Postulated Adjuvant Therapeutic Strategies for COVID-19

Abstract

The number of COVID-19 patients is still growing exponentially worldwide due to the high transmissibility of the SARS-CoV-2 virus. Therapeutic agents currently under investigation are antiviral drugs, vaccines, and other adjuvants that could relieve symptoms or improve the healing process. In this review, twelve therapeutic agents that could play a role in prophylaxis or improvement of the COVID-19-associated symptoms (as add-on substances) are discussed. Agents were identified based on their known pharmacologic mechanism of action in viral and/or nonviral fields and are postulated to interact with one or more of the seven known mechanisms associated with the SARS-CoV-2 virus: (i) regulation of the immune system; (ii) virus entrance in the cell; (iii) virus replication; (iv) hyperinflammation; (v) oxidative stress; (vi) thrombosis; and (vii) endotheliitis. Selected agents were immune transfer factor (oligo- and polypeptides from porcine spleen, ultrafiltered at <10 kDa; Imuno TF^®), anti-inflammatory natural blend (Uncaria tomentosa, Endopleura uchi and Haematoccocus pluvialis; Miodesin^®), zinc, selenium, ascorbic acid, cholecalciferol, ferulic acid, spirulina, N-acetylcysteine, glucosamine sulfate potassium hydrochloride, trans-resveratrol, and maltodextrin-stabilized orthosilicic acid (SiliciuMax^®). This review gives the scientific background on the hypothesis that these therapeutic agents can act in synergy in the prevention and improvement of COVID-19-associated symptoms.

Keywords: COVID-19; SARS-CoV-2; adjuvant; compounding; coronavirus; dietary supplement; drug; immunological; pharmacology; therapeutics.

Figure 1

Time course of COVID-19 through the different stages of the infection, and the possible effect of the selected therapeutic agents in different stages of the syndrome. Adapted from Siddiqi [30]. ARDS: Acute respiratory distress syndrome. SIRS: Systemic inflammatory response syndrome. CRP: C-reactive protein. LDH: Lactate dehydrogenase. NT-proBNP: N-terminal-pro hormone BNP (brain natriuretic peptide).

Figure 2

(a) Structure of transfer factor fractions. (b) Schematic representation of the induction of immune response by transfer factor. Adapted from Salazar-Ramiro et al. [57].

Figure 3

Innate immune response and adaptative response of coronaviruses infections and potential targets for immunoregulation by selected therapeutic agents. Adapted from Dosch et al. [126].

Figure 4

Main effects known to date of SARS-CoV-2 on human organism and sites of action. URT: Upper respiratory tract. ALI: Acute lung injury. ARDS: Acute respiratory distress syndrome. Adapted from Zhang et al. [36].