Abstract: International Journal of Molecular Sciences Review Lactoferrin as Protective Natural Barrier of Respiratory and Intestinal Mucosa against Coronavirus Infection and Inflammation Elena Campione 1, *, Terenzio Cosio 1 , Luigi Rosa 2 , Caterina Lanna 1 , Stefano Di Girolamo 3 , Roberta Gaziano 4 , Piera Valenti 2,† and Luca Bianchi 1,† 1 2 3 4 * † Dermatologic Unit, Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; terenziocosio@gmail.com (T.C.); caterinalanna.cl@gmail.com (C.L.); luca.bianchi@uniroma2.it (L.B.) Department of Public Health and Infectious Diseases, University of Rome La Sapienza, 00185 Rome, Italy; luigi.rosa@uniroma1.it (L.R.); piera.valenti@uniroma1.it (P.V.) Department of Otorhinolaryngology, University of Rome Tor Vergata, 00133 Rome, Italy; stefano.di.girolamo@uniroma2.it Department of Experimental Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; roberta.gaziano@uniroma2.it Correspondence: campioneelena@hotmail.com These authors contributed equally to this work. Received: 17 June 2020; Accepted: 9 July 2020; Published: 11 July 2020



 Abstract: Recently, the world has been dealing with a devastating global pandemic coronavirus infection, with more than 12 million infected worldwide and over 300,000 deaths as of May 15th 2020, related to a novel coronavirus (2019-nCoV), characterized by a spherical morphology and identified through next-generation sequencing. Although the respiratory tract is the primary portal of entry of SARS-CoV-2, gastrointestinal involvement associated with nausea, vomiting and diarrhoea may also occur. No drug or vaccine has been approved due to the absence of evidence deriving from rigorous clinical trials. Increasing interest has been highlighted on the possible preventative role and adjunct treatment of lactoferrin, glycoprotein of human secretions part of a non-specific defensive system, known to play a crucial role against microbial and viral infections and exerting anti-inflammatory effects on different mucosal surfaces and able to regulate iron metabolism. In this review, analysing lactoferrin properties, we propose designing a clinical trial to evaluate and verify its effect using a dual combination treatment with local, solubilized intranasal spray formulation and oral administration. Lactoferrin could counteract the coronavirus infection and inflammation, acting either as natural barrier of both respiratory and intestinal mucosa or reverting the iron disorders related to the viral colonization. Keywords: coronavirus; SARS; lactoferrin