Sensitization with babassu mesocarp induces activation of murine splenocytes against tumor cells

Attallea speciosa Mart. (babassu) fruit contains a mesocarp that is rich in carbohydrates with immunomodulatory effects. The induction of the tolerogenic response is a tumor escape mechanism, and immunomodulator adjuvants have been studied to reestablish host immunogenicity. This study evaluates the adjuvant potential of babassu mesocarp carbohydrates in a tumor model. The babassu mesocarp extraction (BME) yield was 75.54%, and the total sugar concentration was 29.79 mg ml-1 containing monosaccharides, reducing sugars, polysaccharides and 0.506 mg ml-1 total protein. Chromatography analysis identified glucose, sucrose and fructose. Sensitization increased the spleen weight in the tumor group compared with the control, and a comparatively lower frequency of T helper and higher frequency of B-lymphocytes was also observed. The tumor+BME group had more cytotoxic T lymphocytes compared with the control. After co-culture with cancer cells, the tumor splenocytes showed lower proliferation, lower frequency of T helper cells and higher concentrations of interleukin (IL)-2, IL-6 and IL-10. However, the tumor+BME splenocytes presented results similar to the control, suggesting a reduction in the regulatory response of the tumor group. These results demonstrated that BME sensitization with cancer cells modulated an immune response in Balb/c animals, indicating an immunogenic effect. Key words: Arecaceae, Attallea speciosa Mart., adjuvant, carbohydrate, antitumor.