Zinc is known to modulate antiviral and antibacterial immunity and regulate inflammatory response. Despite the lack of clinical data, certain indications suggest that modulation of zinc status may be beneficial in COVID‑19. In vitro experiments demonstrate that Zn2+ possesses antiviral activity through inhibition of SARS‑CoV RNA polymerase. This effect may underlie therapeutic efficiency of chloroquine known to act as zinc ionophore. Indirect evidence also indicates that Zn2+ may decrease the activity of angiotensin‑converting enzyme 2 (ACE2), known to be the receptor for SARS‑CoV‑2. Improved antiviral immunity by zinc may also occur through up‑regulation of interferon α production and increasing its antiviral activity. Zinc possesses anti‑inflammatory activity by inhibiting NF‑κB signaling and modulation of regulatory T‑cell functions that may limit the cytokine storm in COVID‑19. Improved Zn status may also reduce the risk of bacterial co‑infection by improving mucociliary clearance and barrier function of the respiratory epithelium, as well as direct antibacterial effects against S. pneumoniae. Zinc status is also tightly associated with risk factors for severe COVID‑19 including ageing, immune deficiency, obesity, diabetes, and atherosclerosis, since these are known risk groups for zinc deficiency. Therefore, Zn may possess protective effect as preventive and adjuvant therapy of COVID‑19 through reducing inflammation, improvement of mucociliary clearance, prevention of ventilator‑induced lung injury, modulation of antiviral and antibacterial immunity. However, further clinical and experimental studies are required.
Perspectives and conclusions
The obtained data demonstrate that adequate zinc status of the individual increases immune reactivity. Correspondingly, inadequate zinc supply may predispose to infectious diseases of upper and lower respiratory tract. Although the therapeutic effects of Zn are considered as inconsistent, the existing evidence-based data indicate efficiency of Zn supplementation and improvement of Zn status in prevention of pneumonia and its complications due to anti-inflammatory effect of zinc.Certain indirect indications of the potential antiviral effect of Zn against nCoV-2019 exist, although their biomedical relevance is yet to be studied. In view of recent data on clinical course of the disease, it appears that adequate Zn status may possess protective effect as adjuvant therapy of COVID-19 through reducing lung inflammation, improvement of mucociliary clearance, prevention of ventilator-induced lung injury, modulation of antibacterial and antiviral immunity especially in elderly (Fig. 1). Further clinical and experimental studies are strongly required to elucidate the potential role of Zn deficiency in COVID-19 susceptibility, as well as effects of Zn supplementation, and the underlying mechanisms.
Reference & source information : https://www.spandidos-publications.com/10.3892
Read More on :