Therapeutic Potentials of Antiviral Plants Used in Traditional African Medicine With COVID-19 in Focus: A Nigerian Perspective

Abstract

The coronavirus disease 2019 (COVID-19) pandemic is caused by an infectious novel strain of coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which was earlier referred to as 2019-nCoV. The respiratory disease is the most consequential global public health crisis of the 21st century whose level of negative impact increasingly experienced globally has not been recorded since World War II. Up till now, there has been no specific globally authorized antiviral drug, vaccines, supplement or herbal remedy available for the treatment of this lethal disease except preventive measures, supportive care and non-specific treatment options adopted in different countries via divergent approaches to halt the pandemic. However, many of these interventions have been documented to show some level of success particularly the Traditional Chinese Medicine while there is paucity of well reported studies on the impact of the widely embraced Traditional African Medicines (TAM) adopted so far for the prevention, management and treatment of COVID-19. We carried out a detailed review of publicly available data, information and claims on the potentials of indigenous plants used in Sub-Saharan Africa as antiviral remedies with potentials for the prevention and management of COVID-19. In this review, we have provided a holistic report on evidence-based antiviral and promising anti-SARS-CoV-2 properties of African medicinal plants based on in silico evidence, in vitro assays and in vivo experiments alongside the available data on their mechanistic pharmacology. In addition, we have unveiled knowledge gaps, provided an update on the effort of African Scientific community toward demystifying the dreadful SARS-CoV-2 micro-enemy of man and have documented popular anti-COVID-19 herbal claims emanating from the continent for the management of COVID-19 while the risk potentials of herb-drug interaction of antiviral phytomedicines when used in combination with orthodox drugs have also been highlighted. This review exercise may lend enough credence to the potential value of African medicinal plants as possible leads in anti-COVID-19 drug discovery through research and development.

Natural Products as Potential Lead Compounds for Drug Discovery Against SARS-CoV-2

“…The terpenoids (diterpenoids and triterpenoids) were the most abundant among the isolated NPs, constituting 26.19% of the isolated compounds. This was followed by alkaloids (19.05%), flavonoids (11.90%), diarylheptanoids (9.52%), phenolics (4.76%), saponin (2.38%) and xanthones (2.38%), which showed a similar trend to previous studies [ 17 – 19 ].…”

“…Several excellent reviews have recently been published on NPs with the potential for treating SARS-CoV-2 infection [ 17 – 19 ]. Other reviews have focused on antiviral agents with potential for the drug development for the treatment of COVID-19 using crude extracts from plants [ 20 , 21 ].…”

“…compounds that have been predicted computationally (via molecular docking, molecular dynamics, pharmacophore searches, etc.) have been described [ 19 ]. The current study is intended to provide an update of the isolated NPs with the potential to be developed into drugs for the treatment of COVID-19, i.e.…”

Traditional medicines for COVID‐19: Perspectives from clinical pharmacologists

“…Recent reviews of African natural products that have therapeutic potential for COVID-19 provide useful starting points. 5,12 We conducted an informal assessment of the COVID-19 clinical trials registered on https://clinicaltrials.gov and https://pactr.samrc.…”

“…1 In many communities, traditional medicine is an important contributor to primary health care building on a longstanding cultural acceptability in its use [2][3][4] with anecdotal estimates of 80-90% of rural populations relying on plant-based traditional medicines for this purpose. 5 During the Ebola Virus Disease outbreak of 2014-2016, Balde et al documented several recipes of herbal therapies, however, none were studied in conventional clinical trials. 6 Most individuals who provide traditional medicine therapy are highly respected in their community.…”