Comparison between Peritoneal Macrophage Activation by Bougainvillea xbuttiana Extract and LPS and/or Interleukins

Abstract

Activation of macrophages may be one of the possible approaches in modulating inflammation. We previously reported that Bougainvillea xbuttiana extract showed an immunomodulatory activity. Here we compare the activation of macrophages exposed to B. xbuttiana extract and compare it with the other treatments such as LPS, IL-4, and IL-10. The cytotoxic effect of extract on peritoneal macrophages was determined by the technique of violet crystal staining. To verify the activation of macrophages we used the tests of vacuolization, hydrogen peroxide production, and percentages of cellular expansion and phagocytosis. The levels of interleukins secreted by macrophages treated with the extract, LPS, and cytokines were determined by the biological assay for the determination of TNF levels and by ELISA for all other interleukins. NO levels were evaluated by colorimetric reactions using Griess reagent. Our results showed that B. xbuttiana extract induced (a) low cytotoxicity percentages, (b) increased vacuolization, hydrogen peroxide production and cell expansion and phagocytosis percentages, and (c) decreased production of TNF-α, IFN-γ, IL-1β, and IL-6 and potentiated production of IL-4, IL-10 and TGF-β. These results suggest that B. xbuttiana extract was able to activate the murine macrophages in a manner similar to those macrophages exposed to IL-4 and IL-10.