We. Hardman et al., Three percent dietary fish oil concentrate increased efficacy of doxorubicin against MDA-MB 231 breast cancer xenografts, CLIN CANC R, 7(7), 2001, pp. 2041-2049
Omega 3 polyunsaturated fatty acids (the type of fat found in fish oil) hav
e been used to kill or slow the growth of cancer cells in culture and in an
imal models and to increase the effectiveness of cancer chemotherapeutic dr
ugs. An AIN-76 diet containing 5% corn oil (CO) was modified to contain 3%
w/w fish oil concentrate (FOC) and 2% CO to test whether a clinically appli
cable amount of FOC Is beneficial during doxorubicin (DOX) treatment of can
cer xenografts in mice. Compared with the diet containing 5% CO, consumptio
n of FOC increased omega 3 pollyunsaturated fatty acids and lipid peroxidat
ion in tumor and liver, significantly decreased the ratio of glutathione pe
roxidase activity to superoxide dismutase activity (a putative indicator of
increased oxidative stress) in tumor but not in the liver, and significant
ly decreased the tumor-growth rate. The decreased glutathione peroxidase:su
peroxide dismutase ratio, indicating an altered redox state, in the tumor o
f FOG-fed mice was significantly correlated with decreased tumor-growth rat
e. Assay of the body weight change, blood cell counts, and number of micron
uclei in peripheral erythrocytes indicated that the toxicity of DOX to the
host mouse was not increased in mice fed FOG. Thus, a small amount of FOC i
ncreased the effectiveness of DOX but did not increase the toxicity of DOX
to the host mouse. These positive results justify clinical testing of POC i
n conjunction with cancer chemotherapy.