Mechanisms of Action Proposed mechanisms of vitamin C activity in the prevention and treatment of cancer include: (1) enhancement of the immune system by increased lymphocyte production; (2) stimulation of collagen formation, necessary for "walling off" tumors; (3) inhibition of hyaluronidase, keeping the ground substance around the tumor intact and preventing metastasis;4 (4) inhibition of oncogenic viruses; (5) correction of an ascorbate deficiency, often seen in cancer patients; (6) expedition of wound healing after cancer surgery;5 (7) enhancement of the effect of certain chemotherapy drugs, such as tamoxifen, cisplatin, DTIC and others;6-8 (8) reduction of the toxicity of other chemotherapeutic agents, such as Adriamycin;9 (9) prevention of cellular free radical damage;10 (10) neutralization of carcinogenic substances.11 Taking a closer look at the phenomenon of hyaluronidase inhibition Cameron, Pauling and Leibovitz wrote in "Ascorbic Acid and Cancer: A Review": ..."the dangerous features of neoplastic cell behavior (invasiveness, selective nutrition, and perhaps growth) are caused by microenvironmental depolymerization. In turn, this matrix destabilization is brought about by constant exposure to lysosomal glycosidases continually released by the neoplastic cells. Finally, ascorbate is involved in the natural restraint of this degradative enzyme activity."12 Proper collagen formation is an important factor in the encapsulation of tumors or the slowing of metastasis via the development of an almost impermeable barrier (known as the schirrus response). Ascorbic acid plays an important role in collagen synthesis and stability. A lack of ascorbate significantly reduces hydroxylation of proline and lysine to hydroxyproline and hydroxylysine, respectively, jeopardizing proper collagen cross-linking. This leads to instability of the triple helix of collagen which, in turn, results in increased collagen catabolism. In vitro, vitamin C also has been found to increase collagen synthesis by fibroblasts.12 Cancer patients tend to be immuno-compromised, demonstrating low lymphocyte ascorbate levels. The immune surveillance system is important, both in inhibiting the initiation phase of cancerous growth, and also in the prevention of spread. Ascorbate supplementation increases the number and effectiveness of lymphocytes and enhances phagocytosis.12 (Altern Med Rev 1998;3(3):174-186) Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.