Natural zeolite clinoptilolite: new adjuvant in anticancer therapy

Natural silicate materials, including zeolite clinoptilolite, have been sho wn to exhibit diverse biological activities and have been used successfully as a vaccine adjuvant and for the treatment of diarrhea. We report a novel use of finely ground clinoptilolite as a potential adjuvant in anticancer therapy. Clinoptilolite treatment of mice and dogs suffering from a variety of tumor types led to improvement in the overall health status, prolongati on of life-span, and decrease in tumors size. Local application of clinopti lolite to skin cancers of dogs effectively reduced tumor formation and grow th. In addition, toxicology studies on mice and rats demonstrated that the treatment does not have negative effects. In vitro tissue culture studies s howed that finely ground clinoptilolite inhibits protein kinase B (c-Akt), induces expression of p21(WAF1/CIP1) and p27(KIP1) tumor suppressor protein s, and blocks cell growth in several cancer cell lines. These data indicate that clinoptilolite treatment might affect cancer growth by attenuating su rvival signals and inducing tumor suppressor genes in treated cells.