Mode of action of an herbal mixture preparation for improving gastric accommodation in functional dyspepsia patients

In functional dyspepsia, impaired gastric accommodation has been found in a significant proportion of cases, however, the underlying cause of this disorder is poorly understood. Amara oral drops is traditionally used for treatment of gastrointestinal dysmotility and contains an herbal mixture of nine hydroethanolic herbal extracts (Artemisia abstinthium, Centaurium erythraea, Cichorium intybus, Gentiana lutea, Juniperus communis, Millefolii herba, Peucedanum ostruthium, Salvia officinalis and Taraxacum). The study aim was to investigate the herbal mixture’s mechanisms to improve gastrointestinal motility disorders such as gastric accommodation by identifying the specific targets.

We investigated the functional activity of several G-protein-coupled-receptors known to play a role in the pathogenesis of gastrointestinal disorders, i.e. muscarinic M3 and M2, opioid μ (OP1) and several serotonin receptors (5-HT1B, 5-HT1D, 5-HT3, 5-HT7 and 5-HT1A). The dry extracts were prepared from the commercial medicinal product Amara oral drops or from the ethanolic tinctures. The herbal mixture potentially impaired the activity of OP1 and M2 receptors, shown by inhibition of intracellular cAMP release (IC₅₀: 304 and 219 μg/mL, respectively). Furthermore, Juniperus, Salvia and Peucedanum extracts impaired M2 receptors’ activity (IC₅₀: 32, 20.1 and 20.8 μg/mL, respectively), whereas Gentiana, Artemisia, Cichorium and Juniperus inhibited OP1 receptors’ activity (IC₅₀: 41.7, 21.7, 104 and 24.6 μg/mL, respectively). However, serotonin and M3 receptors’ activity was not affected. These data suggest that the Amara herbal extract has an effect on central motility-regulating receptors involved in gastrointestinal disorders. Additionally, different activity profiles of the individual extracts act together, resulting in an increase of the overall preparation’s efficacy.

Publication History

Article published online:
16 November 2023