Carnosine has antioxidant properties and is efficient in the treatment of chemically-induced inflammatory lesions in animals. However, some studies question its biological significance as antioxidant and show lack of protection and even pro-oxidant effect of carnosine in systems containing nickel and iron ions. The ability of carnosine to: (1) reduce Fe 3π into Fe 2π ions; (2) protect deoxyribose from oxidation by Fe 2π -, Fe 3π -, and Cu 2π -H 2 O 2 -EDTA systems; (3) protect DNA from damage caused by Cu 2π -, and Fe 2π -H 2 O 2 -ascorbate systems; (4) inhibit HClO-and H 2 O 2 -peroxidase-induced luminol dependent chemiluminescence was tested in vitro. At concentration 10 mM carnosine reduced 16.6∫0.5 nmoles of Fe 3π into Fe 2π ions during 20 min. incubation and added to plasma significantly increased its ferric reducing ability. Inhibition of deoxyribose oxidation by 10 mM carnosine reached 56∫5, 40∫11 and 30∫11% for systems containing Fe 2π , Fe 3π and Cu 2π ions, respectively. The damage to DNA was decreased by 84∫9 and 61∫14% when Cu 2π -, and Fe 2π -H 2 O 2 -ascorbate systems were applied. Combination of 10 mM histidine with alanine or histidine alone (but not alanine) enhanced 1.3 and 2.3 times (PϽ0.05) the DNA damage induced by Fe 2π -H 2 O 2 -ascorbate. These amino acids added to 10 mM carnosine decreased 3.1-fold (PϽ0.05) its protective effect on DNA. Carnosine at 10 and 20 mM decreased by more than 90% light emission from both chemiluminescent systems. It is concluded that carnosine has significant antioxidant activity especially in the presence of transition metal ions. However, hydrolysis of carnosine with subsequent histidine release may be responsible for some pro-oxidant effects.

IntroductionThe aim of this study was to evaluate the effect of melatonin on blood pressure in patients with essential hypertension receiving medical treatment and with type 2 diabetes in good metabolic control.Material and methodsThe study lasted 8 weeks. Patients were equipped with a 24-hour ambulatory blood pressure monitor and took melatonin (3 mg a day in the evening) for 4 weeks. The patients were divided into four groups: group 1 (n = 32) including dippers, group 2 (n = 34) non-dippers treated with melatonin; and two control groups: group 3 (n = 28) including dippers and group 4 (n = 30) non-dippers treated without melatonin. After 4 weeks patients took melatonin for the next 4 weeks (5 mg a day). In each visit were analyzed: systolic, diastolic and mean blood pressure in both day and night time.ResultsWe observed that 29.5% non-dippers (n = 10) treated with melatonin in a dose of 3 mg/day achieved features of dippers compared to control group (p < 0.05). Five mg of melatonin per day restored normal diurnal blood pressure rhythm in 32.4% non-dippers (n = 11, p < 0.05). In non-dippers treated with melatonin significant decreases of diastolic, systolic and mean night blood pressure values (p < 0.05) were observed.ConclusionsMore than 30% of non-dippers with type 2 diabetes treated with melatonin were restored to the normal circadian rhythm of blood pressure. The effect of melatonin in both doses (3 mg and 5 mg) was significant for non-dippers only and included nocturnal systolic, diastolic and mean arterial pressure.

IntroductionLong-lasting arterial hypertension causes left ventricular hypertrophy (LVH) and impairs left ventricular diastolic function. Our aim was to compare echocardiographic parameters between hypertensive patients defined as dippers and non-dippers during ambulatory blood pressure (BP) monitoring.Material and methodsWe analysed 61 consecutive subjects with treated hypertension undergoing 24-h BP monitoring and transthoracic echocardiographic examination and included in the study patients with preserved left ventricular ejection fraction (EF ≥ 50%). Echocardiographic and arterial pressure parameters were compared between the group classified as dippers (n = 26, 57 ±13 years, 16 males) and non-dippers (n = 35, 60 ±12 years, 24 males) according to present or absent decrease of BP during the night > 10%. Echocardiographic data were compared between both groups and control subjects without hypertension.ResultsDippers had lower average systolic, diastolic and mean arterial pressure during the night hours but did not differ according to the mean pressure calculated from a 24-hour period. All echocardiographic parameters were similar in dippers and non-dippers. All patients with arterial hypertension presented with larger dimension of both ventricles and left atrium, thicker left ventricular walls, higher LV mass and mass index and preserved EF and E/A ratio as compared with normotensive controls. Normal geometry, concentric remodelling and eccentric hypertrophy were similarly distributed in both groups. Concentric hypertrophy was more prevalent in non-dippers as compared to the dippers (71.4% vs. 38.5%, p < 0.043).ConclusionsThe concentric type of LVH is the prevalent pattern in non-dippers. Non-dipping blood pressure pattern may be responsible for the development of left ventricular concentric hypertrophy secondary to hypertension.

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IntroductionAtherosclerosis leading to coronary artery disease (CAD) is a chronic inflammatory condition. Interleukin 35 (IL-35) released by regulatory T cells (Tregs) has been found to be associated with CAD in the Chinese population. However, nothing is known about the relation between IL-35 concentrations and cholesterol levels. The aim of the study was to assess the levels of IL-35 in CAD patients and healthy subjects from a Caucasian population, and to analyze the relationship between IL-35 and the levels of total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, left ventricular ejection fraction (LVEF), sex and postmenopausal status.Material and methodsThirty-one patients with CAD and 30 healthy controls were included in the study. Levels of plasma IL-35 were analyzed by ELISA. The LVEF was assessed by transthoracic echocardiographic examination. Plasma levels of cholesterol fractions and C-reactive protein (CRP) were assessed by immunoenzymatic methods.ResultsThe CAD patients had higher levels of IL-35 as compared to healthy controls (58.1 ±16.6 pg/ml vs. 5.35 ±3.35 pg/ml; p < 0.001). IL-35 levels negatively correlated with total and LDL cholesterol concentrations (R = –0.31, p < 0.01) and positively correlated with HDL cholesterol in men (R = 0.53, p < 0.01). In women, IL-35 levels negatively correlated with LVEF (R = –0.29, p < 0.05) and positively with the duration of postmenopausal status (R = 0.55, p < 0.01).ConclusionsThese results suggest a possible association between high levels of IL-35 and CAD.