Pinellia ternata attenuates carotid artery intimal hyperplasia and increases endothelial progenitor cell activity via the PI3K/Akt signalling pathway in wire-injured rats.

CONTEXT: Clinically, Pinellia ternata (Thunb.) Breit. (Araceae) (PT) has been widely used in the treatment of atherosclerosis and hyperlipidaemia, but the underlying mechanisms are still not clearly understood. OBJECTIVE: This research was conducted to confirm the mechanism by which PT affects carotid artery intimal hyperplasia. MATERIALS AND METHODS: An intestinal hyperplasia Sprague-Dawley rat model was established by carotid artery injury. The rats were randomly divided into five groups (n = 8): sham, model, PT (with daily intragastric administration of 10 g/mL/kg PT tubers water extract), PT+LY294002 (with intraperitoneal injection of 50 mg/kg LY294002 + 10 g/mL/kg PT) and endothelial progenitor cells (EPCs) (with injection of 5 × 105/cells), and treated for 4 or 8 weeks. RESULTS: HE staining showed that PT attenuated intimal hyperplasia. RT-PCR, Western blotting and immunohistochemistry showed that PT increased the expression of vascular endothelial growth factor (VEGF) and eNOS in the atherosclerotic carotid artery. PT increased the Dil-acLDL+/FITC-UEA-1+ population (from 0.41 ± 0.085% to 0.60 ± 0.092%) in the blood, decreased TCHO, TG, LDL-C, IL-6 and TNF-α levels, and increased HDL-C and IL-10 levels in the blood. However, these changes were reversed by the PI3K/Akt pathway inhibitor LY294002. DISCUSSION AND CONCLUSIONS: PT can be developed as an atherosclerosis and carotid intimal hyperplasia treatment drug. Therefore, further study will focus on the effects of PT on intimal hyperplasia in wire-injured atherosclerosis patients and explore in depth some other relevant molecular mechanisms.

Mid-dose losartan mitigates diabetes-induced hepatic damage by regulating iNOS, eNOS, VEGF, and NF-κB expressions

Background/aim: Losartan, an antihypertensive drug, is highly preferred in patients with diabetes mellitus (DM) and hypertension because of its retarding effect on diabetic nephropathy. In this study, we investigated the potential therapeutic effect of different doses of losartan on hepatic damage in a streptozotocin (STZ, 50 mg/kg)-induced DM model in rats. Materials and methods: In this study, five different groups were formed: control, DM, low-dose losartan (5 mg/kg), mid-dose losartan (20 mg/kg), and high-dose losartan (80 mg/kg). Liver tissues of experimental groups were evaluated immunohistochemically for TUNEL, iNOS, eNOS, VEGF, and NF-κB pathways. In addition to immunohistochemical analysis, analyses of SOD and MDA, which are oxidative stress markers, were also performed and the results were evaluated together. Results: When biochemical and immunohistochemical findings were evaluated together, it was found that the results obtained from the mid-dose losartan group were closer to those of the control than the other groups. Conclusion: This study indicated that mid-dose losartan administration may have a therapeutic effect by inhibiting apoptosis and regulating iNOS, eNOS, VEGF, and NF-κB protein expressions in DM-induced hepatic damage.

Rosuvastatin alleviates the development of monocrotaline-induced pulmonary hypertension in rats.

Statins can increase endothelial function through enhancement of the expression and activity of endothelial nitric oxide synthase (eNOS). The aim of this study is to evaluate the effect of rosuvastatin on the number of circulating endothelial progenitor cells (EPCs) and endothelial expression of eNOS in monocrotaline-induced pulmonary hypertensive rats. Sixty Sprague-Dawley (SD) rats were divided into three groups of 20: control (group A), pulmonary hypertension (PAH) + rosuvastatin group (group B), and PAH (group C). Monocrotaline (MCT; 60 mg/kg) was injected (intraperitoneally) to induce PAH. Rats in group B received rosuvastatin [10 mg/(kg. day)] for 2 weeks. Peripheral blood (5 mL) was aspirated from the femoral artery of each rat before and after 2 weeks of treatment. Mononuclear cells were isolated and subcultured to obtain EPCs. Small and moderately sized pulmonary arteries were collected 2 weeks later for histological analyses. eNOS gene expression in endothelial cells of pulmonary arteries were then determined at mRNA and protein levels. eNOS expression at mRNA and protein levels and the number of circulating EPCs were reduced significantly in groups B and C compared with group A (P less than 0.05), and a significant difference between group B and group C (P less than 0.05) was observed. Vascular remodeling in small and moderately sized pulmonary arteries was attenuated markedly in group B compared with group C. These results suggest that rosuvastatin can ameliorate the remodeling of pulmonary arteries in MCT-induced PAH rats by increasing the number of circulating EPCs and eNOS upregulation.

Hyperhomocysteinaemia in rats is associated with erectile dysfunction by impairing endothelial nitric oxide synthase activity.

To investigate the effect of hyperhomocysteinaemia (HHCy) on penile erectile function in a rat model, a methionine-rich diet was used in which erectile function, the reproductive system, and nitric oxide synthase were characterized. The intracavernous pressure, apomorphine experiments, measurement of oxidative stress, hematoxylin and eosin staining, immunohistochemistry analysis, reverse transcription-polymerase chain reactions and measurement of endothelial nitric oxide synthase activity were utilized. Our results showed that erections in the middle-dose, high-dose, and interference (INF) groups were significantly lower than the control (P < 0.05). INF group, being fed with vitamins B and folic acid, demonstrated markedly improved penile erections compared with the middle-dose group (P < 0.05). HHCy-induced eNOS and phospho-eNOS protein expression was reduced and the antioxidant effect was markedly impaired. The data of the present data provide evidence that HHCy is a vascular risk factor for erectile dysfunction by impairing cavernosa endothelial nitric oxide synthase activity. Intake of vitamins B can alleviate this abnormality.

Influence of Electroacupuncture Stimulation on Nitric Monoxide Production in Vascular Endothelial Cells in Rats.

BACKGROUND/AIM: In Chinese medicine, blood stasis termed as 'Oketsu' means 'preceding state' or 'symptomatic of sickness'. Traditional Chinese medicine may improve blood flow by vasodilation or blood clotting inhibition. Although acupuncture influences the blood circulatory system, its underlying mechanisms remain unclear. Herein we evaluated changes in NO, as reflected by changes in NO2 (-), platelet aggregation, oxidative stress and endocrine responses after acupuncture stimulation in rats. MATERIALS AND METHODS: Acupuncture stimulation was administered to rats randomly divided into five groups: control, N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME) injection, restraint stress (RS), restraint plus acupuncture stimulation (RA), and restraint plus acupuncture with L-NAME (RLA). RESULTS: Compared to those in the RS group, levels of NO2 (-), endothelial nitric oxide synthase (NOS) protein and its mRNA significantly increased and those of hydroperoxide and soluble P-selectin significantly decreased in the RA group. CONCLUSION: Acupuncture stimulation regulates vascular endothelium NOS function and affects vascular resistance and blood characteristics through NO. Additionally, NO produced may modulate excessive reactive oxygen development and blood platelet activation.

Effect of Xin Mai Jia on atherosclerosis in rats.

We investigated the therapeutic effect of Xin Mai Jia (XMJ) on atherosclerosis (AS) in rats. Rat models of AS were established by peritoneally injecting vitamin D, feeding a high-fat diet, and inducing balloon injuries in rats. The stomachs of the rats were irrigated continuously for 10 weeks with XMJ. Blood lipid- and hemorheology-related indices of blood samples were detected. Pathological changes in the right common carotid arterial tissues were also determined. The protein expression levels of endothelial nitric oxide synthase, angio-tensin-1, and endothelin-1 were determined by western blotting. XMJ reduced cholesterol, trigylecride, and low-density lipoprotein levels as well as blood viscosity, sedimentation, and hematocrit. Furthermore, XMJ alleviated vascular endothelial injury and reduced/eliminated atherosclerotic plaques. In contrast, XMJ significantly increased the endothelium-dependent relaxing response of the AS rat models. The western blotting results showed that XMJ upregulated endothelial nitric oxide synthase but downregulated angiotensin-1 and endothelin-1. XMJ prevented the development of AS by regulating blood lipid levels, hemorheology, and vascular function.

Polydatin Restores Endothelium-Dependent Relaxation in Rat Aorta Rings Impaired by High Glucose: A Novel Insight into the PPARß-NO Signaling Pathway.

Polydatin, a natural component from Polygonum Cuspidatum, has important therapeutic effects on metabolic syndrome. A novel therapeutic strategy using polydatin to improve vascular function has recently been proposed to treat diabetes-related cardiovascular complications. However, the biological role and molecular basis of polydatin's action on vascular endothelial cells (VECs)-mediated vasodilatation under diabetes-related hyperglycemia condition remain elusive. The present study aimed to assess the contribution of polydatin in restoring endothelium-dependent relaxation and to determine the details of its underlying mechanism. By measuring endothelium-dependent relaxation, we found that acetylcholine-induced vasodilation was impaired by elevated glucose (55 mmol/L); however, polydatin (1, 3, 10 µmol/L) could restore the relaxation in a dose-dependent manner. Polydatin could also improve the histological damage to endothelial cells in the thoracic aorta. Polydatin's effects were mediated via promoting the expression of endothelial NO synthase (eNOS), enhancing eNOS activity and decreasing the inducible NOS (iNOS) level, finally resulting in a beneficial increase in NO release, which probably, at least in part, through activation of the PPARß signaling pathway. The results provided a novel insight into polydatin action, via PPARß-NO signaling pathways, in restoring endothelial function in high glucose conditions. The results also indicated the potential utility of polydatin to treat diabetes related cardiovascular diseases.

Polyphenol-enriched diet prevents coronary endothelial dysfunction by activating the Akt/eNOS pathway.

INTRODUCTION AND OBJECTIVES: The Mediterranean diet, rich in polyphenols, has shown to be cardioprotective. However the mechanisms involved remain unknown. We investigated whether supplementation with a pomegranate extract rich in polyphenols renders beneficial effects on coronary function in a clinically relevant experimental model and characterized the underlying mechanisms. METHODS: Pigs were fed a 10-day normocholesterolemic or hypercholesterolemic diet. Half of the animals were given a supplement of 625 mg/day of a pomegranate extract (Pomanox; 200 mg punicalagins/day). Coronary responses to escalating doses of vasoactive drugs (acetylcholine, calcium ionophore, and sodium nitroprusside) and L-NG-monomethylarginine (endothelial nitric oxide-synthase inhibitor) were measured using flow Doppler. Akt/endothelial nitric oxide-synthase axis activation, monocyte chemoattractant protein-1 expression, oxidative deoxyribonucleic acid damage in the coronary artery, and lipoprotein resistance to oxidation were evaluated. RESULTS: In dyslipidemic animals, Pomanox supplementation prevented diet-induced impairment of endothelial relaxation, reaching vasodilatory values comparable to normocholesterolemic animals upon stimulation with acetylcholine and/or calcium ionophore. These beneficial effects were associated with vascular Akt/endothelial nitric oxide-synthase activation and lower monocyte chemoattractant protein-1 expression. Pomanox supplementation reduced systemic oxidative stress (higher high-density lipoprotein-antioxidant capacity and higher low-density lipoprotein resistance to oxidation) and coronary deoxyribonucleic acid damage. Normocholesterolemic animals elicited similar drug-related vasodilation regardless of Pomanox supplementation. All animals displayed a similar vasodilatory response to sodium nitroprusside and L-NG-monomethylarginine blunted all vasorelaxation responses except for sodium nitroprusside. CONCLUSIONS: Pomanox supplementation hinders hyperlipemia-induced coronary endothelial dysfunction by activating the Akt/endothelial nitric oxide-synthase pathway and favorably counteracting vascular inflammation and oxidative damage.

Interaction of recombinant octameric hemoglobin with endothelial cells.

Hemoglobin-based oxygen carriers (HBOCs) may generate oxidative stress, vasoconstriction and inflammation. To reduce these undesirable vasoactive properties, we increased hemoglobin (Hb) molecular size by genetic engineering with octameric Hb, recombinant (r) HbßG83C. We investigate the potential side effects of rHbßG83C on endothelial cells. The rHbßG83C has no impact on cell viability, and induces a huge repression of endothelial nitric oxide synthase gene transcription, a marker of vasomotion. No induction of Intermolecular-Adhesion Molecule 1 and E-selectin (inflammatory markers) transcription was seen. In the presence of rHbßG83C, the transcription of heme oxygenase-1 (oxidative stress marker) is weakly increased compared to the two other HBOCs (references) or Voluven (control). This genetically engineered octameric Hb, based on a human Hb ßG83C mutant, leads to little impact at the level of endothelial cell inflammatory response and thus appears as an interesting molecule for HBOC development.

Diabetic nephropathy is resistant to oral L-arginine or L-citrulline supplementation.

Our recent publication showed that pharmacological blockade of arginases confers kidney protection in diabetic nephropathy via a nitric oxide (NO) synthase (NOS)3-dependent mechanism. Arginase competes with endothelial NOS (eNOS) for the common substrate L-arginine. Lack of L-arginine results in reduced NO production and eNOS uncoupling, which lead to endothelial dysfunction. Therefore, we hypothesized that L-arginine or L-citrulline supplementation would ameliorate diabetic nephropathy. DBA mice injected with multiple low doses of vehicle or streptozotocin (50 mg/kg ip for 5 days) were provided drinking water with or without L-arginine (1.5%, 6.05 g·kg(-1)·day(-1)) or L-citrulline (1.66%, 5.73 g·kg(-1)·day(-1)) for 9 wk. Nonsupplemented diabetic mice showed significant increases in albuminuria, blood urea nitrogen, glomerular histopathological changes, kidney macrophage recruitment, kidney TNF-α and fibronectin mRNA expression, kidney arginase activity, kidney arginase-2 protein expression, and urinary oxidative stress along with a significant reduction of nephrin and eNOS protein expression and kidney nitrite + nitrate compared with normal mice after 9 wk of diabetes. Surprisingly, L-arginine or L-citrulline supplementation in diabetic mice did not affect any of these parameters despite greatly increasing kidney and plasma arginine levels. These findings demonstrate that chronic L-arginine or L-citrulline supplementation does not prevent or reduce renal injury in a model of type 1 diabetes.

Chronic treatment with ticagrelor limits myocardial infarct size: an adenosine and cyclooxygenase-2-dependent effect.

OBJECTIVE: In a phase III clinical trial (PLATelet inhibition and patient Outcomes, PLATO), ticagrelor provided better clinical outcomes than clopidogrel in patients with acute coronary syndromes. In addition to P2Y12-receptor antagonism, ticagrelor prevents cell uptake of adenosine and has proven able to augment adenosine effects. Adenosine protects the heart against ischemia-reperfusion injury. We compared the effects of clopidogrel and ticagrelor on myocardial infarct size (IS). APPROACH AND RESULTS: Rats received oral ticagrelor (0, 75, 150, or 300 mg/kg/d) or clopidogrel (30 or 90 mg/kg/d) for 7 days and underwent 30-minute coronary artery ligation and 24-hour reperfusion. Area at risk was assessed by blue dye and IS by 2,3,5-triphenyl-tetrazolium-chloride. Cyclooxygenase-2 (COX2) enzyme activity was assessed by ELISA and expression by real-time polymerase chain reaction. Mechanism responsible was explored using adenosine-receptor antagonist (CGS15943, an A2A/A1 antagonist) or cyclooxygenase inhibition by either aspirin (5, 10, or 25 mg/kg) or specific cyclooxygenase-1 (SC560) or COX2 (SC5815) inhibitors. Ticagrelor, dose-dependently, reduced IS, whereas clopidogrel had no effect. Adenosine-receptor antagonism blocked the ticagrelor effect and COX2 inhibition by SC5815, or high-dose aspirin attenuated the IS-limiting effect of ticagrelor, whereas cyclooxygenase-1 inhibition or low-dose aspirin had no effect. Ticagrelor, but not clopidogrel, upregulated COX2 expression and activity. Also this effect was blocked by adenosine-receptor antagonism. Ticagrelor, but not clopidogrel, increased Akt and endothelial nitric oxide synthase phosphorylation. CONCLUSIONS: Ticagrelor, but not clopidogrel, reduces myocardial IS. The protective effect of ticagrelor was dependent on adenosine-receptor activation with downstream upregulation of endothelial nitric oxide synthase and COX2 activity.

Antenatal maternally-administered phosphodiesterase type 5 inhibitors normalize eNOS expression in the fetal lamb model of congenital diaphragmatic hernia.

PURPOSE: Pulmonary hypertension (pHTN), a main determinant of survival in congenital diaphragmatic hernia (CDH), results from in utero vascular remodeling. Phosphodiesterase type 5 (PDE5) inhibitors have never been used antenatally to treat pHTN. The purpose of this study is to determine if antenatal PDE5 inhibitors can prevent pHTN in the fetal lamb model of CDH. METHODS: CDH was created in pregnant ewes. Postoperatively, pregnant ewes received oral placebo or tadalafil, a PDE5 inhibitor, until delivery. Near term gestation, lambs underwent resuscitations, and lung tissue was snap frozen for protein analysis. RESULTS: Mean cGMP levels were 0.53±0.11 in placebo-treated fetal lambs and 1.73±0.21 in tadalafil-treated fetal lambs (p=0.002). Normalized expression of eNOS was 82%±12% in Normal-Placebo, 61%±5% in CDH-Placebo, 116%±6% in Normal-Tadalafil, and 86%±8% in CDH-Tadalafil lambs. Normalized expression of ß-sGC was 105%±15% in Normal-Placebo, 82%±3% in CDH-Placebo, 158%±16% in Normal-Tadalafil, and 86%±8% in CDH-Tadalafil lambs. Endothelial NOS and ß-sGC were significantly decreased in CDH (p=0.0007 and 0.01 for eNOS and ß-sGC, respectively), and tadalafil significantly increased eNOS expression (p=0.0002). CONCLUSIONS: PDE5 inhibitors can cross the placental barrier. ß-sGC and eNOS are downregulated in fetal lambs with CDH. Antenatal PDE5 inhibitors normalize eNOS and may prevent in utero vascular remodeling in CDH.

Mg supplementation protects against ritonavir-mediated endothelial oxidative stress and hepatic eNOS downregulation.

Ritonavir (RTV), a prototypical protease inhibitor currently used as a key component of anti-HIV therapy, is known for its endothelial and hepatic toxicity. The effects of RTV and magnesium supplementation on cultured bovine endothelial cell (EC) and rat hepatic endothelial nitric oxide synthase (eNOS) status were investigated. RTV dose-dependently (5-30 µM) decreased EC viability after 48 h; high Mg (2mM) significantly attenuated the lost viability. ECs incubated with 15 µM RTV for 6 to 24h resulted in two- to fourfold elevation of oxidized glutathione and a 25% loss of total glutathione. At 24h, EC superoxide production due to RTV was detected by dihydroethidium staining and increased 41% when quantified by flow cytometry; altered glutathione status and superoxide levels were both substantially reversed by 2mM Mg. RTV reduced eNOS mRNA (-25% at 24 h) and led to decreased eNOS dimer/monomer ratios; nitric oxide-derived products decreased 40%; both changes were attenuated by Mg supplementation. In male Lewis-Brown Norway rats, RTV administration (75 mg/kg/day, 5 weeks) resulted in an 85% increase in plasma 8-isoprostane and a 23% decrease in hepatic eNOS mRNA; concomitantly, eNOS protein decreased 75%, whereas plasma nitrite level was reduced 48%. Dietary Mg supplementation (sixfold higher than control) prevented the eNOS mRNA decrease along with lowering 8-isoprostane and restored the eNOS protein and plasma nitrite levels comparable to controls. In conclusion, Mg attenuates RTV-mediated EC oxidative eNOS dysfunction and downregulation of hepatic eNOS expression; we suggest that Mg can serve as a beneficial adjunct therapeutic against RTV-mediated eNOS toxicity.

Protective effect of sildenafil on liver injury induced by intestinal ischemia/reperfusion.

BACKGROUND: This study evaluated the protective effect of sildenafil on liver injury induced by intestinal ischemia-reperfusion. METHODS: Forty female Sprague Dawley rats were divided into 4 groups: sham-control (SC), ischemia (I), ischemia-reperfusion (IR), and ischemia-reperfusion+sildenafil (SIL; sildenafil gavaged at 50mg/kg before operating). A 2-h ischemia-reperfusion was performed by clamping the superior mesenteric artery. Liver function, plasma alanine (ALT) and aspartate (AST) aminotransferase, and intestinal and liver malondialdehyde (MDA) were measured at the end of the experiment. Intestinal and liver tissue damage was examined by histology. Liver samples were immunologically stained for endothelial nitric oxide synthase (eNOS) and proliferating cell nuclear antigen (PCNA). RESULTS: The ALT and AST levels were highest in the IR group and were lower in the SIL group (p<0.05). Intestinal MDA levels were statistically higher in the IR group than in the SC, I and SIL groups. Liver MDA levels were significantly higher in the IR group than in the I and SC groups (p<0.05) and higher than in the SIL group (p>0.05). Intestinal damage based on Chiu scoring was more severe in the IR than in the SIL group (p<0.05). Sildenafil reduced damage and also increased eNOS and PCNA immunoreactivity in liver tissue. CONCLUSIONS: Sildenafil shows a protective effect on intestinal ischemia-reperfusion-induced liver injury, possibly by decreasing vascular resistance through increased nitric oxide levels.

Pien Tze Huang inhibits tumor angiogenesis in a mouse model of colorectal cancer via suppression of multiple cellular pathways.

Angiogenesis plays an essential role in cancer progression, which therefore has become an attractive target for anticancer treatment. Tumor angiogenesis is tightly regulated by multiple signaling pathways that usually function redundantly; in addition, crosstalk between these pathways forms a complicated network that is regulated by compensatory mechanisms. Given the complexity of pathogenic mechanisms underlying tumor angiogenesis, most currently used angiogenesis inhibitors that only target single pathways may be insufficient and probably generate drug resistance, thus, increasing the necessity for development of novel anticancer agents. Traditional Chinese medicines (TCM) are receiving great interest since they have relatively fewer side-effects and have been used for thousands of years to clinically treat various types of diseases including cancer. Pien Tze Huang (PZH), a well-known traditional Chinese formulation that was first prescribed 450 years ago, has long been used as an alternative remedy for cancers. However, the precise mechanism of PZH's anticancer activity remains to be further elucidated. Using a colorectal cancer mouse xenograft model, in the present study, we evaluated the effect of PZH on tumor angiogenesis and investigated the underlying molecular mechanisms. We found that PZH inhibited tumor growth since PZH treatment resulted in decrease in both tumor volume and tumor weight in CRC mice. In addition, PZH suppressed the activation of several signaling pathways such as STAT3, Akt and MAPKs. Consequently, the inhibitory effect of PZH on these pathways resulted in the inhibition of tumor angiogenesis as demonstrated by the decrease of microvessel density in tumor tissues. Moreover, PZH treatment reduced the expression of angiogenic factors including iNOS, eNOS, VEGF-A, bFGF as well as their specific receptors VEGFR2 and bFGFR. Altogether, our findings suggest that inhibition of tumor angiogenesis via suppression of multiple signaling pathways might be one of the mechanisms whereby PZH affects cancers.

Flos lonicerae extracts and chlorogenic acid protect human umbilical vein endothelial cells from the toxic damage of perfluorooctane sulphonate.

Chlorogenic acid (CGA), one of the most common phenolic acids, is found in many food and traditional Chinese herbs. Various bioactivities of CGA are studied. However, little is known about these properties of Flos Lonicerae extracts, and the difference in the effect between Flos Lonicerae extracts and CGA has not been reported. CGA was identified in Flos Lonicerae extracts by HPLC and determined qualitatively by quadrupole ion trap mass spectrometry. In this study, we evaluated the effect of Flos Lonicerae extracts and CGA on inflammatory-related gene expression, adhesion molecule expression and reactive oxygen species (ROS) production in perfluorooctane sulphonate (PFOS)-treated human umbilical vein endothelial cells (HUVECs). The suppression of transcription of IL-1ß, IL-6, COX-2, and P-Selectin genes with Flos Lonicerae extracts was greater than that of CGA in PFOS-treated HUVECs, while the degree of suppression on PFOS-induced expression of NOS3 and ICAM-1 was greater for CGA. Furthermore, the suppressive effect of Flos Lonicerae extracts on adhesion of monocytes onto PFOS-induced HUVECs was greater than that of CGA. In addition, Flos Lonicerae extracts and CGA were highly effective in reducing ROS although their effects were almost comparable. So, Flos Lonicerae extracts exhibited antioxidant activity and CGA was a major contributor to this activity. These results suggest that Flos Lonicerae extracts could be useful to prevent PFOS-mediated inflammatory diseases.

Hydrogen water consumption prevents osteopenia in ovariectomized rats.

BACKGROUND AND PURPOSE: Accumulating evidence indicates an important role of oxidative stress in the progression of osteoporosis. Recently, it was demonstrated that hydrogen gas, as a novel antioxidant, could selectively reduce hydroxyl radicals and peroxynitrite anion to exert potent therapeutic antioxidant activity. The aim of the present work was to investigate the effect of hydrogen water (HW) consumption on ovariectomy-induced osteoporosis. EXPERIMENTAL APPROACH: Ovariectomized rats were fed with HW (1.3 ± 0.2 mg·L⁻¹) for 3 months. Then, blood was collected and femur and vertebrae were removed for evaluation of the effect of HW on bone. KEY RESULTS: HW consumption in ovariectomized rats had no significant effect on oestrogen production, but prevented the reduction of bone mass including bone mineral content and bone mineral density in femur and vertebrae, and preserved mechanical strength including ultimate load, stiffness, and energy, and bone structure including trabecular bone volume fraction, trabecular number, and trabecular thickness in femur, and preserved mechanical strength including ultimate load and stiffness, and bone structure including trabecular bone volume fraction and trabecular number in vertebrae. In addition, treatment with HW abated oxidative stress and suppressed IL-6 and TNF-α mRNA expressions in femur of ovariectomized rats; treatment with HW increased femur endothelial NOS activity and enhanced circulating NO level in ovariectomized rats. CONCLUSIONS AND IMPLICATIONS: HW consumption prevents osteopenia in ovariectomized rats possibly through the ablation of oxidative stress induced by oestrogen withdrawal.

Antihypertensive effects of extract from Picrasma quassiodes (D. Don) Benn. in spontaneously hypertensive rats.

UNLABELLED: ETHNOPHARMACOLOGICA RELEVANCE: Picrasma quassiodes (D. Don) Benn. (PQB) is a widely used herbal medicine used for gastroenteritis, snakebite, infection and hypertension in China. The aim of the study was to investigate the possible antihypertensive mechanisms on spontaneously hypertensive rats (SHR) of the extract from Picrasma quassiodes (D. Don) Benn. MATERIALS AND METHODS: In the in vivo study, extract from Picrasma quassiodes (D. Don) Benn. at the dose of 50, 100, 200mg/kg and captopril (12.5mg/kg) were administrated to different group of SHR rats by gavage for six consecutive weeks after the blood pressures were firstly measured. At the end of the study, rats serum nitric oxide (NO) was measured by the nitrate reductase method; superoxide dismutase (SOD) and malondialdehyde (MDA) activities were measured by the colorimetric method; the expression of aorta endothelial nitric oxide synthase (eNOS) was measured by immunohistochemical analysis. RESULTS: The results showed that the oral administration of PQB could lower the systolic blood pressure (SBP) of SHR rats. In addition, the serum level of NO in SHR treated with PQB (100 and 200mg/kg) was increased dramatically (P<0.05, P<0.01), but administration with captopril had no significant effect. The expression of aorta eNOS was markedly increased when treated with PQB. The serum SOD levels were increased with treatment of PQB (100 and 200mg/kg; P<0.05, P<0.01). All the effects of these parameters were comparable to that of the SHR control group. CONCLUSIONS: Our results disclosed that PQB is effective to lower blood pressure of SHR, its antihypertensive effect is probably associated with lowering oxidative stress by reducing SOD activity, preserving endothelial function and increasing the expression of eNOS to regulate NO and directly relax artery.

Effect of long-term piceatannol treatment on eNOS levels in cultured endothelial cells.

Piceatannol (3, 3', 4, 5'-tetrahydroxy-trans-stilbene) is a naturally occurring phytochemical found in passion fruit (Passiflora edulis) seeds. Previously, we demonstrated that piceatannol has acute vasorelaxant effects in rat thoracic aorta. It was suggested that endothelial NO synthase (eNOS) might be involved in piceatannol-induced acute vasorelaxation. Here, we investigated the expression of eNOS in EA.hy926 human umbilical vein cells after long-term treatment with piceatannol, and compared this effect with that of resveratrol, an analog of piceatannol. Long-term treatment with piceatannol up-regulated eNOS mRNA expression and increased eNOS protein expression in a dose-dependent manner. Moreover, piceatannol increased the levels of phosphorylated eNOS. Treatment with resveratrol also increased eNOS expression, but to a lesser degree than piceatannol. These findings indicate that piceatannol may improve vascular function by up-regulating eNOS expression.

Nitric oxide rescues thalidomide mediated teratogenicity.

Thalidomide, a sedative drug given to pregnant women, unfortunately caused limb deformities in thousands of babies. Recently the drug was revived because of its therapeutic potential; however the search is still ongoing for an antidote against thalidomide induced limb deformities. In the current study we found that nitric oxide (NO) rescues thalidomide affected chick (Gallus gallus) and zebrafish (Danio rerio) embryos. This study confirms that NO reduced the number of thalidomide mediated limb deformities by 94% and 80% in chick and zebrafish embryos respectively. NO prevents limb deformities by promoting angiogenesis, reducing oxidative stress and inactivating caspase-3 dependent apoptosis. We conclude that NO secures angiogenesis in the thalidomide treated embryos to protect them from deformities.