Analysis of Osmotic Pump-Administered Xylitol in a Syngeneic Mouse Melanoma Model

This study aimed to evaluate the effects of continuous xylitol administration via a subcutaneous osmotic minipump in a B16F10 syngeneic mouse model, including histological examination and metabolomic analysis. The B16F10 syngeneic model for human melanoma consisted of 6–8-week-old C57BL/6 male mice subcutaneously injected with five × 105 B16F10 cells suspended in 100 μl PBS in the right flank. The mice were randomly assigned to two groups: Group 1 was the treatment group, which received 10% xylitol-loaded pumps (n = 10), while Group 2 was the control group, which received saline-loaded pumps (n = 10). Alzet minipumps were implanted subcutaneously in the left flank of B16F10-injected mice once more than 50% of all mice developed palpable tumors. After pump implantation surgery, the mice were monitored daily and weighed twice to three times per week. Tumor sizes were measured with calipers 2–3x per week, and all mice were euthanized when their tumors became too large (20 mm on any axis or 2,000 mm3). The tumor size was reduced by approximately 35% by volume in the xylitol-treated group. The xylitol group may have a longer survival time, but this was not statistically significant (Kaplan-Meier). The metabolomic analysis suggests that xylitol significantly alters the tumor’s metabolism, potentially enhancing the host immune response.