Abstract
PURPOSE: The Coronavirus 2019 (COVID-19) pandemic is an international public health emergency. Vaccines, and acute infection drugs are currently unknown, and when available, expense and distribution issues may impede distribution in undeserved areas. The aim of this systematic review was to summarize the evidence regarding cinchona bark (CB) for its potential anti-viral properties against COVID-19
STUDY DESIGN: A current literature and historical text review was conducted, limited to articles having full text or abstracts available in English, using Google Scholar, Pubmed-NCBI, ScienceDirect, and WebMD, and online book publications, with key search words, including synthetic CB analogues: chloroquine-hydroxychloroquine (CQ/HCQ) derivatives.
RESULTS: Several related in-vitro studies, editorials, and expert consensus papers on quinine analogue anti-viral treatment papers and historical treatises have been published. A March 2020 CQ drug trial ongoing in China, has just reported breakthrough efficacy evidence for COVID-19 pneumonia. However, there are severe CQ shortages and direct evidence for the anti-viral therapeutic use of CB is sparse, several centuries old, and controversial.
CONCLUSION: CB was for centuries known to be a natural source of quinine from which modern synthetically manufactured analogues anti-viral purposed drugs such as CQ/HCQ are based. CB may also possess anti COVID-19 activity as its historical derivatives, but with the same potential for life-threatening adverse reactions and severe drug interaction complications akin to its analogues. Issues with herbal quality control, prescriber dose inexperience, perceived risk underestimation by self-prescribers, and a misinformed propensity for consumer fraud are other concerns. However, analogue drug risk-benefit ratios indicate CB may also have some value for acute COVID-19 (cytokine storm) infection management. The existing evidence and evolving breakthrough CQ efficacy findings in China, shadowed by CQ shortage, highlight a need for modern and timely investigation of CB as cost-effective alternative COVID-19 pneumonia monotherapy.
