Gallic acid diminishes pro-inflammatory interferon-γ- and interleukin-17-producing sub-populations in vitro in patients with psoriasis

• Published in: Immunologic research 2023-06, Vol.71 (3), p.475-487
• Main Authors: Tsiogkas, Sotirios G., Apostolopoulou, Konstantina, Mavropoulos, Athanasios, Grammatikopoulou, Maria G., Dardiotis, Efthimios, Zafiriou, Efterpi, Bogdanos, Dimitrios P.
• Format: Article
• Language: English
• Subjects: Acetic acid; Allergology; Anthocyanins; Anti-inflammatory agents; Biomedical and Life Sciences; Biomedicine; CD3 antigen; CD4 antigen; CD56 antigen; Cytokines - metabolism; Flow cytometry; Gallic acid; Gallic Acid - pharmacology; Green tea; Humans; Immunology; In vivo methods and tests; Inflammation; Interferon; Interferon-gamma - metabolism; Interleukin 17; Interleukin 23; Internal Medicine; Ionomycin; Medicine/Public Health; Monocytes; NF-κB protein; Original; Original Article; Phenolic acids; Phenols; Phorbol 12-myristate 13-acetate; Psoriasis; Psoriasis - drug therapy; Psoriasis vulgaris; Skin diseases; Stat3 protein; Transcription factors; γ-Interferon
• ISSN: 0257-277X; 1559-0755
• DOI: 10.1007/s12026-023-09361-9

Psoriasis is an inflammation of the skin mediated via the IL-23/Thl17/IL-17 pathway. We have previously demonstrated that the anthocyanin delphinidin diminishes in vitro the IL-17 and IFN-γ production of peripheral monocytes isolated by psoriasis patients (PBMCs). The degradation product of delphinidin is gallic acid (GA). This phenolic acid compound found in fruits, red wine, or green tea exerts pleiotropic antioxidant, anticarcinogenic, antimicrobial, and anti-inflammatory properties. Previous research has demonstrated the inhibitory effect of GA on pro-inflammatory transcription factors, such as STAT3, RORγt, and NF-κB, or cytokines as IL-1β and TNF, which contribute to psoriasis development. We investigated the effect of GA in vitro on PBMCs, which were stimulated ex vivo, from 40 individuals (28 diagnosed with psoriasis vulgaris and 12 healthy controls (HCs)). In our experiments, PBMCs were cultured untreated or were activated in the presence of phorbol 12-myristate 13-acetate/ionomycin with or without GA. We utilized multicolor flow cytometry to assess the production of inteleukin-17 (IL-17) and interferon-γ (IFN-γ) in T and NK cells. GA did not alter the fractions of IL-17- or IFN-γ-producing T and IFN-γ-producing NK cells in HCs. However, in psoriasis patients, the effect of GA on that cell population was significant. Specifically, GA decreased the frequency of IL-17-producing cells within the CD3 + (T) and CD3 + CD4 + (Th) compartment; the frequency of IFN-γ-producing cells within the CD3 + , CD3 + CD4 + , and CD3 + CD4 − (Tc) compartment, and the frequency of IFN-γ-producing cells within the CD3 − CD56 + (NK) compartment. Whether GA’s effect also appears in vivo needs to be investigated in future.