[#2009-02] Comparative study of antioxidant activity and antiproliferative effect of hot water and ethanol extracts from the mushroom Chaga (Inonotus obliquus), Honghai Hu et al.

Comparative study of antioxidant activity and antiproliferative effect of hot water and ethanol extracts from the mushroom Chaga (Inonotus obliquus)

Honghai Hu,¹ Zhenya Zhang,¹ Zhongfang Lei,²•* Yingnan Yang,¹ and Norio Sugiura^l

Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan’

 Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China²

The medicinal mushroom Chaga (Inototus obliquus) is a traditional and widely used multi-functional fungus. Hot water (50 °C, 70 °C, and 80 °C) and ethanol crude extracts of I. obliquus were investigated for their antioxidant activity with superoxide dismutase (SOD) and (1,1-diphenyl-2-picryhydrazyl) (DPPH) radical-scavenging activity assays. We also investigated the antiproliferative effects and ability of the extracts to induce apoptosis in human colon cancer DLD-1 cells. Among the four extracts, the ethanol extract (EE) exhibited the strongest SOD-like activity and antiproliferative effect on DLD-1 cells, and exposure to the EE resulted in the induction of apoptosis, whereas no apoptosis was observed in DLD-1 cells exposed to the hot water extracts (HWEs). HWE at 70 °C (HWE70) exhibited the strongest DPPH radical-scavenging activity (EC5O, 126 μg/ml), whereas the EE showed the weakest activity (EC50, 224 μg/m1). The different biological activities among the four extracts may be attributed to differences in their chemical composition, partially supported by polysaccharide, protein and phenolic content, and the H-NMR spectra.