Scientists at Academia Sinica said they have cracked the mystery of how polysaccharides in the reishi mushroom act to activate the human immune system and fight against cancer, and have shared their discovery with the world.
A research team headed by Academia Sinica President Wong Chi-huey (翁啟惠) and assistant research fellow Wu Chung-yi (吳宗益) has proven that a crude extract of fucose-containing polysaccharides from reishi mushrooms named F3, can induce antibodies to recognize tumor-associated carbohydrate antigens on cancer cells and kill them.
According to Academia Sinica, the nation’s top academic research institute, the research on reishi polysaccharides’ cancer-fighting effects was started by a group headed by National Yang-Ming University professor Hsu Hsien-yeh (許先業), which injected F3 into mice with lung cancer and discovered that the extract could slow tumor growth, although it did not know how the mechanism worked.
Thanks to a glycan array — a sample-screening method — designed by the Wong-Wu team, it was found that sera from mice immunized with F3 contained the antibodies that recognize the tumor antigens known as Globo H, as well as related structures.
Moreover, the researchers also found that inhibition of tumor growth is directly related to the amount of these types of antibodies. In other words, the larger the amount of Globo H-recognizing antibodies, the smaller the tumor, Academia Sinica said.
The team then separated F3 into a fucose-enriched extract called FMS for immunization and found that FMS can induce even more anti-Globo H antibodies and thus, more effectively inhibit tumor growth.
The study further demonstrated that the fucose residue is the key to the reishi mushroom’s cancer-fighting ability, proven by the finding that the cancer-fighting activity was reduced dramatically when the fucose residue was removed.
With assistance from other research teams, the effective structures of the fucose-containing saccharides were elucidated.
The Wong-Wu team established the molecular mechanism of reishi polysaccharides with regard to their cancer-fighting activity.
The results were published in the current issue of the US journal Proceedings of the National Academy of Sciences, under the title: “Immunization of fucose-containing polysaccharides from reishi mushroom induces antibodies to tumor-associated Globo H-series epitopes.”
The first authors of the paper are named as Liao Shih-fen, a doctoral student at the Institute of Biochemical Sciences of National Taiwan University, and Liang Chi-hui, who is conducting post-doctoral research at the Genomics Research Center of Academia Sinica.