Methylene blue may have a role in the treatment of COVID-19

Abstract

In this paper, we raise the hypothesis that Methylene Blue may be a treatment option for Corona Virus Disease of 2019 specially when combined with Non Steroid Anti-Inflammatory Drugs. In previous publications including ours, the role of kininogen system has been postulated. A correlation between clinical findings of the disease and this mechanism has been drawn to denote a pivotal role of kininogen-kallikrein system in pathophysiology of the disease. Therein the possible role of Icatibant, Ecallantide and Aprotinin in the treatment of this disease has been raised. Here we want to emphasize on an important post-receptor mechanism of bradykinin that is Nitric Oxide. We came to this aim because we found out how access to these novel treatment nominees may be expensive and unaffordable. For this reason we are focusing on possible role of an old albeit "mysterious" drug namely Methylene Blue. This medication may abort effects of Bradykinin by inhibition of Nitric Oxide synthase inhibitor and promote oxygen saturation while it is inexpensive and ubiquitously accessible. Clinical studies cannot be over emphasized.

Keywords: Angiotensin-converting enzyme 2; Aprotinin; Bradykinin; COVID-19; Ecallantide; Icatibant; Methylene blue; NSAID; SARS-CoV-2.

Fig. 1

Schematic illustration of Bradykinin/NO pathway involved in SARS-CoV-2 infection (COX2: Cyclooxygenase2; EDHF: Endothelium-Derived Hyper-polarizing Factor; NO: Nitric Oxide; NOS: Nitric Oxide Synthase; NSAID: Non-Steroid Anti-Inflammatory Drug; PGI2: Prostaglandin I2).