Lethal Human Coronaviruses Infections-Origins, and Characteristics

CoVs are single-stranded RNA viruses which belong to the order Nidovirales, family Coronaviridae, and subfamily Coronavirinae. The viruses are subdivided into four genera on the basis of genotypic and serological characters which are Alpha-, Beta-, Gamma, and Deltacoronavirus, and among them, the first two genera are those which infect humans. The most important coronaviruses are CoV-229E (Alpha), CoV-NL-63 (Alpha), CoV-HKU-1 (Beta), CoV-OC43 (Beta), SARS-CoV (Beta), MERS-CoV (Beta) and SARS-CoV-2 (Beta). Natural hosts of HCoV-229E and HCoV-NL63 are bats and palm civets, respectively, while the natural hosts of HCoV-OC43 and HCoV-HKU1 are cattle and mice respectively. For SARS-CoV, natural hosts are palm civets and bats and camles introduced as natural hosts for MERS-CoV. The goal of this manuscript is a review on human coronaviruses from human coronavirus OC43 to SARS-CoV-2. Extracts from Artemisia annua, Lycoris radiate, Lidera aggregate, Isatis indigotica, Torreya Nucifera and Houttuynia Cordata showed anti-SARS effects.