Aframomum melegueta K Schum (A. melegueta), an herbaceous plant renowned for its medicinal seeds, was investigated for its potential immunomodulatory effects in vitro and in vivo using ethanolic and methanolic extracts. The immunomodulatory effect was evaluated by measuring antibody titers using the agglutination technique, while anti-inflammatory activity was assessed in a carrageenan-induced mouse paw edema model. In vitro immunomodulatory activity was measured by lysozyme release from neutrophils. Additionally, white blood cell counts were analyzed post-extracts treatment. The MTT assay was employed to determine cytotoxicity, and the biochemical parameters of liver toxicity were evaluated. Remarkably, both extracts exhibited a dose-dependent reduction in paw edema (p < 0.001), with the most significant reduction observed at 1 g/kg (78.13 and 74.27% for ethanolic and methanolic extracts, respectively). Neutrophil degranulation was significantly inhibited in a dose-dependent manner (p < 0.003), reaching maximal inhibition at 100 μg/mg (60.78 and 39.7% for ethanolic and methanolic extracts, respectively). In comparison to the control group, both antibody production and white blood cell counts were reduced. Neither of the extracts showcased any cytotoxicity or toxicity. These findings suggest that A. melegueta extracts exhibit immunosuppressive and anti-inflammatory activities due to the presence of various biomolecules.
