TW-01, a piperazinedione-derived compound, inhibits Ras-mediated cell proliferation and angioplasty-induced vascular restenosis.

PURPOSE: Vascular smooth muscle cell (VSMC) proliferation plays a critical role in the pathogenesis of atherosclerosis and restenosis. This study investigated piperazinedione derived compound TW-01-mediated inhibitory effects on VSMC proliferation and intimal hyperplasia. METHODS: Cell proliferation was determined using [(3)H]-thymidine incorporation and MTT assay; cell cycle distribution was measured using flow cytometry; proteins and mRNA expression were determined using western blotting and RT-PCR analyses; DNA binding activity of nuclear factor-κB (NF-κB), as measured using enzyme-linked immunosorbent assays (ELISA); in vivo effects of TW-01 were determined using balloon angioplasty in the rat. RESULTS: TW-01 significantly inhibited cell proliferation. At the concentrations used, no cytotoxic effects were observed. Three predominant signaling pathways were inhibited by TW-01: (a) extracellular signal-regulated kinase (ERK)1/2 mitogen-activated protein kinase (MAPK) activation and its downstream effectors of c-fos, c-jun, and c-myc; (b) DNA binding activity of nuclear factor-κB (NF-κB); and, (c) Akt/protein kinase B (PKB) and cell cycle progression. Furthermore, TW-01 also inhibited Ras activation, a shared upstream event of each of these signaling cascades. In vascular injury studies, oral administration of TW-01 significantly suppressed intimal hyperplasia induced by balloon angioplasty. CONCLUSION: The present study suggests that TW-01 might be a potential candidate for atherosclerosis treatment.

The Roles of 4ß-Hydroxywithanolide E from Physalis peruviana on the Nrf2-Anti-Oxidant System and the Cell Cycle in Breast Cancer Cells.

4[Formula: see text]-Hydroxywithanolide E is an active component of the extract of Physalis peruviana that has been reported to exhibit antitumor effects. Although the involvement of reactive oxygen species (ROS) production and the ataxia-telangiectasia mutated protein (ATM)-dependent DNA damage signaling pathway in 4[Formula: see text]-hydroxywithanolide E-induced apoptosis of breast cancer MCF-7 cells was demonstrated in our previous study, the relationship between ROS production and the cellular defense system response in 4[Formula: see text]-hydroxywithanolide E-induced cell death requires further verification. The present study suggests that ROS play an important role in 4[Formula: see text]-hydroxywithanolide E-induced MCF-7 cell death in which anti-oxidants, such as glutathione or N-acetylcysteine, can resist the 4[Formula: see text]-hydroxywithanolide E-induced accumulation of ROS and cell death. Furthermore, N-acetylcysteine or glutathione can reverse the 4[Formula: see text]-hydroxywithanolide E-induced changes in the cell cycle distribution and the expression of cell cycle regulators. We found that the 4[Formula: see text]-hydroxywithanolide E-induced ROS accumulation was correlated with the upregulation of Nrf2 and Nrf2-downstream genes, such as antioxidative defense enzymes. In general, the activity of Nrf2 is regulated by the Ras signalling pathway. However, we demonstrated that Nrf2 was activated during 4[Formula: see text]-hydroxywithanolide E-induced MCF-7 cell death in spite of the 4[Formula: see text]-hydroxywithanolide E-induced inhibition of the Ras/Raf/ERK pathway. The activity and protein expression of superoxide dismutase and catalase were involved in the 4[Formula: see text]-hydroxywithanolide E-induced ROS production in MCF-7 cells. Furthermore, 4[Formula: see text]-hydroxywithanolide E was demonstrated to significantly reduce the sizes of the tumor nodules in the human breast cancer MDA-MB231 xenograft tumor model.

ATR-Chk1 signaling inhibition as a therapeutic strategy to enhance cisplatin chemosensitivity in urothelial bladder cancer.

DNA damage responses contribute to cisplatin resistance; however, therapeutic strategies to overcome cisplatin resistance have not yet been established. Here, we demonstrate that inhibition of ATR-Chk1 pathway with the potent inhibitor WYC0209 sensitizes bladder cancer cells to cisplatin. In the clinical microarray profile, high ATR expression is associated with poor prognosis in bladder cancer patients who receive chemotherapy. We show that pharmacological and genetic suppressing of ATR sensitized cells to cisplatin. Treatment with WYC0209 or siATR increased levels of cisplatin-DNA adducts, concomitant with decreased levels of p-glycoprotein expression. Additionally, Combinations of cisplatin and WYC0209 show synergistic activity against bladder cancer. Ultimately, WYC0209 enhanced the anti-tumor effects of cisplatin and suppressed p-glycoprotein expression in bladder cancer xenografts. These results indicate that inhibiting ATR-Chk1 activation with WYC0209 suppresses p-glycoprotein expression and increases cisplatin activity in bladder cancer. Our findings collectively suggest that ATR-Chk1 is a target for improving the efficacy of cisplatin in bladder cancer.

Anti-inflammatory and cytotoxic compounds from Solanum macaonense.

One new cerebroside, macaocerebroside A (1), and 15 known compounds (2-16) were isolated from Solanum macaonense for the first time. In an antineutrophilic inflammatory assay, four caffeic acid derivatives (2-5) were active against superoxide anion generation with IC50 values of 3.3-4.8 µM; especially, 3 inhibited elastase release with an IC50 value of 4.0 µM. Additionally, kaempferol (8) also showed inhibition against elastase release with an IC50 value of 4.0 µM. In a cytotoxic assay, rutin (14) had selective moderate cytotoxicity toward human lung (A549), bladder (NTUB1), and prostate (DU145) cancer cell lines with IC50 values of 34.6, 41.3, and 31.8 µM, respectively.

Novel oral histone deacetylase inhibitor, MPT0E028, displays potent growth-inhibitory activity against human B-cell lymphoma in vitro and in vivo.

Histone deacetylase (HDAC) inhibitor has been a promising therapeutic option in cancer therapy due to its ability to induce growth arrest, differentiation, and apoptosis. In this study, we demonstrated that MPT0E028, a novel HDAC inhibitor, reduces the viability of B-cell lymphomas by inducing apoptosis and shows a more potent HDAC inhibitory effect compared to SAHA, the first HDAC inhibitor approved by the FDA. In addition to HDACs inhibition, MPT0E028 also possesses potent direct Akt targeting ability as measured by the kinome diversity screening assay. Also, MPT0E028 reduces Akt phosphorylation in B-cell lymphoma with an IC50 value lower than SAHA. Transient transfection assay revealed that both targeting HDACs and Akt contribute to the apoptosis induced by MPT0E028, with both mechanisms functioning independently. Microarray analysis also shows that MPT0E028 may regulate many oncogenes expression (e.g., TP53, MYC, STAT family). Furthermore, in vivo animal model experiments demonstrated that MPT0E028 (50-200 mg/kg, po, qd) prolongs the survival rate of mice bearing human B-cell lymphoma Ramos cells and inhibits tumor growth in BJAB xenograft model. In summary, MPT0E028 possesses strong in vitro and in vivo activity against malignant cells, representing a potential therapeutic approach for cancer therapy.

Inhibitory effects of butein on cancer metastasis and bioenergetic modulation.

Tumor metastasis is the major obstacle for cancer treatment. Previous studies have shown that butein exhibits antiangiogenesis property and anticancer effects in different kinds of human cancer cells. However, the effects of butein on metastasis and energy metabolism of cancer cells are mostly unknown. This study showed that butein significantly inhibited invasion of cancer cells without acting in a cytotoxic fashion. It was further demonstrated that butien dramatically suppressed cancer metastasis by an in vivo CAM-intravasation model. Additionally, butein concentration-dependently repressed the expression and activity of matrix metalloproteinase-9 (MMP-9) and urokinase plasminogen activator (uPA). The study indicated that butein may repress MMP-9 and uPA proteolytic activities and subsequently inhibit cancer metastasis via Akt/mTOR/p70S6K translational machinery. Moreover, butein may partly suppress cancer metastasis by down-regulating ATP synthesis via both oxidative and glycolytic metabolism. The results suggest that butein is a potential antimetastatic agent worthy of further development for cancer treatment.

Moscatilin inhibits migration and metastasis of human breast cancer MDA-MB-231 cells through inhibition of Akt and Twist signaling pathway.

Breast cancer metastasis is more resistant to chemotherapy and radiotherapy than is cancer of the visceral tissues; therefore, new treatment strategies are urgently needed. Moscatilin, derived from the orchid Dendrobrium loddigesii, has shown anticancer activity. We evaluated the mechanism by which moscatilin suppresses the migration and metastasis of human breast cancer MDA-MB-231 cells in vitro and in vivo. We demonstrated that moscatilin significantly inhibits MDA-MB-231 cell migration by using scratch assays and Boyden chambers. Transcriptional factors inducing epithelial-mesenchymal transition, such as Twist, Snail, and Akt, play important roles in cell migration and cancer metastasis. Moscatilin inhibited the mRNA and protein expression of Twist, but not that of Snail, and subsequently inhibited N-cadherin expression. However, these effects were reversed by constitutively expressing active myristoylated (myr)-Akt and Twist overexpression. Moscatilin also suppressed Akt phosphorylation. However, Akt overexpression reversed the inhibitory effects of moscatilin on phospho-Akt protein expression but not its effects on Twist. The moscatilin-mediated inhibition of cell migration was reversed by Akt and Twist overexpression, demonstrating that moscatilin blocked cell migration by inhibiting Akt and Twist. In an MDA-MB-231 metastatic animal model, moscatilin (100 mg/kg) significantly suppressed breast cancer metastasis to the lungs and reduced the number of metastatic lung nodules and lung weight without causing any toxicity. These results indicated that moscatilin inhibited MDA-MB-231 cell migration via Akt- and Twist-dependent pathways; this finding was consistent with moscatilin's antimetastatic activity in vivo. Therefore, moscatilin may be an effective compound for the prevention of human breast cancer metastasis.

Anticancer activity of MPT0E028, a novel potent histone deacetylase inhibitor, in human colorectal cancer HCT116 cells in vitro and in vivo.

Recently, histone deacetylase (HDAC) inhibitors have emerged as a promising class of drugs for treatment of cancers, especially subcutaneous T-cell lymphoma. In this study, we demonstrated that MPT0E028, a novel N-hydroxyacrylamide-derived HDAC inhibitor, inhibited human colorectal cancer HCT116 cell growth in vitro and in vivo. The results of NCI-60 screening showed that MPT0E028 inhibited proliferation in both solid and hematological tumor cell lines at micromolar concentrations, and was especially potent in HCT116 cells. MPT0E028 had a stronger apoptotic activity and inhibited HDACs activity more potently than SAHA, the first therapeutic HDAC inhibitor proved by FDA. In vivo murine model, the growth of HCT116 tumor xenograft was delayed and inhibited after treatment with MPT0E028 in a dose-dependent manner. Based on in vivo study, MPT0E028 showed stronger anti-cancer efficacy than SAHA. No significant body weight difference or other adverse effects were observed in both MPT0E028-and SAHA-treated groups. Taken together, our results demonstrate that MPT0E028 has several properties and is potential as a promising anti-cancer therapeutic drug.

Synthesis and biological evaluation of 1-arylsulfonyl-5-(N-hydroxyacrylamide)indoles as potent histone deacetylase inhibitors with antitumor activity in vivo.

A series of 1-arylsulfonyl-5-(N-hydroxyacrylamide)indoles has been identified as a new class of histone deacetylase inhibitors. Compounds 8, 11, 12, 13, and 14 demonstrated stronger antiproliferative activities than 1 (SAHA) with GI(50) values ranging from 0.36 to 1.21 µM against Hep3B, MDA-MB-231, PC-3, and A549 human cancer cell lines. Lead compound 8 showed remarkable HDAC 1, 2, and 6 isoenzymes inhibitory activities with IC(50) values of 12.3, 4.0, 1.0 nM, respectively, which are comparable to 1. In in vivo efficacy evaluation against lung A549 xenograft model, 8 displayed better antitumor activity than compound 1.

Dehydrocostuslactone suppresses angiogenesis in vitro and in vivo through inhibition of Akt/GSK-3ß and mTOR signaling pathways.

The traditional Chinese medicine component dehydrocostuslactone (DHC) isolated from Saussurea costus (Falc.) Lipschitz, has been shown to have anti-cancer activity. Angiogenesis is an essential process in the growth and progression of cancer. In this study, we demonstrated, for the first time, the anti-angiogenic mechanism of action of DHC to be via the induction of cell cycle progression at the G0/G1 phase due to abrogation of the Akt/glycogen synthase kinase-3ß (GSK-3ß)/cyclin D1 and mTOR signaling pathway. First, we demonstrated that DHC has an anti-angiogenic effect in the matrigel-plug nude mice model and an inhibitory effect on human umbilical vein endothelial cell (HUVEC) proliferation and capillary-like tube formation in vitro. DHC caused G0/G1 cell cycle arrest, which was associated with the down-regulation of cyclin D1 expression, leading to the suppression of retinoblastoma protein phosphorylation and subsequent inhibition of cyclin A and cdk2 expression. With respect to the molecular mechanisms underlying the DHC-induced cyclin D1 down-regulation, this study demonstrated that DHC significantly inhibits Akt expression, resulting in the suppression of GSK-3ß phosphorylation and mTOR expression. These effects are capable of regulating cyclin D1 degradation, but they were significantly reversed by constitutively active myristoylated (myr)-Akt. Furthermore, the abrogation of tube formation induced by DHC was also reversed by overexpression of Akt. And the co-treatment with LiCl and DHC significantly reversed the growth inhibition induced by DHC. Taken together, our study has identified Akt/GSK-3ß and mTOR as important targets of DHC and has thus highlighted its potential application in angiogenesis-related diseases, such as cancer.

Chrysin restores PDGF-induced inhibition on protein tyrosine phosphatase and reduces PDGF signaling in cultured VSMCs.

Previous studies have shown that an increased intake of dietary flavonoids is associated with a decreased risk of cardiovascular diseases (CVDs). PDGF is a major mitogen for vascular smooth muscle cell (VSMC) and participates in the pathogenesis of many CVDs. The study investigated whether the flavone chrysin affected PDGF functions in VSMCs and neointma formation in rat artery. We found that chrysin concentration-dependently inhibited PDGF-induced proliferation and chemotaxis and reduced PDGF signaling in VSMCs. Chrysin attenuated H(2)O(2) signaling and PDGF-induced reactive oxygen species production and NADPH oxidase activation but did not interfere with PDGF binding to VSMCs. The further analyses revealed that chrysin relieved PDGF-induced inhibition on activity of protein tyrosine phosphatase (PTP) and reduced PDGF-induced oxidation of PTP cysteinyl active site. Moreover, it inhibited PDGF receptor autophosphorylation induced by low-dose vanadate (an inhibitor for PTP). The effect of chrysin, but not of the flavonoid (-)-epigallocatechin-3-gallate and antioxidant N-acetylcysteine, on PDGF signaling and PTP activity was reversed by depletion of intracellular glutathione (GSH), suggesting an involvement of chrysin on GSH/glutaredoxin system for PTP reactivation. Finally, to demonstrate the effectiveness of chrysin in vivo, we showed that oral administration of chrysin before and after angioplasty could reduce neointima formation in balloon-injured carotid artery in rats. In conclusion, we provide here evidence that chrysin can regulate intracellular PTP activity during PDGF signaling, inhibits PDGF-induced VSMC proliferation and chemotaxis, and reduces arterial intima hyperplasia in vivo.

Anti-neutrophilic inflammatory secondary metabolites from the traditional Chinese medicine, Tiankuizi.

Through bioassay-guided fractionation, thirteen compounds (1-13) were isolated from the dry root of Semiaquilegia adoxoides, known as Tiankuizi in traditional Chinese medicine (TCM). Among these, four benzoic acid derivatives (1, 2, 4, 5), one 4,6-dimethoxy-5-methyl-2H-pyran-2-one (10) and one 1,2,3-propanetriol (13) were found for the first time in S. adoxoides. This is the first record of compound 10 from a natural source. 4-Hydroxybenzoic acid (1) and 3,4-dihyroxybenzoic acid (2) showed selective inhibition against elastase release and superoxide anion generation, with IC50 values of 3.20 and 6.21 microg/mL, respectively. Compound 1 had 7-fold better activity than the positive control against elastase release induced by human neutrophils. Overall, our studies demonstrated Tiankuizi (S. adoxoides) as a potential TCM and isolates 1 and 2 as promising lead compounds for neutrophilic inflammatory diseases.

Denbinobin suppresses breast cancer metastasis through the inhibition of Src-mediated signaling pathways.

Denbinobin (5-hydroxy-3,7-dimethoxy- 1,4-phenanthraquinone), a biologically active chemical isolated from Ephemerantha lonchophylla, has been demonstrated to display anti-cancer activity. Breast cancer is the leading cause of female mortality, and the high mortality is mainly attributable to metastasis. Src kinase activity is elevated in many human cancers, including breast cancer, and is often associated with aggressive disease. In the present study, we examined the anti-metastatic effects of denbinobin through decreasing Src kinase activity in human and mouse breast cancer cells. Denbinobin caused significant block of Src kinase activity in both human and mouse breast cancer cells. Moreover, phosphorylation of the signaling molecules focal adhesion kinase, Crk-associated substrate and paxillin downstream of Src was also inhibited by denbinobin. Furthermore, denbinobin inhibited the in vitro migration, invasion and in vivo metastasis of breast cancers in a mouse metastatic model. The denbinobin-treated group showed a significant reduction in tumor metastasis, orthrotopic tumor volume, and spleen enlargement compared to the control group. In addition, transfection of breast cancer cells with a plasmid coding for a constitutively active Src prevented the denbinobin-mediated phosphorylation of Src and downstream molecules and cell migration. Our findings provide evidences that denbinobin inhibits Src-mediated signaling pathways involved in controlling breast cancer migration and metastasis, suggesting that it has therapeutic potential in breast cancer treatment.

The indazole derivative YD-3 specifically inhibits thrombin-induced angiogenesis in vitro and in vivo.

Angiogenesis is a process that involves endothelial cell proliferation, migration, invasion, and tube formation, and the inhibition of these processes has implications for angiogenesis-mediated disorders. The purpose of this study was to examine the antiangiogenic efficacy of YD-3 [1-benzyl-3(ethoxycarbonylphenyl)-indazole], a selective thrombin inhibitor, on thrombin-induced endothelial cell proliferation and neoangiogenesis in a murine Matrigel model. First, the effect of YD-3 on angiogenesis was evaluated in vivo using the mouse Matrigel implant model. Plugs treated with 1 and 10 µM of YD-3 inhibited neovascularization induced by thrombin, protease-activated receptor (PAR) 1, and PAR-4, but not by vascular endothelial growth factor, in a concentration-dependent manner over 7 days. These results indicate that YD-3 has specific antiangiogenic activity on thrombin. YD-3 also inhibited (in a concentration-dependent manner) the ability of thrombin, PAR-1, and PAR-4, but not PAR-2, to induce the proliferation of human umbilical vascular endothelial cells, using a [³H]thymidine incorporation assay. YD-3 predominantly inhibited thrombin-induced vascular endothelial growth factor receptor 2 (Flk-1) expression, but not extracellular signal-regulated kinase 1/2 phosphorylation, using Western blot analysis. YD-3 may have benefit in elucidating pathophysiology induced by thrombin-induced angiogenesis.

Antitumor agents. 272. Structure-activity relationships and in vivo selective anti-breast cancer activity of novel neo-tanshinlactone analogues.

Neo-tanshinlactone (1) and its previously reported analogues, such as 2, are potent and selective in vitro antibreast cancer agents. The synthetic pathway to 2 was optimized from seven to five steps, with a better overall yield. Structure-activity relationships studies on these compounds revealed some key molecular determinants for this family of antibreast agents. Several derivatives (19-21 and 24) exerted potent and selective antibreast cancer activity with IC(50) values of 0.3, 0.2, 0.1, and 0.1 microg/mL, respectively, against the ZR-75-1 cell lines. Compound 24 was 2- to 3-fold more potent than 1 against SK-BR-3 and ZR-75-1. Importantly, 21 exhibited high selectivity; it was 23 times more active against ZR-75-1 than MCF-7. Compound 20 had an approximately 12-fold ratio of SK-BR-3/MCF-7 selectivity. In addition, analogue 2 showed potent activity against a ZR-75-1 xenograft model, but not PC-3 and MDA-MB-231 xenografts, as well as high selectivity against breast cancer cell line compared with normal breast tissue-derived cell lines. Further development of lead compounds 19-21 and 24 as clinical trial candidates is warranted.

Moscatilin repressed lipopolysaccharide-induced HIF-1alpha accumulation and NF-kappaB activation in murine RAW264.7 cells.

In the present study, we investigated the signaling pathways involved in the inhibition of cyclooxygenase 2 (COX-2) and iNOS by moscatilin under LPS challenge in murine macrophage-derived cell line RAW264.7. The results showed that moscatilin (10-100 microM) had a significant inhibition in a concentration-dependent manner on proinflammatory enzymes (COX-2 and iNOS) expression and macrophage activation under LPS (100 ng/mL) treatment. Hypoxia-inducible factor 1 (HIF-1)alpha was reported to initiate inflammation under cytokine stimulation or hypoxic conditions. In addition, the increase in transcriptional activity and translation process of HIF-1alpha under LPS stimulation resulted in HIF-1alpha accumulation. Moscatilin, a purified compound from Chinese herbs, had a dominant repression on HIF-1alpha expression via down regulating HIF-1alpha mRNA without inhibition of cell viability, translation machinery, or proteasome-mediated degradation of HIF-1alpha. Moreover, the results showed that moscatilin suppressed nuclear translocation of nuclear factor (NF)-kappaB subunits, p65 and p50, and NF-kappaB activity by inhibiting phosphorylation of inhibitor of kappaBalpha. Taken together, we demonstrated that moscatilin inhibited both COX-2 and iNOS expressions after LPS treatment in RAW264.7. Furthermore, the inhibition of moscatilin seemed to be dependent on the repression of HIF-1alpha accumulation and NF-kappaB activation.

CHM-1, a new vascular targeting agent, induces apoptosis of human umbilical vein endothelial cells via p53-mediated death receptor 5 up-regulation.

CHM-1 (2'-fluoro-6,7-methylenedioxy-2-phenyl-4-quinolone) has been identified as a potent antitumor agent in human hepatocellular carcinoma; however, its role in tumor angiogenesis is unclear. This study investigated the effects of CHM-1 and the mechanisms by which it exerts its antiangiogenic and vascular disrupting properties. Using a xenograft model antitumor assay, we found that CHM-1 significantly inhibits tumor growth and microvessel formation. Flow cytometry, immunofluorescence microscopy, and cell death enzyme-linked immunosorbent assay kit revealed that CHM-1 inhibits growth of human umbilical vein endothelial cells (HUVEC) by induction of apoptotic cell death in a concentration-dependent manner. CHM-1 also suppresses HUVEC migration and capillary-like tube formation. We were able to correlate CHM-1-induced apoptosis in HUVEC with the cleavage of procaspase-3, -7, and -8, as well as with the cleavage of poly(ADP-ribose) polymerase by Western blotting assay. Such sensitization was achieved through up-regulation of death receptor 5 (DR5) but not DR4 or Fas. CHM-1 was also capable of increasing the expression level of p53, and most importantly, the induction of DR5 by CHM-1 was abolished by p53 small interfering RNA. Taken together, the results of this study indicate that CHM-1 exhibits vascular targeting activity associated with the induction of DR5-mediated endothelial cell apoptosis through p53 up-regulation, which suggests its potential as an antivascular and antitumor therapeutic agent.

Evodiamine represses hypoxia-induced inflammatory proteins expression and hypoxia-inducible factor 1alpha accumulation in RAW264.7.

Inflammation and low oxygen diffusion are recognized characteristics of cardiovascular diseases such as atherosclerosis. Evodiamine, extracted from the traditional Chinese herb, Evodia rutaecarpa, is a bioactive anti-inflammatory alkaloid. The objective of this study was to investigate whether evodiamine could repress hypoxia-induced inflammatory response. We showed that evodiamine repressed not only COX-2 and iNOS expression but also prostaglandin E2 release in a concentration-dependent manner under hypoxic conditions. Furthermore, our studies indicated that COX-2 mRNA was inhibited by evodiamine, implying that transcriptional activity is involved in the mechanistic pathway. It is striking that hypoxia-inducible factor 1alpha (HIF-1alpha) inhibitor, camptothecin, suppressed hypoxia-induced COX-2 expression rather than pyrrolidine dithiocarbamate, a nuclear factor kappaB inhibitor. In addition, our studies have confirmed that evodiamine inhibited HIF-1alpha, which accounted for the transcriptional activity of COX-2, rather than nuclear factor kappaB in RAW264.7 cells. Finally, evodiamine did not affect either the level of HIF-1alpha mRNA or the degradation rate of HIF-1alpha protein, but it regulated the translational process of HIF-1alpha. We found that hypoxia-evoked phosphorylation of Akt and p70S6K was blocked after evodiamine treatment, in addition to the inhibition of phosphorylation of 4E-BP. These results suggest that the mechanism of repression of hypoxia-induced COX-2 expression by evodiamine is through the inhibition of HIF-1alpha at the translational level and is primarily mediated via dephosphorylation of Akt and p70S6K. Therefore, evodiamine could be an effective therapeutic agent against inflammatory diseases involving hypoxia.

Baicalein attenuates intimal hyperplasia after rat carotid balloon injury through arresting cell-cycle progression and inhibiting ERK, Akt, and NF-kappaB activity in vascular smooth-muscle cells.

Baicalein (5,6,7-trioxyflavone-7-O-beta-D-glucuronide) derived from the Chinese herb Scutellaria baicalensis is well known as a lipoxygenase inhibitor. We investigated baicalein-mediated inhibitory effects on vascular smooth-muscle cell (VSMC) proliferation and intimal hyperplasia by balloon angioplasty in the rat. In vascular injury studies, baicalein significantly suppressed intimal hyperplasia by balloon angioplasty. Baicalein significantly inhibited cell proliferation via a lipoxygenase-independent pathway using [(3)H]thymidine incorporation, 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT), and flow cytometry assays. At the concentrations used, no cytotoxic effect on cell culture was found. Baicalein blocks cell-cycle progression in S/G2/M phase, consistent with the cell-cycle effects, baicalein significant inhibited cyclin D1, p42/44 mitogen-activated protein kinase (MAPK), and Akt phosphorylation without change in the other cell-cycle regulatory proteins. Furthermore, baicalein attenuated serum-induced deoxyribonucleic acid (DNA) binding activity of nuclear factor kappa B (NF-kappaB). These results show that baicalein blocks cell proliferation via blocking cell-cycle progression and proliferating events, including p42/44 MAPK and Akt activations as well as NF-kappaB activation. It also inhibits intimal hyperplasia after balloon vascular injury in the rat, indicating the therapeutic potential for treating restenosis after arterial injury.