Metabolic syndrome (MetS) is a clinical manifestation characterized by a plethora of comorbidities, including hyperglycemia, abdominal obesity, arterial hypertension, and dyslipidemia. All MetS comorbidities participate to induce a low-grade inflammation state and oxidative stress, typical of this syndrome. MetS is related to an increased risk of cardiovascular diseases and early death, with an important impact on health-care costs. For its clinic management a poly-pharmaceutical therapy is often required, but this can cause side effects and reduce the patient’s compliance. For this reason, finding a valid and alternative therapeutic strategy, natural and free of side effects, could represent a useful tool in the fight the MetS. In this context, the use of functional foods, and the assumption of natural bioactive compounds (NBCs), could exert beneficial effects on body weight, blood pressure and glucose metabolism control, on endothelial damage, on the improvement of lipid profile, on the inflammatory state, and on oxidative stress. This review focuses on the possible beneficial role of NBCs in the prevention and in the clinical management of MetS and its comorbidities.

Glutathione transferase P1-1 (GSTP1-1) is expressed in some human tissues and is abundant in mammalian erythrocytes (here termed e-GST). This enzyme is able to detoxify the cell from endogenous and exogenous toxic compounds by using glutathione (GSH) or by acting as a ligandin. This review collects studies that propose GSTP1-1 as a useful biomarker in different fields of application. The most relevant studies are focused on GSTP1-1 as a biosensor to detect blood toxicity in patients affected by kidney diseases. In fact, this detoxifying enzyme is over-expressed in erythrocytes when unusual amounts of toxins are present in the body. Here we review articles concerning the level of GST in chronic kidney disease patients, in maintenance hemodialysis patients and to assess dialysis adequacy. GST is also over-expressed in autoimmune disease like scleroderma, and in kidney transplant patients and it may be used to check the efficiency of transplanted kidneys. The involvement of GSTP in the oxidative stress and in other human pathologies like cancer, liver and neurodegenerative diseases, and psychiatric disorders is also reported. Promising applications of e-GST discussed in the present review are its use for monitoring human subjects living in polluted areas and mammals for veterinary purpose.

The most common manifestation of cardiovascular (CV) diseases is the presence of arterial hypertension (AH), which impacts on endothelial dysfunction. CV risk is associated with high values of systolic and diastolic blood pressure and depends on the presence of risk factors, both modifiable and not modifiable, such as overweight, obesity, physical exercise, smoking, age, family history, and gender. The main target organs affected by AH are the heart, brain, vessels, kidneys, and eye retina. AH onset can be counteracted or delayed by adopting a proper diet, characterized by a low saturated fat and sodium intake, a high fruit and vegetable intake, a moderate alcohol consumption, and achieving and maintaining over time the ideal body weight. In this review, we analyzed how a new nutritional approach, named caloric restriction diet (CRD), can provide a significant reduction in blood pressure values and an improvement of the endothelial dysfunction. In fact, CRD is able to counteract aging and delay the onset of CV and neurodegenerative diseases through the reduction of body fat mass, systolic and diastolic values, free radicals production, and oxidative stress. Currently, there are few studies on CRD effects in the long term, and it would be advisable to perform observational studies with longer follow-up.

Crocus sativus L., commonly known as saffron, is a precious spice coming from Asia, in particular from Iran, the country leader in its production. The spice is derived exclusively from dried stigmas and it is the most expensive one in the world. The areas of application of saffron are multiple, in fact ranging across the food, drinks, pharmaceuticals and cosmetics sectors. As is the case with other phytochemicals, not only the final product but also saffron by-products are considered a valuable source of bioactive natural compounds. In fact, its healthy effects, especially as antioxidants and anti-inflammatories (via reducing pro-inflammatory cytokines), are well-recognized in internal medicine. In particular, its healthy effects are related to counteracting degenerative maculopathy, depression and anxiety, neurodegenerative diseases, metabolic syndrome, cancer and chronic kidney disease, by promoting glucose metabolism. In this review, we summarize the most important papers in which saffron has turned out to be a valuable ally in the prevention and treatment of these pathologies. Moreover, we would like to promote the use of saffron by-products as part of a bio-circular economy system, aimed at reducing wastes, at maximizing the use of resources and at promoting environmental and economic sustainability.

Metabolic acidosis is a severe complication of chronic kidney disease (CKD) which is associated with nefarious impairments such as bone demineralization, muscle wasting, and hormonal alterations, for example, insulin resistance. Whilst it is possible to control this condition with alkali treatment, consisting in the oral administration of sodium citrate or sodium bicarbonate, this type of intervention is not free from side effects. On the contrary, opting for the implementation of a targeted dietetic-nutritional treatment for the control of CKD metabolic acidosis also comes with a range of additional benefits such as lipid profile control, increased vitamins, and antioxidants intake. In our review, we evaluated the main dietary-nutritional regimens useful to counteract metabolic acidosis, such as the Mediterranean diet, the alkaline diet, the low-protein diet, and the vegan low-protein diet, analyzing the potentialities and limits of every dietary-nutritional treatment. Literature data suggest that the Mediterranean and alkaline diets represent a valid nutritional approach in the prevention and correction of metabolic acidosis in CKD early stages, while the low-protein diet and the vegan low-protein diet are more effective in CKD advanced stages. In conclusion, we propose that tailored nutritional approaches should represent a valid therapeutic alternative to counteract metabolic acidosis.

Chronic kidney disease (CKD) is one of the most common chronic non-communicable degenerative diseases and it represents an important risk factor for cardiovascular morbidity and mortality. The Mediterranean diet, in which extra virgin olive oil (EVOO) is the main source of vegetal fats, represents a nutritional-diet regimen that is useful for the treatment of CKD and its comorbidities. We tested two different EVOOs, characterized by a high (Synergy) and medium (Luxolio) content of minor polar compounds (MPCs), detected by HPLC-DAD-MS analysis, in 40 nephropathic patients, at a dose of 40 mL/day for 9 weeks. We evaluated the effects of these two EVOOs on renal function, body composition, oxidative stress, and inflammatory state, after 9 weeks of EVOOs consumption (T1) and after 2 months of wash-out (T2). We observed an improvement of renal function biomarkers (estimated-glomerular filtration rate, albuminuria, azotemia, uric acid), lipid profile, oxidative stress, inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein) and in body composition at T1. These healthy effects were greater and persisted over time after the wash-out period in Synergy patients. The high MPC EVOO content seems to exert an antioxidant and anti-inflammatory effect in nephropathic patients and these protective actions are maintained over time.