An overview on Leucosidea sericea Eckl. & Zeyh.: A multi-purpose tree with potential as a phytomedicine

Ethnopharmacological relevance: Leucosidea sericea (the sole species in this genus) is a tree species found in southern Africa and possesses several therapeutical effects against infectious diseases in humans and livestock. This review aims to document and summarize the botany, phytochemical and biological properties of Leucosidea sericea.

Materials and methods: Using the term 'Leucosidea sericea', we systematically searched literature including library catalogues, academic dissertations and databases such as PubMed, SciFinder, Web of Science, Google Scholar and Wanfang. Taxonomy of the species was validated using 'The Plant List' (www.theplantlist.org).

Results: Leucosidea sericea remains a widely used species among the different ethnic groups in southern Africa. The species is a rich source of approximately 50 essential oils and different classes of phytochemicals (phenolics, phloroglucinols, cholestane triterpenoids, alkaloids and saponins) which may account for their diverse biological properties. Documented biological activities which were mainly observed under in vitro systems included antimicrobial, anti-parasitic, antioxidant, acetylcholinesterase (AChE) inhibition and anti-inflammatory properties. Preliminary safety tests on Leucosidea sericea extracts suggest moderate cytotoxic effects based on a few cell lines that were investigated.

Conclusions: Leucosidea sericea possesses diverse medicinal potential with the antimicrobial, anti-parasitic, antioxidant and anti-inflammatory activities being the most prominent. The relative abundance and tendency of Leucosidea sericea to evade in nature suggest an abundant reservoir of raw materials for potential commercialization (upon validation of its pharmacological potential). However, more stringent investigations on the extracts (and isolated bioactive compounds) focusing on the mode of actions, which will inevitably unravel their pharmacokinetics, pharmacodynamics and clinical relevance remain pertinent.