Usefulness of herbal medicines in the prevention and management of coronavirus disease-2019 (COVID-19) and its symptoms: A review

Background: Various studies have been conducted to identify drug candidates to combat the virus, meanwhile some persons believe that consuming herbal medicines or medicinal plants that act as immunomodulators can prevent or even cure COVID-19. It was reported that about 85% of COVID-19 patients in China received combined treatment with Traditional and Complementary Medicine and regular medication. Recent systematic review has shown that herbal medicines can be significantly effective in alleviating different disease symptoms, including COVID-19. Objectives: The study was conducted to identify different herbal preparations and medicinal plants used in the prevention of COVI-19 and its symptoms. Methods: About twenty-five (25) different journal articles obtained from Pubmed, Elsevier, Hindawi, PLOS ONE, African Journals Online (AJOL), Lancet, Research gate, Google scholar and other journal hubs, relating to the use of herbal medicines and medicinal plants on prevention management of COVID-19 and related infection and its symptoms were reviewed and summarized to generate useful data and document the various herbs and medicinal plants employed in managing COVID-19. Results: From the results obtained, various plants have been tested across the globe as possible candidate in the prevention and management of COVID-19 symptoms. Some of the notable medicinal plants reported to have such properties include Artemisia annua, neem tree ( Azadirachta indica ) , Garlic ( Allium sativum ) , Lime or Lemon ( Citrus limonum ) , Ginger ( Zingiber officinale, Xanthorrhizol ( Curcuma xanthorrhiza ) , Cinchona bark ( Cinchona sp. ) , purple coneflower ( Echinacea purpurea ) , among others. Conclusion: Herbal medicines might have the capabilities to regulate the production and release of proinflammatory cytokines, interfere with the development of the virus in host cells, and modify certain molecular pathways related to the RAA system; hence many herbal agents might be useful in the prevention and possible treatment of COVID-19.