Exploring the Effects of Kyung-Ok-Ko on Psoriasis-like Skin Inflammation

Objectives: Psoriasis is a chronic inflammatory skin disorder marked by abnormal keratinocyte differentiation, excessive proliferation, and immune system dysregulation. Kyung-Ok-Go (KOG), a traditional herbal medicine containing Poria cocos, Panax ginseng, Rehmannia glutinosa, and honey, has long been used to promote vitality and regulate immune responses. Despite its historical use, the effects of KOG on psoriasis have not been thoroughly investigated. This study aimed to explore the anti-inflammatory and anti-proliferative properties of KOG extract in an in vitro psoriasis-like model using HaCaT keratinocytes.Methods: Psoriasis-like inflammation was induced in HaCaT cells using an M5 cytokine cocktail comprising IL-17A, IL-22, IL-1α, OSM, and TNF-α. The cytotoxicity of KOG extract was evaluated using an MTT assay. The mRNA expression of psoriasis-associated markers—including KRT6, IL-6, TNF-α, CCL2, CCL20, and CXCL1—was quantified via real-time RT-PCR. Additionally, Western blot analysis was performed to assess the phosphorylation of MAPKs (ERK1/2, JNK, and p38) and the degradation of IkB-α in the NF-kB signaling pathway.Results: KOG extract showed no cytotoxic effects at concentrations up to 10 mg/ml. Treatment with KOG significantly suppressed the M5-induced overexpression of KRT6, proinflammatory cytokines (IL-6, TNF-α), and chemokines (CCL2, CCL20, CXCL1) in HaCaT cells. Notably, KOG selectively inhibited the phosphorylation of p38 MAPK, while having no significant effect on ERK1/2, JNK, and IkB-α signaling.Conclusions: KOG extract mitigates psoriasis-like skin inflammation by reducing keratinocyte hyperproliferation and inflammatory mediator expression, predominantly through inhibition of the p38 MAPK pathway. These findings suggest that KOG holds promise as a potential therapeutic agent for treating inflammatory skin conditions such as psoriasis.