Couroupita guianensis bark decoction: From Amazonian medicine to the UHPLC-HRMS chemical profile and its role in inflammation processes and re-epithelialization.

In the Amazon rainforest, the shamans of the Mayantuyacu site use the healing virtues of decoctions and teas from different parts of the Couroupita guianensis Aubl. (Lecythidaceae) trees as remedies in Ashaninka medicine. However, composition of the remedy and the underlying mechanism remain unclear. This study was designed to compare the metabolite profile of Couroupita guianensis bark decoction produced by Amazonian shamans with that obtained under standardised laboratory conditions and to investigate biological properties of both decoction and isolated constituents in skin wound healing process and inflammation. The chemical analyses were carried out by Ultra-High-Performance Liquid Chromatography coupled with UV and High-Resolution Mass Spectrometry detectors (UHPLC-UV-HRMS). 1D and 2D-NMR experiments were performed to identify the main decoction constituents. The decoction and pure compound effect on keratinocyte migration was determined by the in vitro wound healing model; the mechanism of action was elucidated by western blot analysis. UHPLC-UV-HRMS analysis revealed the occurrence of polyphenolic compounds as catechins, ellagitannins and, notably, of unusual sulphated derivatives of ellagic acid isolated for the first time from Couroupita guianensis bark. A new natural sulphated molecule [4-(2″-O-sulphate- β-D-glucuronopyranosyl) ellagic acid] was identified as the potential active compound responsible for the efficacy of bark decoction stimulating wound healing in human HaCaT keratinocytes. The molecular mechanism involved the induction of pro-migratory pathways mediated by ERK and AKT phosphorylation and the increase of MMP2 expression in HaCaT cells. At the same time, the treatment inhibited inflammation interfering with NFkB activation. Beyond identifying a new bioactive compound, the overall results scientifically validate the traditional use of Couroupita guianensis bark decoction as an anti-inflammatory remedy. Moreover, the beneficial effects on keratinocytes suggest promising therapeutic applications in skin diseases. Copyright © 2023 Elsevier B.V. All rights reserved.