Genistein suppresses psoriasis-related inflammation through a STAT3-NF-κB-dependent mechanism in keratinocytes.

Psoriasis is a chronic recurrent skin inflammatory disease, and inhibition of inflammation may be an effective means of treating psoriasis. The flavonoid genistein has a clear anti-inflammatory effect. However, the anti-psoriatic effects of genistein and their underlying mechanisms remain unclear. In this study, we investigated the effects of genistein on imiquimod (IMQ)-induced psoriasis-like skin lesions in vivo and explored the mechanisms underlying those effects in vitro. It was found that genistein can significantly improve IMQ-induced pathological scores of cutaneous skin lesions in mice, reduce epidermal thickness, and inhibit the expression of inflammatory factors，including interleukin (IL)-1β, IL-6, tumour necrosis factor-alpha (TNF-α), chemokine ligand 2 (CCL2), IL-17 and IL-23. In vitro studies, genistein inhibited the proliferation of human keratinocyte HaCaT cells and inhibited the expression of inflammatory factors in a dose-dependent manner which induced by TNFα. Further researches showed that genistein could also significantly inhibit phosphorylated STAT3 (pSAT3) expression in IMQ mice dorsal skin and in TNF-α-induced HaCaT cells. The inhibitory effect of genistein on the expression of IL-6, IL-23 and TNF-α was weakened after Stat3 siRNA in HaCaT cells. Genistein could also significantly inhibit TNF-α induced the nuclear translocation of NF-κB, and inhibit the phosphorylation of I-kBα (pI-kBα). After combining with NF-κB blocker BAY 11-7082, the effect of genistein down-regulate the expression of TNF-α and VEGFA was attenuated in HaCaT cells. The results suggest that genistein may be developed for the treatment of psoriasis lesions.

Wang A ，Wei J ，Lu C ，Chen H ，Zhong X ，Lu Y ，Li L ，Huang H ，Dai Z ，Han L ... -  《-》

Perillyl alcohol inhibits keratinocyte proliferation and attenuates imiquimod-induced psoriasis like skin-inflammation by modulating NF-κB and STAT3 signaling pathways.

Psoriasis is a chronic inflammatory and proliferative skin disease characterized by pathological skin lesions which significantly impact the quality of life. Recent studies have been proven that inhibitors of farnesyltransferase enzyme showed significant anti-psoriatic activity. Perillyl alcohol (POH) is one such natural molecule having anti proliferative, anti-inflammatory and anti-oxidant properties by inhibiting farnesyltransferase enzyme which further down regulates NF-κB and STAT3 via Ras/Raf/MAPK pathway. Hence, in the current study we aimed to find the effect of POH on human keratinocytes (HaCat) cells in in-vitro and IMQ induced psoriatic like skin inflammation model in mice. POH significantly decreased the intracellular ROS levels and inhibited the phosphorylation of NF-κB and STAT3 in in-vitro. It was found that POH (200 mg/kg, topical application) has reduced the epidermal hyperplasia, psoriasis area and severity index (PASI) scoring; splenomegaly in imiquimod (IMQ) induced psoriatic mice. Further, POH treatment has decreased the pro-inflammatory serum cytokine levels such as IL-6, IL-12/23, TNF-α and IL-1β and also reduced the expression levels of various inflammatory proteins, COX-2, iNOS, IL-17A, IL-22, NF-кB and STAT3 evidenced by Immunoblotting studies from skin samples. The levels of endogenous antioxidants like glutathione GSH, SOD, Nrf2 were restored to normal levels upon POH treatment. POH downregulated the proteins levels of TLR7, TLR8, CyclinD1 and mRNA expression of Bcl-2 in the skin samples when compared to the IMQ group. POH has ameliorated the hyper-keratosis and acanthosis which was evidenced by histopathology. Collectively, our results suggest that POH has a promising therapeutic application for ameliorating psoriasis-like skin inflammation.

Sudha Yalamarthi S ，Puppala ER ，Abubakar M ，Saha P ，Challa VS ，Np S ，Usn M ，Gangasani JK ，Naidu VGM ... -  《-》

Astragaloside IV suppresses the proliferation and inflammatory response of human epidermal keratinocytes and ameliorates imiquimod-induced psoriasis-like skin damage in mice.

Liu T ，Ai L ，Jiang A ，Wang Y ，Jiang R ，Liu L ... -  《-》

The potential of Diosgenin in treating psoriasis: Studies from HaCaT keratinocytes and imiquimod-induced murine model.

Psoriasis is a cutaneous disease mainly characterized by keratinocyte hyperproliferation, abnormal epidermal differentiation, inflammation and angiogenesis. In this study, we aimed to report the therapeutic potential of Diosgenin on psoriasis-like models and explore the underlying mechanisms. For in vitro studies, we initially evaluated the bioeffects of Diosgenin on keratinocytes by detecting the cell viability, cell cycle and apoptosis in HaCaT cells. To mimic psoriatic conditions, we established hyperproliferative model by stimulating HaCaT cells with LPS/IL-22 and inflammatory model by LPS/TNF-α stimulation. Meanwhile, differentiation in HaCaT cells and angiogenesis in HUVECs/HMEC-1 were observed. The influence of Diosgenin on above-mentioned conditions was examined. For in vivo studies, we dosed imiquimod (IMQ) -induced mice with Diosgenin and conducted hematoxylin-eosin (HE), TUNEL assay and immunohistochemistry (IHC) to evaluate histological changes, apoptosis and the status of keratinocyte proliferation, epidermal differentiation, vascularity and cutaneous inflammatory cell infiltration respectively. Results showed that Diosgenin inhibited HaCaT cell growth through cell cycle arrest and NFκB inhibition while induced apoptosis by regulating Caspase3, Bax and Bcl-2 protein expression. After Diosgenin treatment, NFκB nuclear translocation and IL-22 receptor dependent pathways were suppressed in LPS/IL-22 induced HaCaT cells respectively. Furthermore, Diosgenin downregulated proinflammatory cytokines through TLR4/Myd88 inhibition and upregulated several differentiation markers' expression in HaCaT cells. Additionally, Diosgenin inhibited vascular formation partially by reducing the VEGF-α expression in keratinocytes. In animal studies, Diosgenin attenuated psoriatic lesions on mice accordingly. This study suggests that Diosgenin might be a promising candidate for developing anti-psoriatic agents.

Wu S ，Zhao M ，Sun Y ，Xie M ，Le K ，Xu M ，Huang C ... -  《-》

Daphnetin inhibits proliferation and inflammatory response in human HaCaT keratinocytes and ameliorates imiquimod-induced psoriasis-like skin lesion in mice.

Gao J ，Chen F ，Fang H ，Mi J ，Qi Q ，Yang M ... -  《-》