Abdol Ghaffar Ebadi - Department of Agriculture, Jouybar Branch, Islamic Azad University, Jouybar, Iran
Mohaddeseh Larypoor - Department of Microbiology, Faculty of Biological Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran
Ali Akhavan Sepahi - Science Campus, Faculty of Biological Sciences, University of Tehran, Tehran, Iran

By determining the quality of food, the sense of smell can play a protective role in humans and determine the suitability of a food for consumption. Sometimes anosmia is presented as a possible disease, and some only present it as a clinical symptom of a specific disease. Anosmia can be caused by the use of drugs, poisons, inflammation, tumor, infection, and some miscellaneous factors. Regarding infection, some viruses, including influenza and Covid-۱۹, can also cause loss of the sense of smell. The chief signs were dry cough, fever, followed by diarrhea, vomiting, and other digestive disorders. According to current evidence, rapid taste or smell loss could also happen as a result of infection with Covid-۱۹. Anosmia refers to the smell inability, and specific anosmia refers to the incapability to recognize a specific smell. Several mechanisms have been proposed for Covid-۱۹-induced anosmia. The possibility of the olfactory receptor neurons death infected with the virus is a plausible mechanism for the loss of the smell sense caused by the Covid-۱۹ infection. Also, another possibility of anosmia is the mechanism of injury caused by the Covid-۱۹ virus to the olfactory epithelium. Olfactory stem cells can potentially be relevant to restore the function of olfactory. The olfactory epithelium has neural stem cells that maintain dynamic neurogenesis throughout life. Understanding the cellular and molecular mechanisms governing these olfactory stem cells is helpful in using them for therapeutic purposes. The aim of this study is to review the anosmia induced by Covid-۱۹ along with the possible mechanisms of its creation and the strategy of stem cell therapy in restoring the sense of smell.

Anosmia, COVID-۱۹, molecular mechanisms, Stem cell therapy