Protective effects of benidipine on hydrogen peroxide-induced injury in rat isolated hearts

Nutraceutical activation of Sirt1: a review

The deacetylase sirtuin 1 (Sirt1), activated by calorie restriction and fasting, exerts several complementary effects on cellular function that are favourable to healthspan; it is often thought of as an 'anti-aging' enzyme. Practical measures which might boost Sirt1 activity are therefore of considerable interest. A number of nutraceuticals have potential in this regard. Nutraceuticals reported to enhance Sirt1 synthesis or protein expression include ferulic acid, tetrahydrocurcumin, urolithin A, melatonin, astaxanthin, carnosic acid and neochlorogenic acid. The half-life of Sirt1 protein can be enhanced with the natural nicotinamide catabolite N1-methylnicotinamide. The availability of Sirt1's obligate substrate NAD+ can be increased in several ways: nicotinamide riboside and nicotinamide mononucleotide can function as substrates for NAD+ synthesis; activators of AMP-activated kinase-such as berberine-can increase expression of nicotinamide phosphoribosyltransferase, which is rate limiting for NAD+ synthesis; and nutraceutical quinones such as thymoquinone and pyrroloquinoline quinone can boost NAD+ by promoting oxidation of NADH. Induced ketosis-as via ingestion of medium-chain triglycerides-can increase NAD+ in the brain by lessening the reduction of NAD+ mediated by glycolysis. Post-translational modifications of Sirt1 by O-GlcNAcylation or sulfonation can increase its activity, suggesting that administration of glucosamine or of agents promoting hydrogen sulfide synthesis may aid Sirt1 activity. Although resveratrol has poor pharmacokinetics, it can bind to Sirt1 and activate it allosterically-as can so-called sirtuin-activating compound drugs. Since oxidative stress can reduce Sirt1 activity in multiple ways, effective antioxidant supplementation that blunts such stress may also help preserve Sirt1 activity in some circumstances. Combination nutraceutical regimens providing physiologically meaningful doses of several of these agents, capable of activating Sirt1 in complementary ways, may have considerable potential for health promotion. Such measures may also amplify the benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors in non-diabetic disorders, as these benefits appear to reflect upregulation of Sirt1 and AMP-activated protein kinase activities.

Network pharmacology-based therapeutic mechanism of Kuanxiong aerosol for angina pectoris

ETHNOPHARMACOLOGICAL RELEVANCE

Kuanxiong aerosol has been reported to be an effective and safe clinical treatment for angina pectoris (AP).

AIM OF THE STUDY

To explore the potential pharmacological mechanism of Kuanxiong aerosol by combined methods of network pharmacology prediction and experimental verification.

MATERIALS AND METHODS

Networks of Kuanxiong aerosol-associated targets and AP-related genes were constructed through STRING database. Potential targets and pathway enrichment analysis related to the therapeutic efficacy of Kuanxiong aerosol were identified using Cytoscape and Database for Annotation, Visualization and Integrated Discovery (DAVID). To explore the mechanism of action of Kuanxiong aerosol, its in vitro effects on myocardial hypoxia, inflammatory cytokines, and oxidative injury, and its in vivo pharmacological effects on myocardial ischemia and cardiac fibrosis were studied in rat models.

RESULTS

Network pharmacology analysis revealed that the potential targets mainly include the Fas ligand (FASLG), interleukin 4 (IL4), and catalase (CAT), which mediated the processes of apoptosis, and cellular responses to hypoxia, lipopolysaccharide (LPS), reactive oxygen species (ROS), and mechanical stimulus. Multiple pathways, such as the hypoxia-inducible factor 1 (HIF1) and tumor necrosis factor (TNF) pathways were found to be closely related to the pharmacological protective mechanism of Kuanxiong aerosol against AP. In addition, Kuanxiong aerosol suppressed the hypoxia, LPS, and hydrogen peroxide (H₂O₂)-induced injuries of H9c2 cardiomyocytes through the regulation of HIF1A, suppressed expression of IL6 and TNF, and antioxidant property. In the rat model of myocardial ischemia, Kuanxiong aerosol was found to lower the creatine kinase (CK), creatine kinase-myocardial band (CK-MB), and lactate dehydrogenase (LDH) levels, without altering the hemodynamic function. Kuanxiong aerosol was capable of attenuating cardiac fibrosis and improving cardiac function in a cardiac fibrosis rat model.

CONCLUSIONS

This study revealed that the pharmacological mechanisms of Kuanxiong aerosol for AP therapy were related to anti-myocardial ischemia, anti-inflammation, and anti-oxidation via a non-hemodynamic manner, indicating that Kuanxiong aerosol is a preferable drug clinically for AP treatment due to its both preventive and protective effects.

Using urine metabolomics to understand the pathogenesis of infant respiratory syncytial virus (RSV) infection and its role in childhood wheezing

BACKGROUND

Respiratory syncytial virus (RSV) infection in infants causes significant morbidity and is the strongest risk factor associated with asthma. Metabolites, which reflect the interactions between host cell and virus, provide an opportunity to identify the pathways that underlie severe infections and asthma development.

OBJECTIVE

To study metabolic profile differences between infants with RSV infection, and human rhinovirus (HRV) infection, and healthy infants. To compare infant metabolic differences between children who do and do not wheeze.

METHODS

In a term birth cohort, urine was collected while healthy and during acute viral respiratory infection with RSV and HRV. We used ¹H-NMR to identify urinary metabolites. Multivariate and univariate statistics were used to discriminate metabolic profiles of infants with either RSV ARI, or HRV ARI, and healthy infants. Multivariable logistic regression was used to assess the association of urine metabolites with 1st-, 2nd-, and 3rd-year recurrent wheezing.

RESULTS

Several metabolites in nicotinate and nicotinamide metabolism pathways were down-regulated in infants with RSV infection compared to healthy controls. There were no significant differences in metabolite profiles between infants with RSV infection and infants with HRV Infection. Alanine was strongly associated with reduced risk of 1st-year wheezing (OR 0.18[0.0, 0.46]) and 2nd-year wheezing (OR 0.31[0.13, 0.73]), while 2-hydroxyisobutyric acid was associated with increased 3rd-year wheezing (OR 5.02[1.49, 16.93]) only among the RSV infected subset.

CONCLUSION

The metabolites associated with infant RSV infection and recurrent-wheezing are indicative of viral takeover of the cellular machinery and resources to enhance virulence, replication, and subversion of the host immune-response, highlighting metabolic pathways important in the pathogenesis of RSV infection and wheeze development.

The effects of 1,4-dimethylpyridine in metastatic prostate cancer in mice

BACKGROUND

We previously showed that 1-methylnicotinamide (1-MNA) and its analog 1,4-dimethylpyridine (1,4-DMP) could inhibit the formation of lung metastases and enhance the efficacy of cyclophosphamide-based chemotherapy in the model of spontaneously metastasizing 4T1 mouse mammary gland tumors. In the present study, we aimed to investigate whether the previously observed activity of pyridine compounds pertains also to the prevention and the treatment of metastatic prostate tumors, in a combined chemotherapy with docetaxel.

METHODS

Cancer-preventing activity of 1,4-DMP was studied in the model of prostate tumors spontaneously arising in C57BL/6-Tg (TRAMP)8247Ng/J (TRAMP) mice. The efficacy of the combined chemotherapy, comprising simultaneous use of 1,4-DMP and docetaxel, was evaluated in the orthotopic mouse model of human PC-3M-luc2 prostate cancer. The toxicity of the applied treatment was also determined.

RESULTS

The development of prostate tumors in TRAMP mice remained unaffected after administration of 1,4-DMP. Similarly, no effect of 1,4-DMP was found on the growth of orthotopically transplanted PC-3M-luc2 tumors. However, when 1,4-DMP was administered along with docetaxel, it enhanced the anticancer activity of the chemotherapy. As a result, in PC-3M-luc2-bearing mice statistically significant inhibition of the tumor growth and lower metastases incidence were observed. The decreased metastatic yield is probably related to the diminished platelet activity observed in mice treated with combined therapeutic regimen. Finally, the combined treatment exhibited lowered side effects accompanying docetaxel administration.

CONCLUSIONS

Results presented herein confirm previously published data on the anticancer activity of pyridine compounds and demonstrate that 1,4-DMP may be beneficially implemented into chemotherapy utilizing various cytotoxic agents, directed against multiple metastatic tumor types.

Oral treatment with Lactobacillus rhamnosus attenuates behavioural deficits and immune changes in chronic social stress

BACKGROUND

Stress-related disorders involve systemic alterations, including disruption of the intestinal microbial community. Given the putative connections between the microbiota, immunity, neural function, and behaviour, we investigated the potential for microbe-induced gut-to-brain signalling to modulate the impact of stress on host behaviour and immunoregulation.

METHODS

Male C57BL/6 mice treated orally over 28 days with either Lactobacillus rhamnosus (JB-1) ™ or vehicle were subjected to chronic social defeat and assessed for alterations in behaviour and immune cell phenotype. 16S rRNA sequencing and mass spectrometry were employed to analyse the faecal microbial community and metabolite profile.

RESULTS

Treatment with JB-1 decreased stress-induced anxiety-like behaviour and prevented deficits in social interaction with conspecifics. However, JB-1 did not alter development of aggressor avoidance following social defeat. Microbial treatment attenuated stress-related activation of dendritic cells while increasing IL-10+ regulatory T cells. Furthermore, JB-1 modulated the effect of stress on faecal metabolites with neuroactive and immunomodulatory properties. Exposure to social defeat altered faecal microbial community composition and reduced species richness and diversity, none of which was prevented by JB-1. Stress-related microbiota disruptions persisted in vehicle-treated mice for 3 weeks following stressor cessation.

CONCLUSIONS

These data demonstrate that despite the complexity of the gut microbiota, exposure to a single microbial strain can protect against certain stress-induced behaviours and systemic immune alterations without preventing dysbiosis. This work supports microbe-based interventions for stress-related disorders.

Niacin Alternatives for Dyslipidemia: Fool's Gold or Gold Mine? Part II: Novel Niacin Mimetics

Two cardiovascular outcome trials established niacin 3 g daily prevents hard cardiac events. However, as detailed in part I of this series, an extended-release (ER) alternative at only 2 g nightly demonstrated no comparable benefits in two outcome trials, implying the alternative is not equivalent to the established cardioprotective regimen. Since statins leave a significant treatment gap, this presents a major opportunity for developers. Importantly, the established regimen is cardioprotective, so the pathway is likely beneficial. Moreover, though effective, the established cardioprotective regimen is cumbersome, limiting clinical use. At the same time, the ER alternative has been thoroughly discredited as a viable substitute for the established cardioprotective regimen. Therefore, by exploiting the pathway and skillfully avoiding the problems with the established cardioprotective regimen and the ER alternative, developers could validate cardioprotective variations facing little meaningful competition from their predecessors. Thus, shrewd developers could effectively tap into a gold mine at the grave of the ER alternative. The GPR109A receptor was discovered a decade ago, leading to a large body of evidence commending the niacin pathway to a lower cardiovascular risk beyond statins. While mediating niacin's most prominent adverse effects, GPR109A also seems to mediate anti-lipolytic, anti-inflammatory, and anti-atherogenic effects of niacin. Several developers are investing heavily in novel strategies to exploit niacin's therapeutic pathways. These include selective GPR109A receptor agonists, niacin prodrugs, and a niacin metabolite, with encouraging early phase human data. In part II of this review, we summarize the accumulated results of these early phase studies of emerging niacin mimetics.

1-methylnicotinamide and its structural analog 1,4-dimethylpyridine for the prevention of cancer metastasis

Background

1-methylnicotinamide (1-MNA), an endogenous metabolite of nicotinamide, has recently gained interest due to its anti-inflammatory and anti-thrombotic activities linked to the COX-2/PGI₂ pathway. Given the previously reported anti-metastatic activity of prostacyclin (PGI₂), we aimed to assess the effects of 1-MNA and its structurally related analog, 1,4-dimethylpyridine (1,4-DMP), in the prevention of cancer metastasis.

Methods

All the studies on the anti-tumor and anti-metastatic activity of 1-MNA and 1,4-DMP were conducted using the model of murine mammary gland cancer (4T1) transplanted either orthotopically or intravenously into female BALB/c mouse. Additionally, the effect of the investigated molecules on cancer cell-induced angiogenesis was estimated using the matrigel plug assay utilizing 4T1 cells as a source of pro-angiogenic factors.

Results

Neither 1-MNA nor 1,4-DMP, when given in a monotherapy of metastatic cancer, influenced the growth of 4T1 primary tumors transplanted orthotopically; however, both compounds tended to inhibit 4T1 metastases formation in lungs of mice that were orthotopically or intravenously inoculated with 4T1 or 4T1-luc2-tdTomato cells, respectively. Additionally, while 1-MNA enhanced tumor vasculature formation and markedly increased PGI₂ generation, 1,4-DMP did not have such an effect. The anti-metastatic activity of 1-MNA and 1,4-DMP was further confirmed when both agents were applied with a cytostatic drug in a combined treatment of 4T1 murine mammary gland cancer what resulted in up to 80 % diminution of lung metastases formation.

Conclusions

The results of the studies presented below indicate that 1-MNA and its structural analog 1,4-DMP prevent metastasis and might be beneficially implemented into the treatment of metastatic breast cancer to ensure a comprehensive strategy of metastasis control.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0389-9) contains supplementary material, which is available to authorized users.

Hypoglycemic activities of lyophilized powder of Gynura divaricata by improving antioxidant potential and insulin signaling in type 2 diabetic mice

Background

Diabetes mellitus is a serious disease affecting about 5% of people worldwide. Although several studies have indicated hypoglycemic activities of Gynura divaricata (GD), the mechanisms by which GD improves the symptoms of diabetes remain unclear.

Objective

The aim of this study was to investigate the potential hypoglycemic effects of GD.

Design

The leaves and stems of GD were prepared and lyophilized into a powder, which was added to the diet of mice with type 2 diabetes induced by a high-fat diet in combination with streptozotocin for 4 weeks. During this period, fasting blood glucose (FBG) levels and body weight of mice were measured. In addition, at the end of the experiment, a series of assays was performed.

Results

GD administration effectively alleviates insulin resistance and induces a decrease in FBG by 59.54% in 1.2% (L) GD-treated diabetic group and 56.13% in 4.8% (H) GD-treated diabetic group after 4 weeks, respectively, relative to diabetic model mice. The antioxidant capacity was improved by increasing the activities of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) by 64.87% and 53.42% in treatment group H, compared to diabetic model mice, while GD treatment induced a significant decrease in malondialdehyde (MDA) level by 50% in treatment group L, compared to the level in diabetic model mice. Furthermore, glucose metabolism was ameliorated by the increased glycogen synthesis in the livers of diabetic mice. In addition, we also demonstrated that the messenger RNA (mRNA) and protein expression levels of AKT, PI3K and PDK-1, which are involved in insulin signaling, were significantly increased.

Conclusions

Oral administration of the GD-lyophilized powder has been effectively hypoglycemic, which is done by activating insulin signaling and improving antioxidant capacity in mice with type 2 diabetes.

Antiatherosclerotic Effects of 1-Methylnicotinamide in Apolipoprotein E/Low-Density Lipoprotein Receptor-Deficient Mice: A Comparison with Nicotinic Acid

1-Methylnicotinamide (MNA), the major endogenous metabolite of nicotinic acid (NicA), may partially contribute to the vasoprotective properties of NicA. Here we compared the antiatherosclerotic effects of MNA and NicA in apolipoprotein E (ApoE)/low-density lipoprotein receptor (LDLR)-deficient mice. ApoE/LDLR(-/-) mice were treated with MNA or NicA (100 mg/kg). Plaque size, macrophages, and cholesterol content in the brachiocephalic artery, endothelial function in the aorta, systemic inflammation, platelet activation, as well as the concentration of MNA and its metabolites in plasma and urine were measured. MNA and NicA reduced atherosclerotic plaque area, plaque inflammation, and cholesterol content in the brachiocephalic artery. The antiatherosclerotic actions of MNA and NicA were associated with improved endothelial function, as evidenced by a higher concentration of 6-keto-prostaglandin F1 α and nitrite/nitrate in the aortic ring effluent, inhibition of platelets (blunted thromboxane B2 generation), and inhibition of systemic inflammation (lower plasma concentration of serum amyloid P, haptoglobin). NicA treatment resulted in an approximately 2-fold higher concentration of MNA and its metabolites in urine and a 4-fold higher nicotinamide/MNA ratio in plasma, compared with MNA treatment. In summary; MNA displays pronounced antiatherosclerotic action in ApoE/LDLR(-/-) mice, an effect associated with an improvement in prostacyclin- and nitric oxide-dependent endothelial function, inhibition of platelet activation, inhibition of inflammatory burden in plaques, and diminished systemic inflammation. Despite substantially higher MNA availability after NicA treatment, compared with an equivalent dose of MNA, the antiatherosclerotic effect of NicA was not stronger. We suggest that detrimental effects of NicA or its metabolites other than MNA may limit beneficial effects of NicA-derived MNA.

Ongoing controversies surrounding cardiac remodeling: is it black and white-or rather fifty shades of gray?

Cardiac remodeling describes the heart's multimodal response to a myriad of external or intrinsic stimuli and stressors most of which are probably only incompletely elucidated to date. Over many years the signaling molecules involved in these remodeling processes have been dichotomized according to a classic antagonistic view of black and white, i.e., attributed either a solely maladaptive or entirely beneficial character. By dissecting controversies, recent developments and shifts in perspective surrounding the three major cardiac signaling molecules calcineurin (Cn), protein kinase A (PKA) and calcium/calmodulin-dependent kinase II (CaMKII), this review challenges this dualistic view and advocates the nature and dignity of each of these key mediators of cardiac remodeling as a multilayered, highly context-sensitive and sophisticated continuum that can be markedly swayed and influenced by a multitude of environmental factors and crosstalk mechanisms. Furthermore this review delineates the importance and essential contributions of degradation and proteolysis to cardiac plasticity and homeostasis and finally aims to integrate the various aspects of protein synthesis and turnover into a comprehensive picture.

Effects of N1-methylnicotinamide on oxidative and glycooxidative stress markers in rats with streptozotocin-induced diabetes mellitus

OBJECTIVES

This study was focused on the monitoring how the anti-inflammatory substance, N(1)-methylnicotinamide (MNA), could influence oxidation and glycooxidation stress markers in rats under conditions of streptozotocin (STZ)-induced diabetes mellitus.

METHODS

Diabetes mellitus was induced in 60 male Wistar rats by intraperitoneal injection of STZ and after 7 days diabetic animals were allocated to five groups according to the dose of MNA administered for 7 weeks. The degree of DNA damage in lymphocytes, as well as advanced glycation endproducts (AGEs), protein carbonyls, lipid peroxides, and total antioxidant capacity (TEAC) in plasma were measured.

RESULTS

Glycation damage to proteins (represented by AGEs level) was significantly increased in all diabetic groups compared to untreated non-diabetic animals. MNA did not affect TEAC of plasma in any group of diabetic rats. Supplementation of diabetic rats with MNA at the dose of 200 mg/kg resulted in decreased protein carbonyls (from 0.0818±0.0091 to 0.0558±0.0044 nmol/mg proteins; P<0.05, n=15) and DNA oxidation, reflected by the levels of 8-oxoG (0.6302±0.085 vs. 0.9213±0.108 8-oxoG/10(6) G; P<0.05, n=15), compared to untreated diabetic animals.

DISCUSSION

Our results demonstrated that MNA at suitable concentrations could influence oxidative modifications of proteins and DNA.

Diaquabis(5-bromo-2-hydroxybenzoato)bis(N-methylnicotinamide)zinc(II)

The title mononuclear complex mol­ecule, [Zn(C₇H₄BrO₃)₂(C₇H₈N₂O)₂(H₂O)₂], has a crystallographically imposed centre of symmetry. The zinc(II) atom is coordinated by two N atoms from two N-methyl­nicotinamide ligands, two O atoms from two 5-bromo­salicylate anions and two aqua O atoms in a slightly distorted octa­hedral geometry. Intra­molecular O—H⋯O hydrogen-bonding inter­actions are present. In the crystal structure, mol­ecules are linked by inter­molecular O—H⋯O and N—H⋯O hydrogen bonds, forming a two-dimensional network perpendicular to [100].

Simultaneous determination of nicotinic acid and its four metabolites in rat plasma using high performance liquid chromatography with tandem mass spectrometric detection (LC/MS/MS)

A sensitive and specific liquid chromatography electrospray ionization-tandem mass spectrometry method for the simultaneous quantitation of nicotinic acid (NicA) and its metabolites nicotinamide (NA), 1-methylnicotinamide (MNA), 1-methyl-2-pyridone-5-carboxamide (M2PY) and 1-methyl-4-pyridone-5-carboxamide (M4PY) in rat plasma has been developed and validated. As an internal standard, 6-chloronicotinamide was used. The samples (100 microL) were subjected to deproteinization with acetonitrile (200 microL) and then, after centrifugation, 150 microL of the supernatant was transferred into conical vial and evaporated. Dry residue was reconstituted in 100 microL of the ACN/water (10:90, v/v) mixture. Chromatography was performed on a Waters Spherisorb 5 microm CNRP 4.6 x 150 mm analytical column with gradient elution using a mobile phase containing acetonitrile and water with 0.1% of formic acid. The full separation of all compounds was achieved within 15 min of analysis. Detection was performed by an Applied Biosystems MDS Sciex API 2000 triple quadrupole mass spectrometer set at unit resolution. The mass spectrometer was operated in the selected reactions monitoring mode (SRM), monitoring the transition of the protonated molecular ions m/z 153-110 for M2PY, 153-136 for M4PY, 124-80 for NicA, 123-80 for NA and 137-94 for MNA. The mass spectrometric conditions were optimized for each compound by continuously infusing the standard solution at the rate of 5 microL/min using a Harvard infusion pump. Electrospray ionization (ESI) was used for ion production. The instrument was coupled to an Agilent 1100 LC system. The precision and accuracy for both intra- and inter-day determination of all analytes ranged from 1.3% to 13.3% and from 94.43% to 110.88%. No significant matrix effect (ME) was observed. Stability of compounds was established in a battery of stability studies, i.e. bench-top, autosampler and long-term storage stability as well as freeze/thaw cycles. The method proved to be suitable for various applications. In particular using this method we detected increased concentration of MNA and its metabolites in rat plasma after treatment with exogenous MNA (100 mg/kg), as well as increased concentration of endogenous NA and MNA in rat plasma in the early phase of hypertriglyceridemia development in rats fed high-fructose diet.

NMR-based metabolomics of urine for the atherosclerotic mouse model using apolipoprotein-E deficient mice

NMR-based metabolomics of mouse urine was used in conjunction with the traditional staining and imaging of aortas for the characterization of disease advancement, that is, plaque formation in untreated and drug-treated apolipoprotein-E (apoE) knockout mice. The metabolomics approach with multivariate analysis was able to differentiate the captopril-treated from the untreated mice in general agreement with the staining results. Principal component analysis showed a pattern shift in both the drug-treated and untreated samples as a function of time that could possibly be explained as the effect of aging. Allantoin, a marker attributed to captopril treatment was elevated in the drug-treated mice. From partial least squares-discriminant analysis, xanthine and ascorbate were elevated in the untreated mice and were possible markers of plaque formation in the apoE knockout mice. Several additional peaks in the spectra characterizing the study endpoint were found but their respective metabolite identities were unknown.

Radical scavenging and NO-releasing properties of selected β-adrenoreceptor antagonists

It is claimed that novel beta-adrenolytic drugs possess superior antioxidant properties as compared to classical selective or non-selective beta-adrenoceptor antagonists. Here we tested this notion by analyzing radical scavenging properties of selected beta-adrenolytic drugs and their ability to release nitric oxide in biological preparations. Selective beta1-adrenolytics such as nebivolol, atenolol, metoprolol and non-selective beta-adrenolytics with alpha1-receptor blocking properties such as carvedilol and labetalol were chosen for analysis. NO-releasing properties of nebivolol and carvedilol distinguished third generation beta-adrenolytics from their older counterparts while the reactivity towards hydroxyl and peroxyl radicals discerns only carvedilol but not nebivolol. Thus, superior clinical efficacy of third generation beta-adrenolytics may be related to their ability to release NO rather then to their direct antioxidant properties.

Benidipine, an anti-hypertensive drug, inhibits reactive oxygen species production in polymorphonuclear leukocytes and oxidative stress in salt-loaded stroke-prone spontaneously hypertensive rats

Oxidative stress is associated with exacerbation of renal injuries in hypertension. In clinical studies benidipine hydrochloride (benidipine), a dihydropyridine calcium channel blocker with antioxidant activity, reduced oxidative stress. However, the mechanism of suppression of oxidative stress remains to be fully characterized. Reactive oxygen species production by polymorphonuclear leukocyte plays important pathological roles in hypertension. Therefore, we examined the effects of benidipine both on reactive oxygen species production of human polymorphonuclear leukocytes and oxidative stress of an animal model. Human peripheral polymorphonuclear leukocytes or polymorphonuclear leukocyte-like differentiated HL-60 cells were used to examine effects of benidipine (0.1-30 microM) on formyl-Met-Leu-Phe-induced reactive oxygen species production, calcium mobilization, NADPH oxidase activation and phosphorylation of protein kinase C substrates. High-salt (8% NaCl) loaded stroke-prone spontaneously hypertensive rats were treated with or without benidipine (1, 3, 10 mg/kg/day) for 2 weeks, and thiobarbituric acid reactive substances, a plasma oxidative stress marker, and renal expression of oxidative stress-induced genes were measured. Benidipine concentration-dependently suppressed formyl-Met-Leu-Phe-induced reactive oxygen species production in polymorphonuclear leukocytes more potently than other calcium channel blockers such as amlodipine, azelnidipine, nitrendipine and nifedipine. Benidipine partially inhibited all of intracellular Ca(2+) elevation, protein kinase C activation and NADPH oxidase activation. Salt loading in stroke-prone spontaneously hypertensive rats augmented plasma thiobarbituric acid reactive substances levels; renal dysfunction; and renal expression of transforming growth factor-beta, collagen I and collagen III mRNAs; which were attenuated by benidipine treatment. These results indicate that benidipine prevents the polymorphonuclear leukocyte-derived reactive oxygen species production, which is due at least in part to its antioxidant action and inhibition of Ca(2+)/protein kinase C/NADPH oxidase signaling. The attenuation of reactive oxygen species production might contribute to the drug's reduction of oxidative stress and renal injuries in hypertension.

Effects of benidipine, a long-lasting dihydropyridine-Ca2+ channel blocker, on cerebral blood flow autoregulation in spontaneously hypertensive rats

Chronic hypertension shifts cerebral blood flow (CBF) autoregulation towards higher blood pressure. We examined whether or not benidipine, a long-lasting dihydropyridine calcium channel blocker (CCB), improves the CBF autoregulation in spontaneously hypertensive rats (SHRs). CBF was analyzed by laser-Doppler flowmetry during stepwise hypotension by controlled bleeding. The lower limit of CBF autoregulation was calculated as the mean arterial blood pressure at which CBF decreased by 10% of the baseline. Mean arterial blood pressure and cerebral vascular resistance in SHRs were higher than those in normotensive Wistar rats. Oral administration of benidipine (3 mg/kg) for 8 d lowered the mean arterial blood pressure and cerebral vascular resistance, which were equivalent to the effects of amlodipine (3 mg/kg), another CCB, or candesartan (1 mg/kg), an Angiotensin II type-1 receptor blocker. The lower limit of CBF autoregulation in SHRs (142+/-4 mmHg) was significantly shifted to a higher-pressure level compared with Wistar rats (59+/-2 mmHg). The lower limit of CBF autoregulation was significantly lower in the benidipine-treated group (91+/-4 mmHg) than that in the control SHRs, and similar to that of the amlodipine group (97+/-6 mmHg). Benidipine reduced the lower limit of CBF autoregulation more effectively than candesartan (109+/-4 mmHg). In conclusion, benidipine shifted the limit of CBF autoregulation towards lower blood pressure in SHRs under hypotensive conditions by hemorrhage. These results suggest that benidipine may be useful for the treatment of hypertensive patients with the elderly or cerebrovascular disorders, in whom autoregulation of CBF is impaired.

Oxidant-induced activation of type I protein kinase A is mediated by RI subunit interprotein disulfide bond formation

Here we demonstrate that type I protein kinase A is redoxactive, forming an interprotein disulfide bond between its two regulatory RI subunits in response to cellular hydrogen peroxide. This oxidative disulfide formation causes a subcellular translocation and activation of the kinase, resulting in phosphorylation of established substrate proteins. The translocation is mediated at least in part by the oxidized form of the kinase having an enhanced affinity for alpha-myosin heavy chain, which serves as a protein kinase A (PKA) anchor protein and localizes the PKA to its myofilament substrates troponin I and myosin binding protein C. The functional consequence of these events in cardiac myocytes is that hydrogen peroxide increases contractility independently of beta-adrenergic stimulation and elevations of cAMP. The oxidant-induced phosphorylation of substrate proteins and increased contractility is blocked by the kinase inhibitor H89, indicating that these events involve PKA activation. In essence, type I PKA contains protein thiols that operate as redox sensors, and their oxidation by hydrogen peroxide directly activates the kinase.

Topical application of 1-methylnicotinamide in the treatment of rosacea: a pilot study

Rosacea is a chronic facial dermatosis with a progressive course, which is characterized by the presence of erythema, papules, pustules, telangiectasias and sebaceous gland hyperplasia. However, the aetiology is still unknown; genetic predisposition, gastrointestinal disorders (Helicobacter pylori), infestations with Demodex folliculorum and environmental stimuli are considered to be involved in the inflammatory process. A metabolite of nicotinamide, 1-methylnicotinamide (MNA(+)), has anti-inflammatory properties, and this is the first study to test the effectiveness of this agent in treating rosacea. In total, 34 patients with rosacea were treated with a gel containing 0.25% MNA(+) as a chloride salt, twice daily for 4 weeks, after which improvement was observed in 26/34 cases. The improvement was good in 9/34 and moderate in 17/34, but no clinical effect was noted in seven subjects. In only one case was skin irritation given as the reason for treatment withdrawal. These results indicate that MNA(+) might be a useful agent for treating rosacea.

Benidipine, a long-acting calcium channel blocker, inhibits oxidative stress in polymorphonuclear cells in patients with essential hypertension

To study the relationship between blood pressure and oxidative stress in leukocytes, the effect of benidipine on these variables was compared with that of a placebo. Hypertensive patients were randomly assigned benidipine 4 mg (n=40) or placebo (n=40), and treated for 6 months. Oxidative stress in polymorphonuclear cells (PMNs) was measured by gated flow cytometry. There was a significant relationship between systolic or diastolic arterial pressure and reactive oxygen species (ROS) formation by PMNs in the benidipine group (r=0.61, p<0.01) and in the placebo group (r=0.58, p<0.01). After administration of 4 mg benidipine, ROS formation by PMNs fell by 32 arbitrary units (n=40, p<0.01). After administration of placebo, ROS formation by PMNs decreased by 0.6 arbitrary units (n=40, p=0.31) (p<0.01 for differing treatment effects). There was a significant relationship between the decrease in systolic arterial pressure and the decrease in ROS formation by PMNs in the benidipine group (r=0.52, p<0.01), but not in the placebo group (r=-0.08, p=0.61). There was also a significant relationship between the decrease in diastolic arterial pressure and decrease in ROS formation by PMNs in the benidipine group (r=0.65, p<0.01) but not in the placebo group (r=-0.09, p=0.59). In hypertensive patients, we observed a significant relationship between systolic or diastolic blood pressure and ROS formation by PMNs, and found that benidipine decreased oxidative stress in PMNs of hypertensive patients, at least in part by decreasing blood pressure.

Effects of benidipine, a dihydropyridine-Ca2+ channel blocker, on expression of cytokine-induced adhesion molecules and chemoattractants in human aortic endothelial cells

Benidipine hydrochloride (benidipine) is a dihydropyridine-Ca2+ channel blocker with antioxidant properties. We examined the effects of benidipine on cytokine-induced expression of adhesion molecules and chemokines, which play important roles in the adhesion of monocytes to endothelium. Pretreatment of human aortic endothelial cells (HAECs) with benidipine (0.3-10 micromol/l) for 24 h significantly suppressed cytokine-induced vascular cell adhesion molecule-1 (VCAM-1) and intracellular cell adhesion molecule-1 (ICAM-1) mRNA and protein expression, resulting in reduced adhesion of THP-1 monocytes. Benidipine also suppressed induction of monocyte chemoattractant protein (MCP)-1 and interleukin-8. Benidipine inhibited redox-sensitive transcriptional nuclear factor-kappaB (NF-kappaB) pathway, as determined by Western blotting of inhibitory kappaB (IkappaB) phosphorylation and luciferase reporter assay. Results of analysis using optical isomers of benidipine and antioxidants suggested that these inhibitory effects were dependent on pharmacological effects other than Ca2+ antagonism such as antioxidant effects. Benidipine may thus have anti-inflammatory properties and benefits for in the treatment of atherosclerosis.