Mapping Cutaneous Tissue Distribution of Sesquiterpene Lactone Goyazensolide Using MALDI Imaging

Abstract Species of Lychnophora, popularly known in Brazil as "Arnica-da-serra", are widely used in topical preparations as analgesics and anti-inflammatories. The most commonly used species is Lychnophora ericoides, and studies of seasonal and circadian rhythms show greater stability for phenolic constituents than for sesquiterpene lactones (an opposite behavior was observed). These lactones are considered defensive substances; thus, they were found in significant quantities in border regions between two biomes, at least for L. ericoides. Herbalists often report that seasonality influences on the increase of lactone levels in leaves and may have increase the allergenic potential. In the present study, we sought to develop a methodology for imaging tissues treated with solutions of the sesquiterpene lactone goyazensolide to observe skin retention using the Franz cell model. To this end, MALDI-MS parameters were optimized for imaging generation, and an LC-MS/MS protocol was used to confirm goyazensolide skin retention. The obtained data revealed that sesquiterpene lactones strongly bind to the skin structure.