Quest Journals Journal of Medical and Dental Science Research Volume 8~ Issue 8 (2021) pp: 35-38 ISSN(Online) : 2394-076X ISSN (Print):2394-0751 www.questjournals.org *Corresponding Author: Irfan Gous Mulla 35 | Page Research Paper Elevated levels of serum MDA and Nitric Oxide in covid- 19 patients: A case control study Aarti K Salve 1 , Sarita A Basu 2 , Irfan G Mulla 1* ,Sharad B Kole 3 ,Sunil Kharge 4 Abhishek Talathi 5 1,1* Senior Lecturer, Department of Biochemistry Yogita Dental College and Hospital ,Khed, Maharashtra 2 Reader , Department of Biochemistry Yogita Dental College and Hospital ,Khed, Maharashtra . 3 Professor and Head, Department of Physiology and Biochemistry,Yogita Dental College and Hospital Khed, Maharashtra. 4 Assistant Professor ,Department of Biochemistry ,PIMS , Urun Islampur ,Maharashtra. 5 HOD, Department of Public Health Dentistry, Yogita Dental College and Hospital Khed, Maharashtra. *Corresponding Author : Irfan Gous Mulla , Senior Lecturer Department of Biochemistry ,Yogita Dental College and Hospital , Khed, Maharashtra. ABSTRACT The interaction between oxidative stress and inflammatory cytokines can lead to several organ failures in Covid-19 patients who proceed to worsening condition. In view of this we planned our study to investigate the oxidative stress by measuring Nitric Oxide and MDA level in hospitalized Covid-19 patients and compared with healthy controls: A case control study. Key Word: MDA, NO, ROS ,RNS. Received 10 August, 2021; Revised: 24 August, 2021; Accepted 26 August, 2021 © The author(s) 2021. Published with open access at www.questjournals.org I. INTRODUCTION Over the last few months, a new strain of human coronavirus, SARS-CoV 2(also known as 2019- nCoV), has caught the world’s seven continents attention with its rapid global spread, affecting at least 200 countries and territories, infecting more than 3,000,000 and claiming more than 202,597 lives worldwide (1). A WHO report from the 19 th May 2020, confirmed 4,731,458 COVID -19 positive cases from 213 countries worldwide, of which 1,477,516 cases were reported in the United States of America, 231,606 cases in Spain, 225,886 cases in Italy, 246,410 in the United Kingdome, 84,500 in China (the origin of the pandemic) and 101,139 cases in India. (4) Viral infections causing respiratory complications are known to change host cell redox homeostasis, which involves balancing ROS/ RNS as a critical event (5). In airway epithelial cells, virus induced ROS was found to originate from diverse oxidase activities, including NADPH oxidases, dual oxidase, and xanthine oxidase (5). RNA viruses were suggested to utilize oxidative stress during infection to control genome RNA capping and genome replication (6,7,8).NO is formed by the oxidative deamination of the amino acid L-arginine by nitric oxide synthases (NOS). (9 ) Biogenesis of higher levels of NO can suppress type 1 helper Tcell- dependent immune responses, which can impair type 2 helper T-cell-biased immunological host responses (10). eNOS is mostly present in endothelial cells and its functionality can be restored with renin- and angiotensin- converting enzyme-inhibitors or angiotensin receptor blockers, both commonly used to regulate blood pressure in hypertensive patients (11). The entry point of the coronavirus has been recognized to be Angiotensin Converting Enzyme 2 (ACE2) receptors, which are expressed in endothelial and epithelial cells (12). ACE2 pathway is known to modulate a cascade of events including vascular compliance and vasodialation (13). In primary lung epithelial cells validated by biopsies of COVID-19 patients, SARS-CoV-2 induced oxidative stress due to mitochondrial dysfunction The lungs are the preferred target of COVID-19 by the large area exposed to viruses, they are among the most oxygenated organs in the human body.However, during pathological events, such as viral infections, there may be an increase in the production of oxidant species not neutralized by the antioxidant system, resulting in oxidative stress that promotes cellular damage through protein denaturation, changes in the functions of nucleic acid, lipid peroxidation, and cell death.COVID-19 triggers inflammatory