Effects of Chitosan on Xenograft Models of Melanoma in C57BL/6 Mice and Hepatoma Formation in SCID Mice

According to the World Health Organization, Complementary and alternative medicine (CAM) is a comprehensive term referring to traditional medical treatments and various forms of indigenous medicines, also known as indigenous or folk medicine. Cancer patients often use CAM in the form of nutritional supplements, psychological techniques and natural medical approaches in the place of or in parallel to conventional medicine. The present study aimed to determine if Chitosan can inhibit lung metastasis and hepatoma formation, by studying xenograft of B16F10 melanoma cells in C57BL/6 mice and of Smmu 7721 cells in SCID mice, respectively. For the lung metastasis model, after a five-week treatment, the survival rates of B6 mice were 15% for the control group and 35%, 20%, 45% and 40% for the 320,000 kDa, 173,000 kDa, 86,000 kDa and 8,000 kDa molecular-weight treatment groups, respectively. Chitosan treatment dramatically increased lifespan and inhibited tumor metastasis especially in treatment groups of the low-molecular weight compound. For the hepatoma growth model, the size of the liver tumor mass was approximately >14 mm in the control group. In comparison to the control group, the tumor mass grew slowly with Chitosan treatment, especially at the low-molecular weight treatment group. Chitosan slowed-down the rate of tumor growth but did not inhibit tumor formation. Data presented herein demonstrate that Chitosan has anticancer effects and thus further study of the substance is warranted to examine for mechanisms of action and optimal dosage. In 2008 there were approximately 12.7 million cancer cases worldwide, with 6.6 million cases affecting men and 6.0 million women. The total number is expected to increase to 21 million by year 2030. Lung cancer is the most common cancer worldwide, contributing 1.61 million (nearly 13%) of the total number of new cases diagnosed in 2008 (1). Liver cancer is the sixth most common cancer in the world, with 750,000 new cases diagnosed in 2008. This accounted for