Chemopreventive effects of dietary mustard oil on colon tumor development.

Fatty acid composition of dietary fat is one of the detrimental factors in colon cancer development. Fats containing omega 6-polyunsaturated fatty acids (e.g. corn oil) enhance and omega 3-polyunsaturated fatty acids (e.g. fish oil) reduce chemically-induced colon cancer in animal studies. The purpose of this study is to investigate the effects of dietary mustard oil (containing omega 3-polyunsaturated fatty acid) on azoxymethane-induced colon cancer in rats and compare with corn and fish oil treated groups. Colon tumor incidence and multiplicity were found to be 90, 75, and 50% and 1.7, 0.8, and 0.4 tumors/rat in corn, fish and mustard oil treated groups respectively. Omega-3 polyunsaturated fatty acid levels were highest in serum and colon microsomal fractions of the fish oil group followed by the mustard oil group. Corn oil group had the highest level of omega 6-polyunsaturated fatty acid levels in serum and colon microsomal fractions. The results indicate that dietary mustard oil is more effective in preventing colon cancer in rats than dietary fish oil.

Chemopreventive effects of alpha-santalol on skin tumor development in CD-1 and SENCAR mice.

Studies from our laboratory have indicated skin cancer chemopreventive effectsof sandalwood oil in CD-1 mice. The purpose of this investigation was to study the skin cancer chemopreventive effects of alpha-santalol, a principal component of sandalwood oil in CD-1 and SENCAR mice. alpha-Santalol was isolated from sandalwood oil by distillation under vacuum and characterized by nuclear magnetic resonance and gas chromatography-mass spectrometry. Chemopreventive effects of alpha-santalol were determined during initiation and promotion phase in female CD-1 and SENCAR mice. Carcinogenesis was initiated with 7,12-dimethylbenz(a)anthracene and promoted with 12-O-tetradecanoylphorbol-13-acetate (TPA). The effects of alpha-santalol treatment on TPA-induced epidermal ornithine decarboxylase (ODC) activity and (3)H-thymidine incorporation in epidermal DNA of CD-1 and SENCAR mice were also investigated. alpha-Santalol treatment during promotion phase delayed the papilloma development by 2 weeks in both CD-1 and SENCAR strains of mice. alpha-Santalol treatment during promotion phase significantly (P < 0.05) decreased the papilloma incidence and multiplicity when compared with control and treatment during initiation phase during 20 weeks of promotion in both CD-1 and SENCAR strains of mice. alpha-Santalol treatment resulted in a significant (P < 0.05) inhibition in TPA-induced ODC activity and incorporation of (3)H-thymidine in DNA in the epidermis of both strains of mice. alpha-Santalol significantly prevents papilloma development during promotion phase of 7,12-dimethylbenz(a)anthracene-TPA carcinogenesis protocol in both CD-1 and SENCAR mice, possibly by inhibiting TPA-induced ODC activity and DNA synthesis. alpha-Santalol could be an effective chemopreventive agent for skin cancer. Additional experimental and clinical studies are needed to investigate the chemopreventive effect of alpha-santalol in skin cancer.