Mechanistic insights into corona viruses and covid-19: unravelling the possible treatment strategies with emphasis on plant-derived bioactive compounds

Pandemic coronaviruses being zoonotic have been the potential cause of worldwide social, economic, and mortality stress causing certain illnesses like severe acute respiratory syndrome coronavirus-1 (SARS-CoV-1) in 2002, Middle East respiratory syndrome coronavirus (MERS-CoV) in 2013, and severe acute respiratory syndrome coronavirus-2 (SARS-CoV- 2) in 2019. Because of severity of illness, various types of organs are damaged or even destroyed by these coronaviruses that in turn cause neurological, hepatic, and respiratory issues. Several vaccines are now either licensed or through phase III studies. Majority of vaccines use a recombinant spike glycoprotein, either based on mRNA (the Moderna and Pfizer- BioNTech vaccines), via adenovirus vector (the Oxford-AstraZeneca and Johnson & Johnson vaccines), via whole inactivated SARS-CoV-2 virus (Sinovac Biotech vaccines), or by injection of the protein itself (the Novavax vaccine). Moreover, nano vaccines and nano antiviral drugs could be prepared for targeted and sustained delivery. In the current scenario, there is a need to analyze the bestowing role of non -pharmacological mediators like nutraceuticals along with dietary supplements besides nano -biotechnological approaches to minimize the risk of SAR-CoV-2 infection by moderating the signs and symptoms related with COVID -19. A good dietary pattern is essential for individuals in preventing them from getting immunocompromised due to weakened immune system resulting from poor nutritional status. Phytochemicals biosynthesized by plants have potent antiviral activities to fight against SAR-CoV-2 by disrupting virus life cycle. Evidently, this development driven a concentration on phytochemicals from therapeutic plants to search new lead molecules, with an emphasis specifically on antiviral drugs. Such natural products inspire community efforts to raise funds that help researchers to investigate more phytochemicals for COVID-19 antiviral drug development. Most importantly, inclusion of plant -derived bioactive compounds along with the contemporary allopathic regimens have been anticipated to improve the evolvement of therapeutics against COVID 19.