The multi-herbal preparation STW5 is a clinically proven drug to ameliorate symptoms of functional gastro-intestinal diseases[1]. Both, anti-inflammatory and motility-modulating effects are part of its mechanism of action.
In the present study, an in-depth investigation of the impact of STW5 on intestinal inflammation was performed in the small intestine of adult mice, based on full thickness gut wall samples and isolated myenteric plexus preparations.
For that purpose, a pro-inflammatory cytokine mixture (IL1ß, TNFα, IFNγ) was injected into the supporting blood vessel arcades of small intestinal segments with or without additional STW 5 luminal perfusion. Subsequently various cytokines were analyzed in the gut wall homogenates using multiplex-ELISA. Inflammation was induced in myenteric plexus cultures in vitro using the same cytokine cocktail. Cytokines in cell culture supernatants from cultures with and without treatment with STW5 were compared.
Multiplex analysis showed a higher amount of the pro-inflammatory cytokines G-CSF, IL-6 and LIF under inflammatory conditions in both, gut wall homogenates and myenteric plexus cultures. Treatment with STW5 leads to a reduction of the cytokine concentrations in the homogenates and myenteric plexus culture supernatants. The cytokines RANTES, GM-CSF and IL-22 could be reduced only in the gut wall homogenates, when treated with STW-5.
In conclusion, the multicomponent herbal drug STW5 leads to a reduced release of pro-inflammatory cytokines in the small intestinal gut wall and shows also a direct anti-inflammatory effect on the enteric nervous system under induced inflammation.
[1] Michael S, Abdel-Aziz H, Weiser D, Muller CE, Kelber O, Nieber K. Adenosine A2A receptor contributes to the anti-inflammatory effect of the fixed herbal combination STW 5 (Iberogast®) in rat small intestinal preparations. Naunyn-Schmiedeberg's archives of pharmacology 2012; 385: 411-421