Ocoxin oral solution® as a complement to irinotecan chemotherapy in the metastatic progression of colorectal cancer to the liver

Colorectal cancer (CRC) is an aggressive disease in which patients usually die due to its metastatic progression to the liver. Up to date, irinotecan is one of the most used chemotherapeutic agents to treat CRC metastasis with demonstrated efficacy. However, the severity of the side effects constitute the main limitation to its use in the treatment. Consequently, new complementary therapies are being developed to avoid these adverse effects while maintaining the efficacy of the antitumoral drugs. Ocoxin oral solution (OOS®) is a nutritional mixture containing biologically active compounds with demonstrated antitumoral and immunomodulatory effects. Thus, we aimed to analyze the effect of OOS® as a suitable complement to irinotecan therapy in the treatment of CRC metastasis to the liver. First, the effect of OOS®, irinotecan and the combination of both on the viability of C26 cells was tested in vitro and in vivo. Second, the expression of caspase-3, Ki67 and the macrophage infiltration by F4/80 marker was quantified in liver tissue sections by immunohistochemistry. Finally, mRNA microarray study was carried out on tumor cells isolated from tumor-bearing livers collected from mice subjected to the above treatments. Our results show that OOS® administered as a complementary therapy to irinotecan reduced tumor cell viability in vitro. Moreover, irinotecan administered either alone or in combination with 100 µl OOS® from the 7th day after tumor cell inoculation decreased the metastatic growth in the liver. Besides, several genes with binding and catalytic activities showed to be deregulated by RNA microarray analysis. In conclusion, OOS®, when administered as a complement to irinotecan, reduced the metastatic development of colorectal cancer to the liver. Additionally, the overall health state of the animals improved. These results point out OOS® as a potential supplement to the anti-tumoral treatments used in clinical settings in patients suffering from disseminated colorectal cancer.