Luteolin as an adjuvant effectively enhances CTL anti-tumor response in B16F10 mouse model

Luteolin, a naturally found dietary flavonoid, has a wide range of beneficial biological effects, including effects against tumors and oxidants. Studies proved that luteolin can modulate immune responses. In this study, we investigated the function of luteolin as an antitumor vaccine adjuvant (to treat malignant melanoma) in vitro and in vivo. We found that Luteolin may activated the PI3K-Akt pathways in APCs (Antigen Presenting Cells), induced the activation of APCs, enhanced CTL (Cytotoxic T Lymphocyte) responses, and inhibited tolerogenic T cells. To prove the role of CD8⁺T cells in immune process, we sorted the CD8⁺T cells from the immunized mice and transferred them to the B16F10 tumor-bearing mice, the result showed that the survival rate was improved. We also observed that in the mice immunized with Luteolin as an adjuvant, the tumor growth was significantly reduced. Taken together, the result demonstrated that luteolin showed promising properties as a vaccine adjuvant for treating malignant melanoma.