Age and sex-related serum changes in nitric oxide: Correlations with serological markers

Hydroxytyrosol, a Promising Supplement in the Management of Human Stroke: An Exploratory Study

Hydroxytyrosol (HT) is a bioactive olive oil phenol with beneficial effects in a number of pathological situations. We have previously demonstrated that an HT-enriched diet could serve as a beneficial therapeutic approach to attenuate ischemic-stroke-associated damage in mice. Our exploratory pilot study examined this effect in humans. Particularly, a nutritional supplement containing 15 mg of HT/day was administered to patients 24 h after the onset of stroke, for 45 days. Biochemical and oxidative-stress-related parameters, blood pressure levels, serum proteome, and neurological and functional outcomes were evaluated at 45 and 90 days and compared to a control group. The main findings were that the daily administration of HT after stroke could: (i) favor the decrease in the percentage of glycated hemoglobin and diastolic blood pressure, (ii) control the increase in nitric oxide and exert a plausible protective effect in oxidative stress, (iii) modulate the evolution of the serum proteome and, particularly, the expression of apolipoproteins, and (iv) be beneficial for certain neurological and functional outcomes. Although a larger trial is necessary, this study suggests that HT could be a beneficial nutritional complement in the management of human stroke.

Hydroxytyrosol, the Major Phenolic Compound of Olive Oil, as an Acute Therapeutic Strategy after Ischemic Stroke

Stroke is one of the leading causes of adult disability worldwide. After ischemic stroke, damaged tissue surrounding the irreversibly damaged core of the infarct, the penumbra, is still salvageable and is therefore a target for acute therapeutic strategies. The Mediterranean diet (MD) has been shown to lower stroke risk. MD is characterized by increased intake of extra-virgin olive oil, of which hydroxytyrosol (HT) is the foremost phenolic component. This study investigates the effect of an HT-enriched diet directly after stroke on regaining motor and cognitive functioning, MRI parameters, neuroinflammation, and neurogenesis. Stroke mice on an HT diet showed increased strength in the forepaws, as well as improved short-term recognition memory probably due to improvement in functional connectivity (FC). Moreover, mice on an HT diet showed increased cerebral blood flow (CBF) and also heightened expression of brain derived neurotrophic factor (Bdnf), indicating a novel neurogenic potential of HT. This result was additionally accompanied by an enhanced transcription of the postsynaptic marker postsynaptic density protein 95 (Psd-95) and by a decreased ionized calcium-binding adapter molecule 1 (IBA-1) level indicative of lower neuroinflammation. These results suggest that an HT-enriched diet could serve as a beneficial therapeutic approach to attenuate ischemic stroke-associated damage.

Circulating markers of nitric oxide homeostasis and cardiometabolic diseases: insights from population-based studies

Emerging data suggest that impaired nitric oxide (NO) homeostasis has a key role in development of cardiometabolic disorders. The association between circulating levels of NO metabolites, i.e. nitrate and nitrite (NOx), and risk of chronic diseases has not yet been fully clarified. This work aims to address epidemiologic aspects of NO metabolism and discusses different physiologic and pathophysiologic conditions influencing circulating NOx. Further, cross-sectional associations of serum NOx with metabolic disorders are described and along the way, potential short-term and long-term power of serum NOx for predicting cardiometabolic outcomes are reviewed. Results from population-based studies show that circulating NOx is affected by aging, smoking habits, pregnancy, menopause status, thyroid hormones, and various pathologic conditions including type 2 diabetes, insulin resistance, hypertension, and renal dysfunction. Lifestyle factors, especially dietary habits, but also smoking habits and the degree of physical activity influence NO homeostasis and the circulating levels of NOx. Elevated serum NOx, due to increased iNOS activity, is associated with increased incidence of metabolic syndrome, different obesity phenotypes, and cardiovascular events.

Shorter telomere length predicts poorer immunological recovery in virologically suppressed HIV-1-infected patients treated with combined antiretroviral therapy

BACKGROUND

Successful combined antiretroviral therapy (cART) does not always result in complete CD4 T-cell recovery despite the effective control of HIV replication. Because telomere dysregulation can lead to an abnormal cell proliferation, we hypothesized that the lack of CD4 recovery may be related to telomere defects; We thus evaluated the association between telomere length (TL) and CD4 T-cell recovery 48 weeks after cART initiation in virologically suppressed patients, and its possible relationship to oxidative stress (OS) and nitrosative stress (NOx) markers.

METHODS

We studied HIV-infected patients on stable cART who achieved a viral load <50 copies per milliliter after 48 weeks of their first cART. Leukocyte TL was measured and categorized into tertiles. We calculated mean increases in CD4 T-cell at 48 weeks from cART initiation and used multivariate linear regression models to estimate differences in mean increases according to tertiles of TL.

RESULTS

One hundred thirty-two patients, 86% male, 81% <50 years at cART initiation were studied. Mean increases in CD4 were greater in patients with long TL than in those with medium and short TLs (P = 0.007). After adjustment for sex, age, CD4 T-cell counts, viral load, and hepatitis C infection at cART initiation, differences in mean CD4 T-cell count increases according to TL remained statistically significant (P = 0.02). Additional adjustment for NOx and OS did not change the results.

CONCLUSION

A lower immunological response despite a successful virological response is associated with a shorter TL. The effect is not related to NOx or OS.

Levels of nitric oxide metabolites in cerebrospinal fluid in cluster headache

The pathophysiology of cluster headache (CH) is only partly understood. Nitric oxide (NO), a potent vasodilator, has been suggested to be involved, and increased plasma levels of nitrite, a stable product on NO degradation, have been identified in the active period and in remission. The aim of our study was to investigate the role of NO in CH by measuring its oxidation products, nitrite and nitrate, in the cerebrospinal fluid (CSF), a biological compartment closer to the supposed focus of the disorder. We collected CSF from 14 episodic CH patients. Lumbar puncture (LP) was performed at two occasions: in active period between headache attacks, and in remission, not earlier than three weeks after the last CH attack. Eleven healthy volunteers served as controls. To estimate NO production, we determined the levels of NO-oxidation end products (NOx), that is, the sum of nitrite and nitrate, by using capillary electrophoresis. CH patients in the active period had significantly increased NOx levels (mean 9.3, 95% confidence interval [CI] 8.5-10.1) compared with those in remission (mean 7.6, 95% CI 6.9-8.2; p < 001) and control subjects (mean 6.2, 95% CI 4.9-7.5; p < 0.001). CH patients also had statistically significant enhanced NOx levels in remission compared with those of control subjects (p = 0.034). CSF was also analysed with regard to inflammatory parameters and protein content. CSF showed signs of pleocytosis or oligoclonal bands or albumin increase in 43% of CH patients although these results were not conclusive. We suggest that CH patients have a generally raised NO tonus, both in the active period and in remission. We interpret these results as indications of a basal hyperfunction of the L-arginine-NO pathway, possibly as an expression of inflammatory activity, and sensitization of pain pathways. This is the first study analysing NOx in CSF in CH, and the results support NO involvement in the pathogenesis of CH.