Abstract
Hapten-induced contact hypersensitivity (CHS) is widely utilized to induce immune activation in animal models of allergic contact dermatitis. Our previous findings suggested that the 95% EtOH extract of Wikstroemia indica (L.) C. A. Mey. has antiallergic and anti-inflammatory effects in DNCB-treated CHS SKH-1 hairless mice. The aim of this study was to evaluate the protective effects of compounds isolated from the EtOAc fraction of W. indica in RBL-2H3 cells and 2,4-dinitrochlorobenzene- (DNCB-) induced CHS mice. Of eight compounds in W. indica, that is, umbelliferone, daphnoretin, wikstrocoumarin, (+)-syringaresinol, tricin, (+)-lariciresinol, erythro-guaiacylglycerol-β-coniferyl ether, and quercitrin, quercitrin exhibited the most antiallergic activity against antigen-induced β-hexosaminidase release and IL-4 mRNA expression, which are markers of degranulation in RBL-2H3 cells. After a 7-sensitizing period, 14 days of DNCB treatment with or without topical pimecrolimus (1%) or quercitrin (0.5%) treatment, quercitrin was found to suppress DNCB-induced increases in serum IL-4 and IgE concentrations and transepidermal water loss. These results indicate that quercitrin has therapeutic potential for treatment of allergies and allergy-related contact dermatitis.
Highlights
Contact hypersensitivity (CHS) is one of the most common skin inflammatory diseases and affects 15–20% of individuals worldwide [1]
Contact hypersensitivity is a type IV delayed hypersensitivity mediated by T cells and manifests as an eczematous skin condition that occurs when a substance that acts as an allergen or hapten comes into contact with skin [2,3,4]
When sensitized skin is reexposed to a hapten, the elicitation phase of CHS begins. is reexposure of hapten to “sensitized” T cells results in the explosive differentiation and proliferation of T cells [9], and cytokines secreted by these T cells stimulate cells in skin, which leads to the recruitment of T cells and the enhancement of inflammation at hapten-challenged sites [9, 10]. e cytokines of INF-c, interleukin 4 (IL-4), and IL-17 play major roles during the elicitation phase [5, 6]
Summary
Contact hypersensitivity (CHS) is one of the most common skin inflammatory diseases and affects 15–20% of individuals worldwide [1]. Contact hypersensitivity occurs in two phases, namely, a sensitization phase and an elicitation phase [5]. E sensitization phase occurs when a hapten applied to skin is first introduced to the immune system [6, 7]. Ese sensitized naive T cells migrate to epidermis and differentiate into effector T cells [4, 8]. When sensitized skin is reexposed to a hapten, the elicitation phase of CHS begins. Is reexposure of hapten to “sensitized” T cells results in the explosive differentiation and proliferation of T cells [9], and cytokines secreted by these T cells stimulate cells in skin, which leads to the recruitment of T cells and the enhancement of inflammation at hapten-challenged sites [9, 10]. Flavonoids act as pigments that color fruits and flowers and are
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
