Chloroquine inhibits vasodilation induced by ATP-sensitive potassium channels in isolated rat aorta.

This study examined the effect of chloroquine on vasodilation induced by levcromakalim in isolated endothelium-denuded rat aortas and clarified the underlying mechanisms. We examined the effects of chloroquine, hydroxychloroquine, lipid emulsion, reactive oxygen species (ROS) scavenger N-acetyl-ʟ-cysteine (NAC), and KATP channel inhibitor glibenclamide on levcromakaliminduced vasodilation. The effects of chloroquine, hydroxychloroquine, NAC, and levcromakalim on membrane hyperpolarization and ROS production were examined in aortic vascular smooth muscle cells (VSMCs). Chloroquine inhibited levcromakalim-induced vasodilation more than hydroxychloroquine. NAC attenuated chloroquine-mediated inhibition of levcromakalim-induced vasodilation, while lipid emulsion had no effect. Glibenclamide eliminated levcromakalim-induced vasodilation in aortas pretreated with chloroquine. Chloroquine and hydroxychloroquine inhibited levcromakalim-induced membrane hyperpolarization in VSMCs. Chloroquine and hydroxychloroquine both produced ROS, but chloroquine produced more. NAC inhibited chloroquine-induced ROS production in VSMCs. Collectively, these results suggest that, partially through ROS production, chloroquine inhibits levcromakalim-induced vasodilation. In addition, chloroquine-induced KATP channel-induced vasodilation impairment was not restored by lipid emulsion.

Lipid emulsion attenuates propranolol-induced early apoptosis in rat cardiomyoblasts.

OBJECTIVE: Propranolol is used to treat several cardiovascular diseases; however, toxic doses of propranolol cause severe myocardial depression and cardiac arrest. The aim of this study was to examine the effects of lipid emulsion (LE) on cardiotoxicity induced by toxic doses of propranolol in H9C2 rat cardiomyoblast cell line and to elucidate the underlying mechanism. METHODS: The experimental groups comprised control, propranolol alone, esmolol alone, or LE followed by propranolol or esmolol treatment, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine (NAC) followed by propranolol treatment. The effects of propranolol, esmolol, NAC, and LE, alone or in combination, on cell viability, apoptosis, and ROS production were examined. Additionally, we investigated the effect of LE on propranolol concentration. RESULTS: LE and NAC reversed the inhibition of cell viability induced by propranolol (p < .001). However, LE had no effect on the inhibition of cell viability caused by esmolol. The LE inhibited propranolol-induced expressions of cleaved caspase-3 (p < .001), caspase-9 (p < .001), and Bax (p < .01), but not caspase-8. NAC inhibited the propranolol-induced expression of cleaved caspase-3. LE inhibited propranolol-induced early apoptosis, but had no effect on late apoptosis. Additionally, LE inhibited the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells generated by propranolol. It attenuated propranolol-induced ROS production. However, it had no effect on propranolol concentration. CONCLUSION: LE inhibits early apoptosis caused by a toxic dose of propranolol by suppressing the intrinsic apoptotic pathway, via direct inhibition of ROS production.

Hexane extract of aged black garlic reduces cell proliferation and attenuates the expression of ICAM-1 and VCAM­1 in TNF-α-activated human endometrial stromal cells.

Increasing evidence indicates the potentially crucial roles of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the pathological process underlying endometriosis. The present study aimed to investigate the effects of a hexane extract of aged black garlic (HEABG) on the proliferation and expression of ICAM-1 and VCAM-1 in tumor necrosis factor-α (TNF-α)-activated human endometrial stromal cells (HESCs) isolated from patients with endometriosis. HESCs were isolated from endometriotic tissues obtained from women with advanced endometriosis who underwent laparoscopic surgery for ovarian endometrioma (n=18). Cell proliferation and cell cycle analysis were assessed by WST-1 assay and flow cytometry, respectively. The expression of ICAM-1 and VCAM-1 was measured by flow cytometry, immunofluorescence staining, immunoblotting and quantitative reverse transcriptase-PCR. The secretion of interleukin-6 (IL-6) was determined by enzyme-linked immunosorbent assay (ELISA). The activation of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) was detected by electrophoretic mobility shift assay (EMSA) and the activation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38 MAPK was analyzed by immunoblotting. Cell proliferation and cell cycle progression were significantly suppressed by HEABG in the TNF-α-induced HESCs through the inhibition of the ERK and JNK signaling pathways. Remarkably, the treatment of the HESCs with HEABG potently suppressed the TNF-α-induced ICAM-1 and VCAM-1 transcript and protein expression by inhibiting the activation of NF-κB and AP-1 transcription factors. Our results suggest that HEABG may be effective in the prevention and treatment of endometriosis in humans.

PI3Kγ activation is required for LPS-induced reactive oxygen species generation in respiratory epithelial cells.

OBJECTIVE: In this study, we investigated the molecular basis of reactive oxygen species (ROS) generation induced by lipopolysaccharide (LPS) in A549 cells--an alveolar epithelial cell line. EXPERIMENTAL DESIGN: A549 cells or normal human bronchial epithelial (NHBE) cells were stimulated with LPS. ROS generation was measured in A549 cells or NHBE cells pre-treated with a selective inhibitor of phosphatidylinositol 3-kinase γ (PI3Kγ), AS 605240, PI3Kγ siRNA, or a ROS scavenger, pyridoxamine (PM). RESULTS: Treatment of A549 cells or NHBE cells with LPS caused a significant increase in intracellular ROS generation. Pretreatment with the PI3Kγ inhibitor, AS 605240 decreased the LPS-induced increase of ROS generation, phosphorylation of Akt, and production of phosphatidyl 3,4,5-trisphosphate in A549 cells. In addition, interference with siRNA for PI3Kγ significantly reduced LPS-induced ROS generation in A549 cells. Treatment of A549 cells with LPS or hydrogen peroxide increased the nuclear factor-κB (NF-κB) in the nucleus, accompanying an increase in phosphorylation of inhibitory κB-α, degradation of the protein, and reduction of cytosolic NF-κB. Pretreatment with AS 605240 reduced these LPS-induced changes. In addition, pretreatment with PM or N-acetyl cysteine resulted in inhibition of nuclear NF-κB activation. CONCLUSION: These results suggest that PI3Kγ plays a key role in LPS-induced ROS generation in alveolar epithelial cells, thereby activating NF-κB.

Curcumin attenuates TNF-α-induced expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and proinflammatory cytokines in human endometriotic stromal cells.

Curcumin, a naturally occurring polyphenolic compound from Curcuma longa, has long been used in folk medicine as an antiinflammatory remedy in Asian countries. Endometriosis is a chronic gynecological inflammatory disorder in which immune system deregulation may play a role in its initiation and progression. A number of mediators, including cell adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1); proinflammatory cytokines such as tumour necrosis factor-α (TNF-α), interleukin-1 (IL-1), IL-6 and IL-8; and chemokines such as monocyte chemotactic protein-1 (MCP-1), play key roles in the pathogenesis of endometriosis. The aim of our study was to explore the effect of curcumin on the expression of these critical molecules in human ectopic endometriotic stromal cells isolated from women with endometriosis. Endometriotic stromal cells treated with curcumin showed marked suppression of TNF-α-induced mRNA expression of ICAM-1 and VCAM-1. Curcumin treatment also significantly decreased the TNF-α-induced cell surface and total protein expression of ICAM-1 and VCAM-1 in a dose-dependent manner. In addition, treatment of endometriotic stromal cells with curcumin markedly inhibited TNF-α-induced secretion of IL-6, IL-8 and MCP-1. Furthermore, curcumin inhibited the activation of transcription factor NF-κB, a key regulator of inflammation, in human endometriotic stromal cells. These findings suggest that curcumin may have potential therapeutic uses in the prevention and treatment of endometriosis.

5-Hydroxymethylfurfural from black garlic extract prevents TNFα-induced monocytic cell adhesion to HUVECs by suppression of vascular cell adhesion molecule-1 expression, reactive oxygen species generation and NF-κB activation.

5-Hydroxymethylfurfural (5-HMF) is a common Maillard reaction product; the reaction occurs during heat-processing and the preparation of many types of foods and beverages. Although 5-HMF has been proposed to have harmful effects, recently, its beneficial effects, including antioxidant, cytoprotective and antitumor effects have become increasingly apparent. It was found recently that a chloroform extract of aged black garlic shows antiinflammatory properties when administered to human umbilical vein endothelial cells (HUVECs). This study investigated the antiinflammatory potential of 5-HMF purified from the chloroform extract of aged black garlic in tumor necrosis factor-α (TNF-α)-stimulated HUVECs. Treatment of HUVECs with 5-HMF strongly suppressed TNF-α-induced cell surface and total protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1) as well as their mRNA expression. In addition, 5-HMF significantly inhibited TNF-α-induced reactive oxygen species formation, and markedly reduced THP-1 monocyte adhesion to TNF-α-stimulated HUVECs. Furthermore, 5-HMF significantly inhibited NF-κB transcription factor activation in TNF-α-stimulated HUVECs. The data provide new evidence of the antiinflammatory properties of 5-HMF in support of its potential therapeutic use for the prevention and management of vascular diseases such as atherosclerosis through mechanisms involving the inhibition of VCAM-1 expression and NF-κB activation in vascular endothelial cells.

Chloroform extract of aged black garlic attenuates TNF-α-induced ROS generation, VCAM-1 expression, NF-κB activation and adhesiveness for monocytes in human umbilical vein endothelial cells.

Aged black garlic is a type of fermented garlic (Allium sativum) which has been used in Oriental countries for a long time because of various biological properties of garlic derivatives. The current study explored the potential of the chloroform extract of aged black garlic (CEABG) in attenuating the activities of adhesion molecules in tumor necrosis factor-α (TNF-α)-stimulated human umbilical vein endothelial cells (HUVECs). The study was performed on HUVECs that were pretreated with 30 µg/mL of CEABG before TNF-α treatment. Treatment of HUVECs with CEABG significantly inhibited TNF-α-induced reactive oxygen species (ROS) formation. HUVECs treated with CEABG showed markedly suppressed TNF-α-induced mRNA expression of VCAM-1, but little alteration in ICAM-1 and E-selectin mRNA expression. CEABG treatment also significantly decreased the TNF-α-induced cell surface and total protein expression of VCAM-1 without affecting ICAM-1 and E-selectin expression. In addition, treatment of HUVECs with CEABG markedly reduced THP-1 monocyte adhesion to TNF-α-stimulated HUVECs. Furthermore, CEABG significantly inhibited NF-κB transcription factor activation in TNF-α-stimulated HUVECs. The data provide new evidence of the antiinflammatory properties of CEABG that may have a potential therapeutic use for the prevention and treatment of vascular diseases such as atherosclerosis through mechanisms involving the inhibition of VCAM-1 expression and NF-κB activation in vascular endothelial cells.