Renyi Wu 1Lujing Wang 1Hsiao-Chen Dina Kuo 1Ahmad Shannar 1Rebecca Peter 1Pochung Jordan Chou 1Shanyi Li 1Rasika Hudlikar 1Xia Liu 1 2Zhigang Liu 1 3George J Poiani 4 5Louis Amorosa 5Luigi Brunetti 4 6Ah-Ng Kong 1Free 

Abstract 

The current pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has presented unprecedented challenges to the healthcare systems in almost every country around the world. Currently, there are no proven effective vaccines or therapeutic agents against the virus. Current clinical management includes infection prevention and control measures and supportive care including supplemental oxygen and mechanical ventilatory support. Evolving research and clinical data regarding the virologic SARS-CoV-2 suggest a potential list of repurposed drugs with appropriate pharmacological effects and therapeutic efficacies in treating COVID-19 patients. In this review, we will update and summarize the most common and plausible drugs for the treatment of COVID-19 patients. These drugs and therapeutic agents include antiviral agents (remdesivir, hydroxychloroquine, chloroquine, lopinavir, umifenovir, favipiravir, and oseltamivir), and supporting agents (Ascorbic acid, Azithromycin, Corticosteroids, Nitric oxide, IL-6 antagonists), among others. Vitamin C is an essential nutrient and plays significant roles within the human body. It can neutralize free radicals and assist to prevent or reverse cellular damage as a potent antioxidant agent. It is also involved in some biological processes, many of which are associated with immune health [77].

Moreover, vitamin C appears to be effective as an antiviral agent, especially against influenza viruses [78]. Many studies showed that vitamin C positively affects the development and maturation of T lymphocytes and NK (natural killer) cells involved in the immune response to viral agents. It also contributes to the inhibition of reactive oxygen species (ROS) production and to the remodulation of the cytokine network typical of systemic inflammatory syndrome were discharged [81]. Moreover, high-dose (1.5 mg/kg body weight) vitamin C has been used for several decades clinically and an NIH panel also documented clearly that this dose regimen is safe and has no major side effects [8182].