A Systematic Review of Garlic and Ginger as Medicinal Spices against Viral Infections

Abstract

Garlic (Allium sativum) and Ginger (Zingiber officinale) are globally utilized herbal medicinal spices. This systematic review discussed available evidence on the direct and indirect antiviral activities of garlic and ginger. Studies investigating the antiviral activities of garlic and ginger were searched and retrieved from four databases, including Google Scholar, PubMed, Science direct, and MEDLINE. Data search and retrieval were done up to 15 October 2021. A total of 28 studies were included in this systematic review (garlic = 18 studies; ginger = 10 studies). Fresh garlic aqueous extract and fresh ginger hot water extract were the most investigated forms of garlic and ginger, respectively. There was minimal evidence on the prophylactic antiviral effect of garlic and ginger, moderate evidence on the therapeutic and prophylactic/therapeutic antiviral effects, and minimal evidence on the enhancement of the immune system against viral infections. The low-moderate quality evidence on the direct and indirect antiviral effects of garlic and ginger has provided the necessary background to instigate further high-quality investigations to validate the current information, address the grey areas, and provide valuable insights into the possible utility of garlic and ginger as raw materials in drug development against viral infections.