The influence of rutin on the weight, metastasis and melanin content of B16 melanotic melanoma in C57BL/6 mice.

The influence of rutin on the growth rate and tumor weight of B16 melanoma as well as melanin content and ultrastructure of melanoma cells and metastasis formation was studied in mice. All mice were injected s.c. into the left flank with 0.2 ml of suspension containing 10(6) B16 melanoma cells. The experimental groups were treated with a solution of rutin i.p. every two days with total doses of 1, 5 or 10 mg/mouse. The rutin was dissolved in DMSO. The control groups of mice were injected with 0.2 ml 0.9% NaCl and 0.2 ml DMSO. Increasing doses of rutin 1, 5 or 10 mg per mouse caused augmentation of the tumor mass to 2400 mg, 2600 mg and 2800 mg respectively, whereas the tumor weight of the control group was 980 mg. The median number of lung metastases in the control groups was 12; after treatment with 5 or 10 mg of rutin, the number of lung colonies increased to 19 and 27, respectively. The administration of 10 mg rutin inhibited melanin formation by about 43%. The melanosomes in the experimental groups were in the 2nd or 3rd stage, and the low content of melanin was noticed.