Suppression of histamine-induced increase of endothelial permeability via nitric oxide production by Bixa orellana leaves extract

Previously reported pharmacological activity of Bixa orellana L. (Bixaceae) includes its ability to neutralize edema-forming effects of Bothrops asper venom (Nunez V., et al, 2004). Study on the mechanism of its anti-edema activity is thus far lacking. The purpose of this study was to examine the effects of aqueous extract of B. orellana (AEBO) leaves on endothelial permeability and the permeability-regulator molecule, nitric oxide (NO), during inflammatory stimulation by histamine. This study demonstrated that AEBO (0.1mg/ml -0.4mg/ml) significantly (p<0.05) suppressed histamine-induced increased endothelial permeability in human umbilical veins endothelial cells (HUVECs), where maximal inhibition was 90.2% at concentration and time point of 0.4mg/ml and 15min, respectively. Histamine-mediated NO formation in HUVECs was significantly reduced by all concentration of AEBO in a dose-dependent manner. 0.4mg/ml showed maximal inhibition where it reduced NO level from 12.51±0.07µM to 11.3±0.07µM (65.4% inhibition). On the other hand, 0.1 and 0.2mg/ml of AEBO suppressed NO production at 21.70% and 34.50%, respectively. To verify that AEBO will produce similar effects to exogenous source of NO as to endogenous NO, NO donor, sodium nitroprusside (SNP) was used. AEBO showed significant effects in scavenging NO radicals released by SNP where maximal inhibition was 51.2% at 0.4mg/ml. These results indicate that AEBO suppressed increased endothelial permeability by re-establishing normal NO production in HUVECs. This study justifies the use of Bixa orellana in traditional medicine by showing its potential in regulating endothelial cell barrier function

Cryptotanshinone attenuates in vitro oxLDL-induced pre-lesional atherosclerotic events.

Development of early stage atherosclerosis involves the activation of endothelial cells by oxidized low-density lipoprotein (oxLDL) with subsequent increases in endothelial permeability and expression of adhesion molecules favoring the adherence of monocytes to the endothelium. Cryptotanshinone (CTS), a major compound derived from the Chinese herb Salvia miltiorrhiza, is known for its protective effects against cardiovascular diseases. The aim of this study was to determine whether CTS could prevent the oxLDL-induced early atherosclerotic events. OxLDL (100 µg/mL) was used to increase endothelial permeability and induce monocyte-endothelial cell adhesion in human umbilical vein endothelial cells (HUVECs). Endothelial nitric oxide (NO) concentrations, a permeability-regulating molecule, and expressions of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were measured. Results show that a) endothelial hyperpermeability was suppressed by 94 % (p < 0.005), b) monocyte adhesion by 105 % (p < 0.01), and c) ICAM-1 and VCAM-1 expressions by 90 % (p < 0.01) and 150 % (p < 0.005), respectively, when CTS was applied. In contrast, CTS increased NO levels by 129 % (p < 0.01) and was found to be noncytotoxic in the concentrations between 1-10 µM. These findings indicate that CTS suppresses an increase in endothelial permeability, likely due to the restoration of NO bioavailability in endothelial cells. They also indicate that CTS may attenuate monocyte adhesion to endothelial cells through the inhibition of adhesion molecules' expression. Thus, CTS may play an important role in the prevention of early or pre-lesional stage of atherosclerosis

10H‐3,6‐Diazaphenothiazines triggered the mitochondrial‐dependent and cell death receptor‐dependent apoptosis pathways and further increased the chemosensitivity of MCF‐7 breast cancer cells via inhibition of AKT1 pathways

Breast cancer is one of the leading causes of death in cancer categories, followed by lung, colorectal, and ovarian among the female gender across the world. 10H-3,6-diazaphenothiazine (PTZ) is a thiazine derivative compound that exhibits many pharmacological activities. Herein, we proceed to investigate the pharmacological activities of PTZ toward breast cancer MCF-7 cells as a representative in vitro breast cancer cell model. The PTZ exhibited a proliferation inhibition (IC50 = 0.895 µM) toward MCF-7 cells. Further, cell cycle analysis illustrated that the S-phase checkpoint was activated to achieve proliferation inhibition. In vitro cytotoxicity test on three normal cell lines (HEK293 normal kidney cells, MCF-10A normal breast cells, and H9C2 normal heart cells) demonstrated that PTZ was more potent toward cancer cells. Increase in the levels of reactive oxygen species results in polarization of mitochondrial membrane potential (ΔΨm), together with suppression of mitochondrial thioredoxin reductase enzymatic activity suggested that PTZ induced oxidative damages toward mitochondria and contributed to improved drug efficacy toward treatment. The RT2 PCR Profiler Array (human apoptosis pathways) proved that PTZ induced cell death via mitochondria-dependent and cell death receptor-dependent pathways, through a series of modulation of caspases, and the respective morphology of apoptosis was observed. Mechanistic studies of apoptosis suggested that PTZ inhibited AKT1 pathways resulting in enhanced drug efficacy despite it preventing invasion of cancer cells. These results showed the effectiveness of PTZ in initiation of apoptosis, programmed cell death, toward highly chemoresistant MCF-7 cells, thus suggesting its potential as a chemotherapeutic drug

Cryptotanshinone inhibits TNF-α-induced early atherogenic events in vitro

Endothelial dysfunction has been implicated in the pathogenesis of atherosclerosis. Salvia miltiorrhiza (danshen) is a traditional Chinese medicine that has been effectively used to treat cardiovascular disease. Cryptotanshinone (CTS), a major lipophilic compound isolated from S. miltiorrhiza, has been reported to possess cardioprotective effects. However, the anti-atherogenic effects of CTS, particularly on tumor necrosis factor-α (TNF-α)-induced endothelial cell activation, are still unclear. This study aimed to determine the effect of CTS on TNF-α-induced increased endothelial permeability, monocyte adhesion, soluble intercellular adhesion molecule 1 (sICAM-1), soluble vascular cell adhesion molecule 1 (sVCAM-1), monocyte chemoattractant protein 1 (MCP-1) and impaired nitric oxide production in human umbilical vein endothelial cells (HUVECs), all of which are early events occurring in atherogenesis. We showed that CTS significantly suppressed TNF-α-induced increased endothelial permeability, monocyte adhesion, sICAM-1, sVCAM-1 and MCP-1, and restored nitric oxide production. These observations suggest that CTS possesses anti-inflammatory properties and could be a promising treatment for the prevention of cytokine-induced early atherogenesis

A bismuth diethyldithiocarbamate compound promotes apoptosis in HepG2 carcinoma, cell cycle arrest and inhibits cell invasion through modulation of the NF-κB activation pathway

The compound with R = CH2CH3 in Bi(S2CNR2)3 (1) is highly cytotoxic against a range of human carcinoma, whereas that with R = CH2CH2OH (2) is considerably less so. Both 1 and 2 induce apoptosis in HepG2 cells with some evidence for necrosis induced by 2. Based on DNA fragmentation, caspase activities and human apoptosis PCR-array analysis, both the extrinsic and intrinsic pathways of apoptosis have been shown to occur. While both compounds activate mitochondrial and FAS apoptotic pathways, compound 1 was also found to induce another death receptor-dependent pathway by induction of CD40, CD40L and TNF-R1 (p55). Further, 1 highly expressed DAPK1, a tumour suppressor, with concomitant down-regulation of XIAP and NF-κB. Cell cycle arrest at the S and G2/M phases correlates with the inhibition of the growth of HepG2 cells. The cell invasion rate of 2 is 10-fold higher than that of 1, a finding correlated with the down-regulation of survivin and XIAP expression by 1. Compounds 1 and 2 interact with DNA through different binding motifs with 1 interacting with AT- or TA-specific sites followed by inhibition of restriction enzyme digestion; 2 did not interfere with any of the studied restriction enzymes

G2/M cell cycle arrest on HT-29 cancer cells and toxicity assessment of triphenylphosphanegold(I) carbonimidothioates, Ph3PAu[SC(OR) = NPh], R = Me, Et, and iPr, during zebrafish development

Phosphanegold(I) thiolates, Ph3PAu[SC(OR) = NPh], R = Me (1), Et (2) and iPr (3), were previously shown to be significantly cytotoxic toward HT-29 cancer cells and to induce cell death by both intrinsic and extrinsic apoptotic pathways whereby 1 activated the p73 gene, and each of 2 and 3 activated p53; 2 also caused apoptotic cell death via the c-Jun N-terminal kinase/mitogen-activated protein kinase pathway. Apoptosis pathways have been further evaluated by mitochondrial cytochrome c measurements and annexin V screening, confirming apoptotic pathways of cell death. Cell cycle analysis showed the majority of treated HT-29 cells were arrested at the G2/M checkpoint after 24 h; results of both assays were confirmed by changes in populations of relevant genes (PCR array analysis). Cell invasion studies showed inhibition of metastasis through Matrigel™ matrix to 17–22% cf. untreated cells. LC50 values were determined in zebrafish (8.36, 8.17, and 7.64 μM for 1–3). Finally, the zebrafish tolerated doses of 1 and 2 up to 0.625 μM, and 3 was tolerated at even higher doses of up to 1.25 μM

Pathogenic Gram-positive bacteria are highly sensitive to triphenylphosphanegold(O-alkylthiocarbamates), Ph3PAu[SC(OR)=N(p-tolyl)] (R = Me, Et and iPr)

The phosphanegold(I) thiocarbamides, Ph3PAu{SC(OR)=NC6H4Me-4} for R = Me (1), Et (2) and iPr (3), have been shown to have essentially linear gold atom coordination geometries defined by phosphane-P and thiolate-S atoms, and exhibit minimum inhibitory concentration (MIC) values in the range of 1–37 μg/ml against four Gram-positive bacteria, namely Bacillus cereus, Enterococcus faecalis, Enterococcus faecium and Staphylococcus aureus; compounds 1–3 are less potent against a broad panel of 16 Gram-negative bacteria. As the minimum bactericidal concentration values were quite similar to the MIC values, compounds 1–3 are effective bactericidal agents. The specific action against the four Gram-positive bacteria suggests they function by inhibition of peptidoglycan synthesis

Molecular mechanisms of apoptosis and cell selectivity of zinc dithiocarbamates functionalized with hydroxyethyl substituents

In the solid state each of three binuclear zinc dithiocarbamates bearing hydroxyethyl groups, {Zn[S2CN(R)CH2CH2OH]2}2 for R = iPr (1), CH2CH2OH (2), and Me (3), and an all alkyl species, [Zn(S2CNEt2)2]2 (4), features a centrosymmetric {ZnSCS}2 core with a step topology; both 1 and 3 were isolated as monohydrates. All compounds were broadly cytotoxic, specifically against human cancer cell lines compared with normal cells, with greater potency than cisplatin. Notably, some selectivity were indicated with 2 being the most potent against human ovarian carcinoma cells (cisA2780), and 4 being more cytotoxic toward multidrug resistant human breast carcinoma cells (MCF-7R), human colon adenocarcinoma cells (HT-29), and human lung adenocarcinoma epithelial cells (A549). Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis in HT-29 cells is demonstrated via both extrinsic and intrinsic pathways. Compounds 2–4 activate the p53 gene while 1 activates both p53 and p73. Cell cycle arrest at the S and G2/M phases correlates with inhibition of HT-29 cell growth. Cell invasion is also inhibited by 1–4 which is correlated with down-regulation of NF-κB

The influence of R substituents in triphenylphosphinegold(I) carbonimidothioates, Ph 3PAu[SC(OR) = NPh] (R = Me, Et and iPr), upon in vitro cytotoxicity against the HT-29 colon cancer cell line and upon apoptotic pathways

The Ph3PAu[SC(OR) = NPh], R = Me (1), Et (2) and iPr (3), compounds are significantly cytotoxic to the HT-29 cancer cell line with1 being the most active. Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis is demonstrated and both the extrinsic and intrinsic pathways of apoptosis have been shown to occur. Compound1 activates the p73 gene, whereas each of2 and3 activates the p53 gene. An additional apoptotic mechanism is exhibited by2, that is, via the JNK/MAP pathway

Hypoxic-mediated oxidative stress condition and hydroxyapatite-inducing osteogenic differentiation of human mesenchymal stem cells: a mathematical modelling study

Avascular necrosis (AVN) of the bones remains a major clinical challenge. Fractures in the talus, the scaphoid, and the neck of the femur are especially challenging to heal due to the low blood vessel network and the lack of collateral blood supply. These fractures are associated with high rates of nonunion and increased infections that require repeated operations. Conventional treatments by autografting or allografting bone replacement and synthetic bone implants have limitations, including the invasiveness of operative procedures, tissue supply insufficiency, and the risk of host rejection. The advancement in tissue engineering has revealed the potential of stem cells as restorative agents for bone injuries. The administration of mesenchymal stem cells (MSCs) into the talus, the scaphoid, and the neck of the femur could produce enhanced osteogenesis via the manipulation of MSC culture conditions. In this study, we used hydroxyapatite as the nanomaterial, and hypoxic milieu to enhance MSC differentiation capacity into the osteogenic lineage, allowing for more rapid and efficient bone cell replacement treatment. Our results demonstrate 1% oxygen and 12.5 μg/mL of hydroxyapatite (HAP) as the optimal conditions to incorporate the osteogenic medium for the osteogenic induction of MSCs. We also established a proof of concept that the addition of HAP and hypoxic conditions could augment the osteoinductive capacity of MSCs. We also developed an accurate mathematical model to support future bone cell replacement therapy