Rosmarinic acid as the effective compound in Cordia americana

In Brazil medicinal plants have been widely used for the treatment of diseases in folk medicine. However, the effective compounds responsible for the biological effects are widely unknown. The objective of this study was to characterize the phytochemical profile and to identify bioactive compounds in the leaves of Cordia americana (Boraginaceae) [1]. The biological activity of the constituents and the ethanolic extract were investigated for the inhibition of 5-lipoxygenase, p38α MAPK, TNFα release and fibroblast scratch assay, targeting different aspects of inflammatory and wound healing processes. The phytochemical studies (i.e., 1D, 2D NMR and MS) have led to the identification of flavonols, phenolic compounds and phytosterols. Quantification analysis showed that rosmarinic acid (RA) is the main compound with an amount of 8.44% in the ethanolic extract. RA as well as the ethanolic extract exhibited the highest inhibitory effects on 5-lipoxygenase (IC₅₀=0.97 and 0.69µg/ml, resp.) and p38α MAPK (IC₅₀=1.16 and 3.25µg/ml, resp.). Additionally, RA inhibited the release of TNFα to 36.75±1.55% at a concentration of 36.03µg/ml, which can be considered as moderately active. The ethanolic extract showed a lower inhibition of 30.3±0.75% at a concentration of 100µg/mL. RA also exhibited slight stimulatory activity on proliferation and migration of fibroblasts indicating that it may partially contribute to the wound healing effects of this plant. We demonstrated for the first time pharmacological effects of C. americana and we provided evidences for a crucial role of RA as the major player.

Acknowledgements: Financial support from the government Baden-Württemberg (Zukunftsoffensive IV) is gratefully acknowledged.

References: 1. Sobral, M. et al (2006). Flora arbórea e arborescente do Rio Grande do Sul, Brasil. RiMa Publisher. Porto Alegre.