LAUSR

Abstract Inflammation associated with sexually transmitted infection (STIs) often results from delayed diagnosis or treatment, and may result in life-threatening complications. The root or stem bark of plants selected in this study are used by traditional healers in the management of STIs and to treat the associated inflammation. This study evaluated the anti-inflammatory activities of 12 South African medicinal plants used traditionally in the treatment of STIs and the associated inflammation. Acetone extracts were tested for anti-inflammatory activity against 15-lipoxygenase (15-LOX), xanthine oxidase (XO) and inducible nitric oxide production in lipopolysaccharide (LPS) stimulated RAW 264.7 macrophage cells. The free radical and nitric oxide scavenging capacity was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and nitric oxide inhibition assays. The MTT assay was used to determine the cytotoxic effect of the extracts on RAW 264.7 macrophages and Vero cells. Preliminary phytochemical analysis was carried out using NMR spectroscopy, Gas Chromatography Mass Spectroscopy (GC–MS) analysis and the determination of total phenolic and flavonoid contents. The root bark extract of Lannea schweinfurthii had the highest inhibitory activity against 15-LOX (IC50 = 40 ± 3 μg/mL) while C. abbreviata best inhibited XO (IC50 = 46.8 ± 1.5 μg/mL). Extracts of Ficus abutilifolia, Faurea saligna and Zanthoxylum capense showed significant suppression of inducible nitric oxide production with IC50 values comparable to quercetin (IC50