Ameliorative potential of phytochemicals against side effects of COVID-19 drugs: A review

The pandemic of coronavirus disease-19 (COVID-19) remains to nag human race with its more infectious second wave in most of highly populated countries including India. Till date, no specific antiviral drug is discovered or developed which is cent-per-cent effective against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19. The efficacy of developed vaccines are said to reduce severity of disease, but the mutation led to origin of more infectious variants. In such scenario, medical management of COVID-19 largely depends upon repurposed drugs like azithromycin, remdesivir, chloroquine, hydroxychloroquine and tocilizumab. However, none of these repurposed drugs is devoid of side effects or drug-induced toxicities which may be fatal too sometimes. Scientific research literature on phytochemicals hints that these miracle phytomolecules may not only be useful in direct therapeutic effect but also have potential to reduce or ameliorate the side-effects of current repurposed drugs used in treatment of COVID-19. This review critically elaborates the side-effects of COVID-19 drugs and the six potential phytochemicals, viz., quercetin, baicalein, kaempferol, curcumin, catechins and gingerols which have potentials to ameliorate such side-effects. The very purpose of the review paper is to promote the scientific studies on these phytomolecules in the management of COVID-19, as there are predictions that human kind has to learn to live with this disease.