A New Dimension of Maitake D-Fraction from Maitake mushroom:  Activation of BAK-1 Anti-Cancer Gene

Ken Babal, C.N.

For more than three decades, scientists have been studying the immune enhancing, antitumor properties of Maitake mushroom. Much research has focused on D-fraction, a concentrated extract containing a protein-bound beta glucan, which has been shown to stimulate vital components of cellular immunity such as T cells, B cells, macrophages and natural killer (NK) cells.1

An important breakthrough occurred in 2000 when researchers at New York Medical College found that D-fraction has strong apoptosis-inducing activity against prostate cancer cells in vitro.2 Apoptosis is cell death programmed by a specific set of so-called suicide genes. Scientists have discovered that all cells, including cancer cells, have this potential to self-destruct. Sensuke Konno, Ph.D. and fellow researchers discovered that D-fraction can induce almost total apoptosis in cell culture in twenty-four hours.

Apoptosis is an essential process for maintaining homeostasis in humans and animals. It’s nature’s way of getting rid of cells that are not needed, either because they were generated in excess or have become harmful to the organism. The ability of cancer cells to avoid apoptosis and continue to proliferate is a fundamental feature of the disease. For this reason, apoptosis has been a major focus of cancer research. Developing novel molecules that promote apoptosis advances our understanding of the mechanisms behind tumor cell proliferation, which may lead to effective cancer therapies.

Fast Forward to 2011

The current study elucidates a new dimension of D-fraction, elevating it to yet another level. The research demonstrates an antitumor effect in breast cancer cells by activating a gene known to promote apoptosis.3 It corroborates the apoptotic action observed earlier with prostate cancer cells and reveals other mechanisms at work.

In the study, a group of researchers from Portugal and Argentina assessed the activity of D-fraction on cell viability (survival) and apoptosis on a strain of human breast cancer cells. Five different concentrations and one untreated control were incubated for twenty-four hours. It was discovered that the cells treated with D-fraction exhibited decreased cell viability in a dose-dependent manner, meaning that the higher the D-fraction concentration the more pronounced the effect. Using a genomic analysis, twenty-two pro-apoptosis genes were found to be up-regulated, particularly the BAK-1 gene, broadly recognized for its apoptotic activity. The apoptotic effect of D-fraction was further corroborated by an increase in cytochrome C, an intermediate chemical released by mitochondria in response to pro-apoptotic stimuli.

Researchers concluded that D-fraction has strong anti-cancer properties in breast cancer cells through BAK-1 gene expression. This is highly significant because it places D-fraction in a unique category apart from ordinary “immune boosters,” antioxidants and apoptosis-inducers.

Treat Your Genes Right

Science shows that our health is influenced by our genes and that flawed genes compromise health by producing inferior biochemicals. We know that many diseases are caused by inherited defective genes. Certain disadvantaged genes, called single nucleotide polymorphisms (SNPs), lead to higher incidence, earlier onset and greater severity of certain diseases. In addition, they are responsible for lower responses to medical treatment and subsequent lower survival rates than the general population.

Although we are stuck with the genes we inherit from our parents, we can control how we treat our genes. We are beginning to understand that diet can override defective genes, and that supplementing with natural substances can jump-start good ones. This emerging, gene-based science, called nutrigenomics, addresses the interactions of nutrients and genes. With regard to BAK-1, D-fraction was able to activate the pro-apoptotic gene by almost 25 times compared with control.

Breast cancer is the most frequently diagnosed cancer in women. In men, its equivalent is prostate cancer. Incidence of both types continues to increase. In other words, all of us know someone who has or has had breast or prostate cancer. While researchers search for cures, an effective and rapid treatment is mandatory. In the meantime, scientific studies elucidate and enrich our understanding of gene therapy. The success of D-fraction from Maitake mushroom may open the door to a new form of treatment for breast and prostate cancers.


1.  Kodama, N. et al. “Effect of Maitake (Grifola frondosa) D-Fraction on the Activation of NK Cells in

Cancer Patients,” Journal of Medicinal Food 6 (4) 2003, pp. 371-377.

2.  Fullerton, S. et al. “Induction of Apoptosis in Human Prostatic Cancer Cells with B-Glucan (Maitake

Mushroom Polysaccharide),” Molecular Urology, Vol. 4, No.1, 2000.

3.  Soares, R. et al. “Maitake (D Fraction) Mushroom Extract Induces Apoptosis in Breast Cancer Cells by BAK-1 Gene Activation,” Journal of Medicinal Food XX(X) 2011, pp. 1-10.