Antitumor effects of different Ganoderma lucidum spore powder in cell- and zebrafish-based bioassays

Ganoderma lucidum spore (GLS) is gaining recognition as a medicinal part of G. lucidum and has been reported to possess various pharmacological properties, such as antitumor activity. In this work, wall-broken GLS powder (BGLSP) and wall-removed GLS powder (RGLSP), two kinds of GLS powder with different manufacturing techniques, were compared in terms of contents of active constituents and in vivo and in vitro antitumor effects. The ultraviolet and visible spectrophotometry method was used to determine the contents of polysaccharides and total triterpenoids in BGLSP and RGLSP. Seventeen individual triterpenoids were further quantified using ultra-high-performance liquid chromatography and quantitative analysis of multi-components by single marker. The antitumor effects of BGLSP and RGLSP were evaluated using in vitro cell viability assay against human gastric carcinoma SGC-7901, lung carcinoma A549 and lymphoma Ramos and further validated by in vivo zebrafish xenograft models with transplanted SGC-7901, A549 and Ramos. The results showed that the contents of polysaccharides, total triterpenoids and individual triterpenoids of RGLSP were significantly higher than those of BGLSP. Although both BGLSP and RGLSP inhibited the three tumor cell lines in vitro in a dose-dependent manner, the inhibitory effects of RGLSP were much better than those of BGLSP. In the in vivo zebrafish assay, RGLSP exhibited more potent inhibitory activities against tumors transplanted into the zebrafish compared with BGLSP, and the inhibition rates of RGLSP reached approximately 78%, 31% and 83% on SGC-7901, A549 and Ramos, respectively. The results indicated that the antitumor effects of GLS were positively correlated with the contents of the polysaccharides and triterpenoids and demonstrated that the wall-removing manufacturing technique could significantly improve the levels of active constituents, and thereby enhance the antitumor activity.