Anti-inflammatory and barrier stabilising effects of myrrh, coffee charcoal and chamomile flower extract in a multicomponent-cell-model of the intestinal mucosa

The combination of myrrh (Commiphora molmol E.), coffee charcoal (Coffea Arabica L.) and chamomile flower dry extract (Matricaria chamomilla L.), known as Myrrhinil-Intest^® has a long tradition in the treatment of gastrointestinal disorders in Germany. Recent clinical evidence suggests its efficacy in the therapy of inflammatory bowel diseases (IBD)^[ [ ¹ ] ^]. However, the mechanisms of action remain to be fully elucidated.

The present study aimed to evaluate the effects of myrrh, coffee charcoal and chamomile flower extract on pro-inflammatory communication between immune and epithelial cells and the resulting barrier dysfunction. A complex co-culture-cell-model allowed the simultaneous investigation of these two IBD-characteristics.

To model the intestinal mucosa a monolayer of 90 % Caco-2 and 10 % HT29-MTX cells was differentiated on transwell-inserts for 21 days. Co-cultivation with LPS-activated THP-1 macrophages over 48 h served as inflammatory stimulus. Concomitantly the cells were treated with various concentrations of plant extracts. Cytokine (IL6, TNF) and chemokine (IL8, MCP-1) release into the supernatant were quantified by ELISA. The transepithelial electrical resistance (TEER) was measured to evaluate effects on the barrier function.

Myrrh, coffee charcoal and chamomile flower showed concentration-dependant effects on the release of pro-inflammatory mediators to varying extent. In addition a TEER-increase of inflamed monolayers could be observed with higher concentrations of myrrh and coffee charcoal. The respective IC₅₀ and EC₅₀ values are presented in table 1.

All three plant extracts exhibited anti-inflammatory properties. A barrier stabilising effect could be shown for myrrh and coffee charcoal. In both fields myrrh displayed the most distinct pharmacological activity.

Tab. 1 Summary of the half maximal effective and inhibitory concentrations (EC₅₀ and IC₅₀) of the plant extracts on the TEER and the release of cytokines and chemokines

	EC50 - TEER increase	IC50 – inhibition of mediator release
		IL6	TNF	IL8	MCP-1
Myrrh extract (Commiphora molmol E.)	67 µg/ml	9 µg/ml	13 µg/ml	34 µg/ml	36 µg/ml
Coffee charcoal extract (Coffea Arabica L.)	108 µg/ml	129 µg/ml	–	62 µg/ml	132 µg/ml
Chamomile flower dry extract (Matricaria chamomilla L.)	–	–	35 µg/ml	62 µg/ml	–

• References

• 1 Langhorst J. et al. Alimentar Pharmacol Ther 2013; 38 (05) : 490-500