Inflammatory responses and pain are the first lines of action triggered by the body’s immune response to fight off infections [1]. They play a major role in the etiology of sexually transmitted infections (STIs) and could lead to more chronic inflammatory diseases when treatment is delayed [2]. The anti-inflammatory activities of twelve plants used traditionally in the treatment of STIs were investigated in this study. Acetone extracts of selected plant parts were tested for inhibitory activity against 15-lipoxygenase (15-LOX), xanthine oxidase (XO) and inducible nitric oxide production in lipopolysaccharide (LPS) stimulated RAW 264.7 murine macrophages. Cytotoxic assessment of extracts was also conducted on murine macrophages and Vero cells using the MTT assay. Extract of Lannea schweinfurthii was most active against 15-LOX (IC50 40 ± 3 µg/mL), this was followed by the extracts of Ficus abutilifolia, Cassia abbreviata and Pseudolachnostylis maprouneifolia. Interestingly, activities against XO was recorded for the first time for most of the extracts and the best activity was observed with extract of C. abbreviata (IC50 46.8 ± 1.5 µg/mL). All the extracts showed a dose-dependent suppression of inducible nitric oxide production in murine macrophages. Particularly, extracts of F. abutilifolia, Faurea saligna, and Zanthoxylum capense had activities comparable to quercetin used as the positive control (IC50 < 30.0 µg/mL). Most of the extracts showed mild or no toxic effect against tested cells lines. The exception was however observed with the stem bark extracts of Z. capense which had low (4.4%) murine macrophage viability at the highest tested concentration (100 µg/mL). Findings from this study reveal the potential of active extracts as new sources of anti-inflammatory compounds which can be further explored for the management of STI related inflammation.
[1]Jang, M. et al., J Med Food, 2014; 17(6): 678-685.
[2]Sutcliffe, S. et al., J Urol., 2006; 175(5): 1937-1942.