Current Prevention of COVID-19: Natural Products and Herbal Medicine

Abstract

Starting from December 2019, novel coronavirus disease 2019 (COVID-19) pandemic has caused tremendous economic loss and unprecedented health crisis across the globe. While the development of cure is at full speed, less attention and fewer effort have been spent on the prevention of this rapidly spreading respiratory infectious disease. Although so far, several vaccine candidates have advanced into clinical trials, limited data have been released regarding the vaccine efficacy and safety in human, not mention the long-term effectiveness of those vaccines remain as open question yet. Natural products and herbal medicines have been historically used for acute respiratory infection and generally show acceptable toxicity. The favorable stability for oral formulation and ease of scaling up manufacture make it ideal candidate for prophylactic. Hereby, we summarized the most recent advance in SARS-CoV-2 prevention including vaccine development as well as experimental prophylactics. Mainly, we reviewed the natural products showing inhibitory effect on human coronavirus, and discussed the herbal medicines lately used for COVID-19, especially focused on the herbal products already approved by regulatory agency with identifiable patent number. We demonstrated that to fill in the response gap between appropriate treatment and commercially available vaccine, repurposing natural products and herbal medicines as prophylactic will be a vigorous approach to stop or at least slow down SARS-CoV-2 transmission. In the interest of public health, this will lend health officials better control on the current pandemic.

The green tea catechin epigallocatechin gallate inhibits SARS-CoV-2 infection

“…to have anti-SARS-CoV-2 activity in vitro. In China, 85 % of SARS-CoV-2 infected patients have received in addition to conventional therapies also Traditional Chinese Medicine (TCM) treatment and current knowledge was recently summarized [17][18][19].…”

Epigallocatechin-3-gallate, an active ingredient of Traditional Chinese Medicines, inhibits the 3CLpro activity of SARS-CoV-2

“…Over the past few decades, natural compounds of plant-based origin have been extensively studied as an exciting class of pharmacologically active molecules [ [22] , [23] , [24] ]. In particular, many natural products have demonstrated potent activity against CoVs [ 25 ]. Glycyrrhizic acid, baicalin, quercetin have been reported to inhibit the replication of SARS-CoV in vitro [ [26] , [27] , [28] ].…”

Therapeutic Intervention of COVID-19 by Natural Products: A Population-Specific Survey Directed Approach

“…When efficacy, safety in human, and the long-term effectiveness of traditional approaches to treat COVID-19 remain as open questions, yet NP, due to their effects on acute respiratory infection, generally acceptable toxicity, amenability for oral formulation, and ease of scalability for manufacture make ideal candidates for prophylactic and therapeutic purposes [ 52 ].…”

“…Studies of applicability of NP to large populations and specifically to high risk populations are very limited [ 52 ]. While we have recognized NP’s antiviral and antinflammatory properties, we have not addressed the risk of adverse events.…”