Oral administration of vermicompost tea ameliorates eczema skin inflammation via regulation of Th2 immune response

ABSTRACT Vermicompost tea (VCT) is the effluent or leachate with a honey-brown colour collected during vermicomposting, an ecologically significant process essential to today’s organic and regenerative agriculture. Dried earthworm, a.k.a. dilong (DL, meaning “earth dragon”) in traditional Chinese herbal medicine, has long been used as a key component to treat diverse skin diseases, including eczema. In the present study, we hypothesized that VCT might have a positive influence on eczema therapy. It was found that the oral application of 50% VCT in mouse model reduced the ear allergic scores and alleviated the histological changes caused by eczema. Furthermore, the levels of Th2-associated and pro-inflammatory cytokines (namely IL-4 and IL-13 in serum) and IgE (in serum and ear tissues) were significantly reduced by VCT. Therefore, oral administration of 50% VCT exerts immunomodulatory effects on the development of eczema, suggesting its potential as a nutraceutical candidate for eczema treatment. GRAPHICAL ABSTRACT