Functional foods as immunomodulators: Tackling the SARS-CoV-2 related cytokine storm–A review

Coronavirus disease 2019 (COVID-19) caused by the novel coronavirus, SARS-CoV-2 continues to strain the health systems globally. Although various therapeutics are being explored for COVID-19 management, such as antiviral drugs, monoclonal antibodies, immunosuppressant drugs, anticoagulants, and the likes, the continuous evolution of the virus as well as symptoms associated with the disease keep offering challenges in its management, thereby necessitating the involvement of a non-linear approach to tackle the disease. In addition to the direct damage caused by the virus to the host, one peculiar phenomenon that occurs is the self-sabotaging immune response leading to cytokine storm syndrome, which contributes to the severity of the disease and higher mortality rates. The cytokine storm is associated with an unrestricted production of pro-inflammatory cytokines, thereby causing acute respiratory distress and sepsis. Functional foods are known to possess immunomodulatory and anti-inflammatory bioactive compounds that are capable of suppressing proinflammatory cytokines while increasing the levels of anti-inflammatory cytokines, through suppression and activation of signaling pathways. This article reviews the immunomodulatory and anti-inflammatory activities of functional foods via the mechanisms involved therein, and warrant their use in the management of COVID-19, as supportive therapies that complement standard treatment regimens.