Ellagic acid suppresses β-defensin2 antimicrobial peptide and CCL20 chemokine in psoriasis-like HaCaT human keratinocyte

Psoriasis is an incurable skin disease with a prevalence of 2–5% worldwide. The main lesions of psoriasis are epidermal hyper-proliferation, skin barrier damage, and excessive inflammatory response. As existing treatments clearly have a lot of limitations to psoriasis patient cure, so it is needed for solutions through natural product-based alternative research. Ellagic acid, a yellow-colored plant-derived polyphenol compound existed much in punica granatum L., is known to have anti-inflammatory and whitening activity but rarely been reported on psoriasis. So, we aimed to study the psoriasis control and mechanism of action at the molecular and cellular level by ellagic acid. First, the cytotoxic concentration was measured using the CCK-8 assay. As a result, no cytotoxicity was observed up to 20 μg/mL concentration, so it was applied to all subsequent experiments. Ellagic acid suppressed the mRNA expression of antimicrobial peptides (AMPs) such as β-defensin2, which are characteristically overexpressed in psoriasis lesions. In addition, it downregulated the mRNA expression level of inflammatory cytokines and chemokines such as CXC motif chemokine ligand 8 (CXCL8) and CC motif chemokine ligand 20 (CCL20). Moreover, we observed that ellagic acid significantly inhibited IκB-phosphorylation in signal pathway through Western blot. Lastly, the trans-epithelial electrical resistance (TEER) assay results also confirmed the skin barrier recovery effect due to the anti-inflammatory activity of ellagic acid. These results suggest ellagic acid has a very high possibility of being developed as a raw material could be applied to patients with sensitive skin or intractable skin diseases like psoriasis.