Ethnomedicinal survey and in vitro confirmation of anti-inflammatory and antispasmodic properties of the termite strain Macrotermes bellicosus used in traditional medicine in the Republic of Benin

Ethnopharmacological relevance: Insects and insect-derived products play a vital role in traditional medicine in many parts of the world since ancient times. Among these insects, fungus-growing termites like Macrotermes bellicosus (M. bellicosus) are widely used in nutrition and traditional medicine in various societies of sub-Saharan Africa. Aim of the study: Aim of the present study was to explore the traditional applications of M. bellicosus and subsequently investigate the anti-inflammatory and spasmolytic activity of samples collected in Benin. Material and methods: An ethnomedicinal survey with thirty active healers in Benin was conducted and the antiinflammatory activity of an ethanolic extract of M. bellicosus was investigated. Thus, LPS-induced TNF alpha release from differentiated human macrophages (THP-1) and IL-8 release from cytokine (IL-1 beta/TNF alpha/IFN gamma)-challenged human intestinal epithelial cells (Caco-2) was measured by enzyme-linked immunosorbent assay. Furthermore, the influence of M. bellicosus extract on basal tone and induced contractions in isolated rat small intestinal preparations was determined to examine the influence on intestinal motility. Results: The survey of 30 active healers demonstrated that M. bellicosus and its products (termites' mound and fungus comb) are used in Benin for therapeutic purposes mainly to treat infectious and inflammatory diseases including digestive disorders, snake bites and diarrhea. It was found that M. bellicosus extract inhibited both LPS-induced TNF alpha release from human macrophages and cytokine-induced IL-8 release from intestinal epithelial cells comparable to budesonide. In addition, isometric contraction measurement with isolated rat small intestinal preparations demonstrated a mild spasmolytic effect of the termite extract in higher concentrations with a suppression of induced contractions and relaxation of basal tone. Conclusion: M. bellicosus which is used in traditional medicine in Benin to treat infectious and inflammatory diseases showed anti-inflammatory activity by inhibiting pro-inflammatory cytokine release and a moderate influence on intestinal motility.