IgG1 and IgG2a anti- Leishmania promastigote extract (LE) antibody levels in mice immunized with LE, associated or not with babassu aqueous extract (BAE). IgG2a (A) and IgG1 (B) antibodies were detected by ELISA as detailed in the Material and Methods, in sera prepared from blood samples collected 10 days after the end of the immunization. Groups of five to eight BALB/c mice were immunized by two subcutaneous injections of LE, associated with BAE (LE + BAE), or of Al(OH)3-adsorbed LE, also associated with BAE (LE-Al(OH)
+ BAE), 14 days apart. Groups of control mice were also immunized with LE emulsified in complete Freund's adjuvant (LE + CFA), with LE without BAE (LE), and with Al(OH)3-adsorbed LE without BAE (LE-Al(OH)
), following the same immunization protocol. Each injection contained a total of 250 μg of LE and/or 5 mg of BAE. A negative control group was injected with a saline solution in place of the immunizing injections (Saline). The boxes represent the 10-90 percentile intervals and the median values of the results, and the vertical bars the value ranges. P < 0.001, Kruskal-Wallis test. *, P ≤ 0.007; **, P ≤ 0.003; ***, P ≤ 0.009; ****, P ≤ 0.016; Mann-Whitney U test.