Discovery of highly potent tubulin polymerization inhibitors: Design, synthesis, and structure-activity relationships of novel 2,7-diaryl-[1,2,4]triazolo[1,5-a]pyrimidines.

By removing 5-methyl and 6-acetyl groups in our previously reported compound 3, we designed a series of novel 2,7-diaryl-[1,2,4]triazolo[1,5-a]pyrimidine derivatives as potential tubulin polymerization inhibitors. Among them, compound 5e displayed low nanomolar antiproliferative efficacy on HeLa cells which was 166-fold higher than the lead analogue 3. Interestingly, 5e displayed significant selectivity in inhibiting cancer cells over HEK-293 (normal human embryonic kidney cells). In addition, 5e dose-dependently arrested HeLa in G2/M phase through the alterations of the expression levels of p-cdc2 and cyclin B1, and caused HeLa cells apoptosis by regulation of expressions of cleaved PARP. Further evidence demonstrated that 5e effectively inhibited tubulin polymerization and was 3-fold more powerful than positive control CA-4. Moreover, molecular docking analysis indicated that 5e overlapped well with CA-4 in the colchicine-binding site. These studies demonstrated that 2,7-diaryl-[1,2,4]triazolo[1,5-a]pyrimidine skeleton might be used as the leading unit to develop novel tubulin polymerization inhibitors as potential anticancer agents.

Synthesis and biological evaluation of benzofuran-based 3,4,5-trimethoxybenzamide derivatives as novel tubulin polymerization inhibitors.

A new series of derivatives characterized by the presence of the 3,4,5-trimethoxylbenzamide substituted benzofurans were synthesized and evaluated for antiproliferative activity against four cancer cell lines and one normal human cell line. Among them, derivative 6g with greatest cytotoxicity significantly inhibited the growth of MDA-MB-231, HCT-116, HT-29 and HeLa cell lines with IC50 values of 3.01, 5.20, 9.13, and 11.09 µM, respectively. Importantly, 6g possessed excellent selectivity over non-tumoral cell lines HEK-293 (IC50 > 30 µM). Moreover, mechanistic studies revealed that 6g induced HeLa cells arrested in G2/M phase in a concentration-dependent manner, and inhibited polymerization of tubulin via a consistent way with CA-4. In general, these observations suggest that 6g is a promising anti-cancer lead and is worth further investigation to generate potential antitumor agents.

Discovery and optimization of 3,4,5-trimethoxyphenyl substituted triazolylthioacetamides as potent tubulin polymerization inhibitors.

Based on our previous research, three series of new triazolylthioacetamides possessing 3,4,5-trimethoxyphenyl moiety were synthesized, and evaluated for antiproliferative activities and inhibition of tubulin polymerization. The most promising compounds 8b and 8j demonstrated more significant antiproliferative activities against MCF-7, HeLa, and HT-29 cell lines than our lead compound 6. Moreover, analogues 8f, 8j, and 8o manifested more potent antiproliferative activities against HeLa cell line with IC50 values of 0.04, 0.05 and 0.16 µM, respectively, representing 100-, 82-, and 25-fold improvements of the activity compared to compound 6. Furthermore, the representative compound, 8j, was found to induce significant cell cycle arrest at the G2/M phase in HeLa cell lines via a concentration-dependent manner. Meanwhile, compound 8b exhibited the most potent tubulin polymerization inhibitory activity with an IC50 value of 5.9 µM, which was almost as active as that of CA-4 (IC50 = 4.2 µM). Additionally, molecular docking analysis suggested that 8b formed stable interactions in the colchicine-binding site of tubulin.

1,3,4-tri-O-galloyl-6-O-caffeoyl-ß-D-glucopyranose, a new anti-proliferative ellagitannin, regulates the expression of microRNAs in HepG(2) cancer cells.

OBJECTIVE: MicroRNAs (miRNAs) play important roles in cell proliferation, differentiation and apoptosis. 1, 3, 4-tri-O-galloyl-6-O-caffeoyl-ß-D-glucopyranose (BJA32515) is a new natural ellagitannin compound extracted from Balanophora Japonica MAKINO. The effect of BJA32515 on the expression of miRNAs in cancer cells has not yet been explored. Objective The present study was carried out to examine the changes in miRNA expression profiles in human HepG(2) hepatocarcinoma cells following BJA32515 exposure. METHODS: The proliferation of BJA32515-exposed HepG(2) cells was assessed using a colorimetric assay (cell counting kit-8). The miRNA expression profile of the cancer cells was analyzed using a miRNA array and quantitative real-time PCR. Apoptosis was assessed by annexin V and propidium iodide staining. RESULTS: BJA32515 inhibited the cell proliferation and increased apoptosis in HepG(2) cancer cells. The exposure to BJA32515 also caused alterations in the miRNA expression profile in the cells, with 33 miRNAs upregulated and 59 down-regulated. The up-regulation of let-7a and miR-29a and the down-regulation of miR-373 and miR-197 were verified by quantitative real-time PCR. CONCLSION: BJA32515-modifed miRNA expression may mediate the antiproliferative effect of this compound in HepG(2) cancer cells.

Geniposide inhibits high glucose-induced cell adhesion through the NF-kappaB signaling pathway in human umbilical vein endothelial cells.

AIM: To investigate whether geniposide, an iridoid glucoside extracted from gardenia jasminoides ellis fruits, inhibits cell adhesion to human umbilical vein endothelial cells (HUVECs) induced by high glucose and its underlying mechanisms. METHODS: HUVECs were isolated from human umbilical cords and cultured. The adhesion of monocytes to HUVECs was determined using fluorescence-labeled monocytes. The mRNA and protein levels of vascular cell adhesion molecule-1 (VCAM-1) and endothelial selectin (E-selectin) were measured using real-time RT-PCR and ELISA. Reactive oxygen species (ROS) production was measured using a fluorescent probe. The amounts of nuclear factor-kappa B (NF-kappaB) and inhibitory factor of NF-kappaB (IkappaB) were determined using Western blot analysis. The translocation of NF-kappaB from the cytoplasm to the nucleus was determined using immunofluorescence. RESULTS: Geniposide (10-20 mumol/L) inhibited high glucose (33 mmol/L)-induced adhesion of monocytes to HUVECs in a dose-dependent manner. This compound (5-40 mumol/L) also inhibited high glucose-induced expression of VCAM-1 and E-selectin at the gene and protein levels. Furthermore, geniposide (5-20 micromol/L) decreased ROS production and prevented IkappaB degradation in the cytoplasm and NF-kappaB translocation from the cytoplasm to the nucleus in HUVECs. CONCLUSION: Geniposide inhibits the adhesion of monocytes to HUVECs and the expression of CAMs induced by high glucose, suggesting that the compound may represent a new treatment for diabetic vascular injury. The mechanism underlying this inhibitory effect may be related to the inhibition of ROS overproduction and NF-kappaB signaling pathway activation by geniposide.

[Bioequivalence evaluation of orally disintegrating tablet of pentoxyverine citrate].

OBJECTIVE: To evaluate the bioequivalence of orally disintegrating tablets of pentoxyverine citrate (tested preparation) in healthy male volunteers. METHODS: A single oral dose of the tested and reference preparations at 25 mg were given to 20 healthy volunteers in a randomized two-period cross-over design. Plasma pentoxyverine citrate concentrations were determined by HPLC-MS/ESI+ method. The pharmacokinetic parameters were calculated and the bioequivalence of the two preparations were evaluated using DAS program. RESULTS: The Tmax, Cmax, AUC0 15 and AUC0infinity of tested and reference preparations were 1.62-/+0.75 h and 2.52-/+1.21 h, 62.28-/+33.06 microg/L and 59.72-/+33.25 microg/L, 234.44-/+130.01 microg.h.L(-1) and 228.77-/+129.24 microg.h.L(-1), 246.80-/+136.19 microg.h.L(-1) and 244.11-/+140.73 microg.h.L(-1), respectively. The 90% confidence interval of C(max), AUC0 15 and AUC0infinity of tested preparations were 81.4%-138.4%, 86.0%-123.3% and 86.5%-121.2%, respectively. CONCLUSION: The tested and reference preparations are bioequivalent.

[Cough-relieving, analgesic and antibiotic effects of durian shell extracts: a study in mice].

OBJECTIVE: To investigate the cough-relieving, analgesic and antibiotic effects of durian shell extract (DSE) in relieving cough and its analgesic and antibiotic effects. METHODS: The effect of DSE in relieving cough was assessed in mice challenged with ammonia and SO(2) to induce coughing. The analgesic and antibiotic effects of DSE in mice were evaluated by hot plate test and twisting reaction induced by acetic acid, and by minimal inhibitory concentration (MIC) and disc-agar diffusion tests, respectively. RESULTS: Compared with the control group, the mice treated with 300 and 900 mg/kg DSE showed significantly prolonged latency with decreased number of coughing induced by ammonia and SO(2), and the effect was dose-dependent. DSE markedly prolonged the latency and decreased the twisting number of the mice induced by acetic acid without affecting the pain threshold in hot plate test. DSE produced no significant inhibitory effects against Staphylococcus aureus, Staphylococcus epidermidis, or E. coli, and showed a week inhibition against Bacillus aeruginosus. CONCLUSION: DSE shows obvious effect in relieving cough and produces better analgesic effect against chemical factor-induced pain than against physical agent-induced pain sensation. DSE has a moderate inhibitory effect against Bacillus aeruginosus.

[Naringin inhibits monocyte adhesion to high glucose-induced human umbilical vein endothelial cells].

OBJECTIVE: To investigate the inhibitory effect of naringin on monocyte adhesion to high glucose-induced human umbilical vein endothelial cells (HUVECs). METHODS: Cultured HUVECs isolated from human umbilical cords were pretreated with or without naringin and induced with high glucose (33 mmol/L) for 48 h. Human monocyte THP-1 cells, after labeling with BCECF-AM, were co-cultured with the HUVECs for 30 min. The labeled THP-1 cells adhering to HUVECs were observed under fluoroscence microscope, and the inhibitory effect of naringin on the cell adhesion was evaluated by measuring the adhering cell density. Western blot analysis was used to detect the expressions of the adhesion molecules in the HUVECs, and reactive oxygen species (ROS) production in the HUVECs was measured using an oxidation-sensitive fluorescent probe (DCFH-DA). The nuclear extracts of the HUVECs were prepared to examine the expression of nuclear factor-kappa B (NF-kappaB) in the cell nuclei by Western blotting. RESULTS: HUVECs in high-glucose culture showed increased adhesion to THP-1 cells and enhanced expressions of the cell adhesion molecules, which were significantly attenuated by pretreatment with naringin (10-50 microg/ml). High glucose induced DCF-sensitive intracellular ROS production in the HUVECs, and this effect was inhibited by naringin pretreatment of the cells. Naringin also suppressed high glucose-induced increment of NF-kappaB expression in the cell nuclei of HUVECs. CONCLUSION: Naringin can suppress high glucose-induced vascular inflammation possibly by inhibiting ROS production and NF-kappaB activation in HUVECs.

Effect of astragaloside IV on hepatic glucose-regulating enzymes in diabetic mice induced by a high-fat diet and streptozotocin.

AIM: Hepatic glycogen phosphorylase (GP) and glucose-6-phosphatase (G6Pase) are important in control of blood glucose homeostasis, and are considered to be potential targets for antidiabetic drugs. Astragaloside IV has been reported to have a hypoglycemic effect. However, the biochemical mechanisms by which astragaloside IV regulates hepatic glucose-metabolizing enzymes remain unknown. The present study examines whether GP and G6Pase mediate the hypoglycemic effect of astragaloside IV. METHODS: Type 2 diabetic mice were treated with astragaloside IV for 2 weeks. Blood glucose and insulin levels were measured by a glucometer and the ELISA method, respectively. Total cholesterol (TC) and triglyceride (TG) levels were determined using Labassay kits. Activities of hepatic GP and G6Pase were measured by the glucose-6-phosphate dehydrogenase-coupled reaction. The mRNA and protein levels of both enzymes were determined by real-time RT-PCR and Western blotting. RESULTS: Astragaloside IV at 25 and 50 mg/kg significally decreased the blood glucose, TG and insulin levels, and inhibited the mRNA and protein expression as well as enzyme activity of GP and G6Pase in diabetic mice. CONCLUSIONS: Astragaloside IV exhibited a hypoglycemic effect in diabetic mice. The hypoglycemic effect of this compound may be explained, in part, by its inhibition of hepatic GP and G6Pase activities.

Genipin inhibits endothelial exocytosis via nitric oxide in cultured human umbilical vein endothelial cells.

AIM: Exocytosis of endothelial Weibel-Palade bodies, which contain von Willebrand factor (VWF), P-selectin and other modulators, plays an important role in both inflammation and thrombosis. The present study investigates whether genipin, an aglycon of geniposide, inhibits endothelial exocytosis. METHODS: Human umbilical vein endothelial cells (HUVECs) were isolated from umbilical cords and cultured. The concentration of VWF in cell supernatants was measured using an ELISA Kit. P-selectin translocation on the cell surface was analyzed by cell surface ELISA. Cell viability was measured using a Cell Counting Kit-8. Mouse bleeding times were measured by amputating the tail tip. Western blot analysis was used to determine the amount of endothelial nitric oxide synthase (eNOS) and phospho-eNOS present. Nitric oxide (NO) was measured in the cell supernatants as nitrite using an NO Colorimetric Assay. RESULTS: Genipin inhibited thrombin-induced VWF release and P-selectin translocation in HUVECs in a dose- and time-dependent manner. The drug had no cytotoxic effect on the cells at the same doses that were able to inhibit exocytosis. The functional study that demonstrated that genipin inhibited exocytosis in vivo also showed that genipin prolonged the mouse bleeding time. Furthermore, genipin activated eNOS phosphorylation, promoted enzyme activation and increased NO production. L-NAME, an inhibitor of NOS, reversed the inhibitory effects of genipin on endothelial exocytosis. CONCLUSION: Genipin inhibits endothelial exocytosis in HUVECs. The mechanism by which this compound inhibits exocytosis may be related to its ability to stimulate eNOS activation and NO production. Our findings suggest a novel anti-inflammatory mechanism for genipin. This compound may represent a new treatment for inflammation and/or thrombosis in which excess endothelial exocytosis plays a pathophysiological role.

Effect of geniposide, a hypoglycemic glucoside, on hepatic regulating enzymes in diabetic mice induced by a high-fat diet and streptozotocin.

AIM: Hepatic glycogen phosphorylase (GP) and glucose-6-phosphatase (G6Pase) play an important role in the control of blood glucose homeostasis and are proposed to be potential targets for anti-diabetic drugs. Geniposide is an iridoid glucoside extracted from Gardenia jasminoides Ellis fruits and has been reported to have a hypoglycemic effect. However, little is known about the biochemical mechanisms by which geniposide regulates hepatic glucose-metabolizing enzymes. The present study investigates whether the hypoglycemic effect of geniposide is mediated by GP or G6Pase. METHODS: Type 2 diabetic mice, induced by a high-fat diet and streptozotocin injection, were treated with or without geniposide for 2 weeks. Blood glucose levels were monitored by a glucometer. Insulin concentrations were analyzed by the ELISA method. Total cholesterol (TC) and triglyceride (TG) levels were measured using Labassay kits. Activities of hepatic GP and G6Pase were measured by glucose-6-phosphate dehydrogenase-coupled reaction. Real-time RT-PCR and Western blotting were used to determine the mRNA and protein levels of both enzymes. RESULTS: Geniposide (200 and 400 mg/kg) significantly decreased the blood glucose, insulin and TG levels in diabetic mice in a dose-dependent manner. This compound also decreased the expression of GP and G6Pase at mRNA and immunoreactive protein levels, as well as enzyme activity. CONCLUSION: Geniposide is an effective hypoglycemic agent in diabetic mice. The hypoglycemic effect of this compound may be mediated, at least in part, by inhibiting the GP and G6Pase activities.

[Isolation and characterization of the anti-HIV active component from Eucommia ulmoides].

OBJECTIVE: To investigate the anti-HIV effects of Eucommia ulmoides Oliver, so as to provide experimental basis for searching a new efficacious drug for treatment of AIDS. METHODS: Using phytochemistry to isolate compounds from Eucommia ulmoides Oliver, the inhibitory activity of Samples on the HIV gp41 six-helix bundle formation was determined by a modified sandwich ELISA and PAGE. RESULTS: The Samples from Eucommia ulmoides Oliver had potent inhibitory activity on the HIV gp41 six-helix bundle formation. CONCLUSION: Eucommia uloides Oliver can inhibit HIV by targeting HIV gp41.

[Hydrocamptothecin promotes the mRNA expression of Wnt signaling inhibitor DKK-1].

OBJECTIVE: To investigate the effects of hydrocamptothecin on the expression of Wnt signaling pathway inhibitor DKK-1 in tumor cells. METHODS: Human HepG2, Hep3B, LoVo and U251 cells were treated with the antitumor drug Hydrocamptothecin. DKK-1 mRNA expression in the cells was detected with RT-PCR, and beta-catenin expression was measured by fluorescence-activated cell sorting (FACS). RESULTS: DKK mRNA in Hep3B, HepG2, LoVo and U251 cells was significantly increased after hydrocamptothecin treatment for 24 h, and the percentage of beta-catenin-positive cells and fluorescence intensity for beta-catenin expression was lowered in the cells after the treatment. CONCLUSION: Hydrocamptothecin promotes mRNA expression of Wnt signaling pathway inhibitor DKK-1 in Hep3B, HepG2, LoVo and U251 cells.

[Inhibitory effect of polysaccharides on the six-alpha-helix bundle formation of HIV gp41 protein].

OBJECTIVE: To compare the in vitro inhibitory effect of expolysaccharides from Streptomyces, polysaccharides of Ganoderma lucidum and rice bran on six-alpha-helix bundle formation of HIV gp41 protein. METHODS: The amount of six-alpha-helix bundle formed in the presence of N36 and C34 was tested by ELISA in response to treatments with different doses of polysaccharides. RESULTS: Expolysaccharides from Streptomyces potentially inhibited six-alpha-helix bundle formation with the effective concentration (IC(50)) of 145.48-/+7.25 mg /L. Polysaccharides of Ganoderma lucidum and rice bran showed no effect on the six-alpha-helix bundle formation. CONCLUSION: Expolysaccharides from Streptomyces can inhibit the six-alpha-helix bundle formation of HIV gp41, whereas polysaccharides of Ganoderma lucidum and rice bran do not exhibit such activity.

[Anti-oncogene p53-induced expression of secreted frizzled-related protein, a Wnt signaling inhibitor].

OBJECTIVE: To investigate the effects of anti-oncogene p53 on the expression of secreted frizzled-related protein (sFRP), a Wnt pathway inhibitor. METHODS: Human hepatocarcinoma Hep3B cells were transfected with a replication-defective adenovirus encoding p53 (Adp53), and Adp53 transgene expression was measured by fluorescence-activated cell sorting (FACS) and sFRP mRNA expression detected by reverse transcriptional (RT)-PCR. RESULTS: sFRP mRNA expression in Hep3B cells was potentiated 20 h after the transfection with Adp53, reaching the peak level at 32 h. Dose-effect studies revealed that Adp53 at the doses of 0.5, 5 and 50 pfu/cell could promote the expression of sFRP mRNA, with the highest expression occurred with the dose of 5 pfu/cell. CONCLUSION: Ectogenetic p53 promotes mRNA expression of Wnt signaling pathway inhibitor sFRP in Hep3B cells.

Effect of E1B mutant adenovirus on p53-deficient leukemic cells.

OBJECTIVE: To study the effect of E1B mutant adenovirus (dl1520) on 3 p53-deficient leukemic cell lines K562, Jurkat and HL-60. METHODS: The replication efficiency of dl1520 in the 3 leukemic cell lines was assessed by plaque assay, and the number of cells killed by the adenovirus determined by using trypan-blue in a course of 10 d following the infection. RESULTS: The replication efficiency of dl1520 in the 3 leukemic cell lines was significantly lower than that in the positive control, and no significant cytocidal effect against the 3 cell lines was observed. CONCLUSION: dl1520 can not inhibit the malignant blood cells as K562, Jurkat and HL-60 cell lines.