Background: The fungus growing termites’ species Macrotermes bellicosus are used in traditional medicine in Benin for the treatment of infectious and inflammatory diseases such as digestive disorders, mumps, snake bites, cough, diarrhea, dysentery, and pulmonary infection. In vitro studies revealed that Macrotermes bellicosus is efficient against various pathogenic microorganisms. However, the occurrence of anti-inflammatory effects remains unexplored.
Aim: Aim of the present study was to investigate the anti-inflammatory properties of Macrotermes bellicosus in activated human monocyte-derived macrophages (THP-1) and intestinal epithelial cells (Caco2) on which inflammation was induced in vitro to model the pathophysiology of inflammatory diseases.
Methods: The effect of termite extract was evaluated on LPS-induced TNFα release from differentiated human macrophages (THP-1) and, IL-8 release from human intestinal epithelial cells (Caco-2) induced with a cytokine-mix (IL-1β, TNFα and IFNγ). Production of the pro-inflammatory mediators (TNFα and IL-8) was measured by enzyme-linked immunosorbent assay (ELISA) and IC50 values were determined. Budesonide and dexamethasone served correspondingly as positive control. Concomitant cytotoxicity controls were performed using MTT assay.
Results: It was found that the production of the induced pro-inflammatory cytokines TNFα (IC50: 41.99 μg/mL) and IL-8 (IC50: 56.93 μg/mL) was significantly inhibited after treatment with the termite extract. These effects were concentration-dependent and comparable to those of budesonide and dexamethasone. Moreover, no alteration of cell viability was observed in the applied concentrations of termite extract throughout the assays.
Conclusion: Macrotermes bellicosus used as a traditional medicine showed anti-inflammatory properties in the tested human in vitro cell culture models by inhibiting pro-inflammatory cytokine release. This termite species could be an interesting natural source contributing to the treatment of inflammatory diseases including digestive diseases.
Keywords : Termite, Macrotermes bellicosus , anti-inflammatory activity, Macrotermitinae, Benin.