Recent advances in the bioactive polysaccharides and other key components from Phellinus spp. and their pharmacological effects: A review

Phellinus spp. is one of the largest genera of Hymenochaetaceae with approximately 220 species, such as P. vaninii, P. buamii, P. linteus, and P. igniarius, these species are considered as precious food supplements and medicinal ingredients in China, Korea, Japan, and other Asian countries for over 2000 years. Phellinus spp. contains abundant bioactive polysaccharides and other key components (e.g., phenolics, terpenes, steroids, etc.). Pharmacological investigations have confirmed that bioactive polysaccharides and other important secondary metabolites from Phellinus spp. possess multiple health-promoting benefits, including antitumor, immunomodulatory, anti-inflammatory, antidiabetic, antioxidant, and antimicrobial effects. However, comprehensive evaluations on the preparation and structural characteristics, bioactivities, and toxicology of these functional components (e.g., polysaccharides, phenolics, terpenes, steroids) from various Phellinus spp. species are very limited, which may restrict the practical application of Phellinus spp. This review summarizes the physicochemical characteristics, pharmacological activities, and possible mechanisms of bioactive components from Phellinus spp. according to published studies from 2017 to 2022. It also surveyed the toxicological assessment for safety and applications of different Phellinus spp. species. This review aims to provide useful references and promising directions for the comprehensive development and utilization of Phellinus spp. in functional foods, pharmaceuticals, and cosmetics.