Cardio-light: nitric oxide uncaged

Effects of photobiomodulation therapy (PBMT) over endothelial function in healthy individuals: a preliminary crossover clinical trial

Photobiomodulation therapy (PBMT) causes stimulatory effects that raise cell metabolism. The study aimed to evaluate the effects of PBMT on the endothelial function of healthy individuals. It was a controlled, randomized, crossover, triple-blind trial with 22 healthy volunteers (female: 77.3%), aged 25.45 years which were randomly divided into three groups. PBMT with gallium-aluminum-arsenide (GaAlAs) diode laser (810 nm, continuous-wave mode, 1000 mW, 0.28 cm²) was applied over the radial and ulnar artery regions in two parallel spots: group 1-30 J (n = 22, 107 J/cm²) per spot; group 2-60 J (n = 22, 214 J/cm²) per spot; and group 3-placebo (n = 22, sham). The endothelial function was measured before and immediately after PBMT by the flow-mediated dilation technique (%FMD) with high-resolution ultrasound. Statistical analysis was made with ANOVA for repeated measures, the effect size was measured by Cohen's d, and results are presented as mean and standard error (or 95% confidence intervals). A p-value < 0.05 was considered statistically significant. The %FMD increases 10.4% with 60 J (mean difference = 0.496 mm, 95% CI = 0.42 to 0.57, p < 0.001), 7.3% with 30 J (mean difference = 0.518 mm, 95% CI = 0.44 to 0.59, p < 0.001), and 4.7% with placebo (mean difference = 0.560 mm, 95% CI = 0.48 to 0.63, p < 0.001). We found a small effect size (p = 0.702; d de Cohen = 0.24) without statistical difference between interventions. PBMT with the energy density of 60 J and 30 J did not improve endothelial function.Trial registration number: NCT03252184 (01/09/2017).

Red Light Mitigates the Deteriorating Placental Extracellular Matrix in Late Onset of Preeclampsia and Improves the Trophoblast Behavior

Preeclampsia is a serious pregnancy disorder which in extreme cases may lead to maternal and fetal injury or death. Preexisting conditions which increase oxidative stress, e.g., hypertension and diabetes, increase the mother's risk to develop preeclampsia. Previously, we established that when the extracellular matrix is exposed to oxidative stress, trophoblast function is impaired, and this may lead to improper placentation. We investigated how the oxidative ECM present in preeclampsia alters the behavior of first trimester extravillous trophoblasts. We demonstrate elevated levels of advanced glycation end products (AGE) and lipid oxidation end product 4-hydroxynonenal in preeclamptic ECM (28%, and 32% increase vs control, respectively) accompanied with 35% and 82% more 3-chlorotyrosine and 3-nitrotyrosine vs control, respectively. Furthermore, we hypothesized that 670 nm phototherapy, which has antioxidant properties, reverses the observed trophoblast dysfunction as depicted in the improved migration and reduction in apoptosis. Since NO is critical for placentation, we examined eNOS activity in preeclamptic placentas compared to healthy ones and found no differences; however, 670 nm light treatment triggered enhanced NO availability presumably by using alternative NO sources. Light exposure decreased apoptosis and restored trophoblast migration to levels in trophoblasts cultured on preeclamptic ECM. Moreover, 670 nm irradiation restored expression of Transforming Growth Factor (TGFβ) and Placental Growth Factor (PLGF) to levels observed in trophoblasts cultured on healthy placental ECM. We conclude the application of 670 nm light can successfully mitigate the damaged placental microenvironment of late onset preeclampsia as depicted by the restored trophoblast behavior.

Comparative evaluation of low-level light therapy and ethinyl estradiol and desogestrel combined oral contraceptive for clinical efficacy and regulation of serum biochemical parameters in primary dysmenorrhoea: a prospective randomised multicentre trial

We aimed to compare low-level light therapy with oral contraceptive pills for pain relief and serum levels of nitric oxide and prostaglandin E₂ in patients with primary dysmenorrhoea. This was a randomised, active comparator-controlled, multicentre study. In total, 156 patients were randomised to receive either low-level light therapy with light-emitting diodes (LED) applying on two acupoints, namely, conception vessel 4 (CV4) and CV6 or conventional treatment with oral Marvelon, 30 µg of ethinyl estradiol and 150 µg of desogestrel (DSG/EE), for three consecutive menstrual cycles. The main outcome was the proportion of patients who achieved 33% or more decrease in pain scores measured using the visual analogue scale, which was deemed as efficient rate. Absolute changes in visual analogue scale scores, serum levels of nitric oxide (assessed by nitrites and nitrates reflecting nitric oxide metabolism) and prostaglandin E₂ (measured by enzyme-linked immunosorbent assay) were the secondary outcomes. A total of 135 patients completed the study (73 in the light therapy group and 62 in the DSG/EE group). The efficient rate at the end of treatment was comparable between the groups (73.6% vs. 85.7%, χ² = 2.994, p = 0.084). A more significant reduction in pain scores was observed in the DSG/EE group (39.25% vs. 59.52%, p < 0.001). Serum levels of prostaglandin E₂ significantly decreased from baseline but did not differ between groups (- 109.57 ± 3.99 pg/mL vs. - 118.11 ± 12.93 pg/mL, p = 0.51). Nitric oxide concentration remained stable in both groups. Low-level light therapy with LED-based device applied on acupuncture points CV4 and CV6 demonstrated a similar level of dysmenorrhoea pain reduction to DSG/EE combined contraceptive. Both treatment modalities achieved clinically meaningful levels of pain reduction. Registration on ClinicalTrials.gov: TRN: NCT03953716, Date: April 04, 2019.

Photobiomodulation of the Visual System and Human Health

Humans express an expansive and detailed response to wavelength differences within the electromagnetic (EM) spectrum. This is most clearly manifest, and most studied, with respect to a relatively small range of electromagnetic radiation that includes the visible wavelengths with abutting ultraviolet and infrared, and mostly with respect to the visual system. Many aspects of our biology, however, respond to wavelength differences over a wide range of the EM spectrum. Further, humans are now exposed to a variety of modern lighting situations that has, effectively, increased our exposure to wavelengths that were once likely minimal (e.g., “blue” light from devices at night). This paper reviews some of those biological effects with a focus on visual function and to a lesser extent, other body systems.

Nitric Oxide in Dental Pulp Tissue: From Molecular Understanding to Clinical Application in Regenerative Endodontic Procedures

Nitric oxide (NO), which is synthesized by the enzyme NO synthase (NOS), is a versatile endogenous molecule with multiple biological effects on many tissues and organs. In dental pulp tissue, NO has been found to play multifaceted roles in regulating physiological activities, inflammation processes, and tissue repair events, such as cell proliferation, neuronal degeneration, angiogenesis, and odontoblastic differentiation. However, there is a deficiency of detailed discussion on the NO-mediated interactions between inflammation and reparative/regenerative responses in wounded dental pulp tissue, which is a central determinant of ultimate clinical outcomes. Thus, the purpose of this review is to outline the current molecular understanding on the roles of Janus-faced molecule NO in dental pulp physiology, inflammation, and reparative activities. Based on this knowledge, advanced physicochemical techniques designed to manipulate the therapeutic potential of NOS and NO production in endodontic regeneration procedures are further discussed. Impact statement The interaction between inflammation and reparative/regenerative responses is very important for regenerative endodontic procedures, which are biologically based approaches intended to replace damaged tissues. Inside dental pulp tissue, endogenous nitric oxide (NO) is generated mainly by immunocompetent cells and dental pulp cells and mediates not only inflammatory/immune activities but also signaling cascades that regulate tissue repair and reconstruction, indicating its involvement in both tissue destruction and regeneration. Thus, it is feasible that NO acts as one of the indicators and modulators in dental pulp repair or regeneration under physiological and pathological conditions.