Mycosphere Essays 20: Therapeutic potential of Ganoderma species: Insights into its use as traditional medicine

The genus Ganoderma (Ganodermataceae) has a long history in traditional medicine to improve longevity and health in Asia. Ganoderma has been widely used in multiple therapeutic activities as well as dietary supplements to prevent and treat many diseases. Several classes of bioactive substances have been isolated and identified from Ganoderma, such as polysaccharides, triterpenoids, nucleosides, sterols, fatty acids, protein and alkaloids. There are numerous research publications, which report the abundance and variety of biological actions initiated by the metabolites of Ganoderma. Investigation on different metabolic activities of Ganoderma species has been performed both in vitro and in vivo. In many cases, however, it has been questioned whether Ganoderma is solely a nourishment supplement for wellbeing or merely a helpful medication for restorative purposes. There has been no any conclusive report of human trials using Ganoderma species as a direct control agent for diseases. In addition, there is no evidence supporting the usage of Ganoderma species (excluding G. lucidum) as potential supplements for cancer or other diseases in humans since no preclinical trials have been performed up to date. In this review, the beneficial medicinal properties of several species of Ganoderma (excluding G. lucidum) and their secondary metabolites are discussed. Ganoderma species can be used as a therapeutic drug, but more direct scientific evidence should be made available in the future. The efficiency of Ganoderma in clinical treatments should be substantiated with more biomedical research and their true impact assessed on human health with more standardized clinical evaluations so that the feasibility of biologically active extracts of Ganoderma species in alternative treatments can be recommended.