Chaga mushroom ( Inonotus Obliquus ) is a white rot fungus which mainly grow in north of China, Russuia
and etc. For the chaga mushroom commonly used as the chaga tea, chaga mushroom extract, ingection,
syrup, aerosol and etc. The most important as a folk medicine for treating cancer in China, Russia, North
America for many years.
Studies & researchings have reported that the inonotus obliquus extract ( chaga extract ) contains rich nutrition
ingredients like polysaccharides, polyphenols ( triterpenoids, steroids, ergosterol peroxides, inotodial and
3β-hydroxy-lanosta-8,24-dien-21-al, a lignin-like substance. With these rich nutrition ingreidients, the chaga
extract show the effective biological activities as antioxidant, hepatoprotective, anti viral, anti inflammatory,
anti tumor, platelet aggregation inhibitory. However, the molecular mechanisms responsible for the anti-cancer
effects of I. obliquus are not well understood, despite its increasing usage.
In this study, we mainly investigated and examine the effects of ethanol extract of chaga extract on cell cycle
progression of HT-29 cells, as well as its molecular mechanism in colon cancer cells, HT-29 human colon cancer
cells were cultured in the presence of 2.5 - 10 µg/mL of EEIO, and analyzed the cell cycle arrest by flow
cytometry and the cell cycle controlling protein expression by Western blotting.
Treatment cells with 2.5 - 10 µg/mL of EEIO reduced viable HT-29 cell numbers and DNA synthesis, increased
the percentage of cells in G1 phase, decreased protein expression of CDK2, CDK4, and cyclin D1, increased
expression of p21, p27, and p53, and inhibited phosphorylation of Rb and E2F1 expression. Among inonotus
obliquus fractions, fraction 2 (fractionated by dichloromethane from EEIO) showed the same effect as EEIO
treatment on cell proliferation and cell cycle-related protein levels. These results show and certified that
fraction 2 is the major fraction that induces G1 arrest and inhibits cell proliferation, suggesting chaga mushroom
( Inonotus obliquus ) could be used as a natural anti-cancer ingredient in the food or pharmaceutical industry.