**About the Editors**

#### **Massimo Lucarini**

Massimo Lucarini holds a master's degree in Industrial Chemistry 'cum laude' at the University of Rome "La Sapienza", Italy (1992) and a Ph.D. in Chemistry (University of Rome "La Sapienza"). He works as researcher, at CREA, the Research Centre for Food and Nutrition (www.crea.gov.it). Here, research activity mainly aims to evaluate the nutrient contents of molecules with biological and anti-nutrient activity in foods and diets. An integral part of the research carried out is linked to institutional activity, including food composition tables, dietary guidelines for healthy eating, and evaluations of fraud risk in the agri-food system. The research activity also aims to exchange scientific information and acquire new skills both at national and international levels, through training courses and participation in congresses and seminars. The dissemination activity is carried out through the production of scientific articles and educational and informative activities.

#### **Pasquale Strazzullo**

Prof. Pasquale Strazzullo, MD, FAHA, is President of the Italian Society of Human Nutrition (SINU) and Associate Editor (past-Editor-in-chief) of *Nutrition, Metabolism and Cardiovascular Disease* (*NMCD*), the official journal of the Italian Societies of Human Nutrition, Diabetes and Atherosclerosis. He is the Italian Delegate in the WHO European Salt Action Network. Until last year, he was the Professor of Internal Medicine at Federico II University of Naples Medical School (Department of Clinical Medicine and Surgery), and has been Director of the Department of Clinica Medica as ESH Hypertension Specialist, responsible for the Excellence Centre of Hypertension. His broad areas of interest are the role of nutrition in cardiovascular prevention, the pathophysiology and clinical aspects of the disorders of mineral metabolism, and the metabolic and genetic bases of cardiovascular diseases. He has authored over 350 publications, most of which are in international, peer-reviewed journals.

#### **Antonello Santini**

Antonello Santini, Ph.D., is a Professor of Food Chemistry and Food Chemistry and Analysis of Food and Nutraceuticals at the Department of Pharmacy and at the Department of Agriculture of the University of Napoli Federico II, Napoli, Italy. He is also a visiting professor at the Albanian University of Tirana, Albania. He holds a Ph.D. in Chemical Sciences. His research areas of interest are substantiated by many international collaborations, mainly in the fields of food; food chemistry, nutraceuticals, and functional food; supplements; the recovery of natural compounds using eco-sustainable and environmentally friendly techniques from agro-food byproducts; nanocompounds; nanonutraceuticals; food risk assessments, safety and contaminants; mycotoxins and secondary metabolites; food analysis; and chemistry and food education. He is responsible for several funded research projects. His research activity is substantiated by more than 200 papers in internationally reputed, peer-reviewed journals.

#### **Alessandra Durazzo**

Alessandra Durazzo was awarded a master's degree in Chemistry and Pharmaceutical Technology cum laude in 2003, and a Ph.D. in Horticulture in 2010. She is a researcher at the CREA, Research Centre for Food and Nutrition. The core of her research is the study of chemical, nutritional and bioactive components of food, with particular regard to the wide spectrum of substance classes and their nutraceutical features. Her research activities also address the development, management and updating of bioactive compounds, nutraceuticals and dietary supplements databases; particular attention is given towards the harmonization of analytical procedures and the classification and codification of dietary supplements.

#### **Ginevra Lombardi-Boccia**

Ginevra Lombardi-Boccia graduated with a degree in Biological Science at the "La Sapienza" University of Rome. She is a senior Researcher at the Food Science Laboratories of CREA, Research Centre for Food and Nutrition. She is the co-author of more than 200 international peer-reviewed papers. She is also the Scientific Coordinator and co-leader of research projects aiming to assess the nutritional quality of food and diets and sustainability and innovation in food production. Her current research activities aim to identify and valorize new sustainable sources (e.g., food waste) of nutrients (e.g., proteins and omega3 fatty acids) and bioactive molecules (e.g., carotenoids and phenolics) and at recovering waste from food chains to develop products for the food, nutraceutical and cosmeceutical sectors.

#### **Stefania Sette**

Stefania Sette works at CREA, the Research Centre for Food and Nutrition. Her main scientific activities are: (i) food consumption studies and dietary assessments in Italy and developing countries; (ii) population and nationwide monitoring studies; (iii) nutritional research on food consumption pattern and factors affecting physical conditions; (iv) food preferences and school-meal surveys; (v) exposure assessments to chemicals, in particular, natural and artificial flavourings in foods; (vi) updates of food reference databases to be used in computer-based food systems to generate and process food consumption surveys; and (vii) research on aspects of food and nutrition policies.

## *Editorial* **Sodium Intake and Related Diseases**

**Massimo Lucarini 1,\*, Alessandra Durazzo <sup>1</sup> , Stefania Sette <sup>1</sup> , Ginevra Lombardi-Boccia <sup>1</sup> , Antonello Santini <sup>2</sup> and Pasquale Strazzullo 3,\***


Moderation in the use of salt (sodium chloride) in food and food preparations prevents the tendency of blood pressure to increase with age, and this is documented by many studies in current literature. In contrast, the abuse of salt frequently leads to increases in blood pressure and contributes to the development of hypertension, particularly in overweight or obese people, in diabetics, in the elderly and in genetically predisposed subjects.

Given the well-known relationship between high blood pressure and the risk of cardiovascular disease, high salt consumption is also associated with an increased risk of fatal or otherwise debilitating cardiovascular events, with a high impact on health expenditure.

The reduction of salt consumption leads to a decrease in blood pressure—more so in hypertensive, elderly and obese subjects—and consequently to a reduction in cardiovascular risk. The development of salt-reducing programs for individual, population, and country-level strategies to reduce salt intake is becoming a challenge, considering the general tendency not to change the use of salt. Improving knowledge is a key step for behavioral changes, suggesting the need for effective public health interventions throughout educational campaigns addressed at the implementation of good practices in nutrition [1,2].

The nutritional goal for the adult population has been set at no more than 2000 mg of sodium or 5 g of salt per day, in keeping with the WHO recommendation [3] that applies to all adult individuals, including the elderly, in the absence of different medical/nutritional indications.

At least half of the amount of salt taken individually comes from processed foods and food purchased and/or consumed outside of the home, and for these reasons an effective reduction in salt consumption requires the active participation of the food industry and the awareness of the consumer to the sodium content of the consumed products.

This Special Issue is focused on the role of sodium in the body's physiological processes. Generally, complex mechanisms regulate sodium concentrations in bodily fluids that involve the cardiovascular and endocrine systems, the central nervous system and the autonomic nervous system. The mechanisms involved in the regulation of sodium homeostasis will be the focus of this Special Issue. Some examples are the mechanisms which influence the action of the sodium–potassium pump, the renal tubular reabsorption mechanisms regulated by hormones, such as angiotensin II, and norepinephrine and those of sodium elimination, regulated by dopamine and cyclic AMP. The mechanisms involved at the molecular level of the relationship between sodium intake–blood pressure– cardiovascular disease and stomach cancer are among the focuses of this Special Issue.

The main topics of this Special Issue include: levels of intake and main sources of sodium from the diet: effect on the health status and description of the biochemical processes involved; salt intake and related risks; studies in the management and treatment of sodium intake-related diseases; epidemiological studies of the relationship between salt

**Citation:** Lucarini, M.; Durazzo, A.; Sette, S.; Lombardi-Boccia, G.; Santini, A.; Strazzullo, P. Sodium Intake and Related Diseases. *Int. J. Mol. Sci.* **2021**, *22*, 7608. https://doi.org/10.3390/ ijms22147608

Received: 1 July 2021 Accepted: 12 July 2021 Published: 16 July 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

intake and related diseases: focus on the mechanism of action; delineation of mechanism of actions: *in vitro* and *in vivo* studies; salt and sapidity: mechanisms of taste perception. Chan et al. [4] investigated the MST3 involvement in Na<sup>+</sup> and K<sup>+</sup> homeostasis with increasing dietary potassium intake, in mice fed by diets containing various concentrations of Na<sup>+</sup> and K<sup>+</sup> . The 2% KCl diets induced less MST3 expression in MST3−/<sup>−</sup> mice than that in wildtype (WT) mice. The MST3−/<sup>−</sup> mice had higher WNK4, NKCC2-S130 phosphorylation, and ENaC (epithelial Na channel) expression, resulting in lower urinary Na<sup>+</sup> and K<sup>+</sup> excretion than those of WT mice. Lower urinary Na<sup>+</sup> excretion was associated with elevated plasma [Na<sup>+</sup> ] and hypertension. The authors marked how MST3 maintains Na+/K<sup>+</sup> homeostasis in response to K<sup>+</sup> loading by regulation of WNK4 expression and NKCC2 and ENaC activity [4].

Hirohama et al. [5] showed, using animal models, how PGI2 analog attenuates saltinduced renal injury through the inhibition of inflammation and Rac1-MR activation; this study clearly demonstrated that Beraprost sodium (BPS), a pharmaceutical used in several Asian countries, including Japan and South Korea, as a vasodilator and antiplatelet agent, had renoprotective effects in salt-induced kidney injury, leading to the plausible hypothesis that BPS is therapeutically useful for the treatment of salt-induced renal damage.

Nakayama et al. [6] reported how Na<sup>+</sup> coupled nutrient cotransport-induced luminal negative potential and claudin-15 play an important role in paracellular Na<sup>+</sup> recycling in mouse small intestine; particularly, the authors concluded that Na<sup>+</sup> , which is absorbed by Na<sup>+</sup> -dependent glucose cotransport, is recycled back into the lumen via paracellular Na<sup>+</sup> conductance through claudin-15, which is driven by Na<sup>+</sup> cotransport induced luminal negativity [6].

It is worth mentioning the reviews by Patel and Joseph [7] on sodium intake and heart failure as well as that by Borrelli et al. [8] on sodium intake and chronic kidney disease.

This Special Issue contributes to the field of research on sodium, aiming to better understand its mechanism of action and reference and the relationship between sodium intake and related diseases.

**Author Contributions:** All the authors listed (M.L., A.D., S.S., G.L.-B., A.S. and P.S.) have made a substantial contribution to the work and approved it for publication. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** We would like to thank all the authors and the reviewers of the papers published in this Special Issue for their great contributions and efforts. We are also grateful to the editorial board members and to the staff of the journal for their kind support in all steps necessary for the realization of this Special Issue.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

