Immunomodulatory efficacy of an hydroethanolic extract from Calendula officinalis L. herba in vitro

Calendula officinalis L. is traditionally indicated for the treatment of minor inflammations of the skin and as an aid in healing of minor wounds [ 1 ] that are physiologically accompanied by local inflammation, including activation of the NF-kB pathway and release of pro-inflammatory mediators such as leukotrienes and prostaglandins. Here we aimed to evaluate the anti-inflammatory efficacy of an hydroethanolic extract from Calendula officinalis L. herba . Dry extracts from Calendula officinalis L. were prepared using liquid extracts from fresh aerial parts of the flowering Calendula plant (mother tincture Calendula officinalis 2a Ø (GHP)). NF-kB activation was analysed in a reporter assay with the human Jurkat cell line. Analysis of inhibition of the proinflammatory and pain-related enzymes 5-LOX and COX-2 as part of the arachidonic acid pathway was performed using recombinant human enzymes. Modulation of lipid mediator release was analysed in human M2 macrophages. Calendula herba concentration-dependently inhibited NF-kB activation (IC 50 : 74.9 μg/ml). In a cellfree enzyme inhibition assay, Calendula herba concentration-dependently inhibited both, 5-LOX and COX-2 enzyme activity (IC 50 : 39.6 μg/ml and 29.4 μg/ml). In addition, Calendula herba strongly induced the release of lipid mediators, such as SPM (specialized pro-resolving mediators), 15-LOX products and PUFAs (poly unsaturated fatty acids) in human M2 macrophages at a concentration of 100 μg/ml. These data underline the potent inhibition of inflammatory and pain-related mediators and indicate the pro-resolving capacity of the Weleda Calendula herba extract (Fig. 1). The described mechanisms of action of Calendula herba contribute to the therapeutic efficacy of Calendula preparations. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany