Extract of Polygala tenuifolia Alleviates Stress-Exacerbated Atopy-Like Skin Dermatitis through the Modulation of Protein Kinase A and p38 Mitogen-Activated Protein Kinase Signaling Pathway

Abstract

Atopic dermatitis (AD) and stress create a vicious cycle: stress exacerbates atopic symptoms, and atopic disease elicits stress and anxiety. Targeting multiple pathways including stress and allergic inflammation is, therefore, important for treating AD. In this study, we investigated the remedial value of Polygala tenuifolia Willd. (PTW) for treating immobilization (IMO) stress-exacerbated atopy-like skin dermatitis and its underlying mechanism. Trimellitic anhydride (TMA) was applied to dorsal skin for sensitization and subsequently both ears for eliciting T-cell-dependent contact hypersensitivity in mice, which underwent 2 h-IMO stress and PTW administration for the latter 6 and 9 days in the ear exposure period of TMA, respectively. To elicit in vitro degranulation of human mast cell line-1 (HMC-1), 10 µM substance P (SP) and 200 nM corticotrophin-releasing factor (CRF) were sequentially added with 48 h-interval. PTW extract (500 µg/mL) was added 30 min before CRF treatment. IMO stress exacerbated TMA-induced scratching behavior by 252%, and increased their blood corticosterone levels by two-fold. Treatment with 250 mg/kg PTW significantly restored IMO stress-exacerbated scratching behavior and other indicators such as skin inflammation and water content, lymph node weights, and serum histamine and immunoglobulin E (lgE) levels. Furthermore, it also reversed TMA-stimulated expression of tumor necrosis factor (TNF)-α and interleukin (IL)-4 mRNAs in ear tissues. PTW significantly inhibited SP/CRF-stimulated degranulation of HMC-1 cells, subsequent tryptase secretion, and protein kinase A (PKA) activity. PTW also selectively inhibited p38 mitogen-activated protein kinase (MAPK) phosphorylation in SP/CRF-treated HMC-1 cells. PTW significantly inhibited HMC-1 cell degranulation and alleviated IMO stress-exacerbated atopic dermatitis symptoms by modulating the PKA/p38 MAPK signaling pathway.

Inhibitory effect of carvacrol on lipopolysaccharide-induced memory impairment in rats

“…The expression of inducible brain-derived neurotrophic factor (BDNF), TLR4, and nitric oxide synthase (iNOS) mRNAs using reverse transcription-polymerase chain reaction (RT-PCR) were analyzed. The total RNA isolation and PT-PCR analysis used in the present study was based on a previous study [33]. Total RNA was extracted from the hippocampus and prefrontal cortex of each rat using TRIzol reagent.…”

Identification of candidate medicinal herbs for skincare via data mining of the classic Donguibogam text on Korean medicine

“… 60 45 Polygalae Radix Tonification Polygala tenuifolia extract significantly inhibited HMC-1 cell degranulation and alleviated IMO stress-exacerbated atopic dermatitis symptoms by modulating the PKA/p38 MAPK signaling pathway. 61 46 Polyporus Hydration Polyporus sclerotium exhibited anti-UV activity; this ranked second among 25 herbs evaluated. 62 47 Raphani Semen Anti-inflammation Compounds from Raphanus sativus seeds inhibited NO production in lipopolysaccharide-activated BV-2 cells.…”

Acacia Polyphenol Ameliorates Atopic Dermatitis in Trimellitic Anhydride-Induced Model Mice via Changes in the Gut Microbiota

“…At the onset of atopic dermatitis, skin inflammation occurs and the expression levels of inflammatory markers, such as TNF-α, IL-6, iNOS, and COX-2, increase [ 26 , 27 ]. We observed the skin condition and the effect of AP on the inflammatory reactions using these expression levels as indexes ( Figure 3 and Figure 4 ).…”