Exploring the Pharmacological Properties of Macaranga barteri: Current Evidence and Future Prospects

Macaranga barteri Müll. Arg, the Euphorbiaceae tree, is highly medicinal, with a presence in West African traditional health practices, used in the treatment of various infections, inflammatory diseases and metabolic disorders. Notwithstanding such a long ethnopharmacological tradition, the scientific background of the therapeutic use is still disorganised and very sparse. This review summarises and critically analyses existing data on the botanical profile, phytochemical constituents, pharmacological effects and toxicity of M. barteri in in vitro and in vivo studies. The plant exhibits a rich secondary metabolite composition, with the major classes being flavonoids, triterpenoids, tannins, and phenolic acids, whose bioactive properties provide the basis for the mechanisms of its traditional applications. The antimicrobial, antioxidant, anti-inflammatory, and preliminary anticancer activities have been consistently demonstrated in experiments and are believed to be mediated by a range of mechanisms such as membrane disruption, enzyme inhibition, free radical scavenging, and inhibition of key inflammatory signalling pathways. Other beneficial effects include antidiabetic and hepatoprotective properties, but there is limited supporting evidence. There are concerns about long-term safety, bioavailability and pharmacokinetic behaviour which are not adequately understood, but toxicological assessments suggest that there is a generally acceptable acute safety margin. Collectively, the preclinical data make M. barteri a promising drug discovery and phytomedicine development candidate, but there are still several gaps in the field, such as the lack of standardisation of extraction methods, the lack of mechanistic studies based on purified compounds and the lack of clinical trial data. The translation of this plant's potential into evidence-based therapeutics will require systematic isolation of compounds, pharmacokinetic characterisation of these compounds and carefully designed human trials.