Total Flavonoids of Crocus sativus Petals Release tert-Butyl Hydroperoxide-Induced Oxidative Stress in BRL-3A Cells.

Antioxidant and hepatoprotective activities in vitro of saffron petals were examined in this study for better utilizing saffron (Crocus sativus L.) biowaste. Using the DPPH and ABTS radical scavenging method, we compared the antioxidant activity and the content of total flavonoid extracts from petals (TFESP), stamens (TFESS), and both saffron petals and stamens (TFEMS). The results showed that the antioxidant capacity and the flavonoid content of TFESP were higher than those of TFESS and TFEMS. Then, the hepatoprotective activity of TFESP was determined, and the silymarin was used as a positive control. The main components of TFESP were analysed by ultrahigh performance liquid chromatography (UPLC) photodiode array (PDA)/mass spectrometry (MS) and nuclear magnetic resonance (NMR). The result showed that (1) TFESP could release oxidative liver injury induced by tert-butyl hydroperoxide (t-BHP). (2) TFESP could reduce the accumulation of reactive oxygen species (ROS); enhance the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH); and then improve the total antioxidant capacity (T-AOC) in BRL-3A cells. (3) TFESP could enhance the expression of B-cell lymphoma-2 (BCL-2) and decrease the expression of caspase-3 and caspase-9; increase the expression of Kelch-like ECH-associated protein-1 (Keap-1), nuclear factor, erythroid 2-related factor 2 (Nrf2), superoxide dismutase, and heme oxygenase 1 (HO-1); and downregulate inducible nitric oxide synthase (INOS), interleukin-6 (IL-6), and nuclear factor kappa B-9 (NF-κB-9). (4) The main hepatoprotective component of TFESP was identified as kaempferol-3-o-sophoroside. The mechanism may be that kaempferol-3-o-sophoroside can protect t-BHP-induced cell injury by regulating the expression of antioxidant, antiapoptotic, and anti-inflammatory genes. Thus, saffron petals are a potential hepatoprotective resource worthy of development.

Promotion of Aerobic Exercise Induced Angiogenesis Is Associated With Decline in Blood Pressure in Hypertension: Result of EXCAVATION-CHN1.

[Figure: see text].

Berberine-Promoted CXCR4 Expression Accelerates Endothelial Repair Capacity of Early Endothelial Progenitor Cells in Persons with Prehypertension.

OBJECTIVE: To evaluate whether the berberine treatment can improve endothelial repair capacity of early endothelial progenitor cells (EPCs) from prehypertensive subjects through increasing CXC chemokine receptor 4 (CXCR4) signaling. METHODS: EPCs were isolated from prehypertensive and healthy subjects and cultured. In vivo reendothelialization capacity of EPCs from prehypertensive patients with or without in vitro berberine treatment was examined in a nude mouse model of carotid artery injury. The protein expressions of CXCR4/Janus kinase-2 (JAK-2) signaling of in vitro EPCs were detected by Western blot analysis. RESULTS: CXCR4 signaling and alteration in migration and adhesion functions of EPCs were evaluated. Basal CXCR4 expression was significantly reduced in EPCs from prehypertensive patients compared with normal subjects (P<0.01). Also, the phosphorylation of JAK-2 of EPCs, a CXCR4 downstream signaling, was significantly decreased (P<0.01). Berberine promoted CXCR4/JAK-2 signaling expression of in vitro EPCs (P<0.01). Transplantation of EPCs pretreated with berberine markedly accelerated in vivo reendothelialization (P<0.01). The increased in vitro function and in vivo reendothelialization capacity of EPCs were inhibited by CXCR4 neutralizing antibody or pretreatment with JAK-2 inhibitor AG490, respectively (P<0.01). CONCLUSION: Berberinemodified EPCs via up-regulation of CXCR4 signaling contributes to enhanced endothelial repair capacity in prehypertension, indicating that berberine may be used as a novel potential primary prevention means against prehypertension-related atherosclerotic cardiovascular disease.

Lacidipine improves endothelial repair capacity of endothelial progenitor cells from patients with essential hypertension.

BACKGROUND: Endothelial progenitor cells (EPCs) play a critical role in maintaining the integrity of vascular endothelium following arterial injury. Lacidipine has a beneficial effect on endothelium of hypertensive patients, but limited data are available on EPCs-mediated endothelial protection. This study tests the hypothesis that lacidipine treatment can improve endothelial repair capacity of EPCs from hypertensive patients through increasing CXC chemokine receptor four (CXCR4) signaling. METHODS: In vivo reendothelialization capacity of EPCs from hypertensive patients with or without in vitro lacidipine treatment was examined in a nude mouse model of carotid artery injury. Expression of CXCR4 and alteration in migration and adhesion functions of EPCs were evaluated. RESULTS: Basal CXCR4 expression was markedly reduced in EPCs from hypertensive patients compared with normal subjects. In parallel, the phosphorylation of Janus kinase-2 (JAK-2) of EPCs, a CXCR4 downstream signaling, was also significantly decreased. Lacidipine promoted CXCR4/JAK-2 signaling expression of in vitro EPCs. Transplantation of EPCs pretreated with lacidipine significantly accelerated in vivo reendothelialization. The enhanced in vitro function and in vivo reendothelialization capacity of EPCs were inhibited by shRNA-mediated knockdown of CXCR4 expression or pretreatment with JAK-2 inhibitor AG490, respectively. In hypertensive patients, lacidipine treatment for 4 weeks also resulted in an upregulation of CXCR4/JAK-2 signaling of EPCs, which was associated with augmented EPCs-mediated reendothelialization and improved endothelial function. CONCLUSION: Deterioration of CXCR4 signaling may lead to impaired EPCs-mediated reendothelialization of hypertensive patients. Lacidipine-modified EPCs via a partially CXCR4 signaling contribute to enhanced endothelial repair capacity in hypertension.

Berberine improves endothelial function by reducing endothelial microparticles-mediated oxidative stress in humans.

BACKGROUND: Circulating endothelial microparticles (EMPs) lead to endothelial dysfunction by increasing oxidative stress. Berberine has a beneficial effect on endothelial function, but no data are available on the EMP-mediated oxidative stress. The present study tests the hypothesis that berberine contributes to the improvement of endothelial function in humans via inhibiting EMP-mediated oxidative stress in vascular endothelium. METHODS: Twelve healthy subjects received a 1-month berberine therapy and eleven healthy subjects served as control. Endothelium-dependent and -independent function in the brachial artery was assessed by flow-mediated vasodilation (FMD) and sublingual nitroglyceride-mediated vasodilation (NMD). Circulating EMPs and serum malondialdehyde (MDA) were measured before and after therapy. Furthermore, in vitro human umbilical vein endothelial cells (HUVECs) were stimulated by EMPs with or without presence of anti-oxidant compound apocynin or berberine. Intracellular reactive oxygen species (ROS), nitric oxide (NO) production and NADPH oxidase 4 (Nox4) protein expressions were examined, respectively. RESULTS: The levels of serum MDA and circulating CD31+/CD42- MPs were significantly reduced in the berberine group compared with the control group, which were associated with improvement of FMD. The EMPs in vitro facilitated ROS production and Nox4 protein expression and reduced NO synthesis in HUVECs. These alterations can be reversed by the presence of apocynin or berberine, respectively. CONCLUSION: The present study demonstrated for the first time that EMP-induced upregulation of Nox4 expression may enhance ROS production in HUVECs. Berberine treatment contributes to the amelioration of endothelial function through a partially reducing oxidative stress of vascular endothelium induced by circulating CD31+/CD42- microparticles in humans.

Shear stress-induced activation of Tie2-dependent signaling pathway enhances reendothelialization capacity of early endothelial progenitor cells.

Although endothelial progenitor cells (EPCs) play a pivotal role in the endothelial repair following arterial injury and shear stress has a beneficial effect on EPCs, however, the molecular mechanism underlying the influence of EPCs on the endothelial integrity and the regulation of shear stress on the EPC signaling remained to be studied. Here, we investigated the effects of laminar shear stress on the tyrosine kinase with immunoglobulin and epidermal growth factor homology domain-2 (Tie2)-dependent signaling and its relation to in vivo reendothelialization capacity of human early EPCs. The human early EPCs were treated with shear stress. Shear stress in a dose-dependent manner increased angiopoietin-2 (Ang2)-induced migratory, adhesive and proliferatory activities of EPCs. Transplantation of EPCs treated by shear stress facilitated in vivo reendothelialization in nude mouse model of carotid artery injury. In parallel, the phosphorylation of Tie2 and Akt of EPCs in response to shear stress was significantly enhanced. With treatment of Tie2 knockdown or Akt inhibition, shear stress-induced phosphorylation of Akt and endothelial nitric oxide synthase (eNOS) of EPCs was markedly suppressed. After Tie2/PI3K/Akt/eNOS signaling was blocked, the effects of shear stress on in vitro function and in vivo reendothelialization capacity of EPCs were significantly inhibited. The present findings demonstrate for the first time that Tie2/PI3k/Akt/eNOS signaling pathway is, at least in part, involved in the EPCs-mediated reendothelialization after arterial injury. The upregulation of shear stress-induced Tie2-dependent signaling contributes to enhanced in vivo reendothelialization capacity of human EPCs.

Physical exercise attenuates age-associated reduction in endothelium-reparative capacity of endothelial progenitor cells by increasing CXCR4/JAK-2 signaling in healthy men.

Endothelial progenitor cells (EPCs) play an important role in repairing endothelial injury. Aging is associated with EPC dysfunction. Physical exercise has a beneficial impact on EPC activity. However, whether physical exercise can enhance the endothelial repair capacity of EPCs in healthy men with aging is not clear. Here, we investigated the effects of physical exercise on reendothelialization capacity and CXC chemokine receptor four (CXCR4) signaling in human EPCs. Before and after 12-week exercise, EPCs were isolated from elderly and young men. In vitro function and in vivo reendothelialization capacity of EPCs in a mouse model of carotid artery injury were measured. The expression of CXCR4 and its downstream signaling target Janus kinase-2 (JAK-2) were determined. Before exercise, in vitro function and in vivo reendothelialization capacity of EPCs were significantly reduced in elderly men compared with young men. After exercise intervention, in vitro function and in vivo reendothelialization capacity of EPCs from elderly men were markedly enhanced. Physical exercise increased a higher CXCR4 protein expression and higher JAK-2 phosphorylation levels of EPCs. The augmentation in reendothelialization capacity of EPCs was closely correlated with the upregulation of CXCR4/JAK-2 signaling and improvement of endothelial function. This study demonstrates for the first time that physical exercise attenuates age-associated reduction in endothelium-reparative capacity of EPCs by increasing CXCR4/JAK-2 signaling. Our findings provide insight into the novel mechanisms of physical exercise as a lifestyle intervention strategy to promote vascular health in aging population.