Philippine Medicinal Plants with Potential Immunomodulatory and Anti-SARS-CoV-2 Activities

Abstract

Coronavirus disease 2019 (COVID-19) continues to devastate the world’s health and economy, affecting all aspects of life leading to widespread social disruption. Even as several vaccines have been developed, their availability in developing countries is limited and their efficacy against the variants of SARS-CoV-2 (severe acute respiratory syndrome–coronavirus 2) needs to be continuously assessed. The World Health Organization (WHO) has acknowledged that vaccines alone will not overcome the global challenges of COVID-19. Medicinal plants may provide the needed support. Herein, we identify Philippine medicinal plants that possess phytochemicals with potential anti-SARS-CoV-2 activity and/or immunomodulatory properties that may strengthen one’s immune system against COVID-19. These plants were selected from 100 of the best-studied Philippine medicinal plants with antiviral and immunomodulatory properties. The general antiviral and specific anti-SARS-CoV-2 activities and immunomodulatory properties of the phytochemicals that these plants contained were searched. While many compounds assessed individually using in vitro and in silico techniques suggest potential anti-SARS-CoV-2 or immunomodulatory effects, this review sought to identify the medicinal plants which contain these compounds and which, based on literature, have the best potential application against COVID-19. These plants are Allium spp. bulbs (bawang), Andrographis paniculata (Burm.f.) Nees leaves (sinta), Cocos nucifera L. oil (niyog), Euphorbia hirta L. leaves (tawa-tawa), Euphorbia neriifolia L. leaves (sorosoro), Moringa oleifera Lam. leaves (malunggay), Ocimum basilicum L. leaves (balanoy), Piper nigrum L. seeds (paminta), Vitex negundo L. leaves (lagundi), and Zingiber officinale Roscoe rhizome (luya). This review provides a shortlist that can guide research on possible solutions to COVID-19 using Philippine medicinal plants.