Nicolantonio D'Orazio

Antileukotriene Drugs: Clinical Application, Effectiveness and Safety

Cysteinyl leukotrienes (Cys-LTs) are potent proinflammatory mediators derived from arachidonic acid through the 5-lypoxigenase (5-LO) pathway. They exert important pharmacological effects by interaction with at least two different receptors: Cys-LT(1) and Cys-LT(2). By competitive binding to the Cys-LT(1) receptor, leukotriene receptor antagonist drugs such as montelukast, zafirlukast, and pranlukast, block the effects of Cys-LTs and alleviate the symptoms of many chronic diseases, especially bronchial asthma and allergic rhinitis. Evidence obtained by randomized clinical trials as also by direct experience derived from patients suffering from asthma and allergic rhinitis justifies a broader role for leukotrienes receptor antagonists (LTRAs). Recently published studies and case reports have demonstrated beneficial effects of LTRAs on other diseases commonly associated with asthma (exercise induced asthma, rhinitis, chronic obstructive pulmonary disease, interstitial lung disease, chronic urticaria, atopic dermatitis, allergic fungal disease, nasal polyposis, and paranasal sinus disease) as well as other diseases not connected to asthma (migraine, respiratory syncytial virus postbronchiolitis, systemic mastocytosis, cystic fibrosis, pancreatitis, vulvovaginal candidiasis, cancer, atherosclerosis, eosinophils cystitis, otitis media, capsular contracture, and eosinophilic gastrointestinal disorders). The aim of this review is to show the most recent applications and effectiveness in clinical practice of the LTRAs.

Mediterranean Diet and Cardiovascular Risk Factors: A Systematic Review

The aim of this paper was to systematically review and analyze the epidemiological evidence on the role of Mediterranean diet (MD) in the prevention of cardiovascular diseases (CVD). Fifty-eight studies exploring the relation between MD and lipoprotein concentration, antioxidative capacity and inflammatory markers, hypertension, obesity, diabetes, and metabolic syndrome, were identified and selected. These included 33 cross-sectional, 9 cohort, and 16 intervention studies. Most of the studies showed favorable effects of MD on CVD, although a certain degree of controversy remains in the respect of some issues, as obesity. Important methodological differences and limitations in the studies make difficult to compare results, thus further studies, particularly randomized clinical trials, are needed to finally substantiate the benefits of MD and to shed some lights on mechanisms.

Potential therapeutic effects of natural heme oxygenase-1 inducers in cardiovascular diseases.

SIGNIFICANCE Many physiological effects of natural antioxidants, their extracts or their major active components, have been reported in recent decades. Most of these compounds are characterized by a phenolic structure, similar to that of α-tocopherol, and present antioxidant properties that have been demonstrated both in vitro and in vivo. Polyphenols may increase the capacity of endogenous antioxidant defenses and modulate the cellular redox state. Such effects may have wide-ranging consequences for cellular growth and differentiation. CRITICAL ISSUES The majority of in vitro and in vivo studies conducted so far have attributed the protective effect of bioactive polyphenols to their chemical reactivity toward free radicals and their capacity to prevent the oxidation of important intracellular components. One possible protective molecular mechanism of polyphenols is nuclear factor erythroid 2-related factor (Nrf2) activation, which in turn regulates a number of detoxification enzymes. RECENT ADVANCES Among the latter, the heme oxygenase-1 (HO-1) pathway is likely to contribute to the established and powerful antioxidant/anti-inflammatory properties of polyphenols. In this context, it is interesting to note that induction of HO-1 expression by means of natural compounds contributes to prevention of cardiovascular diseases in various experimental models. FUTURE DIRECTIONS The focus of this review is on the role of natural HO-1 inducers as a potential therapeutic strategy to protect the cardiovascular system against various stressors in several pathological conditions.

Anti-obesity activity of the marine carotenoid fucoxanthin.

Nowadays the global tendency towards physical activity reduction and an augmented dietary intake of fats, sugars and calories is leading to a growing propagation of overweight, obesity and lifestyle-related diseases, such diabetes, hypertension, dyslipidemia and metabolic syndrome. In particular, obesity, characterized as a state of low-level inflammation, is a powerful determinant both in the development of insulin resistance and in the progression to type 2 diabetes. A few molecular targets offer hope for anti-obesity therapeutics. One of the keys to success could be the induction of uncoupling protein 1 (UCP1) in abdominal white adipose tissue (WAT) and the regulation of cytokine secretions from both abdominal adipose cells and macrophage cells infiltrated into adipose tissue. Anti-obesity effects of fucoxanthin, a characteristic carotenoid, exactly belonging to xanthophylls, have been reported. Nutrigenomic studies reveal that fucoxanthin induces UCP1 in abdominal WAT mitochondria, leading to the oxidation of fatty acids and heat production in WAT. Fucoxanthin improves insulin resistance and decreases blood glucose levels through the regulation of cytokine secretions from WAT. The key structure of anti-obesity effect is suggested to be the carotenoid end of the polyene chromophore, which contains an allenic bond and two hydroxyl groups. Fucoxanthin, which can be isolated from edible brown seaweeds, recently displayed its many physiological functions and biological properties. We reviewed recent studies and this article aims to explain essential background of fucoxanthin, focusing on its promising potential anti-obesity effects. In this respect, fucoxanthin can be developed into promising marine drugs and nutritional products, in order to become a helpful functional food.

A comprehensive meta‐analysis on dietary flavonoid and lignan intake and cancer risk: level of evidence and limitations

SCOPE To summarize available evidence on the association between dietary flavonoid as well as lignan intake and cancer risk in observational studies. METHODS AND RESULTS A systematic search on electronic databases of all English language case-control and prospective studies published up to June 2016 was performed. Risk ratios (RRs) and 95% confidence intervals were calculated by random-effects model separately by study design. Heterogeneity and publication bias were tested. Out of the 143 studies included, meta-analyses of prospective studies showed isoflavones significantly associated with decreased risk of lung and stomach cancers and nearly significant breast and colorectal cancers; total flavonoids showed nonsignificant decreased risk of breast cancer. Meta-analyses of case-control studies showed: total and/or individual classes of flavonoids associated with upper aero-digestive tract, colorectal, breast, and lung cancers; isoflavones with ovarian, breast, and colorectal cancers, endometrial and lung cancers. CONCLUSIONS Most evidence reported in previous meta-analyses was driven by case-control studies. Overall results may be promising but are inconclusive. Further prospective cohorts assessing dietary polyphenol exposure and studies using other methods to evaluate exposure (i.e. markers of consumption, metabolism, excretion) are needed to confirm and determine consumption levels required to achieve health benefits.

Antiproliferative effect of oleuropein in prostate cell lines.

Currently, there is increasing interest in the in vivo protective effects of natural antioxidants found in dietary plants against oxidative damage caused by free radical species. Oxidative stress has been invoked as a causative agent in cancer and epidemiological data suggest that the consumption of fruits and vegetables may be associated with a lower incidence of cancer. The fruit of the Olea europaea L. and olive oil contain hundreds of phytochemicals and its extracts have recently been shown to exhibit antioxidant properties, due to the action of oleuropein. In view of these considerations, in this study, we investigated the effects of oleuropein on LNCaP and DU145 prostate cancer cell lines and on BPH-1 non-malignant cells. Oleuropein reduces cell viability and induces thiol group modifications, γ-glutamylcysteine synthetase, reactive oxygen species, pAkt and heme oxygenase-1. Exposing cell cultures to oleuropein induces an antioxidant effect on BPH-1 cells and a pro-oxidant effect on cancer cells. Our results confirm the beneficial properties of olive oil and oleuropein, suggesting its possible use as an adjuvant agent in the treatment of prostatitis, in order to prevent the transformation of hypertrophic to cancerous cells.

Relationship between plasma antioxidant concentrations and carotid intima-media thickness: the Asymptomatic Carotid Atherosclerotic Disease In Manfredonia Study

Background Few studies have examined the relationship among carotid atherosclerosis, vascular risk factors, and antioxidant plasma concentrations, and those that have reported conflicting results. The aim of this study was to assess the relationship between asymptomatic carotid atherosclerosis, as defined by carotid intima-media thickness (CIMT), and inflammatory markers, plasma lipids and serum antioxidant vitamins. Methods and results We examined baseline characteristics of the 640 participants in the Asymptomatic Carotid Atherosclerotic Disease In Manfredonia Study. All participants were asymptomatic with respect to carotid artery disease in 2006-2007 and underwent physical examination with carotid ultrasound investigation, the collection of medical history and laboratory data. Analysis of variance methods were used to examine differences between participants by category of CIMT. Of the 640 participants, 291 did not have evidence of carotid atherosclerosis (CIMT < 0.8mm), 232 were found to have some atherosclerosis (0.8 mm ≤ CIMT < 1.2 mm), and 117 were found to have extensive atherosclerosis (CIMT > 1.2 mm). Among participants with CIMT ≥ 0.8mm, body mass index, blood pressures, total cholesterol, LDL cholesterol, triglycerides, uric acid, C-reactive protein, and fibrinogen were significantly higher, whereas concentrations of vitamin A, vitamin E, lycopene, and β-carotene were all significantly lower when compared with participants who did not show evidence of carotid atherosclerosis (P < 0.001). Conclusion The optimal control of hypertension, diabetes, and dyslipidemia, in addition to smoking cessation and an adequate intake of antioxidant micronutrients from foods represent a key for the prevention of atherosclerotic disease.

Marine Carotenoids against Oxidative Stress: Effects on Human Health

Carotenoids are lipid-soluble pigments that are produced in some plants, algae, fungi, and bacterial species, which accounts for their orange and yellow hues. Carotenoids are powerful antioxidants thanks to their ability to quench singlet oxygen, to be oxidized, to be isomerized, and to scavenge free radicals, which plays a crucial role in the etiology of several diseases. Unusual marine environments are associated with a great chemical diversity, resulting in novel bioactive molecules. Thus, marine organisms may represent an important source of novel biologically active substances for the development of therapeutics. In this respect, various novel marine carotenoids have recently been isolated from marine organisms and displayed several utilizations as nutraceuticals and pharmaceuticals. Marine carotenoids (astaxanthin, fucoxanthin, β-carotene, lutein but also the rare siphonaxanthin, sioxanthin, and myxol) have recently shown antioxidant properties in reducing oxidative stress markers. This review aims to describe the role of marine carotenoids against oxidative stress and their potential applications in preventing and treating inflammatory diseases.

Plasma Lycopene and Antioxidant Vitamins in Asthma: the PLAVA Study

Objective: Scientific evidence suggests that lycopene and antioxidant vitamins have significant antioxidant and protective effects. Methods: This case-control study included 96 subjects (40 asthmatics, 56 healthy control subjects). Baseline blood samples, pulmonary function tests, and clinical and alimentary histories were collected. All subjects were grouped by age, sex, cigarette smoking habit, body mass index, alimentary intake, and atopic status. Results: Serum lycopene concentration was significantly lower in asthmatic subjects than in healthy control subjects (0.10 ± 0.7 μ moL/L vs. 0.16 ± 0.8 μ moL/L − p < 0.001). Serum vitamin A concentration was significantly lower in asthmatics (2.38 ± 0.37 μ moL/L) in respect to control subjects (3.06 ± 0.56 μ moL/L) (p < 0.01). Plasma serum concentration of vitamin E and β-carotene were not found to be different in the two groups. Conclusions: Dietary supplementation or adequate intake of lycopene and vitamin A rich foods may be beneficial in asthmatic subjects.

Leukotrienes in Atherosclerosis: New Target Insights and Future Therapy Perspectives

Atherosclerosis represents an important chronic inflammatory process associated with several pathophysiological reactions in the vascular wall. The arachidonic acid, released by phospholipase A2, is an important substrate for the production of a group of lipid mediators known as leukotrienes, which induce proinflammatory signaling through the activation of specific BLT and CysLT receptors. The interaction of these substances in the vascular wall determines important morphological alterations like the early lipid retention and the accumulation of foam cells, the development of intimal hyperplasia, and advanced atherosclerotic lesions, and it plays an important role in the rupture of atherosclerotic plaque. Many studies regarding myocardial ischemia and reperfusion show that leukotriene signaling may be involved in the development of ischemic injury. For these, reasons both leukotriene synthesis inhibitors and leukotriene receptor antagonists have been suggested for inducing beneficial effects at different stages of the atherosclerosis process and may represent a new therapeutic target in the treatment of atherosclerotic vessel diseases, in particular in acute coronary syndrome.