ankyrin 1 (TRPA1) and/or transient receptor potential vanilloid 1 (TRPV1) activation as well as desensitization. TRPA1
and TRPV1 induce inflammation and play a key role in the
physiology of almost all organs. They may augment sensory
or vagal nerve discharges to evoke pain and several symptoms of COVID-19, including cough, nasal obstruction, vomiting, diarrhea, and, at least partly, sudden and severe loss of
smell and taste. TRPA1 can be activated by reactive oxygen
species and may therefore be up-regulated in COVID-19.
TRPA1 and TRPV1 channels can be activated by pungent
compounds including many nuclear factor (erythroid-derived 2) (Nrf2)-interacting foods leading to channel desensitization. Interactions between Nrf2-associated nutrients and
TRPA1/TRPV1 may be partly responsible for the severity of
some of the COVID-19 symptoms. The regulation by Nrf2 of
TRPA1/TRPV1 is still unclear, but suggested from very limited
clinical evidence. In COVID-19, it is proposed that rapid desensitization of TRAP1/TRPV1 by some ingredients in foods
could reduce symptom severity and provide new therapeutic strategies.