Narrative review of the progress in discovery of anti COVID-19 agents from traditional Chinese medicine using in silico approaches

An outbreak of COVID-19 disease caused by a novel SARS-CoV-2 virus is a major treat public health worldwide. This viral pneumonia is extremely pathogenic and highly infectious with no known treatments at the beginning of the outbreak. Traditional Chinese medicine (TCM) was often used in combination with Western medicine to cure the disease or alleviate symptoms at least. Pharmaceutical industry and academic research groups responded quickly to find possible treatments by searching for antiviral agents or developing vaccines. This mini review explores early use of computational chemistry methods to evaluate the potential of TCM to treat COVID-19 disease. Molecular docking was found to be method of choice as one of approaches that is least computationally and time demanding. This is often complemented with drug target prediction and network pharmacology analyses that allowed identification of molecules and formulations that have highest potential to either affect host-pathogen interaction or treat already infected patients. These in silico studies benefited from structural studies that provided structures of viral targets and from the use of various databases of TCM. It was found that flavonoids have potentially high affinity for druggable targets, however these molecules are not adequate drug candidates due to their poor bioavailability but could provide a basis for drug development. It was suggested that various known formulations could be more effective due to multicomponent multitarget synergistic action of their constituents. However, there is a lack of knowledge of other interactions, including drug-natural products and off-target interactions, that could cause adverse effects. Studies that include molecular dynamics simulations of multicomponent systems and experimental validation of theoretical studies are already underway. Such integrated approach with greater collaboration between research groups has a potential to find a suitable treatment for COVID-19 or a lead molecule for drug development