Babassu aqueous extract (BAE) as an adjuvant for T helper (Th)1-dependent immune responses in mice of a Th2 immune response-prone strain

Abstract

BackgroundThe aqueous extract of a Brazilian palm-tree fruit - the babassu - (BAE) exerts a clear immunostimulative activity in vivo. In the present work, the possibility that BAE can promote Th1 immune responses in mice of a Th2 immune response-prone strain - the BALB/c was investigated. BAE itself, and preparations consisting of Leishmania amazonensis promastigote extract (LE), adsorbed or not to Al(OH)3, and in the presence or not of BAE, were used as immunogens. LE and Al(OH)3 have been shown to preferentially elicit Th2 immune responses.ResultsThe addition of BAE to LE-containing immunogenic preparations, adsorbed or not to Al(OH)3, clearly promoted the in vitro production of interferon γ (IFN-γ), a major Th1-dependent cytokine, and not of interleukin (IL-)4 (a Th2-dependent cytokine), by LE-stimulated splenocytes of immunized BALB/c mice. It also promoted the in vivo formation of IgG2a anti-LE antibodies. However, immunization with LE by itself led to an increased production of IL-4 by LE-stimulated splenocytes, and this production, albeit not enhanced, was not reduced by the addition of BAE to the immunogen. On the other hand, the IL-4 production by LE-stimulated splenocytes was significantly lower in mice immunized with a preparation containing Al(OH)3-adsorbed LE and BAE than in mice immunized with the control preparation of Al(OH)3-adsorbed LE without BAE. Moreover, an increased production of IFN-γ, and not of IL-4, was observed in the culture supernatants of splenocytes, from BAE-immunized mice, which were in vitro stimulated with BAE or which received no specific in vitro stimulus. No differences in IL-10 (an immunoregulatory cytokine) levels in the supernatants of splenocytes from mice that were injected with BAE, in relation to splenocytes from control mice, were observed. The spontaneous ex vivo production of NO by splenocytes of mice that had been injected with BAE was significantly higher than the production of NO by splenocytes of control mice.ConclusionsBased on the results described above, BAE, or biologically active molecules purified from it, should be further investigated as a possible adjuvant, in association or not with aluminium compounds, for the preferential induction of Th1-dependent immune responses against different antigens in distinct murine strains and animal species.

Immunomodulatory and Antimicrobial Activity of Babassu Mesocarp Improves the Survival in Lethal Sepsis

“…The immunomodulatory effect of babassu mesocarp on inflammation has been reported in other studies [3, 9, 10]. The present results confirm this property and also indicate that this action is possibly related to the capacity of compounds present in the extract to inhibit the production of TNF- α and IL-6 cytokines.…”

“…In addition, the mesocarp is able to induce the release of hydrogen peroxide by macrophages suggesting an immunological effect on macrophage activation [9] and acts on cytokine production indicating an immunomodulatory effect [10]. …”

Salivary IgA and periodontal treatment needs in diabetic patients

“…19 Briefly, anti-human IgA (Sigma, Saint Louis, USA) was diluted to a concentration of 50 µg/mL in carbonate-bicarbonate buffer (pH 9.6) and adsorbed onto wells of flat-bottomed ELISA strips (NUNC, Roskilde, Denmark) with overnight incubation at 4 °C. The wells were then washed five times with 0.15 M phosphate-buffered saline (PBS; pH 7.2) containing 0.05% Tween 20 (Promega, Madison, USA; PBS-T) and incubated in PBS containing 1% bovine serum albumin (Sigma; PBS-TA) for 1 h at 37 °C.…”

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

“…Fortes et al (2009) showed that BME exerted an immunomodulatory effect, resulting in increased survival of the animals and a decreased size of the solid Ehrlich tumors when this tumor cell line was pretreated with BME. Guerra et al (2011) demonstrated that immunization with promastigote forms of Leishmania amazonensis and the addition of BME induced a Th1-dependent immune response in Balb/c mice, thus showing promising effects compared with other adjuvants. Despite their poor immunogenicity, the ability of carbohydrates to exert an immunomodulatory effect through the formation of complexes with tumor proteins potentiates immunospecific responses.…”