To compare the anti-inflammatory properties of butyrate with two other SCFAs, namely
acetate and propionate, which have less well-documented effects on inflammation.
The effect of SCFAs on cytokine release from human neutrophils was studied with ELISA.
SCFA-dependent modulation of NF-kappaB 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.
Acetate, propionate and butyrate at 30 mmol/L decreased LPS-stimulated TNFalpha release
from neutrophils, without affecting IL-8 protein release. All SCFAs dose dependently
inhibited NF-kappaB 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.
In the present study propionate and butyrate were equipotent, whereas acetate was
less effective, at suppressing NF-kappaB 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.