Screening of Natural Antivirals Against the COVID-19 Pandemic- A Compilation of Updates

Abstract

Background: Coronavirus disease 2019 (COVID-19), named by WHO, is a public health disaster of the third millennium. This acute respiratory distress syndrome (ARDS) has severe complications like pneumonitis, respiratory failure, shock, multi-organ failure, and finally, death. Despite repurposing of broad-spectrum antivirals, vaccinations, use of mask sanitizers, social distancing, intermittent lockdowns and quarantine, long-term protection or eradication of coronavirus is yet to be achieved. Objectives: This comprehensive review makes a compilation of updates on the screening and evaluation of natural antivirals that are found to show anti-COVID potency. Methods: Literature mining was done in phytotherapy and food research journals, Pubmed, Scopus, Elsevier for collection of latest research updates focusing on screening and evaluation of anti-COVID natural antivirals. Results: In silico molecular docking studies have screened several phytochemicals and food bioactive principles with significant potencies against the corona virus. The anti-COVID potency of the phytochemicals is mostly by restricting the action of enzymes like the main protease (Mpro), 3-chymotrypsin like protease (3CLpro), spike proteins, papain-like protease (ACE2). Free radical scavenging, anti-inflammatory effect, DNA inhibition, prevention of viral attachment, and its penetration into the host body, inhibiting viral replication are other associated mechanisms of bioactive compounds present in plants, vegetables, fruits, spices and marine alga. Different formulations of Ayurveda, Siddha, Unani have shown their ameliorative effects. Many formulations of Traditional Chinese Medicine are under clinical trials. Conclusions: The immense potencies of bioactives that are omnipresent need to be properly utilized for immune-boosting and combat this deadly virus naturistically.