Summary

Study on apoptosis-inducing activities of Ganoderma colossum on Hela cancer cell line

The previous study demonstrated that ethanol extract of Ganoderma colossum has the anti-tumor activity, inhibits the proliferation of Hela cervical cancer cell line in vitro. This study aimed to investigate its mechanism(s) of action. In vitro cytotoxic activities of ethanol extract, water extract, crude polysaccharide and fractionated extracts prepared from G. colossum on cancer cell lines (Hela, MCF-7, NCI-H460 and A549 cell lines) were studied using WST-1 [2-(4-Iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium] and sulforhodamine B assays. The ethanol extract and diethyl ether fraction of G. colossum showed the highest cytotoxic activity on Hela and A549 cancer cell lines compared with other extracts. The antiproliferation effect of G. colossum ethanol extract on Hela cancer cell line was expressed with IC₅₀ = 92.6 ± 9.74 mg/ml. The apoptosis-inducing activities of G. colossum ethanol extract were studied by discrimination between viable and dead cells to be visualized by fluorescence microscopy using vital dyes acridine orange/ethidium bromide, and by measuring chromosomalDNA fragmentation. At the concentration of IC₅₀, G. colossum ethanol extract activated apoptosis-mediated cell death via caspase-independent DNA degradation.

Keywords: Ganoderma colossum, Hela cervical cancer cell line, apoptosis, caspase-independent DNA degradation.