Valuing the extinct species Sophora toromiro: in vitro callus cultures as source potential of prenylated flavonoids for cosmetics

Sophora toromiro is an endemic from the Easter Island. It is classified as extinct in the wild since 1994, but some individuals survive in botanical and private collections. Here, we describe for the first time a promising and efficient in vitro protocol for conservation purposes through micropropagation of S. toromiro from seeds obtained from the Viña del Mar National Botanical Garden, Chile. Whilst Sophora flavescens and S. japonica are currently widely used in cosmetics for its biological activities, S. toromiro is unknown in the sector. Literature survey highlights the potential of S. toromiro as a valuable source of flavonoids particularly isoflavonoids and prenylated isoflavonoids. The latter show a wide range of biological activities, such as anti-cancer, anti-inflammatory, neuroprotective, anti-diabetic etc...and are highly demanded in cosmetics. In addition, for the development of an extract derived from S. toromiro cell culture, an INCI proposed by the Personal Care Products Council (PCPC) could comply with IECI standards, thereby guaranteeing its international recognition and acceptability. To exploit these capacities, we have successfully induced callus development of S. toromiro from in vitro stems. Efforts on callus proliferation and homogeneity are currently being tested, altering concentrations of 2,4-D, in combination with BAP and active charcoal (AC). We aim to obtain culture suspensions allowing a continuous and homogeneous production of metabolites of interest from S. toromiro . The results presented here greatly contribute to the value for this species regarding its potential as a source of phytochemicals with prospective cosmetic benefits through innovative production pathways. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany