Mechanisms involved in the muscle relaxing effects of STW 5 in guinea pig stomach

INTRODUCTION

The herbal preparation STW 5 ameliorates functional dyspepsia partly by relaxing smooth muscle of the proximal stomach, thus improving gastric accommodation. We explored the unknown pathways responsible for this effect by testing targets known to modulate gastric smooth muscle relaxation.

METHODS

STW 5-induced relaxation of smooth muscle strips from guinea pig gastric corpus before and after pharmacological interventions were recorded with force transducers in an organ bath. ORAI1 mRNA expression was tested in the proximal stomach.

KEY RESULTS

Blockade of Ca2+ -activated K+ and Cl- channels, voltage-gated L- or T-type Ca2+ channels, TRPA1-, TRPV1-, adenosine or 5-HT4 receptors, antagonizing ryanodine receptors, inhibiting cyclooxygenase or sarcoplasmic reticulum calcium ATPase did not affect STW 5-evoked relaxation. Likewise, protein-kinase A or G were not involved. However, the relaxation evoked by STW 5 was significantly reduced by phorbol-12-myristat-13-acetat, an activator of protein-kinase C, by 2- aminoethyldiphenylborinate, an inhibitor of the IP3 receptor-mediated Ca2+ release from the sarcoplasmic reticulum or by SKF-96365, a nonselective store-operated calcium entry (SOCE) blocker. Furthermore, the mixed TRPC3/SOCE inhibitor Pyr3, but not the selective TRPC3 blocker Pyr10, reduced the effect of STW 5. Finally, BTP2, a potent blocker of ORAI-coupled SOCE, almost abolished STW 5-evoked relaxation. Expression of ORAI1 could be demonstrated in the corpus/fundus.

CONCLUSIONS & INFERENCES

STW 5 inhibited SOCE, most likely ORAI channels, which are modulated by IP3- and PKC-dependent mechanisms. Our findings impact on the design of drugs to induce muscle relaxation and help identify phytochemicals with similar modes of actions to treat gastrointestinal disturbances.

Functional gastrointestinal disorders in children: Effectivity, safety, and tolerability of the herbal preparation STW-5 (Iberogast®) in general practice

BACKGROUND

Functional gastrointestinal disorders (FGIDs) of the upper and lower digestive system in children and adolescents present with heterogeneous gastrointestinal symptoms and are a common reason for specialist consultations. The herbal medicinal preparation STW-5 has already shown efficacy and safety in clinical studies with more than 7000 adult participants suffering from functional dyspepsia (FD) or irritable bowel syndrome (IBS). Here, we evaluate with a prospective observational study the effectivity and safety of STW-5 in children with FGID under real-life conditions and interpret these data versus the background of controlled clinical studies in a predominantly adult population.

METHODS

This prospective observational study included 980 children (age 3-14 years) with FGID. For inclusion, Rome III criteria were recommended to apply. The inclusion of the patients for treatment with STW-5 followed routine clinical practice. Patients were treated for approximately 1 week. The presence and severity of symptoms was documented at the study start and at the end of treatment period utilizing the adapted gastrointestinal symptom score (GIS). Other target parameters included global effectivity and tolerability assessments as well as adverse events.

RESULTS

The average patient age was 7.6 ± 2.9 years. Most of the patients were treated for IBS (n = 418; 43 %) or FD (n = 259; 26 %), with a mean baseline GIS of 16.1 ± 8.9. During the treatment period, the GIS decreased 76 % to 3.8 ± 4.2. The decrease in symptoms was similar for different age groups, gender, and indications. Patients with a shorter duration of complaints had a lower GIS at study end (p < 0.0001. The global treatment effect was assessed as good or very good by 87-89 % of patients/parents and physicians. Physicians rated the global tolerability as good or very good for 95 % of the patients. Seven patients (0.7 %) reported adverse events.

CONCLUSIONS

The treatment effect of STW-5 in this study was in its range comparable to according data from controlled clinical trials with predominantly adult participants.Thus, supporting robustness of these data generated in an uncontrolled observational setting. The results of this observational study indicate that STW-5 may be an effective and well tolerated treatment option also for children with FGIDs.

Clinical and structural effects of traditional Chinese medicine and the herbal preparation, Iberogast, in a rat model of ulcerative colitis

Plant-sourced formulations such as Iberogast and the traditional Chinese medicine formulation, Cmed, purportedly possess anti-inflammatory and radical scavenging properties. We investigated Iberogast and Cmed, independently, for their potential to decrease the severity of the large bowel inflammatory disorder, ulcerative colitis. Sprague Dawley rats (n = 8/group) received daily 1 mL gavages (days 0-13) of water, Iberogast (100 μL/200 μL), or Cmed (10 mg/20 mg). Rats ingested 2% dextran sulfate sodium or water ad libitum for 7 days commencing on day 5. Dextran sulfate sodium administration increased disease activity index scores from days 6 to 12, compared with water controls (P < .05). On day 10, 200 μL Iberogast decreased disease activity index scores in colitic rats compared with colitic controls (P < .05). Neither Iberogast nor Cmed achieved statistical significance for daily metabolic parameters or colonic crypt depth. The therapeutic effects of Iberogast and Cmed were minimal in the colitis setting. Further studies of plant extracts are required investigating greater concentrations and alternative delivery systems.