Research progress on antiviral effect of active components of traditional Chinese medicine and their mechanisms

In recent years, with the frequent occurrence of viral diseases accompanied by high morbidity and mortality rates, there has been an increasing awareness of importance of antiviral drugs research. Traditional Chinese medicine contain biologically structurally diverse bioactive substances that provide important template structures for pharmaceutical research. Because of its novelty, multicomponent and multi-target characteristics, it is a valuable source for new drug development. The antiviral mechanisms of active components of traditional Chinese medicines include inhibition of viral replication, block binding of virus with receptor, directly killing virus, enhancement of the immune system and inhibition of cytokines/chemokines responses, etc. The active components of traditional Chinese medicine with antiviral active ingredients based on the mechanism of antiviral action were reviewed in this paper, in order to provide a basis for development of antiviral natural drugs to cope with the virus epidemic including the new variant of SARS-CoV-2 and other virus outbreaks that may occur in the future. © 2022 Editorial Office of Chinese Traditional and Herbal Drugs. All rights reserved.

Progress in drug development for treatment of coronavirus disease 2019 (COVID-19)

Since the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the number of SARS-CoV-2 infections has been increasing and health care is facing huge challenges. Innovative drug development in emergency and the development of new indications for the treatment of Coronavirus disease 2019 (COVID-19) on the market have become critical to finding effective drugs and optimal treatment options for COVID-19. The angiotensin converting enzyme 2 (ACE2) -inducing mechanism of SARS-CoV-2 invasion into host cells and the potential therapeutic targets based on SARS-CoV-2 and (or) host include RNA-dependent RNA polymerase, 3-chymotrypsin-like protease, papain like protease, Janus kinase, interleukine-6 and immune modulators etc. Based on the pharmacological mechanism mentioned above the clinical research and development of new indications and innovative drugs for the treatment of COVID-19 have achieved great progress, but no specific drugs have been found. Some traditional Chinese medicines can block the SARS-CoV-2 replication cycle, regulate human immune response and play an important role in the treatment of COVID-19. The new drugs for COVID-19 are undergoing Phase I clinical studies worldwide, and biologic drugs are gaining momentum, accounting for 67% of the total. The problems with the research and development of drugs for COVID-19 treatment in China include inadequate of biological safety laboratories, less research on SARS-CoV-2 reacting mechanisms, shortages of non-clinical cells and animal models, imperfect research platforms for quantitative pharmacological research and training systems of professionals and poor levels of informatization of drug clinical trials and sample detection. It is hoped that China can take this opportunity to improve the ability to develop new drugs in emergency and better protect human health.

[Analysis on medical observation of 1 665 close contacts of COVID-19 cases].

Objective: To understand the identification and medical observation of close contacts of COVID-19 cases in a city and provide scientific basis for the adjustment of the epidemic prevention and control strategies. Methods: Descriptive epidemiological methods were used to analyze the general characteristics of all the close contacts of COVID-19 cases in a city. Throat swabs were collected from the close contacts for real-time fluorescent RT-PCR. The confirmed cases were diagnosed according to diagnosis and treatment of COVID-19 (trial version 5). Results: Among the 1 665 close contacts of COVID-19 cases in a city, 10 were diagnosed as COVID-19 cases during the medical observation period, accounting for 30.30% of all the confirmed cases in a city, most of them were close relatives of the confirmed cases. The longest contact time with the confirmed cases was 8 days and the shortest was 0 days. Ten COVID-19 cases in close contacts constituted to six family clusters. Conclusions: In COVID-19 prevention and control in a city, the active tracking of the transmission chains of the confirmed cases and timely identification of the close contacts were conducted. The people who had close contacts with the confirmed COVID-19 cases within 14 days before onset were all placed under medical observation, which played a key role in the effective prevention and control of COVID-19 epidemic in a city. Nearly one third of COVID-19 cases occurred during the medical observation period, so the infection sources were effectively controlled and transmission routes were effectively blocked, which greatly facilitated the prevention of the clusters of COVID-19 cases.

[Epidemiological investigation of a family clustering of COVID-19].

Objective: To investigate the epidemiological characteristics of a family clustering of COVID-19. Methods: Field epidemiological survey was conducted. Results: Case 1 of the long-term residents from Hubei province was the source of infection of this family clustering. There were 6 cases (from case 2 to case 7) infected in the whole incubation period. The incubation period was more than 14 days for 3 of the second-generation cases. Routes of transmission included respiratory droplets (from case 1 transmitted to case 6, from case 1 to her family members) and close contact (from case 1 to other cases in her family). All the age groups were generally susceptible, while elderly were easier to progress to critically ill. Besides respiratory symptoms, there were also gastrointestinal symptoms, of which diarrhea was the most common one. Conclusions: Family clustering had been an important part for COVID-19 cases.