Role of poly (ADP) ribose polymerase-1 inhibition by nicotinamide as a possible additive treatment to modulate host immune response and prevention of cytokine storm in COVID-19

Abstract

COVID-19 is rapidly spreading contagious disease spreading across the world. Patients at risk are elderly people and those with comorbidity. Early studies done on Chinese patients who suggest cytokine storm to be responsible for lung injury. We need to understand the mechanism of modulating such robust response of immunity and resultant cytokine storm. We suggest nicotinamide, a potential poly ADP ribose polymerase (PARP) inhibitor, as a supportive treatment for the prevention of cytokine storm from injuring the lung parenchyma. Nicotinamide supplementation albeit at high dose may modulate outcome in COVID-19. Nicotinamide was used previously to reduce ventilator-induced lung injury and lung injury due to hypoxia. Nicotinamide congeners are used to treat chronic lung disease like tuberculosis. Certainly, nicotinamide is effective pharmacotherapy in lung injury – whether acute or chronic. Other measures used in treating COVID-19 are focusing on targeting interleukin-6 – a cytokine responsible for mayhem, while few are targeting granulocyte-macrophage colony- stimulating factor. We suggest targeting PARP in addition to other measures to block cytokines. By inhibiting PARP course of COVID-19 may be altered. Understanding the pathophysiology of acute lung injury is crucial. PARP plays a pivotal role on cytokine release in response to any lung injury ranging from viral infection to hypoxia. Various antiviral defenses and immune response need to be studied in detail.