RESUMO
Due to the high mortality rate of COVID-19 and its high variability and mutability, it is essential to know the body's defense mechanisms against this virus. Saliva has numerous functions, such as digestion, protection, and antimicrobial effects. Salivary diagnostic tests for many oral and systemic diseases will be available soon because saliva is a pool of biological markers. The most important antiviral and antibacterial compounds identified in saliva include lysozyme, lactoferrin (LF), mucins, cathelicidin, salivary secretory immunoglobulin (SIgA), chromogranin A, cathelicidin, salivary agglutinin (SAG) (gp340, DMBT1), α, ß defensins, cystatin, histatins, secretory leukocyte protease inhibitor (SLPI), heat shock protein (HSP), adrenomedullin and microRNA (miRNAs). Antimicrobial peptides (AMPs) in saliva could be used in the future as models for designing effective oral microbial antibiotics. The antiviral properties of the peptides in saliva may be one of the future treatments for the COVID-19 virus. In this review, we investigate compounds with antiviral and antibacterial properties in saliva and the importance of these compounds in saliva in exposure to the COVID-19 virus. Due to the transmission route of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) into the oral cavity in the lower and upper respiratory tract, studies of salivary antiviral properties in these patients are very important. Some of the antiviral effects of saliva, especially mucin, α, ß-defensins, IgA, IgG, IgM, lysozyme, SAG, SLPI, and histatins, may play a greater role in neutralizing or eliminating COVID-19.