Anti-inflammatory properties of the short-chain fatty acids acetate and propionate:A study with relevance to inflammatory bowel disease

AIM: To compare the anti-inflammatory properties of butyrate with two other SCFAs,namely acetate and propionate,which have less well-documented effects on inflammation. METHODS: The effect of SCFAs on cytokine release from human neutrophils was studied with ELISA. SCFA-dependent modulation of NF-κB reporter activity was assessed in the human colon adenocarcinoma cell line,Colo320DM. Finally,the effect of SCFAs on gene expression and cytokine release,measured with RT-PCR and ELISA,respectively,was studied in mouse colon organ cultures established from colitic mice. RESULTS: Acetate,propionate and butyrate at 30 mmol/L decreased LPS-stimulated TNFα release from neutrophils,without affecting IL-8 protein release. All SCFAs dose dependently inhibited NF-κB reporter activity in Colo320DM cells. Propionate dose-dependently suppressed IL-6 mRNA and protein release from colon organ cultures and comparative studies revealed that propionate and butyrate at 30 mmol/L caused a strong inhibition of immune-related gene expression,whereas acetate was less effective. A similar inhibition was achieved with the proteasome inhibitor MG-132,but not the p38 MAPK inhibitor SB203580. All SCFAs decreased IL-6 protein release from organ cultures. CONCLUSION: In the present study propionate and butyrate were equipotent,whereas acetate was less effective,at suppressing NF-κB reporter activity,immune-related gene expression and cytokine release in vitro. Our findings suggest that propionate and acetate,in addition to butyrate,could be useful in the treatment of inflammatory disorders,including IBD.