The antitumor potential of cartilage has been investigated extensively in laboratory and animal studies. Some of these studies have assessed the toxicity of cartilage products toward cancer cells in vitro.[1,2] Reviewed in [3,4,5,6]
In one study, cells from 22 freshly isolated human tumors (nine ovary, three lung, two brain, two breast, and one each of sarcoma, melanoma, colon, pancreas, cervix, and testis) and three human cultured cell lines (breastcancer, colon cancer, and myeloma) were treated with Catrix, which is a commercially available powdered preparation of bovine (cow) cartilage. Reviewed in [3,4,6] In the study, the growth of all three cultured cell lines and cells from approximately 70% of the tumor specimens were inhibited by 50% or more when Catrix was used at high concentrations (1–5 mg /mL of culture fluid). However, it is unclear whether the inhibitory effect of Catrix in this study was specific to the growth of cancer cells because the preparation's effect on the growth of normal cells was not tested. In addition, the cytotoxic component of Catrix has not been identified, and it has not been shown that equivalent inhibitory concentrations of this component can be achieved in the bloodstreams of patients who may be treated with either injected or oral formulations of this product. (Refer to the Human/Clinical Studies section of this summary for more information.)
A commercially available preparation of powdered shark cartilage (no brand name given) was reported to have no effect on the growth of human astrocytoma cells in vitro. The shark cartilage product tested in this study, however, was examined at only one concentration (0.75 mg/mL).
The immune system –stimulating potential of cartilage has also been investigated in laboratory and animal studies. In one study, Catrix was shown to stimulate the production of antibodies by mouse B cells (B lymphocytes) both in vitro and in vivo. However, increased antibody production in vivo was observed only when Catrix was administered by intraperitoneal or intravenous injection. It was not observed when oral formulations of Catrix were used. In most experiments, the proliferation of mouse B cells (i.e., normal, nonmalignant cells) in vitro was increasingly inhibited as the concentration of Catrix was increased (tested concentration range, 1–20 mg/mL). Catrix has also been reported to stimulate the activity of mouse macrophages in vivo, Reviewed in [3,6] but results demonstrating this effect have not been published.