Protective Effects and Mechanisms of N-Phenethyl Caffeamide from UVA-Induced Skin Damage in Human Epidermal Keratinocytes through Nrf2/HO-1 Regulation.

The skin provides an effective barrier against physical, chemical, and microbial invasion; however, overexposure to ultraviolet (UV) radiation causes excessive cellular oxidative stress, which leads to skin damage, DNA damage, mutations, and skin cancer. This study investigated the protective effects of N-phenethyl caffeamide (K36) from UVA damage on human epidermal keratinocytes. We found that K36 reduced UVA-induced intracellular reactive oxygen species (ROS) production and induced the expression of the intrinsic antioxidant enzyme heme oxygenase-1 (HO-1) by increasing the translocation of nuclear factor erythroid 2⁻related factor 2 (Nrf2). K36 could inhibit the phosphorylation of extracellular-signal-regulated kinase (ERK) and c-Jun N-terminal kinases (JNK) and reduce UVA-induced matrix metalloproteinase (MMP)-1 and MMP-2 overexpression; it could also elevate the expression of tissue inhibitors of metalloproteinases (TIMP). In addition, K36 ameliorated 8-hydroxy-2'-deoxyguanosine (8-OHdG) induced by UVA irradiation. Furthermore, K36 could downregulate the expression of inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6) and the subsequent production of nitric oxide (NO) and prostaglandin E2 (PGE2). Based on our findings, K36 possessed potent antioxidant, anti-inflammatory, antiphotodamage, and even antiphotocarcinogenesis activities. Thus, K36 has the potential to be used to multifunctional skin care products and drugs.

Contact Lenses Delivering Nitric Oxide under Daylight for Reduction of Bacterial Contamination.

Ocular infection due to microbial contamination is one of the main risks associated with the wearing of contact lens, which demands novel straightforward strategies to find reliable solutions. This contribution reports the preparation, characterization and biological evaluation of soft contact lenses (CL) releasing nitric oxide (NO), as an unconventional antibacterial agent, under daylight exposure. A tailored NO photodonor (NOPD) was embedded into commercial CL leading to doped CL with an excellent optical transparency (transmittance = 100%) at λ ≥ 450 nm. The NOPD results homogeneously distributed in the CL matrix where it fully preserves the photobehavior exhibited in solution. In particular, NO release from the CL and its diffusion in the supernatant physiological solution is observed upon visible light illumination. The presence of a blue fluorescent reporting functionality into the molecular skeleton of the NOPD, which activates concomitantly to the NO photorelease, allows the easy monitoring of the NO delivery in real-time and confirms that the doped CL work under daylight exposure. The NO photoreleasing CL are well-tolerated in both dark and light conditions by corneal cells while being able to induce good growth inhibition of Staphylococcus aureus under visible light irradiation. These results may pave the way to further engineering of the CL with NOPD as innovative ocular devices activatable by sunlight.

Peculiar Effects of Electromagnetic Millimeter Waves on Tumor Development in BALB/c Mice.

The study examined the effects of millimeter electromagnetic waves at a frequency of 130 GHz corresponding to the molecular absorption and radiation spectra of NO and O2 with the total exposition time of 6 h on tumor morphogenesis in 3- and 6-month-old tumor-prone BALB/c mice of both sexes. In experimental mice exposed to electromagnetic radiation, the development of cancer process was slowed down throughout the observation period; moreover, no macroscopic signs of the tumors were revealed. However, in contrast to control mice, experimental animals demonstrated the formation of pathological reactions reflected by hepatic biochemical indices accompanied by the development of dystrophic and microcirculatory alterations in the liver tissue.

Effects of different-intensity laser acupuncture at two adjacent same-meridian acupoints on nitric oxide and soluble guanylate cyclase releases in human.

OBJECTIVES: The aim of this study was to detect the influences of LA at nonacupoint and two adjacent acupoints of pericardium meridian on the releases of NO and sGC in 20 healthy subjects. METHODS: Different intensities (12, 24, 48 mW) of infrared laser were used for irradiating Jianshi (PC5), Ximen (PC4) acupoints and nonacupoint for 20, 40 minutes, respectively. Semi-circular tubes were taped to the skin surface and filled with NO-scavenging compound for 20 minutes to capture NO and sGC, which were measured using spectrophotometry in a blinded fashion. RESULTS: As the increase in the intensity of LA stimulation, the levels of NO releases over acupoints all were significantly increased, NO releases in nonacupoints following the same treatment only changed slightly, sGC amounts were observably enhanced over acupoints, but did not any change in nonacupoint area. Different intensities of LA treatments can sensitively affect the NO and sGC releases over acupoints. This indicated that LA-induced releases of the NO and sGC were specific to acupoints. CONCLUSIONS: This is the first evidence reporting that LA induced significant elevations of NO-sGC releases over acupoints, and the enhanced signal molecules contribute to local circulation, which improves the beneficial effects of the therapy.

Effect of the transdermal low-level laser therapy on endothelial function.

The effect of low-level laser therapy (LLLT) on the cardiovascular system is not fully established. Since the endothelium is an important endocrine element, establishing the mechanisms of LLLT action is an important issue.The aim of the study was to evaluate the effect of transdermal LLLT on endothelial function.In this study, healthy volunteers (n = 40, age = 20-40 years) were enrolled. N = 30 (14 female, 16 male, mean age 30 ± 5 years) constituted the laser-irradiated group (LG). The remaining 10 subjects (6 women, 4 men, mean age 28 ± 5 years) constituted the control group (CG). Participants were subjected to LLLT once a day for three consecutive days. Blood for biochemical assessments was drawn before the first irradiation and 24 h after the last session. In the LG, transdermal illumination of radial artery was conducted (a semiconductor laser λ = 808 nm, irradiation 50 mW, energy density 1.6 W/cm(2) and a dose 20 J/day, a total dose of 60 J). Biochemical parameters (reflecting angiogenesis: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), angiostatin; antioxidative status: glutathione (GSH) and the nitric oxide metabolic pathway: symmetric dimethylarginine (SDMA), asymmetric dimethylarginine (ADMA) and L-arginine) were assessed. In the LG, a significant increase in GSH levels and considerable decrease in angiostatin concentration following the LLLT were observed. No significant differences in levels of the VEGF, FGF, SDMA, ADMA were observed.LLLT modifies vascular endothelial function by increasing its antioxidant and angiogenic potential. We found no significant differences in levels of the nitric oxide pathway metabolites within 24 h following the LLLT irradiation.

[INFLUENCE OF MILLIMETER-WAVE ELECTROMAGNETIC EMISSION ON NITRIC OXIDE SYNTHESIS DURING VESSEL ENDOTHELIUM AGING IN VITRO].

The applying of millimeter-wave electromagnetic emission (EHF-therapy) is an effective method for various age-related pathologies treatment, among other cardio-vascular diseases. During the EHF-emission of aging human endothelial cell cultures it was obtained changing of NO-synthase (eNOS), endothelin-1, angiotensin-2 and vasopressin expression dependence of irradiation exposition. These data have shown that EHF-emission has activated endothelium functional activity, which can play the important role to search for approaches to treatment of arterial hypertension and atherosclerosis.

Visible light-induced nitric oxide release from a novel nitrobenzene derivative cross-conjugated with a coumarin fluorophore.

Nitric oxide (NO) is a well-known free-radical molecule which is endogenously biosynthesised and shows various functions in mammals. To investigate NO functions, photocontrollable NO donors, compounds which release NO in response to light, are expected to be potentially useful. However, most of the conventional NO donors require harmful ultra-violet light for NO release. In this study, two dimethylnitrobenzene derivatives conjugated with coumarins were designed, synthesized and evaluated as photocontrollable NO donors. The optical properties and efficiency of photo-induced NO release were dependent upon the nature of the conjugation system. One of these compounds, Bhc-DNB (1), showed spatiotemporally well-controlled NO release in cultured cells upon exposure to light in the less-cytotoxic visible wavelength range (400-430 nm).

Single-field slice-imaging with a movable repeller: photodissociation of N2O from a hot nozzle.

We present a new photo-fragment imaging spectrometer, which employs a movable repeller in a single field imaging geometry. This innovation offers two principal advantages. First, the optimal fields for velocity mapping can easily be achieved even using a large molecular beam diameter (5 mm); the velocity resolution (better than 1%) is sufficient to easily resolve photo-electron recoil in (2 + 1) resonant enhanced multiphoton ionization of N2 photoproducts from N2O or from molecular beam cooled N2. Second, rapid changes between spatial imaging, velocity mapping, and slice imaging are straightforward. We demonstrate this technique's utility in a re-investigation of the photodissociation of N2O. Using a hot nozzle, we observe slice images that strongly depend on nozzle temperature. Our data indicate that in our hot nozzle expansion, only pure bending vibrations--(0, v2, 0)--are populated, as vibrational excitation in pure stretching or bend-stretch combination modes are quenched via collisional near-resonant V-V energy transfer to the nearly degenerate bending states. We derive vibrationally state resolved absolute absorption cross-sections for (0, v2 ≤ 7, 0). These results agree well with previous work at lower values of v2, both experimental and theoretical. The dissociation energy of N2O with respect to the O((1)D) + N2¹Σ(g)⁺ asymptote was determined to be 3.65 ± 0.02 eV.

Selective X-ray-induced NO photodissociation in haemoglobin crystals: evidence from a Raman-assisted crystallographic study.

Despite their high physiological relevance, haemoglobin crystal structures with NO bound to haem constitute less than 1% of the total ligated haemoglobins (Hbs) deposited in the Protein Data Bank. The major difficulty in obtaining NO-ligated Hbs is most likely to be related to the oxidative denitrosylation caused by the high reactivity of the nitrosylated species with O(2). Here, using Raman-assisted X-ray crystallography, it is shown that under X-ray exposure (at four different radiation doses) crystals of nitrosylated haemoglobin from Trematomus bernacchii undergo a transition, mainly in the ß chains, that generates a pentacoordinate species owing to photodissociation of the Fe-NO bond. These data provide a physical explanation for the low number of nitrosylated Hb structures available in the literature.

Radiation-induced nitric oxide mitigates tumor hypoxia and radioresistance in a murine SCCVII tumor model.

Tumor hypoxia, which occurs mainly as a result of inadequate tissue perfusion in solid tumors, is a well-known challenge for successful radiotherapy. Recent evidence suggests that ionizing radiation (IR) upregulates nitric oxide (NO) production and that IR-induced NO has the potential to increase intratumoral circulation. However, the kinetics of NO production and the responsible isoforms for NO synthase in tumors exposed to IR remain unclear. In this study, we aimed to elucidate the mechanism by which IR stimulates NO production in tumors and the effect of IR-induced NO on tumor radiosensitivity. Hoechst33342 perfusion assay and electron spin resonance oxymetry showed that IR increased tissue perfusion and pO2 in tumor tissue. Immunohistochemical analysis using two different hypoxic probes showed that IR decreased hypoxic regions in tumors; treatment with a nitric oxide synthase (NOS) inhibitor, L-NAME, abrogated the effects of IR. Moreover, IR increased endothelial NOS (eNOS) activity without affecting its mRNA or protein expression levels in SCCVII-transplanted tumors. Tumor growth delay assay showed that L-NAME decreased the anti-tumor effect of fractionated radiation (10Gy×2). These results suggested that IR increased eNOS activity and subsequent tissue perfusion in tumors. Increases in intratumoral circulation simultaneously decreased tumor hypoxia. As a result, IR-induced NO increased tumor radiosensitivity. Our study provides a new insight into the NO-dependent mechanism for efficient fractionated radiotherapy.

Role of extracellular DNA oxidative modification in radiation induced bystander effects in human endotheliocytes.

The development of the bystander effect induced by low doses of irradiation in human umbilical vein endothelial cells (HUVECs) depends on extracellular DNA (ecDNA) signaling pathway. We found that the changes in the levels of ROS and NO production by human endothelial cells are components of the radiation induced bystander effect that can be registered at a low dose. We exposed HUVECs to X-ray radiation and studied effects of ecDNA(R) isolated from the culture media conditioned by the short-term incubation of irradiated cells on intact HUVECs. Effects of ecDNA(R) produced by irradiated cells on ROS and NO production in non-irradiated HUVECs are similar to bystander effect. These effects at least partially depend on TLR9 signaling. We compared the production of the nitric oxide and the ROS in human endothelial cells that were (1) irradiated at a low dose; (2) exposed to the ecDNA(R) extracted from the media conditioned by irradiated cells; and (3) exposed to human DNA oxidized in vitro. We found that the cellular responses to all three stimuli described above are essentially similar. We conclude that irradiation-related oxidation of the ecDNA is an important component of the ecDNA-mediated bystander effect.

Modulation of cytokine and nitric oxide production by keratinocytes, epithelial cells, and mononuclear phagocytes in a co-culture model of inflammatory acne.

INTRODUCTION: Ultraviolet B (UVB, 290 nm to 320 nm) has been reported to modulate the cytokine-mediated inflammatory process in various inflammatory skin conditions, including production of TNF-α, IL-1α, IL-6, IL-8, and IL-10. We constructed an in vitro model system involving co-culture of different cell types to study the effect of UVB on the inflammatory process using nitric oxide (NO) and tumor necrosis factor (TNF)-α as markers of inflammation. OBJECTIVE: This study was conducted to quantitatively assess the products secreted by human epithelial keratinocytes in the presence and absence of macrophages/monocytes. METHODS: Cells were exposed to UVB radiation (50 mJ to 200 mJ per cm2) or treated with bacterial lipopolysaccharide (LPS) as stimulator of inflammatory response. Nitric oxide (NO) was measured by modified Griess assay and TNF-α was measured by quantitative ELISA. For the co-culture system, SC monocytes were seeded in a 24-well Transwell tissue culture plate whereas irradiated keratinocytes were seeded in the individual baskets subsequently placed on top of the monocyte cultures, and samples of culture supernatants were collected at 1 to 6 days. RESULTS: When primary human epidermal keratinocytes (NHEK) were irradiated with UVB, a dose-dependent stimulation of TNF-α production was observed (33% to 200% increase). TNF-α production was not changed significantly in SC monocytes/NHEK co-culture. In contrast, when macrophages were irradiated with UVB, significant inhibition of NO production (40% suppression, P<0.001) was seen. CONCLUSION: This improved model of cutaneous inflammation could use multiple cells to study their interactions and to offer convenience, reproducibility, and a closer approximation of in vivo conditions.

[The influence of circadian rhythms of geomagnetic field variations and the background cosmic radiation on nitric oxide production in human organism].

The circadian rhythms of background gamma-radiation and Ki-indexes of geomagnetic activity (GMF) during August-September 2008, January-February 2010 and March 2011 were studied. The authors show that in summer period the maximum of Ki-indexes and gamma-radiation were at 3 p.m. of local time. In winter these maximums were shifted at more last time. It was suggested that an organism produces the own free radicals as nitric oxide to neutralize radicals from background radiation. They are formed during decay of neutrophiles when GMF-activity falls. On the other side, the production of NO is regulated by melatonin synthesis which has a circadian rhythm.

900 MHz pulse-modulated radiofrequency radiation induces oxidative stress on heart, lung, testis and liver tissues.

Oxidative stress may affect many cellular and physiological processes including gene expression, cell growth, and cell death. In the recent study, we aimed to investigate whether 900 MHz pulse-modulated radiofrequency (RF) fields induce oxidative damage on lung, heart and liver tissues. We assessed oxidative damage by investigating lipid peroxidation (malondialdehyde, MDA), nitric oxide (NOx) and glutathione (GSH) levels which are the indicators of tissue toxicity. A total of 30 male Wistar albino rats were used in this study. Rats were divided randomly into three groups; control group (n = 10), sham group (device off, n = 10) and 900 MHz pulsed-modulated RF radiation group (n = 10). The RF rats were exposed to 900 MHz pulsed modulated RF radiation at a specific absorption rate (SAR) level of 1.20 W/kg 20 min/day for three weeks. MDA and NOx levels were increased significantly in liver, lung, testis and heart tissues of the exposed group compared to sham and control groups (p < 0.05). Conversely GSH levels were significantly lower in exposed rat tissues (p < 0.05). No significantly difference was observed between sham and control groups. Results of our study showed that pulse-modulated RF radiation causes oxidative injury in liver, lung, testis and heart tissues mediated by lipid peroxidation, increased level of NOx and suppression of antioxidant defense mechanism.

Differential activation of NF-κB and nitric oxide in lymphocytes regulates in vitro and in vivo radiosensitivity.

Lymphocytes are more sensitive to radiation in vivo than in vitro. However, the mechanism of this differential response is poorly understood. In the present study, it was found that the lipid peroxidation and cell death were significantly higher in lymphocytes following whole body irradiation (WBI) as compared to lymphocytes exposed to radiation in vitro. EL-4 cells transplanted in mice were also more sensitive to radiation than EL-4 cells irradiated in vitro. DNA repair, as assessed by comet assay, was significantly faster in lymphocytes exposed to 4Gy radiation in vitro as compared to that in lymphocytes obtained from whole body irradiated mice exposed to the same dose of radiation. This was associated with increased NF-κB activation in response to genotoxic stress and lesser activation of caspase in lymphocytes in vitro compared to in vivo. To explain the differential radiosensitivity, we postulated a role of nitric oxide, an extrinsic diffusible mediator of radiosensitivity that has also been implicated in DNA repair inhibition. Nitric oxide levels were significantly elevated in the plasma of whole body irradiated mice but not in the supernatant of cells irradiated in vitro. Addition of sodium nitroprusside (SNP), a nitric oxide donor to cells irradiated in vitro inhibited the repair of DNA damage and enhanced apoptosis (increased Bax to Bcl-2 ratio). Administration of l-NAME, a nitric oxide synthase inhibitor, to mice significantly protected lymphocytes against WBI-induced DNA damage and inhibited in vivo radiation-induced production of nitric oxide. These results confirm that the observed differential radiosensitivity of lymphocytes was due to slow repair of DNA due to nitric oxide production in vivo.

[Age diseases depending on geomagnetic field activity inside the womb period].

Between age diseases two are standing out: oncological and cardiovascular ones. They give a main contribution to mortality of the population. Those who avoid these diseases have a chance to live longer. The author suggests a hypothesis of one common factor, which deviation leads to oncology or cardiovascular illness. Such factor is a production of nitric oxide in the organism, which depends on the geomagnetic activity (GMA). At excess production of nitric oxide the risk of oncopathology (breast cancer, bladder and lung cancer and others) is increased. At low NO level in blood the risk of cardiovascular disease is increased. The ability of the organism to utilize the excess level of NO depends on GMA inside the womb period. The production of nitric oxide in the organism goes by different ways, including NO-synthase activity and destruction of neutrophiles, which depends on the GMA and sun activity.

Fluorimetric-Based Method to Detect and Quantify Total S-Nitrosothiols (SNOs) in Plant Samples.

Accumulating experimental evidence indicates that S-nitrosylation (technically S-nitrosation) events have a central role in plant biology, presumably accounting for much of the widespread influence of nitric oxide (NO) on developmental, metabolic, and stress-related plant responses. Therefore, the accurate detection and quantification of S-nitrosylated proteins and peptides can be particularly useful to determine the relevance of this class of compounds in the ever-increasing number of NO-dependent signaling events described in plant systems. Up to now, the quantification of S-nitrosothiols (SNOs) in plant samples has mostly relied on the Saville reaction and the ozone-based chemiluminescence method, which lacks sensitivity and are very time-consuming, respectively. Taking advantage of the photolytic properties of S-nitrosylated proteins and peptides, the method described in this chapter allows simple, fast, and high-throughput detection of SNOs in plant samples.

Role of nitric oxide in the response to photooxidative stress in prostate cancer cells.

A continuous state of oxidative stress during inflammation contributes to the development of 25% of human cancers. Epithelial and inflammatory cells release reactive oxygen species (ROS) and reactive nitrogen species (RNS) that can damage DNA. ROS/RNS have biological implications in both chemoresistance and tumor recurrence. As several clinically employed anticancer drugs can generate ROS/RNS, we have addressed herein how inducible nitric oxide synthase and nitric oxide (iNOS/•NO) affect the molecular pathways implicated in the tumor response to oxidative stress. To mimic the oxidative stress associated with chemotherapy, we used a photosensitizer (pheophorbide a) that can generate ROS/RNS in a controlled manner. We investigated how iNOS/•NO modulates the tumor response to oxidative stress by involving the NF-κB and Nrf2 molecular pathways. We found that low levels of iNOS induce the development of a more aggressive tumor population, leading to survival, recurrence and resistance. By contrast, high levels of iNOS/•NO sensitize tumor cells to oxidative treatment, causing cell growth arrest. Our analysis showed that NF-κB and Nrf2, which are activated in response to oxidative stress, communicate with each other through RKIP. For this critical role, RKIP could be an interesting target for anticancer drugs. Our study provides insight into the complex signaling response of cancer cells to oxidative treatments as well as new possibilities for the rational design of new therapeutic strategies.

In vitro evaluation of the effects of low-intensity Nd:YAG laser irradiation on the inflammatory reaction elicited by bacterial lipopolysaccharide adherent to titanium dental implants.

BACKGROUND: The bacterial endotoxin lipopolysaccharide (LPS) represents a prime pathogenic factor of peri-implantitis because of its ability to adhere tenaciously to dental titanium implants. Despite this, the current therapeutic approach to this disease remains based mainly on bacterial decontamination, paying little attention to the neutralization of bioactive bacterial products. The purpose of the present study was to evaluate whether irradiation with low-energy neodymium-doped:yttrium, aluminum, and garnet (Nd:YAG) laser, in addition to the effects on bacterial implant decontamination, was capable of attenuating the LPS-induced inflammatory response. METHODS: RAW 264.7 macrophages or human umbilical vein endothelial cells were cultured on titanium disks coated with Porphyromonas gingivalis LPS, subjected or not to irradiation with the Nd:YAG laser, and examined for the production of inflammatory cytokines and the expression of morphologic and molecular markers of cell activation. RESULTS: Laser irradiation of LPS-coated titanium disks significantly reduced LPS-induced nitric oxide production and cell activation by the macrophages and strongly attenuated intercellular adhesion molecule-1 and vascular cell adhesion molecule expression, as well as interleukin-8 production by the endothelial cells. CONCLUSION: By blunting the LPS-induced inflammatory response, Nd:YAG laser irradiation may be viewed as a promising tool for the therapeutic management of peri-implantitis.

Simultaneous SO2 and NO removal from flue gas based on TiO2 photocatalytic oxidation.

A new approach to the simultaneous removal of SO2 and NO from flue gas, by TiO2 photocatalysis based on UV irradiation technology, is presented. Experiments on the simultaneous desulphurization and denitrification were carried out using this photocatalyst in a self-designed photocatalytic reactor. Under the optimal experimental conditions, a removal efficiency of 98% for SO2 and 50% for NO was achieved. Scanning electron microscopy, transmission electron microscopy and X-ray energy spectrometry were used to observe the surface characteristics of the TiO2 photocatalyst. It was found that the surface of the quartz sand carrier was covered with Ti, on which the Si content of the quartz sand carrier was similar to the Ti content, indicating that the quartz sand supported the TiO2 membrane well. Based on the results of X-ray photoelectron spectroscopy (XPS) and chemical analysis of the resulting products, the SO2 and NO removal mechanisms were revealed. Sulphate was the main desulphurization product and nitrite was the main denitrification product. In the removal reaction, NO was rapidly oxidized to NO2 and absorbed in the chemical reaction.