Antioxidant and Hepatoprotective Activities of Crude Polysaccharide Extracts from Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), by Ultrasonic-Circulating Extraction

We recently proposed, and successfully applied, a novel and efficient technique-ultrasonic-circulating extraction (UCE) integrating superfine pulverization-to extract and prepare antioxidant crude polysaccharides other natural active substances from Ganoderma lucidum. The aim of this study was to evaluate the antioxidant and hepatoprotective activities and active ingredients in the powder from UCE (UCEP) through comparison with powder from hot water extraction (HWEP). The DPPH radical, ABTS radical, superoxide anion, total antioxidant activity, and ferric-reducing antioxidant power assay results showed that the UCEP exhibited stronger (P < 0.01) in vitro antioxidant activity than the HWEP. The hepatoprotective activity of the extracts was evaluated against CCl4-induced oxidative damage in the liver. Measurements of reduced glutathione, superoxide dismutase, and malondialdehyde in rat liver; measurements of alanine transaminase, aspartate transaminase, and lactate dehydrogenase in rat blood; and Western blotting for antioxidant proteins of transforming growth factor-β1, heme-oxygenase 1, and glutathione per-oxidase showed that the UCEP had antioxidant activity in vivo either similar to or slightly stronger than (P < 0.1) the HWEP. Further analysis of the active ingredients revealed that the UCEP and HWEP have similar mean yield and total triterpenoid content, but the former has significantly higher (P < 0.05) mean yield and total polysaccharide content than the latter. Our results suggest that the UCEP displays stronger antioxidant activities because of the larger amount of total polysaccharides; the UCEP may be able to be used as an antioxidant and liver protectant.