in this study. On the 28th d of the experiment, rats were executed, the expression of bcl-2 and bax protein was determined immunohistochemically and the apoptotic cells were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate fluorescence nick end labeling (TUNEL) method. At the same time, the rat colon mucosal damage index (CMDI) was calculated. RESULTS: In garlicin treatment group, the positive expression of bcl-2 in lymphocytes decreased and the number of apoptotic cells was more than that in model control group, CMDI was lower than that in model control group. The positive expression of bax in lymphocytes had no significant difference. CONCLUSION: Garlicin can protect colonic mucosa against damage in rat model of UC induced by TNBS enema.