Procyanidin A2 is a potential precursor of 5-(3',4'-dihydroxyphenyl)-γ-valerolactone, exhibits antioxidant, anti-inflammary, anti-hyperglycemia, and anti-type 2 diabetes activities. Procyanidin A2 demonstrates liver cell regenerative activity in scratch wound healing assays and alcohol-induced liver cell injury in vitro.

Here we evaluated Procyanidin A2 as a means of modulating CCL26 production and investigated interactions with the known inflammation modulator, Interferon γ (IFNγ). We used the human lung epithelial cell line A549 and optimized the conditions for inducing CCL26. Cells were exposed to a range of Procyanidin A2 or IFNγ concentrations for varied lengths of time prior to an inflammatory insult of interleukin-4 (IL-4) for 24 h. An enzyme-linked immunosorbent assay was used to measure CCL26 production. Exposing cells to 5 μM Procyanidin A2 (prior to IL-4) reduced CCL26 production by 35% compared with control. Greatest inhibition by Procyanidin A2 was seen with a 2 h exposure prior to IL-4, whereas IFNγ inhibition was greatest at 24 h. Concomitant incubation of Procyanidin A2 and IFNγ did not extend the inhibitory efficacy of Procyanidin A2[1]