Anthocyanins represent the major group of flavonoids in berries as well as one of the most powerful natural antioxidants. The aim of this study was to analyse immunomodulatory activities of purified anthocyanins-rich elderberry extract using porcine epithelial IPEC-1 cells and dendritic cells differentiated from porcine blood monocytes (moDC). We evaluated gene expression of some cytokines (IL-1β, TNF-α, IL-12p35, IL-6, IL-8), adaptor molecule MYD88 and transcription factor NF-κB

Anthocyanins-rich elderberry (Sambucus nigra) extract was prepared and characterized in our previous work (Kšonžeková et al., 2016). Briefly, HPLC-analysis revealed the presence of cyanidin glycosides with the majority of cyanidin 3-sambubioside (43.5%) and cyanidin 3-glucoside (45.5%). In our earlier study, we found out that elderberry extract were not toxic to IPEC-1 cells and had the best antioxidant properties (Kšonžeková et al., 2016).

In this present study, we found anthocyanins-induced immunostimulation of mature or activated moDC (upregulation of mRNA level for IL-1β, TNF-α, IL-12p35) as well as epithelial IPEC-1 cells (upregulation of mRNA level for NF-κB, IL-1β, TNF-α, IL-12p35, IL-6, IL-8). Based on this result, we can assume a potential of anthocyanins to support polarization of memory T-lymphocytes or reprogramming of polarized T-lymphocytes.

For evaluation of anti-inflammatory effect of elderberry extract, eptithelial IPEC-1 cells were stimulated with haemolytic enterotoxigenic Escherichia coli (ETEC) strain 11501 (O149: K88+, STb+, LT+). We observed, that preincubation of IPEC-1 cells with anthocyanins-rich extract had inhibitory effect on ETEC-induced upregulation of NF-κB, MYD88 and IL-1β gene expression (without any effect on the adherence of ETEC to IPEC-1 cells).

In conclusion, we found out that cyanidin glycosides-rich elderberry extract has anti-inflammatory as well as immunomodulatory activities. Therefore, we would like to underline the need for studies focused on immunomodulation induced by natural antioxidants, not only studies aimed at their anti-inflammatory action.