Role of Dietary Crocin in In Vivo Melanoma Tumor Remission

BACKGROUND: Melanoma is a deadly form of malignancy. Early diagnosis might pave the way to cure but its aggressive nature leads to rapid dissemination and colonization of distant organs. Dietary herbs may play a significant role in prevention of cancer. In this study, we tested anti-tumor efficacy of the Crocus sativus derived active constituent crocin, it is well established to have anti-cancer properties in different cancer models by our group and other groups. Notably, crocin is reported to exert anti-proliferative effect on melanoma cells (B16F10) in vitro. However, roles of crocin on in vivo melanoma tumor remission have not yet been reported to our knowledge. MATERIALS AND METHODS: Melanoma tumor model was established by transplanting B16F10 (5 X 105) cells into C57BL/6 mice, which were then observed for tumor development and once the tumor volume reached 6 mm, mice were divided into (Group I: tumor-bearing animals treated with normal saline and Group II: counterparts treated with crocin at 2 mg/kg body weight for 21 days).. Tumor remission and tumor growth related parameters such as tumor silent period (TSP), tumor volume doubling time (VDT), growth delay (GD), and mean survival time (MST) were determined. In addition, serum protein profiles were analyzed. RESULTS: The 21 days crocin treatment significantly reduced the tumor burden in mice, extending the mean survival time significantly as compared to control. Crocin treatment also significantly increased the TGD and TSP and decreased VDT. Furthermore, while serum proteins such as albumin and globulin (alpha1, alpha2, beta, and gamma) were altered due to tumor burden, crocin treatment resulted in their levels near to normal at the end of the experimental period. CONCLUSION: Our study provided clear evidence that crocin may exhibit significant melanoma tumor remission properties by positively modulating tumor growth related parameters. In future, the molecular mechanisms of crocin action should be studied extensively in melanoma models before defining crocin-based melanoma drug formulations.