Lippia javanica

Lippia javanica (Burm.f.) Spreng (Verbenaceae), commonly known as ‘fever tea’, is an erect, highly aromatic, woody shrub that grows up to 2 m in height, with hairy leaves that are thinly veined. The plant is native to central, eastern and southern Africa, and occurs in Botswana, Malawi, Swaziland (Eswatini), Mozambique, Tanzania, Zambia and Kenya. It is traditionally used as a decoction or infusion to treat respiratory and gastro-intestinal conditions, as well as skin infections, and has spiritual significance. Commercially, essential oil of the plant is used as a mosquito repellent and in household fragrances, and dried aerial parts are sold as herbal tea. The in vitro and in vivo pharmacological activities (anti-oxidant, antimalarial and antimicrobial) of the plant extracts and essential oils have been studied extensively, and some of the results confirm the traditional use. The essential oil composition is highly variable and several chemotypes, characterised by carvone, piperitenone, ipsenone and myrcenone, have been identified. Phytochemicals present in the non-volatile fraction of the plant include iridoid glycosides, triterpenoids, flavones and various phenolic compounds. Chromatographic techniques, namely semi-automated high-performance thin-layer chromatography (HPTLC), ultra-performance liquid chromatography, coupled to mass spectrometry (UPLC–MS), and gas chromatography, coupled to mass spectrometry (GC–MS), were used to establish chemical profiles of the solvent extracts and essential oils of L. javanica. The analysis of the oils, using HPTLC and GC–MS/FID, confirmed different chemotypes, whilst HPTLC enabled the identification of theveside and verbascoside. Isoverbascoside, diosmetin and apigenin were further detected using UPLC analysis.