Interactions Between Adenosine Receptors and Cordycepin (3'- Deoxyadenosine) from Cordyceps Militaris: Possible Pharmacological Mechanisms for Protection of the Brain and the Amelioration of Covid-19 Pneumonia

At present, the novel Covid-19 pneumonia is prevalent, affecting millions of people. Here, we summarized the pharmacological basis of adenosine, adenosine receptors, adenosine agonist cordycepin (3'-deoxyadenosine), and Cordyceps product in the brain protection and amelioration of pneumonia to provide useful information to cope with the global pandemic of novel coronavirus (COVID-19). Adenosine, a mediator of innate immunity, is abundantly secreted by the injured lung tissues during inflammation. Through the activation of adenosine receptors A1, A2A, A2B and A3, adenosine plays an important role in protecting against acute lung injury and brain injury. Cordycepin (3-deoxyadenosine) is an activator of adenosine receptors. It can enhance human immunity, promote anti-inflammatory processes, inhibit RNA virus reproduction, protect against brain, lung, liver, heart, and kidney damage, and ameliorate lung-fibrosis in clinical and animal models. Cordyceps and cordycepin products could be used as a potential medicinal adenosine receptor agonist that can play a beneficial role in the amelioration of Covid-19 pneumonia and protection of brain.