Antioxidant Properties of Triterpenoids Isolated from Bagasse-Cultivated Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), at Different Developmental Stages

Although triterpenoids are one of the main active ingredients in Ganoderma lucidum, their accumulation and antioxidant activity during the different developmental stages of G. lucidum cultivation in bagasse remains unclear. In this study, we investigated the content and antioxidant activity of total triterpenoids extracted from G. lucidum strain GL102 during the five growth stages. The obtained results showed that the highest content (12.06 mg/g) was detected in stage 3 (young fruiting body), similar to the contents of ganoderic acids B and G. However, ganoderic acids A and D exhibited maximal contents in stage 5 (spore-ejected fruiting body). The triterpenoids extracted during stage 5 were most capable of scavenging DPPH, OH, and ABTS(+) radicals, with scavenging rates of 65.88%, 86.45%, and 97.91%, respectively. Based on in vivo antioxidant assays conducted on zebrafish, the safe concentration of these triterpenoids was 0.03 mg/mL. At this concentration, the G. lucidum triterpenoids extracted during stage 5 could decrease lipopolysaccharide-induced intracellular reactive oxygen species to a level that was nearly normal (similar to the control group). The accumulation profile and antioxidant activity results reported herein provide the scientific basis needed to promote the utilization of triterpenoids derived from bagasse-cultivated G. lucidum.