Bush tea (Athrixia phylicoides): A review of the traditional uses, bioactivity and phytochemistry

Abstract

Consumption of a refreshing beverage prepared from the dried leaves and twigs of Athrixia phylicoides, commonly referred to as bush tea, is widespread in South Africa. The tea has an illustrious history of use by the indigenous people of southern Africa and has the potential for commercialisation. Several ethnic groups use decoctions and pastes prepared from the plant to treat a multitude of unrelated conditions. This review is aimed at providing a comprehensive overview of the ethnopharmacology, phytochemistry, biological activities, toxicity and commercial aspects of A. phylicoides. Books, containing botanical and ethnopharmacological information were extensively consulted, and electronic databases were searched to acquire relevant articles, with no specific time frame set. Although the majority of the traditional uses indicate that A. phylicoides has strong antimicrobial properties, this is not well supported by scientific data, suggesting that more research is required involving more pathogens and the investigation of a potential alternative mode of action. The secondary metabolites of the plant have been extensively explored and several sesquiterpenes, coumarins, flavonoids and phenol carboxylic acids have been identified. However, there is a paucity of information regarding the chemical variation within the species. A multidisciplinary metabolomic approach involving sophisticated and information-rich technologies, in combination with multivariate analysis, should be undertaken to record chemotypic variation and to identify potential biomarker compounds for quality control. Some of the ethnobotanical uses have been supported through scientific studies, but a window of opportunity exists to contribute data on the pharmacological activities. Despite efforts to facilitate the commercialisation of bush tea in South Africa in an effort to grow the bio-economy of the region, more fundamental research is required to ensure the sustainability and expansion of such an industry. The commercialisation of rooibos and honeybush tea in South Africa is underpinned by basic and applied research and serves as appropriate models for the development of the bush tea industry.