Topical application of Kochia scoparia inhibits the development of contact dermatitis in mice

Abstract

Ethnopharmacological relevanceKochia scoparia (Chenopodiaceae) has been reported to have anti-nociceptive, anti-inflammatory, anti-allergic, and anti-pruritic actions. This study investigated the anti-inflammatory effects of externally applied Kochia scoparia water extract (KSW) in 2,4-dinitrochlorobenzene (DNCB)-induced contact dermatitis mouse model. Materials and methodsTo develop atopic dermatitis-like skin lesions, 100μL of 1% DNCB in acetone/olive oil (4:1) had been applied for three days on shaved dorsal skin. 1% KSW was topically applied to DNCB-induced mice. After KSW treatment, histological analysis was measured by hematoxylin eosin staining. The cytokine and pro-inflammatory expressions were examined using reverse transcription polymerase chain reaction and western blotting analysis. ResultsHistological studies showed that hyperplasia of the epidermis and dermis in the KSW treated group was markedly decreased as compared with the DNCB group. The expression levels of pro-inflammatory cytokine such as IL-1β, and TNF-α mRNA were significantly reduced by topical application of KSW, whereas these cytokines were increased in DNCB-induced dorsal skin. In addition, NF-κB expression was inhibited by KSW treatment in DNCB-induced mice. Similarly, KSW treatment significantly suppressed the expression of several MAP kinases, including ERK1/2, p38, and JNK compared to their expression in DNCB-induced mice. ConclusionsThese findings indicated that KSW ameliorates contact dermatitis via inhibition of the production of several inflammatory mediators. Therefore, external application of KSW may be used for the treatment of contact dermatitis as an alternative therapy.