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

Figure 1 Effects of Short-Chain Fatty Acids on LPS-stimulated TNFα and IL-8 release, and lactate dehydrogenase (LDH) activity in conditioned medium from neutrophil cultures. Cells were exposed to LPS (1 μg/mL) concomitant with acetate, propionate or butyrate (all 30 mmol/L) for 6 h followed by analysis of TNFα (upper panel, bars) and IL-8 (lower panel) protein levels and LDH activity (upper panel, diamonds). n.d: not detectable. mean ± SEM (n = 3), ^aP < 0.05, ^bP < 0.01.

Figure 2 Effects of Short-Chain Fatty Acids on TNFα-induced NF-κB reporter activity in Colo320DM cells. Cells were exposed to TNFα (10 ng/mL) along with acetate (diamonds), propionate (open squares) or butyrate (closed squares) for 24 h. Data is presented as the mean % inhibition of NF-κB activity after normalization to Renilla Luciferase (n = 3).

Figure 3 Dose-dependent effects of propionate in organ cultures from inflamed mouse colon. Dextran sulphate sodium (DSS) was used to induce colonic inflammation. Upper panel: IL-6 mRNA expression (data is shown as changes relative to the expression value obtained in non-inflamed organ cultures). Lower panel: IL-6 protein levels (bars) and lactate dehydrogenase (LDH) activity (diamonds) in culture medium. Organ cultures were exposed to various concentrations of propionate for 24 h. Mean ± SEM (n = 4), ^aP < 0.05, ^bP < 0.01.

Figure 4 Transcriptional profiling of gene expression in Short-Chain Fatty Acid-treated organ cultures. Dextran sulphate sodium (DSS) was used to induce colonic inflammation. (A) Organ cultures were incubated with acetate, propionate or butyrate (all 30 mmol/L) for 24 h followed by analysis of IL-1α, IL-6 and iNOS mRNA levels. Data was normalized to GAPDH mRNA levels and presented as fold change relative to control levels. Mean ± SEM (n = 4). (B) Heat map representation of gene expression changes induced by MG-132, SB203580 (both 10 μmol/L); acetate, propionate and butyrate (all 30 mmol/L). Data was normalized to GAPDH and expressed as the ratio between treatment and control. control (co), acetate (ac), propionate (pr), butyrate (bu), MG-132 (MG), SB203580 (SB).

Figure 5 Effects of Short-Chain Fatty Acids on IL-6 release and lactate dehydrogenase (LDH) activity in organ cultures from inflamed mouse colon. Dextran sulphate sodium (DSS) was used to induce colonic inflammation. Organ cultures were exposed to acetate, propionate or butyrate (all 30 mmol/L) for 24 h followed by analysis of IL-6 level (bars) and LDH activity (diamonds) in culture medium. Mean ± SEM (n = 4), ^bP < 0.01.