Maitake Extracts and Their Therapeutic Potential — A Review

Alternative Medicine Review, Feb, 2001 by Mark Mayell

A mice study with a similar syngeneic tumor design tested a 6-branched beta-1,3 glucan polysaccharide fraction (LELFD) extracted from maitake. The fraction exhibited significant antitumor effects against Meth-A fibrosarcoma cells and IMC carcinoma cells, although it did not inhibit the growth of leukemia cells.[15] Oral doses of the D-fraction have also been shown to have significant antitumor activities against allogenic and syngeneic tumors (Table 1).[30,31]

Table 1: Tumor Growth Inhibition of Oral and Intraperitoneal Administration of Maitake D-Fraction.

Mice      Tumor system              Oral adminis-     Intraperi-
                                      tration          toneal

C3H       MM-46 carcinoma (breast)  64% (1.5 mg)     83.2% (1.0 mg)
CDF1      IMC carcinoma (skin)      75% (1.5 mg)     47.7% (1.0 mg)
C57BL/6   B-46 melanoma (skin)      27.3% (1.5 mg)   25.6% (1.0 mg)

Researchers compared the effects on tumor-beating mice of D-fraction and mitomycin-c (MMC), a popular chemotherapeutic agent, but one that often causes strong side effects. The D-fraction alone inhibited tumor growth more effectively than MMC alone (by a bout 80- and 45 percent, respectively), with the combination being the most effective (tumor inhibition was further enhanced by almost 98 percent). The apparent synergistic effect between maitake and MMC has been attributed to their distinct modes of action, with maitake stimulating the immune system and MMC directly attacking tumor cells.[32]

Unpublished preliminary clinical data on maitake's use as an adjunct to chemotherapy is described by Nanba.[32] He notes, "A non-randomized clinical study using D-fraction was conducted to see if it is effective against advanced cancer patients as it is against animals. A total of 165 cancer patients in stage III-IV, from 25-65 years old, participated in the study and the data was collected under the cooperation of their medical doctors with major university hospitals and cancer treatment clinics in Japan." Patients were administered either tablets containing maitake D-fraction with whole powder, or the maitake tablets along with chemotherapy. According to Nanba," The results suggest that breast, lung, and liver cancers were improved by maitake, but it was less effective against bone and stomach cancers or leukemia." The best response rates were from combining maitake and chemotherapy. Nanba adds, "It should be noted, however, that most of the patients under the maitake treatment claimed improvement of overall symptoms, even when the tumor regression was not observed. Various side effects from chemotherapy such as lost appetite, vomiting, nausea, hair loss, and leukopenia (deficiency of white blood cells) were ameliorated by 90 percent of the patients. Reduction of the pain was also reported by 83 percent of the patients."(Figure 2)

[Figure 2 ILLUSTRATION OMITTED]

Human Immunodeficiency Virus (HIV)

In the late 1980s Japanese researchers determined in a non-controlled animal trial that oral doses of the D-fraction exhibited an enhancing effect on helper T-cells, the target cells of HIV.[30] This was one of the earliest clinical indications that maitake may be a potential treatment for HIV.