Smoke, nicotine, opioids, and cannabinoids effects on the ACE2 protein level and possibility of COVID-19 infection: Suggesting potential preventives and therapeutics

Introduction. The coronavirus caused the pandemic COVID-19 that has an extensive influence in the world. The virus enters and infects body cells through superficial protein ACE2. Each cell possessing ACE2 is potentially vulnerable to this virus. Since the respiratory system is exposed to the environment and has ACE2, it is one of the first candidates infected by the virus. One of the considerable complications in the severe stage of COVID-19 is an intense adaptive immunological response that is detrimental to body organs. Methods. This is a review article. All relevant articles which were accessible were reviewed. Results. Some drugs of abuse may have an adverse or beneficial influence on the disease, and their simultaneity with COVID-19 is remarkable. Nicotine and cholinergic nicotinic receptor agonists seem to decrease the cell's membrane superficial ACE2 protein number; thus, they would be appropriate candidates for COVID-19 prevention and expansion. Both opioids and cannabinoids attenuate the immune system and seem to be adverse for disease incidence but can be beneficial for the severe stage of COVID19. The antitussive effect of some opioids would be advantageous. Furthermore, some opioids are substrates for ACE2 and they bind it. Therefore, they would be an appropriate candidate to design a drug covering ACE2 with a high affinity to prevent coronavirus infection. Conclusion. Some drugs, such as nicotine and opioids, may have beneficial effects on preventing or reducing COVID-19 complications.