The molecular effects of ozone on human hemoglobin oligomerisation pre- and post-COVID-19 infection accompanied by favoured antioxidant roles of cinnamaldehyde and phenyl ethyl alcohol

Abstract

Many studies have shown that oxidative stress plays a pivotal role in pathogenesis of coronavirus disease 2019 (COVID-19). In the present work, a case-study was conducted by comparing human hemoglobin (Hb) oligomerization upon autohemotherapy before and after COVID-19 infection. Structural changes of Hb exposed to different concentrations of ozone (40, 60, and 80 μg/ml) in whole blood, before COVID-19 infection, was compared to Hb exposed to the highest concentration of ozone (80 μg/ml) in whole blood, in the presence of two antioxidants, cinnamaldehyde (Cin) and phenyl ethyl alcohol (PEA), after COVID-19 infection. The structural analyses in this study was performed using various techniques, including DPPH radical scavenging assay, intrinsic fluorescence spectroscopy, circular dichroism (CD) spectroscopy, UV–VIS absorption spectroscopy, SDS-PAGE, dynamic light scattering (DLS), and molecular docking studies. The results showed that Hb oligomerization by ozone increased significantly after COVID-19 infection. In addition, at an ozone concentration of 80 μg/ml, the affinity of heme groups for globin chains and to oxygen molecules were shown to increase, whereas the stability of Hb decreased. In contrary, the addition of Cin and PEA prevented the adverse effects of ozone with PEA showing more efficacy in maintaining the native structure of Hb. Taken together, these results provided insights into the adverse effects of COVID-19 infection on Hb oligomerization and highlighted the importance of an individual's antioxidant capacity in protecting Hb from ozone, especially high ozone concentrations in autohemotherapy, and further emphasised the importance of personalising the concentration of ozone for patient administration, in order to provide a safe and effective autohemotherapy treatment.